From 7572ae8eea831865b7855d2387a1ca013557090f Mon Sep 17 00:00:00 2001
From: Aaron Alef <aaron.alef@code.berlin>
Date: Wed, 8 Sep 2021 16:48:18 +0200
Subject: [PATCH 01/61] feat(base): include lesson05

NOTE: does not work yet
Current output:
```
61
EnableRegister: ff84110c
Kernel process started. EL 1
, ESR: 1fe00000, address, 1434
```
---
 chainloader/include/kernel/peripherals/mini_uart.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/chainloader/include/kernel/peripherals/mini_uart.h b/chainloader/include/kernel/peripherals/mini_uart.h
index 52839ad..51edebc 100644
--- a/chainloader/include/kernel/peripherals/mini_uart.h
+++ b/chainloader/include/kernel/peripherals/mini_uart.h
@@ -1,7 +1,7 @@
 #ifndef    _ROSE_K_P_MINI_UART_H
 #define    _ROSE_K_P_MINI_UART_H
 
-#include "base.h"
+#include "kernel/peripherals/base.h"
 
 #define SYSTEM_CLOCK_FREQ 500000000
 #define BAUD_RATE_REG(target_baudrate) ((SYSTEM_CLOCK_FREQ/target_baudrate/8)-1)

From e28e7ad92b40209aeb2c93fe746f0aa0d6f107f6 Mon Sep 17 00:00:00 2001
From: Aaron Alef <aaron.alef@code.berlin>
Date: Wed, 8 Sep 2021 17:02:54 +0200
Subject: [PATCH 02/61] feat(io): modify printf to allow %p %P for 0x........
 notation

---
 thorn/src/common/printf.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/thorn/src/common/printf.c b/thorn/src/common/printf.c
index 64f38c5..05fea32 100644
--- a/thorn/src/common/printf.c
+++ b/thorn/src/common/printf.c
@@ -205,6 +205,17 @@ void tfp_format (void * putp, putcf putf, char * fmt, va_list va) {
                     unsigned int),16, (ch == 'P'), bf);
                     putchw (putp, putf, w, lz, bf);
                     break;
+                case 'p': case 'P':
+                    putf(putp, '0');
+                    putf(putp, 'x');
+#ifdef  PRINTF_LONG_SUPPORT
+                    if (lng)
+                        uli2a(va_arg(va, unsigned long int),16,(ch=='P'),bf);
+                    else
+#endif
+                    ui2a(va_arg(va, unsigned int),16,(ch=='P'),bf);
+                    putchw(putp,putf,w,lz,bf);
+                    break;
                 case '%' :
                     putf (putp, ch);
                 default:

From 256b9fe032639db343e139e215f3c9b343845f58 Mon Sep 17 00:00:00 2001
From: Aaron Alef <aaron.alef@code.berlin>
Date: Mon, 13 Sep 2021 12:36:19 +0200
Subject: [PATCH 03/61] feat(io): add uart as alternative to mini uart

NOTE: the first uart to be included will be the implementation used
throughout the program
---
 chainloader/include/kernel/peripherals/mini_uart.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/chainloader/include/kernel/peripherals/mini_uart.h b/chainloader/include/kernel/peripherals/mini_uart.h
index 51edebc..52839ad 100644
--- a/chainloader/include/kernel/peripherals/mini_uart.h
+++ b/chainloader/include/kernel/peripherals/mini_uart.h
@@ -1,7 +1,7 @@
 #ifndef    _ROSE_K_P_MINI_UART_H
 #define    _ROSE_K_P_MINI_UART_H
 
-#include "kernel/peripherals/base.h"
+#include "base.h"
 
 #define SYSTEM_CLOCK_FREQ 500000000
 #define BAUD_RATE_REG(target_baudrate) ((SYSTEM_CLOCK_FREQ/target_baudrate/8)-1)

From 0ff6b7fff4eccaa2979cdd87e4c9e417005e78e2 Mon Sep 17 00:00:00 2001
From: Aaron Alef <aaron.alef@code.berlin>
Date: Fri, 17 Sep 2021 10:34:09 +0200
Subject: [PATCH 04/61] style(io): rename hdmi to gpu

---
 thorn/include/common/gpu.h             | 21 +++++++++++++++++++++
 thorn/include/kernel/peripherals/gpu.h | 11 +++++++++++
 thorn/src/common/gpu.c                 |  6 ++++++
 thorn/src/kernel/kernel.c              |  2 ++
 4 files changed, 40 insertions(+)
 create mode 100644 thorn/include/common/gpu.h
 create mode 100644 thorn/include/kernel/peripherals/gpu.h
 create mode 100644 thorn/src/common/gpu.c

diff --git a/thorn/include/common/gpu.h b/thorn/include/common/gpu.h
new file mode 100644
index 0000000..5560f69
--- /dev/null
+++ b/thorn/include/common/gpu.h
@@ -0,0 +1,21 @@
+#ifndef _ROSE_C_GPU_H
+#define _ROSE_C_GPU_H
+
+#include "kernel/mailbox.h"
+
+// Reference:
+// https://jsandler18.github.io/extra/prop-channel.html
+
+#define GPU_SCREEN_WIDTH   1920
+#define GPU_SCREEN_HEIGHT  1280
+
+#define GPU_VIRTUAL_WIDTH  1920
+#define GPU_VIRTUAL_HEIGHT 1280
+
+#define GPU_COLOUR_DEPTH   24
+
+void init_gpu (void);
+
+void * request_framebuffer (void);
+
+#endif //_ROSE_C_GPU_H
\ No newline at end of file
diff --git a/thorn/include/kernel/peripherals/gpu.h b/thorn/include/kernel/peripherals/gpu.h
new file mode 100644
index 0000000..a2886f1
--- /dev/null
+++ b/thorn/include/kernel/peripherals/gpu.h
@@ -0,0 +1,11 @@
+#ifndef _ROSE_K_P_GPU_H
+#define _ROSE_K_P_GPU_H
+
+#define GPU_REQUEST_FRAMEBUFFER     0x40001
+#define GPU_SET_SCREEN_SIZE         0x48003
+#define GPU_SET_VIRTUAL_SIZE        0x48004
+#define GPU_SET_COLOUR_DEPTH        0x48005
+
+#endif //_ROSE_K_P_GPU_H
+
+/* Copyright (C) 2020 Aaron Alef */
\ No newline at end of file
diff --git a/thorn/src/common/gpu.c b/thorn/src/common/gpu.c
new file mode 100644
index 0000000..0bcd57f
--- /dev/null
+++ b/thorn/src/common/gpu.c
@@ -0,0 +1,6 @@
+#include "common/gpu.h"
+
+void init_gpu () {
+
+
+}
diff --git a/thorn/src/kernel/kernel.c b/thorn/src/kernel/kernel.c
index f03d806..dcac9fe 100644
--- a/thorn/src/kernel/kernel.c
+++ b/thorn/src/kernel/kernel.c
@@ -1,6 +1,7 @@
 #include "kernel/mini_uart.h"
 #include "common/printf.h"
 #include "common/utils.h"
+#include "common/gpu.h"
 #include "kernel/mm.h"
 #include "kernel/timer.h"
 #include "kernel/irq.h"
@@ -62,6 +63,7 @@ void kernel_main (int processor_id) {
     
     if (processor_id == current_processor) {
         uart_init ();
+        init_gpu ();
         init_printf (0, putc);
         irq_vector_init ();
         timer_init ();

From 8732d02a0b95c308b343c01fc94ad788799990dd Mon Sep 17 00:00:00 2001
From: Aaron Alef <aaron.alef@code.berlin>
Date: Fri, 17 Sep 2021 13:02:55 +0200
Subject: [PATCH 05/61] feat(io): add mailbox send and read functions
 [untested]

---
 chainloader/src/mailbox.c                  | 65 ++++++++++++++++++++++
 thorn/include/kernel/mailbox.h             | 54 ++++++++++++++++++
 thorn/include/kernel/peripherals/gpu.h     |  1 +
 thorn/include/kernel/peripherals/mailbox.h | 19 +++++++
 4 files changed, 139 insertions(+)
 create mode 100644 chainloader/src/mailbox.c
 create mode 100644 thorn/include/kernel/mailbox.h
 create mode 100644 thorn/include/kernel/peripherals/mailbox.h

diff --git a/chainloader/src/mailbox.c b/chainloader/src/mailbox.c
new file mode 100644
index 0000000..cf12e56
--- /dev/null
+++ b/chainloader/src/mailbox.c
@@ -0,0 +1,65 @@
+#include "kernel/mailbox.h"
+
+void mailbox_send (unsigned int data, channel_t channel) {
+    mbox_message_t msg = {data, channel};
+    
+    while ((MBOX1 + MBOX_STATUS) & MBOX_WRITE_FULL);
+    put32 (MBOX1 + MBOX_WRITE, * (unsigned int *) & msg);
+}
+
+unsigned int mailbox_read (channel_t channel) {
+    unsigned int value;
+    
+    do {
+        // Wait until there's a message
+        while ((MBOX0 + MBOX_STATUS) & MBOX_READ_EMPTY);
+        
+        value = get32 (MBOX0 + MBOX_READ);
+        
+        // Wait until the channel matches (lest four significant bits)
+    } while ((value & 0xF) != channel);
+    
+    // Return most significant bits (actual address)
+    return value >> 4;
+}
+
+unsigned int mailbox_send_tags (channel_t channel, mbox_tag_t * tags) {
+    mbox_property_t * msg = (mbox_property_t *) get_free_page ();
+    
+    // Add tags to message:
+    unsigned int struct_size = 2 * sizeof (unsigned int);
+    struct_size += mailbox_write_tags ((mbox_tag_t * ) (msg + struct_size), tags);
+    
+    // Add end tag and 16 byte-aligned padding:
+    struct_size += (struct_size % 16) ? 32 - (struct_size % 16) : 16;
+    
+    // write struct size to message:
+    msg->struct_size = struct_size;
+    
+    mailbox_send ((unsigned int) msg, channel);
+    return msg;
+}
+
+unsigned int mailbox_write_tags (mbox_tag_t * dest, mbox_tag_t * src) {
+    unsigned int written = 0;
+    while (src->identity) {
+        dest += written;
+        
+        unsigned int buffer_size = src->buffer_size;
+        
+        dest->identity = src->identity;
+        dest->buffer_size = buffer_size;
+        dest->response = 0;
+        
+        
+        for (unsigned int i = 0; i < buffer_size; i ++) {
+            dest->buffer[written] = src->buffer[written];
+        }
+        written += 3 * sizeof (unsigned int) + buffer_size;
+        put32 (dest + written, 0);
+        written += sizeof (unsigned int);
+        put32 (dest + written, 0);
+        written += (written % 16) ? 16 - (written % 16) : 0;
+    }
+    return written;
+}
diff --git a/thorn/include/kernel/mailbox.h b/thorn/include/kernel/mailbox.h
new file mode 100644
index 0000000..a75cf68
--- /dev/null
+++ b/thorn/include/kernel/mailbox.h
@@ -0,0 +1,54 @@
+#ifndef _ROSE_K_MAILBOX_H
+#define _ROSE_K_MAILBOX_H
+
+#include "common/utils.h"
+#include "kernel/peripherals/mailbox.h"
+#include "kernel/mm.h"
+
+// Documentation:
+// https://github.com/raspberrypi/firmware/wiki/Mailbox-property-interface
+
+typedef enum {
+    POWER = 0,
+    FRAMEBUFFER,
+    VIRTUAL_UART,
+    VCHIQ,
+    LEDS,
+    BUTTONS,
+    TOUCH_SCREEN,
+    RESERVED,
+    PROPERTY_ARM_VC,        // Request from ARM for response by VC
+    PROPERTY_VC_ARM         // Request from VC for response by ARM (Currently not in use)
+} channel_t;
+
+
+typedef struct {
+    unsigned int data: 28;      // most significant bits contain shared memory address
+    channel_t channel: 4;   // least four significant bits contain channel
+} mbox_message_t;
+
+typedef struct {
+    unsigned int identity;
+    unsigned int buffer_size;
+    unsigned int response;
+    unsigned char * buffer;
+} mbox_tag_t;
+
+typedef struct {
+    unsigned int struct_size;
+    unsigned int response;
+    mbox_tag_t * tags;
+} mbox_property_t;
+
+
+void mailbox_send (unsigned int data, channel_t channel);
+
+// Returns address of message
+unsigned int mailbox_read (channel_t channel);
+
+unsigned int mailbox_send_tags (channel_t channel, mbox_tag_t * tags);
+
+// Returns total size written
+unsigned int mailbox_write_tags (mbox_tag_t * dest, mbox_tag_t * src);
+
+#endif //_ROSE_K_MAILBOX_H
\ No newline at end of file
diff --git a/thorn/include/kernel/peripherals/gpu.h b/thorn/include/kernel/peripherals/gpu.h
index a2886f1..ec95fd1 100644
--- a/thorn/include/kernel/peripherals/gpu.h
+++ b/thorn/include/kernel/peripherals/gpu.h
@@ -2,6 +2,7 @@
 #define _ROSE_K_P_GPU_H
 
 #define GPU_REQUEST_FRAMEBUFFER     0x40001
+#define GPU_BLANK_SCREEN            0x40002
 #define GPU_SET_SCREEN_SIZE         0x48003
 #define GPU_SET_VIRTUAL_SIZE        0x48004
 #define GPU_SET_COLOUR_DEPTH        0x48005
diff --git a/thorn/include/kernel/peripherals/mailbox.h b/thorn/include/kernel/peripherals/mailbox.h
new file mode 100644
index 0000000..6f8c889
--- /dev/null
+++ b/thorn/include/kernel/peripherals/mailbox.h
@@ -0,0 +1,19 @@
+#ifndef _ROSE_K_P_MAILBOX_H
+#define _ROSE_K_P_MAILBOX_H
+
+#include "base.h"
+
+#define MBOX0           (PBASE + 0xB880)       // Read from CPU
+#define MBOX1           (PBASE + 0xB840)       // Write to CPU
+
+#define MBOX_READ       0x00
+#define MBOX_STATUS     0x18
+#define MBOX_IRQ        0x1C
+#define MBOX_WRITE      0x20
+
+#define MBOX_READ_EMPTY (1 << 30)
+#define MBOX_WRITE_FULL (1 << 31)
+
+#define MBOX_IRQ_ENABLE (1 << 0)
+
+#endif //_ROSE_K_P_MAILBOX_H
\ No newline at end of file

From fc3469f139c0b7c6b2af821a88ea8d24a06f33ff Mon Sep 17 00:00:00 2001
From: Aaron Alef <aaron.alef@code.berlin>
Date: Fri, 17 Sep 2021 14:03:05 +0200
Subject: [PATCH 06/61] feat(io): initialise framebuffer [not working]

NOTE: Absolutely Not Working
---
 thorn/include/common/gpu.h     | 11 ++++++--
 thorn/include/common/stddef.h  |  2 ++
 thorn/include/kernel/mailbox.h |  3 ++-
 thorn/src/common/gpu.c         | 46 +++++++++++++++++++++++++++++++---
 thorn/src/kernel/kernel.c      |  7 +++++-
 5 files changed, 62 insertions(+), 7 deletions(-)

diff --git a/thorn/include/common/gpu.h b/thorn/include/common/gpu.h
index 5560f69..d4042af 100644
--- a/thorn/include/common/gpu.h
+++ b/thorn/include/common/gpu.h
@@ -1,7 +1,11 @@
 #ifndef _ROSE_C_GPU_H
 #define _ROSE_C_GPU_H
 
+#include "common/stdbool.h"
+#include "common/stddef.h"
+#include "kernel/peripherals/gpu.h"
 #include "kernel/mailbox.h"
+#include "kernel/mm.h"
 
 // Reference:
 // https://jsandler18.github.io/extra/prop-channel.html
@@ -14,8 +18,11 @@
 
 #define GPU_COLOUR_DEPTH   24
 
-void init_gpu (void);
+// framebuffer
+static ptr_t fb;
 
-void * request_framebuffer (void);
+bool init_gpu (void);
+
+ptr_t get_fb (void);
 
 #endif //_ROSE_C_GPU_H
\ No newline at end of file
diff --git a/thorn/include/common/stddef.h b/thorn/include/common/stddef.h
index cf32c4e..2d12078 100644
--- a/thorn/include/common/stddef.h
+++ b/thorn/include/common/stddef.h
@@ -5,4 +5,6 @@
 
 #define ptr_t unsigned long
 
+#define byte_t unsigned char
+
 #endif //_ROSE_C_STDDEF_H
\ No newline at end of file
diff --git a/thorn/include/kernel/mailbox.h b/thorn/include/kernel/mailbox.h
index a75cf68..80083c5 100644
--- a/thorn/include/kernel/mailbox.h
+++ b/thorn/include/kernel/mailbox.h
@@ -2,6 +2,7 @@
 #define _ROSE_K_MAILBOX_H
 
 #include "common/utils.h"
+#include "common/stddef.h"
 #include "kernel/peripherals/mailbox.h"
 #include "kernel/mm.h"
 
@@ -31,7 +32,7 @@ typedef struct {
     unsigned int identity;
     unsigned int buffer_size;
     unsigned int response;
-    unsigned char * buffer;
+    byte_t * buffer;
 } mbox_tag_t;
 
 typedef struct {
diff --git a/thorn/src/common/gpu.c b/thorn/src/common/gpu.c
index 0bcd57f..dab151f 100644
--- a/thorn/src/common/gpu.c
+++ b/thorn/src/common/gpu.c
@@ -1,6 +1,46 @@
 #include "common/gpu.h"
 
-void init_gpu () {
-
-
+bool init_gpu () {
+    unsigned int * buffer = (unsigned int *) get_free_page ();
+    
+    mbox_tag_t * screen_size = (mbox_tag_t *) buffer;
+    unsigned int screen_buffer[] = {GPU_SCREEN_WIDTH, GPU_SCREEN_HEIGHT};
+    screen_size->identity = GPU_SET_SCREEN_SIZE;
+    screen_size->buffer_size = 8;
+    screen_size->response = 0;
+    screen_size->buffer = (byte_t *) screen_buffer;
+    
+    mbox_tag_t * virtual_size = (mbox_tag_t * ) (buffer + sizeof (mbox_tag_t));
+    unsigned int virtual_buffer[] = {GPU_VIRTUAL_WIDTH, GPU_VIRTUAL_HEIGHT};
+    virtual_size->identity = GPU_SET_VIRTUAL_SIZE;
+    virtual_size->buffer_size = 8;
+    virtual_size->response = 0;
+    virtual_size->buffer = (byte_t *) virtual_buffer;
+    
+    mbox_tag_t * colour_depth = (mbox_tag_t * ) (buffer + 2 * sizeof (mbox_tag_t));
+    unsigned int colour_depth_buffer = GPU_COLOUR_DEPTH;
+    colour_depth->identity = GPU_SET_COLOUR_DEPTH;
+    colour_depth->buffer_size = 4;
+    colour_depth->response = 0;
+    colour_depth->buffer = (byte_t * ) & colour_depth_buffer;
+    
+    mbox_property_t * msg1 = (mbox_property_t *) mailbox_send_tags (PROPERTY_ARM_VC, (mbox_tag_t *) buffer);
+    if (msg1->response != 0x80000000) return false;
+    
+    byte_t alignment[] = {16};
+    mbox_tag_t request_fb = {
+            GPU_REQUEST_FRAMEBUFFER,
+            8,
+            0,
+            alignment,
+    };
+    mbox_property_t * msg2 = (mbox_property_t *) mailbox_send_tags (PROPERTY_ARM_VC, & request_fb);
+    if (msg2->response != 0x80000000) return false;
+    
+    fb = (ptr_t) (msg2 + 5 * sizeof (unsigned int));
+    return true;
 }
+
+ptr_t get_fb () {
+    return fb;
+}
\ No newline at end of file
diff --git a/thorn/src/kernel/kernel.c b/thorn/src/kernel/kernel.c
index dcac9fe..0dcf41a 100644
--- a/thorn/src/kernel/kernel.c
+++ b/thorn/src/kernel/kernel.c
@@ -63,7 +63,6 @@ void kernel_main (int processor_id) {
     
     if (processor_id == current_processor) {
         uart_init ();
-        init_gpu ();
         init_printf (0, putc);
         irq_vector_init ();
         timer_init ();
@@ -72,6 +71,12 @@ void kernel_main (int processor_id) {
         task_init ();
 
         LOG("Logging works");
+        
+        if (! init_gpu ()) {
+            printf ("Error while initialising framebuffer\r\n");
+        } else {
+            get_fb ();
+        }
     }
     
     while (processor_id != current_processor);

From 2babdc2b81bf26cefaf6bca3eb1b066e149f1890 Mon Sep 17 00:00:00 2001
From: Aaron Alef <aaron.alef@code.berlin>
Date: Tue, 21 Sep 2021 10:02:07 +0200
Subject: [PATCH 07/61] fix(mb): added missing left shift

---
 chainloader/src/mailbox.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/chainloader/src/mailbox.c b/chainloader/src/mailbox.c
index cf12e56..f0c8e93 100644
--- a/chainloader/src/mailbox.c
+++ b/chainloader/src/mailbox.c
@@ -20,7 +20,7 @@ unsigned int mailbox_read (channel_t channel) {
     } while ((value & 0xF) != channel);
     
     // Return most significant bits (actual address)
-    return value >> 4;
+    return ((value >> 4) << 4);
 }
 
 unsigned int mailbox_send_tags (channel_t channel, mbox_tag_t * tags) {

From c46136f36f57947954c2b1fe8f9ead19251ddeb6 Mon Sep 17 00:00:00 2001
From: Aaron Alef <aaron.alef@code.berlin>
Date: Tue, 21 Sep 2021 12:31:10 +0200
Subject: [PATCH 08/61] feat(io): clear UART screen

---
 thorn/src/kernel/mini_uart.c | 1 +
 thorn/src/kernel/uart.c      | 1 +
 2 files changed, 2 insertions(+)

diff --git a/thorn/src/kernel/mini_uart.c b/thorn/src/kernel/mini_uart.c
index e89e266..427f260 100644
--- a/thorn/src/kernel/mini_uart.c
+++ b/thorn/src/kernel/mini_uart.c
@@ -59,6 +59,7 @@ void mini_uart_init (void) {
     
     put32 (AUX_MU_CNTL_REG, 3);
     
+    mini_uart_send_string ("\033[2J\033[H");
     mini_uart_send_string ("Initialised mini UART\r\n");
     
     init_done = true;
diff --git a/thorn/src/kernel/uart.c b/thorn/src/kernel/uart.c
index 1384238..7ac37b2 100644
--- a/thorn/src/kernel/uart.c
+++ b/thorn/src/kernel/uart.c
@@ -56,6 +56,7 @@ void _uart_init (void) {
     // Enable Receive, Transmit, and UART_ itself
     put32 (UART_CR, (1 << 9) | (1 << 8) | (1 << 0));
     
+    _uart_send_string ("\033[2J\033[H");
     _uart_send_string ("Initialised standard UART\r\n");
     
     init_done = true;

From 93f39e4672969e5e3d9b11e3ef0138196d98fe86 Mon Sep 17 00:00:00 2001
From: Aaron Alef <aaron.alef@code.berlin>
Date: Tue, 21 Sep 2021 11:55:39 +0200
Subject: [PATCH 09/61] refactor(io): rewrite mailbox and adapt gpu init to it

NOTE: doesn't work yet - produces

```
Type SYNC_INVALID_EL1h, ESR: 0x96000040, address, 0x81044Type
```
---
 chainloader/src/mailbox.c                  | 44 ++++++++++++----------
 thorn/include/common/gpu.h                 |  4 ++
 thorn/include/kernel/mailbox.h             | 11 +++---
 thorn/include/kernel/peripherals/mailbox.h |  2 +
 thorn/src/common/gpu.c                     | 21 +++++------
 5 files changed, 45 insertions(+), 37 deletions(-)

diff --git a/chainloader/src/mailbox.c b/chainloader/src/mailbox.c
index f0c8e93..0ce766c 100644
--- a/chainloader/src/mailbox.c
+++ b/chainloader/src/mailbox.c
@@ -1,34 +1,38 @@
 #include "kernel/mailbox.h"
 
-void mailbox_send (unsigned int data, channel_t channel) {
-    mbox_message_t msg = {data, channel};
+bool mailbox_request (unsigned int data_ptr, channel_t channel) {
+    mbox_message_t msg;
+    unsigned int * msg_ptr = (unsigned int *) & msg;
+    unsigned int check;
     
-    while ((MBOX1 + MBOX_STATUS) & MBOX_WRITE_FULL);
-    put32 (MBOX1 + MBOX_WRITE, * (unsigned int *) & msg);
-}
-
-unsigned int mailbox_read (channel_t channel) {
-    unsigned int value;
+    * msg_ptr = data_ptr;
+    msg.channel = channel;
+    
+    while ((MBOX0 + MBOX_STATUS) & MBOX_WRITE_FULL);
+    put32 (MBOX0 + MBOX_WRITE, * msg_ptr);
     
     do {
         // Wait until there's a message
         while ((MBOX0 + MBOX_STATUS) & MBOX_READ_EMPTY);
         
-        value = get32 (MBOX0 + MBOX_READ);
+        check = get32 (MBOX0 + MBOX_READ);
         
-        // Wait until the channel matches (lest four significant bits)
-    } while ((value & 0xF) != channel);
+        // Check if it's the response to our message
+    } while (* msg_ptr == check);
+    
+    // Get the pointer to the property request message
+    mbox_property_t * property = (mbox_property_t * ) ((unsigned long) (* msg_ptr & ~ 0xFF));
     
-    // Return most significant bits (actual address)
-    return ((value >> 4) << 4);
+    // Return the message's response code
+    return property->response == MBOX_SUCCESS;
 }
 
-unsigned int mailbox_send_tags (channel_t channel, mbox_tag_t * tags) {
-    mbox_property_t * msg = (mbox_property_t *) get_free_page ();
+unsigned int mailbox_write_msg (unsigned int message[], mbox_tag_t * tags) {
+    mbox_property_t * msg = (mbox_property_t * ) & message;
     
     // Add tags to message:
     unsigned int struct_size = 2 * sizeof (unsigned int);
-    struct_size += mailbox_write_tags ((mbox_tag_t * ) (msg + struct_size), tags);
+    struct_size += mailbox_write_tags ((mbox_tag_t * ) (message + struct_size), tags);
     
     // Add end tag and 16 byte-aligned padding:
     struct_size += (struct_size % 16) ? 32 - (struct_size % 16) : 16;
@@ -36,8 +40,8 @@ unsigned int mailbox_send_tags (channel_t channel, mbox_tag_t * tags) {
     // write struct size to message:
     msg->struct_size = struct_size;
     
-    mailbox_send ((unsigned int) msg, channel);
-    return msg;
+    // return number of bytes written, for reference
+    return struct_size;
 }
 
 unsigned int mailbox_write_tags (mbox_tag_t * dest, mbox_tag_t * src) {
@@ -56,9 +60,9 @@ unsigned int mailbox_write_tags (mbox_tag_t * dest, mbox_tag_t * src) {
             dest->buffer[written] = src->buffer[written];
         }
         written += 3 * sizeof (unsigned int) + buffer_size;
-        put32 (dest + written, 0);
+        put32 ((unsigned int) (dest + written), 0);
         written += sizeof (unsigned int);
-        put32 (dest + written, 0);
+        put32 ((unsigned int) (dest + written), 0);
         written += (written % 16) ? 16 - (written % 16) : 0;
     }
     return written;
diff --git a/thorn/include/common/gpu.h b/thorn/include/common/gpu.h
index d4042af..84061b8 100644
--- a/thorn/include/common/gpu.h
+++ b/thorn/include/common/gpu.h
@@ -18,6 +18,10 @@
 
 #define GPU_COLOUR_DEPTH   24
 
+#define GPU_MAX_MSG_SIZE 64
+
+static volatile unsigned int buffer[GPU_MAX_MSG_SIZE] __attribute__((aligned(16)));
+
 // framebuffer
 static ptr_t fb;
 
diff --git a/thorn/include/kernel/mailbox.h b/thorn/include/kernel/mailbox.h
index 80083c5..908d0f7 100644
--- a/thorn/include/kernel/mailbox.h
+++ b/thorn/include/kernel/mailbox.h
@@ -2,6 +2,7 @@
 #define _ROSE_K_MAILBOX_H
 
 #include "common/utils.h"
+#include "common/stdbool.h"
 #include "common/stddef.h"
 #include "kernel/peripherals/mailbox.h"
 #include "kernel/mm.h"
@@ -41,13 +42,11 @@ typedef struct {
     mbox_tag_t * tags;
 } mbox_property_t;
 
+// Send message and check responses
+bool mailbox_request (unsigned int data_ptr, channel_t channel);
 
-void mailbox_send (unsigned int data, channel_t channel);
-
-// Returns address of message
-unsigned int mailbox_read (channel_t channel);
-
-unsigned int mailbox_send_tags (channel_t channel, mbox_tag_t * tags);
+// Returns total size written
+unsigned int mailbox_write_msg (unsigned int message[], mbox_tag_t * tags);
 
 // Returns total size written
 unsigned int mailbox_write_tags (mbox_tag_t * dest, mbox_tag_t * src);
diff --git a/thorn/include/kernel/peripherals/mailbox.h b/thorn/include/kernel/peripherals/mailbox.h
index 6f8c889..273779c 100644
--- a/thorn/include/kernel/peripherals/mailbox.h
+++ b/thorn/include/kernel/peripherals/mailbox.h
@@ -16,4 +16,6 @@
 
 #define MBOX_IRQ_ENABLE (1 << 0)
 
+#define MBOX_SUCCESS    0x80000000
+
 #endif //_ROSE_K_P_MAILBOX_H
\ No newline at end of file
diff --git a/thorn/src/common/gpu.c b/thorn/src/common/gpu.c
index dab151f..e5987f7 100644
--- a/thorn/src/common/gpu.c
+++ b/thorn/src/common/gpu.c
@@ -1,43 +1,42 @@
 #include "common/gpu.h"
 
 bool init_gpu () {
-    unsigned int * buffer = (unsigned int *) get_free_page ();
-    
-    mbox_tag_t * screen_size = (mbox_tag_t *) buffer;
+    unsigned int tag_buffer[24];
+    mbox_tag_t * screen_size = (mbox_tag_t *) tag_buffer;
     unsigned int screen_buffer[] = {GPU_SCREEN_WIDTH, GPU_SCREEN_HEIGHT};
     screen_size->identity = GPU_SET_SCREEN_SIZE;
     screen_size->buffer_size = 8;
     screen_size->response = 0;
     screen_size->buffer = (byte_t *) screen_buffer;
     
-    mbox_tag_t * virtual_size = (mbox_tag_t * ) (buffer + sizeof (mbox_tag_t));
+    mbox_tag_t * virtual_size = (mbox_tag_t * ) (tag_buffer + sizeof (mbox_tag_t));
     unsigned int virtual_buffer[] = {GPU_VIRTUAL_WIDTH, GPU_VIRTUAL_HEIGHT};
     virtual_size->identity = GPU_SET_VIRTUAL_SIZE;
     virtual_size->buffer_size = 8;
     virtual_size->response = 0;
     virtual_size->buffer = (byte_t *) virtual_buffer;
     
-    mbox_tag_t * colour_depth = (mbox_tag_t * ) (buffer + 2 * sizeof (mbox_tag_t));
+    mbox_tag_t * colour_depth = (mbox_tag_t * ) (tag_buffer + 2 * sizeof (mbox_tag_t));
     unsigned int colour_depth_buffer = GPU_COLOUR_DEPTH;
     colour_depth->identity = GPU_SET_COLOUR_DEPTH;
     colour_depth->buffer_size = 4;
     colour_depth->response = 0;
     colour_depth->buffer = (byte_t * ) & colour_depth_buffer;
     
-    mbox_property_t * msg1 = (mbox_property_t *) mailbox_send_tags (PROPERTY_ARM_VC, (mbox_tag_t *) buffer);
-    if (msg1->response != 0x80000000) return false;
+    mailbox_write_msg (buffer, (mbox_tag_t *) tag_buffer);
+    if (! mailbox_request ((unsigned int) buffer, PROPERTY_ARM_VC)) return false;
     
     byte_t alignment[] = {16};
-    mbox_tag_t request_fb = {
+    volatile mbox_tag_t request_fb = {
             GPU_REQUEST_FRAMEBUFFER,
             8,
             0,
             alignment,
     };
-    mbox_property_t * msg2 = (mbox_property_t *) mailbox_send_tags (PROPERTY_ARM_VC, & request_fb);
-    if (msg2->response != 0x80000000) return false;
+    mailbox_write_msg ((unsigned int) buffer, & request_fb);
+    if (! mailbox_request ((unsigned int) buffer, PROPERTY_ARM_VC)) return false;
     
-    fb = (ptr_t) (msg2 + 5 * sizeof (unsigned int));
+    fb = * ((ptr_t * ) (buffer + 5));
     return true;
 }
 

From b26321a1373ed76a3232774deb3262d244a32a11 Mon Sep 17 00:00:00 2001
From: Aaron Alef <aaron.alef@code.berlin>
Date: Tue, 21 Sep 2021 13:08:04 +0200
Subject: [PATCH 10/61] WIP: add debug showing program gets stuck waiting for
 configuration

---
 chainloader/src/mailbox.c      | 25 ++++++++--
 thorn/include/common/debug.h   | 16 +++++++
 thorn/include/common/gpu.h     |  2 +
 thorn/include/common/logging.h |  5 +-
 thorn/include/kernel/mailbox.h |  7 ++-
 thorn/src/common/debug.c       | 25 ++++++++++
 thorn/src/common/gpu.c         |  9 +++-
 thorn/src/common/printf.c      | 23 +++-------
 thorn/src/kernel/kernel.c      | 51 ++++++++++++---------
 thorn/src/kernel/mailbox.c     | 84 ++++++++++++++++++++++++++++++++++
 10 files changed, 197 insertions(+), 50 deletions(-)
 create mode 100644 thorn/include/common/debug.h
 create mode 100644 thorn/src/common/debug.c
 create mode 100644 thorn/src/kernel/mailbox.c

diff --git a/chainloader/src/mailbox.c b/chainloader/src/mailbox.c
index 0ce766c..ee5b8b7 100644
--- a/chainloader/src/mailbox.c
+++ b/chainloader/src/mailbox.c
@@ -8,31 +8,42 @@ bool mailbox_request (unsigned int data_ptr, channel_t channel) {
     * msg_ptr = data_ptr;
     msg.channel = channel;
     
+    LOG ("Waiting for empty write buffer GPU...");
     while ((MBOX0 + MBOX_STATUS) & MBOX_WRITE_FULL);
+    LOG ("Writing to GPU...");
     put32 (MBOX0 + MBOX_WRITE, * msg_ptr);
     
+    LOG ("Reading response...");
     do {
         // Wait until there's a message
+        LOG ("Waiting for any message...");
         while ((MBOX0 + MBOX_STATUS) & MBOX_READ_EMPTY);
         
+        LOG ("Check message");
         check = get32 (MBOX0 + MBOX_READ);
         
+        LOG ("Check channel");
         // Check if it's the response to our message
     } while (* msg_ptr == check);
     
+    LOG ("Read pointer to property response");
     // Get the pointer to the property request message
     mbox_property_t * property = (mbox_property_t * ) ((unsigned long) (* msg_ptr & ~ 0xFF));
     
+    char * buffer[100];
+    sprinf (buffer, "Returning response code: operation %s",
+            (property->response == MBOX_SUCCESS) ? "succeeded" : "failed");
+    LOG (buffer);
     // Return the message's response code
     return property->response == MBOX_SUCCESS;
 }
 
-unsigned int mailbox_write_msg (unsigned int message[], mbox_tag_t * tags) {
+unsigned int mailbox_write_msg (unsigned int message[], mbox_tag_t * tags, int tags_count) {
     mbox_property_t * msg = (mbox_property_t * ) & message;
     
     // Add tags to message:
     unsigned int struct_size = 2 * sizeof (unsigned int);
-    struct_size += mailbox_write_tags ((mbox_tag_t * ) (message + struct_size), tags);
+    struct_size += mailbox_write_tags ((mbox_tag_t * ) (message + struct_size), tags, tags_count);
     
     // Add end tag and 16 byte-aligned padding:
     struct_size += (struct_size % 16) ? 32 - (struct_size % 16) : 16;
@@ -40,13 +51,15 @@ unsigned int mailbox_write_msg (unsigned int message[], mbox_tag_t * tags) {
     // write struct size to message:
     msg->struct_size = struct_size;
     
+    int_dump (struct_size, (unsigned int *) msg);
+    
     // return number of bytes written, for reference
     return struct_size;
 }
 
-unsigned int mailbox_write_tags (mbox_tag_t * dest, mbox_tag_t * src) {
+unsigned int mailbox_write_tags (mbox_tag_t * dest, mbox_tag_t * src, int tags_count) {
     unsigned int written = 0;
-    while (src->identity) {
+    for (int i = 0; i < tags_count; i ++) {
         dest += written;
         
         unsigned int buffer_size = src->buffer_size;
@@ -55,15 +68,17 @@ unsigned int mailbox_write_tags (mbox_tag_t * dest, mbox_tag_t * src) {
         dest->buffer_size = buffer_size;
         dest->response = 0;
         
-        
         for (unsigned int i = 0; i < buffer_size; i ++) {
             dest->buffer[written] = src->buffer[written];
         }
         written += 3 * sizeof (unsigned int) + buffer_size;
         put32 ((unsigned int) (dest + written), 0);
+        
         written += sizeof (unsigned int);
         put32 ((unsigned int) (dest + written), 0);
+        
         written += (written % 16) ? 16 - (written % 16) : 0;
     }
+    
     return written;
 }
diff --git a/thorn/include/common/debug.h b/thorn/include/common/debug.h
new file mode 100644
index 0000000..913987a
--- /dev/null
+++ b/thorn/include/common/debug.h
@@ -0,0 +1,16 @@
+#ifndef _ROSE_C_DEBUG_H
+#define _ROSE_DEBUG_H
+
+#include "common/stddef.h"
+#include "common/printf.h"
+#include "common/logging.h"
+
+#define CHECKPOINT LOG ("Checkpoint");
+
+void print_hex (unsigned char dec);
+
+void byte_dump (unsigned int size, byte_t * array);
+
+void int_dump (unsigned int size, unsigned int * array);
+
+#endif //_ROSE_C_DEBUG_H
\ No newline at end of file
diff --git a/thorn/include/common/gpu.h b/thorn/include/common/gpu.h
index 84061b8..46b729c 100644
--- a/thorn/include/common/gpu.h
+++ b/thorn/include/common/gpu.h
@@ -1,6 +1,8 @@
 #ifndef _ROSE_C_GPU_H
 #define _ROSE_C_GPU_H
 
+#include "common/printf.h"
+
 #include "common/stdbool.h"
 #include "common/stddef.h"
 #include "kernel/peripherals/gpu.h"
diff --git a/thorn/include/common/logging.h b/thorn/include/common/logging.h
index 00c8758..6db814a 100644
--- a/thorn/include/common/logging.h
+++ b/thorn/include/common/logging.h
@@ -3,8 +3,9 @@
 
 #include "common/printf.h"
 
-#define LOG(msg)        do {                        \
-    printf(__FILE__":%d: %s\r\n", __LINE__, msg);   \
+#define LOG(msg)        do {                                           \
+    static int __counter__ = 0;                                        \
+    printf(__FILE__":%d:[%d] %s\r\n", __LINE__, __counter__++, msg);   \
 } while (0)
 
 #define ASSERT(expr)    do {                        \
diff --git a/thorn/include/kernel/mailbox.h b/thorn/include/kernel/mailbox.h
index 908d0f7..8ef3619 100644
--- a/thorn/include/kernel/mailbox.h
+++ b/thorn/include/kernel/mailbox.h
@@ -7,6 +7,9 @@
 #include "kernel/peripherals/mailbox.h"
 #include "kernel/mm.h"
 
+#include "common/debug.h"
+#include "common/logging.h"
+
 // Documentation:
 // https://github.com/raspberrypi/firmware/wiki/Mailbox-property-interface
 
@@ -46,9 +49,9 @@ typedef struct {
 bool mailbox_request (unsigned int data_ptr, channel_t channel);
 
 // Returns total size written
-unsigned int mailbox_write_msg (unsigned int message[], mbox_tag_t * tags);
+unsigned int mailbox_write_msg (unsigned int message[], mbox_tag_t * tags, int tags_count);
 
 // Returns total size written
-unsigned int mailbox_write_tags (mbox_tag_t * dest, mbox_tag_t * src);
+unsigned int mailbox_write_tags (mbox_tag_t * dest, mbox_tag_t * src, int tags_count);
 
 #endif //_ROSE_K_MAILBOX_H
\ No newline at end of file
diff --git a/thorn/src/common/debug.c b/thorn/src/common/debug.c
new file mode 100644
index 0000000..8a256c6
--- /dev/null
+++ b/thorn/src/common/debug.c
@@ -0,0 +1,25 @@
+#include "common/debug.h"
+
+void print_hex (unsigned char dec) {
+    char fst = dec / 16;
+    char snd = dec % 16;
+    fst = (fst > 9) ? 'A' + fst - 10 : '0' + fst;
+    snd = (snd > 9) ? 'A' + snd - 10 : '0' + snd;
+    printf ("%c%c ", fst, snd);
+}
+
+void byte_dump (unsigned int size, byte_t * array) {
+    for (int i = 0; i < size; i ++) {
+        print_hex (array[i]);
+        if (! ((i + 1) % 4)) printf (" ");
+        if (! ((i + 1) % 80)) printf ("\r\n");
+    }
+    printf ("\r\n");
+}
+
+void int_dump (unsigned int size, unsigned int * array) {
+    for (int i = 0; i < size / sizeof (int); i ++) {
+        printf ("%d\t", array[i]);
+    }
+    printf ("\r\n");
+}
diff --git a/thorn/src/common/gpu.c b/thorn/src/common/gpu.c
index e5987f7..b9281dd 100644
--- a/thorn/src/common/gpu.c
+++ b/thorn/src/common/gpu.c
@@ -23,7 +23,10 @@ bool init_gpu () {
     colour_depth->response = 0;
     colour_depth->buffer = (byte_t * ) & colour_depth_buffer;
     
-    mailbox_write_msg (buffer, (mbox_tag_t *) tag_buffer);
+    
+    printf ("Preparing screen configuration request...\r\n");
+    mailbox_write_msg (buffer, (mbox_tag_t *) tag_buffer, 3);
+    printf ("Sending screen configuration request...\r\n");
     if (! mailbox_request ((unsigned int) buffer, PROPERTY_ARM_VC)) return false;
     
     byte_t alignment[] = {16};
@@ -33,7 +36,9 @@ bool init_gpu () {
             0,
             alignment,
     };
-    mailbox_write_msg ((unsigned int) buffer, & request_fb);
+    printf ("Preparing framebuffer request...\r\n");
+    mailbox_write_msg ((unsigned int) buffer, & request_fb, 1);
+    printf ("Requesting framebuffer...\r\n");
     if (! mailbox_request ((unsigned int) buffer, PROPERTY_ARM_VC)) return false;
     
     fb = * ((ptr_t * ) (buffer + 5));
diff --git a/thorn/src/common/printf.c b/thorn/src/common/printf.c
index 05fea32..4089b52 100644
--- a/thorn/src/common/printf.c
+++ b/thorn/src/common/printf.c
@@ -158,7 +158,7 @@ void tfp_format (void * putp, putcf putf, char * fmt, va_list va) {
                     else
 #endif
                     ui2a (va_arg (va,
-                    unsigned int),10, 0, bf);
+                                  unsigned int), 10, 0, bf);
                     putchw (putp, putf, w, lz, bf);
                     break;
                 }
@@ -169,7 +169,7 @@ void tfp_format (void * putp, putcf putf, char * fmt, va_list va) {
                     else
 #endif
                     i2a (va_arg (va,
-                    int),bf);
+                                 int), bf);
                     putchw (putp, putf, w, lz, bf);
                     break;
                 }
@@ -181,16 +181,16 @@ void tfp_format (void * putp, putcf putf, char * fmt, va_list va) {
                     else
 #endif
                     ui2a (va_arg (va,
-                    unsigned int),16, (ch == 'X'), bf);
+                                  unsigned int), 16, (ch == 'X'), bf);
                     putchw (putp, putf, w, lz, bf);
                     break;
                 case 'c' :
                     putf (putp, (char) (va_arg (va,
-                    int)));
+                                                int)));
                     break;
                 case 's' :
                     putchw (putp, putf, w, 0, va_arg (va,
-                    char*));
+                                                      char*));
                     break;
                 case 'p':
                 case 'P':
@@ -202,20 +202,9 @@ void tfp_format (void * putp, putcf putf, char * fmt, va_list va) {
                     else
 #endif
                     ui2a (va_arg (va,
-                    unsigned int),16, (ch == 'P'), bf);
+                                  unsigned int), 16, (ch == 'P'), bf);
                     putchw (putp, putf, w, lz, bf);
                     break;
-                case 'p': case 'P':
-                    putf(putp, '0');
-                    putf(putp, 'x');
-#ifdef  PRINTF_LONG_SUPPORT
-                    if (lng)
-                        uli2a(va_arg(va, unsigned long int),16,(ch=='P'),bf);
-                    else
-#endif
-                    ui2a(va_arg(va, unsigned int),16,(ch=='P'),bf);
-                    putchw(putp,putf,w,lz,bf);
-                    break;
                 case '%' :
                     putf (putp, ch);
                 default:
diff --git a/thorn/src/kernel/kernel.c b/thorn/src/kernel/kernel.c
index 0dcf41a..9b9e170 100644
--- a/thorn/src/kernel/kernel.c
+++ b/thorn/src/kernel/kernel.c
@@ -61,21 +61,28 @@ void kernel_main (int processor_id) {
     
     static unsigned int current_processor = 0;
     
-    if (processor_id == current_processor) {
+    if (processor_id == 0) {
         uart_init ();
         init_printf (0, putc);
-        irq_vector_init ();
-        timer_init ();
-        enable_interrupt_controller ();
-        enable_irq ();
-        task_init ();
+//        irq_vector_init ();
+//        timer_init ();
+//        enable_interrupt_controller ();
+//        enable_irq ();
+//        task_init ();
 
         LOG("Logging works");
         
-        if (! init_gpu ()) {
-            printf ("Error while initialising framebuffer\r\n");
+        printf ("Initialising Framebuffer...\r\n");
+        int gpu_status = init_gpu ();
+        if (! gpu_status) {
+            printf ("Error while initialising Framebuffer\r\n");
         } else {
-            get_fb ();
+            unsigned long fb = get_fb ();
+            if (! fb) {
+                printf ("Error: Invalid Framebuffer received\r\n");
+            } else {
+                printf ("Received framebuffer: %p\r\n", fb);
+            }
         }
     }
     
@@ -84,17 +91,17 @@ void kernel_main (int processor_id) {
     printf ("Hello, from processor %d\n\r", processor_id);
     
     current_processor++;
-    
-    if (processor_id == 0) {
-        while (current_processor != 4);
-        int res = copy_process (PF_KTHREAD, (unsigned long) & kernel_process, 0, 0);
-        if (res < 0) {
-            printf ("error while starting kernel process");
-            return;
-        }
-        
-        while (1) {
-            schedule ();
-        }
-    }
+
+//    if (processor_id == 0) {
+//        while (current_processor != 4);
+//        int res = copy_process (PF_KTHREAD, (unsigned long) & kernel_process, 0, 0);
+//        if (res < 0) {
+//            printf ("error while starting kernel process");
+//            return;
+//        }
+//
+//        while (1) {
+//            schedule ();
+//        }
+//    }
 }
diff --git a/thorn/src/kernel/mailbox.c b/thorn/src/kernel/mailbox.c
new file mode 100644
index 0000000..dca578e
--- /dev/null
+++ b/thorn/src/kernel/mailbox.c
@@ -0,0 +1,84 @@
+#include "kernel/mailbox.h"
+
+bool mailbox_request (unsigned int data_ptr, channel_t channel) {
+    mbox_message_t msg;
+    unsigned int * msg_ptr = (unsigned int *) & msg;
+    unsigned int check;
+    
+    * msg_ptr = data_ptr;
+    msg.channel = channel;
+    
+    LOG ("Waiting for empty write buffer GPU...");
+    while ((MBOX0 + MBOX_STATUS) & MBOX_WRITE_FULL);
+    LOG ("Writing to GPU...");
+    put32 (MBOX0 + MBOX_WRITE, * msg_ptr);
+    
+    LOG ("Reading response...");
+    do {
+        // Wait until there's a message
+        LOG ("Waiting for any message...");
+        while ((MBOX0 + MBOX_STATUS) & MBOX_READ_EMPTY);
+        
+        LOG ("Check message");
+        check = get32 (MBOX0 + MBOX_READ);
+        
+        LOG ("Check channel");
+        // Check if it's the response to our message
+    } while (* msg_ptr == check);
+    
+    LOG ("Read pointer to property response");
+    // Get the pointer to the property request message
+    mbox_property_t * property = (mbox_property_t * ) ((unsigned long) (* msg_ptr & ~0xFF));
+    
+    char * buffer[100];
+    sprinf (buffer, "Returning response code: operation %s",
+            (property->response == MBOX_SUCCESS) ? "succeeded" : "failed");
+    LOG (buffer);
+    // Return the message's response code
+    return property->response == MBOX_SUCCESS;
+}
+
+unsigned int mailbox_write_msg (unsigned int message[], mbox_tag_t * tags, int tags_count) {
+    mbox_property_t * msg = (mbox_property_t * ) & message;
+    
+    // Add tags to message:
+    unsigned int struct_size = 2 * sizeof (unsigned int);
+    struct_size += mailbox_write_tags ((mbox_tag_t * ) (message + struct_size), tags, tags_count);
+    
+    // Add end tag and 16 byte-aligned padding:
+    struct_size += (struct_size % 16) ? 32 - (struct_size % 16) : 16;
+    
+    // write struct size to message:
+    msg->struct_size = struct_size;
+    
+    int_dump (struct_size, (unsigned int *) msg);
+    
+    // return number of bytes written, for reference
+    return struct_size;
+}
+
+unsigned int mailbox_write_tags (mbox_tag_t * dest, mbox_tag_t * src, int tags_count) {
+    unsigned int written = 0;
+    for (int i = 0; i < tags_count; i++) {
+        dest += written;
+        
+        unsigned int buffer_size = src->buffer_size;
+        
+        dest->identity = src->identity;
+        dest->buffer_size = buffer_size;
+        dest->response = 0;
+        
+        for (unsigned int i = 0; i < buffer_size; i++) {
+            dest->buffer[written] = src->buffer[written];
+        }
+        written += 3 * sizeof (unsigned int) + buffer_size;
+        put32 ((unsigned int) (dest + written), 0);
+        
+        written += sizeof (unsigned int);
+        put32 ((unsigned int) (dest + written), 0);
+        
+        written += (written % 16) ? 16 - (written % 16) : 0;
+    }
+    
+    return written;
+}
\ No newline at end of file

From d8c4d60b1ba8e1f9cb13d55ca3f47fd3921e4b34 Mon Sep 17 00:00:00 2001
From: Max Streitberger <max.streitberger@gmail.com>
Date: Thu, 7 Oct 2021 13:58:47 +0200
Subject: [PATCH 11/61] Work in progress

---
 thorn/src/common/debug.c   |  4 ++--
 thorn/src/common/gpu.c     | 29 +++++++++++++++++++++++++++--
 thorn/src/kernel/mailbox.c |  5 +++--
 3 files changed, 32 insertions(+), 6 deletions(-)

diff --git a/thorn/src/common/debug.c b/thorn/src/common/debug.c
index 8a256c6..82dab7f 100644
--- a/thorn/src/common/debug.c
+++ b/thorn/src/common/debug.c
@@ -8,7 +8,7 @@ void print_hex (unsigned char dec) {
     printf ("%c%c ", fst, snd);
 }
 
-void byte_dump (unsigned int size, byte_t * array) {
+void hex_dump (unsigned int size, byte_t * array) {
     for (int i = 0; i < size; i ++) {
         print_hex (array[i]);
         if (! ((i + 1) % 4)) printf (" ");
@@ -19,7 +19,7 @@ void byte_dump (unsigned int size, byte_t * array) {
 
 void int_dump (unsigned int size, unsigned int * array) {
     for (int i = 0; i < size / sizeof (int); i ++) {
-        printf ("%d\t", array[i]);
+        printf ("%d ", array[i]);
     }
     printf ("\r\n");
 }
diff --git a/thorn/src/common/gpu.c b/thorn/src/common/gpu.c
index b9281dd..a0b8112 100644
--- a/thorn/src/common/gpu.c
+++ b/thorn/src/common/gpu.c
@@ -22,12 +22,37 @@ bool init_gpu () {
     colour_depth->buffer_size = 4;
     colour_depth->response = 0;
     colour_depth->buffer = (byte_t * ) & colour_depth_buffer;
+
+
+    int test_buffer[20] = {0};
+    test_buffer[0] = 80;
+    test_buffer[1] = 0;
+    test_buffer[2] = 0x00048003;
+    test_buffer[3] = 8;
+    test_buffer[4] = 0;
+    test_buffer[5] = 640;
+    test_buffer[6] = 480;
+    test_buffer[7] = 0x00048004;
+    test_buffer[8] = 8;
+    test_buffer[9] = 0;
+    test_buffer[10] = 640;
+    test_buffer[11] = 480;
+    test_buffer[12] = 0x00048005;
+    test_buffer[13] = 4;
+    test_buffer[14] = 0;
+    test_buffer[15] = 24;
+    test_buffer[16] = 0;
+
+    int_dump (sizeof(test_buffer), (unsigned int *) test_buffer);
     
-    
+    for (int i = 0; i < 20; i++) {
+        printf("%d ", tag_buffer[i]);
+    }
+
     printf ("Preparing screen configuration request...\r\n");
     mailbox_write_msg (buffer, (mbox_tag_t *) tag_buffer, 3);
     printf ("Sending screen configuration request...\r\n");
-    if (! mailbox_request ((unsigned int) buffer, PROPERTY_ARM_VC)) return false;
+    if (! mailbox_request ((unsigned int) test_buffer, PROPERTY_ARM_VC)) return false;
     
     byte_t alignment[] = {16};
     volatile mbox_tag_t request_fb = {
diff --git a/thorn/src/kernel/mailbox.c b/thorn/src/kernel/mailbox.c
index dca578e..f1b9ef6 100644
--- a/thorn/src/kernel/mailbox.c
+++ b/thorn/src/kernel/mailbox.c
@@ -10,6 +10,7 @@ bool mailbox_request (unsigned int data_ptr, channel_t channel) {
     
     LOG ("Waiting for empty write buffer GPU...");
     while ((MBOX0 + MBOX_STATUS) & MBOX_WRITE_FULL);
+    
     LOG ("Writing to GPU...");
     put32 (MBOX0 + MBOX_WRITE, * msg_ptr);
     
@@ -31,8 +32,8 @@ bool mailbox_request (unsigned int data_ptr, channel_t channel) {
     mbox_property_t * property = (mbox_property_t * ) ((unsigned long) (* msg_ptr & ~0xFF));
     
     char * buffer[100];
-    sprinf (buffer, "Returning response code: operation %s",
-            (property->response == MBOX_SUCCESS) ? "succeeded" : "failed");
+    sprintf (buffer, "Returning response code: operation %s",
+             (property->response == MBOX_SUCCESS) ? "succeeded" : "failed");
     LOG (buffer);
     // Return the message's response code
     return property->response == MBOX_SUCCESS;

From 9fa3b720b8a3b771a5bb612d31de20919e71aa93 Mon Sep 17 00:00:00 2001
From: BMG93 <brenden.gammill@code.berlin>
Date: Fri, 8 Oct 2021 13:52:18 +0200
Subject: [PATCH 12/61] WIP

---
 thorn/include/common/gpu.h                 |  5 ++
 thorn/include/kernel/peripherals/mailbox.h | 12 ++-
 thorn/src/common/gpu.c                     | 98 ++++++++++++++--------
 thorn/src/kernel/mailbox.c                 |  2 +-
 4 files changed, 77 insertions(+), 40 deletions(-)

diff --git a/thorn/include/common/gpu.h b/thorn/include/common/gpu.h
index 46b729c..bc8044b 100644
--- a/thorn/include/common/gpu.h
+++ b/thorn/include/common/gpu.h
@@ -22,6 +22,9 @@
 
 #define GPU_MAX_MSG_SIZE 64
 
+static volatile unsigned int __attribute__((aligned(16))) mbox[36];
+
+
 static volatile unsigned int buffer[GPU_MAX_MSG_SIZE] __attribute__((aligned(16)));
 
 // framebuffer
@@ -31,4 +34,6 @@ bool init_gpu (void);
 
 ptr_t get_fb (void);
 
+
+
 #endif //_ROSE_C_GPU_H
\ No newline at end of file
diff --git a/thorn/include/kernel/peripherals/mailbox.h b/thorn/include/kernel/peripherals/mailbox.h
index 273779c..6b97426 100644
--- a/thorn/include/kernel/peripherals/mailbox.h
+++ b/thorn/include/kernel/peripherals/mailbox.h
@@ -14,8 +14,16 @@
 #define MBOX_READ_EMPTY (1 << 30)
 #define MBOX_WRITE_FULL (1 << 31)
 
-#define MBOX_IRQ_ENABLE (1 << 0)
-
 #define MBOX_SUCCESS    0x80000000
 
+enum {
+    VIDEOCORE_MBOX = (PBASE + 0x0000B880),
+    MBOX_POLL      = (VIDEOCORE_MBOX + 0x10),
+    MBOX_SENDER    = (VIDEOCORE_MBOX + 0x14),
+    MBOX_CONFIG    = (VIDEOCORE_MBOX + 0x1C),
+    MBOX_RESPONSE  = 0x80000000,
+    MBOX_FULL      = 0x80000000,
+    MBOX_EMPTY     = 0x40000000
+};
+
 #endif //_ROSE_K_P_MAILBOX_H
\ No newline at end of file
diff --git a/thorn/src/common/gpu.c b/thorn/src/common/gpu.c
index a0b8112..2f397ee 100644
--- a/thorn/src/common/gpu.c
+++ b/thorn/src/common/gpu.c
@@ -24,49 +24,73 @@ bool init_gpu () {
     colour_depth->buffer = (byte_t * ) & colour_depth_buffer;
 
 
-    int test_buffer[20] = {0};
-    test_buffer[0] = 80;
-    test_buffer[1] = 0;
-    test_buffer[2] = 0x00048003;
-    test_buffer[3] = 8;
-    test_buffer[4] = 0;
-    test_buffer[5] = 640;
-    test_buffer[6] = 480;
-    test_buffer[7] = 0x00048004;
-    test_buffer[8] = 8;
-    test_buffer[9] = 0;
-    test_buffer[10] = 640;
-    test_buffer[11] = 480;
-    test_buffer[12] = 0x00048005;
-    test_buffer[13] = 4;
-    test_buffer[14] = 0;
-    test_buffer[15] = 24;
-    test_buffer[16] = 0;
+    mbox[0] = 80;
+    mbox[1] = 0;
+    mbox[2] = 0x00048003;
+    mbox[3] = 8;
+    mbox[4] = 0;
+    mbox[5] = 640;
+    mbox[6] = 480;
+    mbox[7] = 0x00048004;
+    mbox[8] = 8;
+    mbox[9] = 0;
+    mbox[10] = 640;
+    mbox[11] = 480;
+    mbox[12] = 0x00048005;
+    mbox[13] = 4;
+    mbox[14] = 0;
+    mbox[15] = 24;
+    mbox[16] = 0;
+    mbox[17] = 0;
+    mbox[18] = 0;
+    mbox[19] = 0;
+    
+
+    int_dump (sizeof(mbox), (unsigned int *) mbox);
+    
+    channel_t ch = PROPERTY_ARM_VC;
+
+    // 28-bit address (MSB) and 4-bit value (LSB)
+    unsigned int r = ((unsigned int)((long) &mbox) &~ 0xF) | (ch & 0xF);
 
-    int_dump (sizeof(test_buffer), (unsigned int *) test_buffer);
+    // Wait until we can write
+    // while (get32(MBOX_STATUS) & MBOX_FULL);
     
-    for (int i = 0; i < 20; i++) {
-        printf("%d ", tag_buffer[i]);
+    // Write the address of our buffer to the mailbox with the channel appended
+    put32(MBOX_WRITE, r);
+
+    while (1) {
+        // Is there a reply?
+         while (get32(MBOX_STATUS) & MBOX_EMPTY);
+
+        // Is it a reply to our message?
+        if (r == get32(MBOX_READ)) return mbox[1]==MBOX_RESPONSE; // Is it successful?
+           
     }
 
-    printf ("Preparing screen configuration request...\r\n");
-    mailbox_write_msg (buffer, (mbox_tag_t *) tag_buffer, 3);
-    printf ("Sending screen configuration request...\r\n");
-    if (! mailbox_request ((unsigned int) test_buffer, PROPERTY_ARM_VC)) return false;
+
+    // for (int i = 0; i < 20; i++) {
+    //     printf("%d ", tag_buffer[i]);
+    // }
+
+    // printf ("Preparing screen configuration request...\r\n");
+    // mailbox_write_msg (buffer, (mbox_tag_t *) tag_buffer, 3);
+    // printf ("Sending screen configuration request...\r\n");
+    // if (! mailbox_request ((unsigned int) mbox, PROPERTY_ARM_VC)) return false;
     
-    byte_t alignment[] = {16};
-    volatile mbox_tag_t request_fb = {
-            GPU_REQUEST_FRAMEBUFFER,
-            8,
-            0,
-            alignment,
-    };
-    printf ("Preparing framebuffer request...\r\n");
-    mailbox_write_msg ((unsigned int) buffer, & request_fb, 1);
-    printf ("Requesting framebuffer...\r\n");
-    if (! mailbox_request ((unsigned int) buffer, PROPERTY_ARM_VC)) return false;
+    // byte_t alignment[] = {16};
+    // volatile mbox_tag_t request_fb = {
+    //         GPU_REQUEST_FRAMEBUFFER,
+    //         8,
+    //         0,
+    //         alignment,
+    // };
+    // printf ("Preparing framebuffer request...\r\n");
+    // mailbox_write_msg ((unsigned int) buffer, & request_fb, 1);
+    // printf ("Requesting framebuffer...\r\n");
+    // if (! mailbox_request ((unsigned int) buffer, PROPERTY_ARM_VC)) return false;
     
-    fb = * ((ptr_t * ) (buffer + 5));
+    // fb = * ((ptr_t * ) (buffer + 5));
     return true;
 }
 
diff --git a/thorn/src/kernel/mailbox.c b/thorn/src/kernel/mailbox.c
index f1b9ef6..e26d3e1 100644
--- a/thorn/src/kernel/mailbox.c
+++ b/thorn/src/kernel/mailbox.c
@@ -33,7 +33,7 @@ bool mailbox_request (unsigned int data_ptr, channel_t channel) {
     
     char * buffer[100];
     sprintf (buffer, "Returning response code: operation %s",
-             (property->response == MBOX_SUCCESS) ? "succeeded" : "failed");
+            (property->response == MBOX_SUCCESS) ? "succeeded" : "failed");
     LOG (buffer);
     // Return the message's response code
     return property->response == MBOX_SUCCESS;

From c8f19e5ddf7670233f535405249f0e63335888d0 Mon Sep 17 00:00:00 2001
From: Aaron Alef <aaron.alef@code.berlin>
Date: Fri, 8 Oct 2021 15:43:39 +0200
Subject: [PATCH 13/61] WIP

---
 thorn/include/common/gpu.h |   3 +-
 thorn/src/common/debug.c   |  13 ++--
 thorn/src/common/gpu.c     | 133 +++++++++++++++++++++++++------------
 3 files changed, 101 insertions(+), 48 deletions(-)

diff --git a/thorn/include/common/gpu.h b/thorn/include/common/gpu.h
index bc8044b..5ad2755 100644
--- a/thorn/include/common/gpu.h
+++ b/thorn/include/common/gpu.h
@@ -22,7 +22,7 @@
 
 #define GPU_MAX_MSG_SIZE 64
 
-static volatile unsigned int __attribute__((aligned(16))) mbox[36];
+static volatile unsigned int __attribute__((aligned(16))) mbox[20];
 
 
 static volatile unsigned int buffer[GPU_MAX_MSG_SIZE] __attribute__((aligned(16)));
@@ -35,5 +35,4 @@ bool init_gpu (void);
 ptr_t get_fb (void);
 
 
-
 #endif //_ROSE_C_GPU_H
\ No newline at end of file
diff --git a/thorn/src/common/debug.c b/thorn/src/common/debug.c
index 82dab7f..563da15 100644
--- a/thorn/src/common/debug.c
+++ b/thorn/src/common/debug.c
@@ -9,16 +9,19 @@ void print_hex (unsigned char dec) {
 }
 
 void hex_dump (unsigned int size, byte_t * array) {
-    for (int i = 0; i < size; i ++) {
-        print_hex (array[i]);
-        if (! ((i + 1) % 4)) printf (" ");
-        if (! ((i + 1) % 80)) printf ("\r\n");
+    for (int i = 0; i < size;) {
+        i += 4;
+        for (int j = 1; j <= 4; j++) {
+            print_hex (array[i - j]);
+        }
+        printf (" ");
+        if (!(i % 32)) printf ("\r\n");
     }
     printf ("\r\n");
 }
 
 void int_dump (unsigned int size, unsigned int * array) {
-    for (int i = 0; i < size / sizeof (int); i ++) {
+    for (int i = 0; i < size / sizeof (int); i++) {
         printf ("%d ", array[i]);
     }
     printf ("\r\n");
diff --git a/thorn/src/common/gpu.c b/thorn/src/common/gpu.c
index 2f397ee..2c4125c 100644
--- a/thorn/src/common/gpu.c
+++ b/thorn/src/common/gpu.c
@@ -1,29 +1,29 @@
 #include "common/gpu.h"
 
 bool init_gpu () {
-    unsigned int tag_buffer[24];
-    mbox_tag_t * screen_size = (mbox_tag_t *) tag_buffer;
-    unsigned int screen_buffer[] = {GPU_SCREEN_WIDTH, GPU_SCREEN_HEIGHT};
-    screen_size->identity = GPU_SET_SCREEN_SIZE;
-    screen_size->buffer_size = 8;
-    screen_size->response = 0;
-    screen_size->buffer = (byte_t *) screen_buffer;
-    
-    mbox_tag_t * virtual_size = (mbox_tag_t * ) (tag_buffer + sizeof (mbox_tag_t));
-    unsigned int virtual_buffer[] = {GPU_VIRTUAL_WIDTH, GPU_VIRTUAL_HEIGHT};
-    virtual_size->identity = GPU_SET_VIRTUAL_SIZE;
-    virtual_size->buffer_size = 8;
-    virtual_size->response = 0;
-    virtual_size->buffer = (byte_t *) virtual_buffer;
-    
-    mbox_tag_t * colour_depth = (mbox_tag_t * ) (tag_buffer + 2 * sizeof (mbox_tag_t));
-    unsigned int colour_depth_buffer = GPU_COLOUR_DEPTH;
-    colour_depth->identity = GPU_SET_COLOUR_DEPTH;
-    colour_depth->buffer_size = 4;
-    colour_depth->response = 0;
-    colour_depth->buffer = (byte_t * ) & colour_depth_buffer;
-
-
+//    unsigned int tag_buffer[24];
+//    mbox_tag_t * screen_size = (mbox_tag_t *) tag_buffer;
+//    unsigned int screen_buffer[] = {GPU_SCREEN_WIDTH, GPU_SCREEN_HEIGHT};
+//    screen_size->identity = GPU_SET_SCREEN_SIZE;
+//    screen_size->buffer_size = 8;
+//    screen_size->response = 0;
+//    screen_size->buffer = (byte_t *) screen_buffer;
+//
+//    mbox_tag_t * virtual_size = (mbox_tag_t * ) (tag_buffer + sizeof (mbox_tag_t));
+//    unsigned int virtual_buffer[] = {GPU_VIRTUAL_WIDTH, GPU_VIRTUAL_HEIGHT};
+//    virtual_size->identity = GPU_SET_VIRTUAL_SIZE;
+//    virtual_size->buffer_size = 8;
+//    virtual_size->response = 0;
+//    virtual_size->buffer = (byte_t *) virtual_buffer;
+//
+//    mbox_tag_t * colour_depth = (mbox_tag_t * ) (tag_buffer + 2 * sizeof (mbox_tag_t));
+//    unsigned int colour_depth_buffer = GPU_COLOUR_DEPTH;
+//    colour_depth->identity = GPU_SET_COLOUR_DEPTH;
+//    colour_depth->buffer_size = 4;
+//    colour_depth->response = 0;
+//    colour_depth->buffer = (byte_t * ) & colour_depth_buffer;
+    
+    /*
     mbox[0] = 80;
     mbox[1] = 0;
     mbox[2] = 0x00048003;
@@ -45,34 +45,86 @@ bool init_gpu () {
     mbox[18] = 0;
     mbox[19] = 0;
     
-
-    int_dump (sizeof(mbox), (unsigned int *) mbox);
     
-    channel_t ch = PROPERTY_ARM_VC;
-
+    int_dump (sizeof (mbox), (unsigned int *) mbox);
+    hex_dump (sizeof (mbox), (unsigned int *) mbox);
+    
     // 28-bit address (MSB) and 4-bit value (LSB)
-    unsigned int r = ((unsigned int)((long) &mbox) &~ 0xF) | (ch & 0xF);
-
+    unsigned int outgoing = ((unsigned int) ((long) mbox) & ~0xF) | (PROPERTY_ARM_VC & 0xF);
+    
     // Wait until we can write
-    // while (get32(MBOX_STATUS) & MBOX_FULL);
+    while (get32 (MBOX0 + MBOX_STATUS) & MBOX_FULL);
     
     // Write the address of our buffer to the mailbox with the channel appended
-    put32(MBOX_WRITE, r);
-
+    put32 (MBOX0 + MBOX_WRITE, outgoing);
+    
+    unsigned int incoming;
     while (1) {
         // Is there a reply?
-         while (get32(MBOX_STATUS) & MBOX_EMPTY);
-
+        while (get32 (MBOX0 + MBOX_STATUS) & MBOX_EMPTY);
+        
+        incoming = get32 (MBOX0 + MBOX_READ);
+        
         // Is it a reply to our message?
-        if (r == get32(MBOX_READ)) return mbox[1]==MBOX_RESPONSE; // Is it successful?
-           
+        if (outgoing == incoming) {
+            int_dump (sizeof (mbox), (unsigned int *) mbox);
+            hex_dump (sizeof (mbox), (unsigned int *) mbox);
+            
+            if (mbox[1] != MBOX_SUCCESS) {
+                return false;
+            }
+            break;
+        }
     }
-
-
+    */
+    
+    mbox[0] = 32;
+    mbox[1] = 0;
+    mbox[2] = 0x00040001;
+    mbox[3] = 8;
+    mbox[4] = 0;
+    mbox[5] = 16;
+    mbox[6] = 0;
+    mbox[7] = 0;
+    
+    int_dump (sizeof (mbox), (unsigned int *) mbox);
+    hex_dump (sizeof (mbox), (unsigned int *) mbox);
+    
+    // 28-bit address (MSB) and 4-bit value (LSB)
+    unsigned int outgoing = ((unsigned int) ((long) mbox) & ~0xF) | (PROPERTY_ARM_VC & 0xF);
+    
+    // Wait until we can write
+    while (get32 (MBOX0 + MBOX_STATUS) & MBOX_FULL);
+    
+    // Write the address of our buffer to the mailbox with the channel appended
+    put32 (MBOX0 + MBOX_WRITE, outgoing);
+    
+    while (1) {
+        // Is there a reply?
+        while (get32 (MBOX0 + MBOX_STATUS) & MBOX_EMPTY);
+        
+        unsigned int incoming = get32 (MBOX0 + MBOX_READ);
+        
+        // Is it a reply to our message?
+        if (outgoing == incoming) {
+            int_dump (sizeof (mbox), (unsigned int *) mbox);
+            hex_dump (sizeof (mbox), (unsigned int *) mbox);
+            
+            if (mbox[1] != MBOX_SUCCESS) {
+                return false;
+            }
+            break;
+        }
+    }
+    
+    
+    fb = * (ptr_t * ) (mbox + 5 * 4);
+    return true;
+    
     // for (int i = 0; i < 20; i++) {
     //     printf("%d ", tag_buffer[i]);
     // }
-
+    
     // printf ("Preparing screen configuration request...\r\n");
     // mailbox_write_msg (buffer, (mbox_tag_t *) tag_buffer, 3);
     // printf ("Sending screen configuration request...\r\n");
@@ -90,8 +142,7 @@ bool init_gpu () {
     // printf ("Requesting framebuffer...\r\n");
     // if (! mailbox_request ((unsigned int) buffer, PROPERTY_ARM_VC)) return false;
     
-    // fb = * ((ptr_t * ) (buffer + 5));
-    return true;
+    // fb = * ((ptr_t * ) (buffer + 20));
 }
 
 ptr_t get_fb () {

From 887b5edf7d9fdd2bb196c86844e4313d4c7c6dea Mon Sep 17 00:00:00 2001
From: Max Streitberger <max.streitberger@gmail.com>
Date: Mon, 11 Oct 2021 09:16:14 +0200
Subject: [PATCH 14/61] chore(make): fix stty baud rate for mac (#22)

---
 Makefile | 1 +
 1 file changed, 1 insertion(+)

diff --git a/Makefile b/Makefile
index f46d029..04d1e09 100644
--- a/Makefile
+++ b/Makefile
@@ -63,6 +63,7 @@ setup-serial-Linux:
 	stty -F $(SERIAL_PORT) $(BAUD_RATE) raw cs8 -ixoff -cstopb -parenb
 
 setup-serial-Darwin:
+	cat -v $(SERIAL_PORT) &
 	stty -f $(SERIAL_PORT) $(BAUD_RATE) raw cs8 -ixoff -cstopb -parenb
 
 resend: reboot send

From d9d0e4881f207f6790ff895b64ef50ff2f6544f2 Mon Sep 17 00:00:00 2001
From: Aaron Alef <aaron.alef@code.berlin>
Date: Thu, 14 Oct 2021 12:25:49 +0200
Subject: [PATCH 15/61] feat(gpu): hardcode printing of four pixels

---
 thorn/include/common/debug.h |  4 +-
 thorn/include/common/gpu.h   | 17 +++++++-
 thorn/src/common/debug.c     |  8 ++--
 thorn/src/common/gpu.c       | 85 ++++++++++++++++++++++++++++--------
 thorn/src/kernel/kernel.c    | 28 +++++++-----
 thorn/src/kernel/mailbox.c   |  4 +-
 6 files changed, 107 insertions(+), 39 deletions(-)

diff --git a/thorn/include/common/debug.h b/thorn/include/common/debug.h
index 913987a..552b19d 100644
--- a/thorn/include/common/debug.h
+++ b/thorn/include/common/debug.h
@@ -9,8 +9,8 @@
 
 void print_hex (unsigned char dec);
 
-void byte_dump (unsigned int size, byte_t * array);
+void byte_dump (byte_t * array);
 
-void int_dump (unsigned int size, unsigned int * array);
+void int_dump (unsigned int * array);
 
 #endif //_ROSE_C_DEBUG_H
\ No newline at end of file
diff --git a/thorn/include/common/gpu.h b/thorn/include/common/gpu.h
index 5ad2755..ce78bd6 100644
--- a/thorn/include/common/gpu.h
+++ b/thorn/include/common/gpu.h
@@ -27,12 +27,25 @@ static volatile unsigned int __attribute__((aligned(16))) mbox[20];
 
 static volatile unsigned int buffer[GPU_MAX_MSG_SIZE] __attribute__((aligned(16)));
 
+typedef struct {
+    byte_t blue;
+    byte_t green;
+    byte_t red;
+    byte_t alpha;
+} color;
+
+extern unsigned int const _vgapal[];
+extern color const * vgapal;
+
+
 // framebuffer
-static ptr_t fb;
+static color * fb;
 
 bool init_gpu (void);
 
-ptr_t get_fb (void);
+void draw (void);
+
+color * get_fb (void);
 
 
 #endif //_ROSE_C_GPU_H
\ No newline at end of file
diff --git a/thorn/src/common/debug.c b/thorn/src/common/debug.c
index 563da15..ca910cb 100644
--- a/thorn/src/common/debug.c
+++ b/thorn/src/common/debug.c
@@ -8,8 +8,8 @@ void print_hex (unsigned char dec) {
     printf ("%c%c ", fst, snd);
 }
 
-void hex_dump (unsigned int size, byte_t * array) {
-    for (int i = 0; i < size;) {
+void hex_dump (byte_t * array) {
+    for (int i = 0; i < * (unsigned int *) array;) {
         i += 4;
         for (int j = 1; j <= 4; j++) {
             print_hex (array[i - j]);
@@ -20,8 +20,8 @@ void hex_dump (unsigned int size, byte_t * array) {
     printf ("\r\n");
 }
 
-void int_dump (unsigned int size, unsigned int * array) {
-    for (int i = 0; i < size / sizeof (int); i++) {
+void int_dump (unsigned int * array) {
+    for (int i = 0; i < * array; i++) {
         printf ("%d ", array[i]);
     }
     printf ("\r\n");
diff --git a/thorn/src/common/gpu.c b/thorn/src/common/gpu.c
index 2c4125c..21f0fd3 100644
--- a/thorn/src/common/gpu.c
+++ b/thorn/src/common/gpu.c
@@ -1,5 +1,26 @@
 #include "common/gpu.h"
 
+unsigned int const _vgapal[] = {
+        0x000000,
+        0x0000AA,
+        0x00AA00,
+        0x00AAAA,
+        0xAA0000,
+        0xAA00AA,
+        0xAA5500,
+        0xAAAAAA,
+        0x555555,
+        0x5555FF,
+        0x55FF55,
+        0x55FFFF,
+        0xFF5555,
+        0xFF55FF,
+        0xFFFF55,
+        0xFFFFFF
+};
+
+color const * vgapal = (color * ) & _vgapal;
+
 bool init_gpu () {
 //    unsigned int tag_buffer[24];
 //    mbox_tag_t * screen_size = (mbox_tag_t *) tag_buffer;
@@ -23,14 +44,13 @@ bool init_gpu () {
 //    colour_depth->response = 0;
 //    colour_depth->buffer = (byte_t * ) & colour_depth_buffer;
     
-    /*
     mbox[0] = 80;
     mbox[1] = 0;
     mbox[2] = 0x00048003;
     mbox[3] = 8;
     mbox[4] = 0;
-    mbox[5] = 640;
-    mbox[6] = 480;
+    mbox[5] = 1920;
+    mbox[6] = 1080;
     mbox[7] = 0x00048004;
     mbox[8] = 8;
     mbox[9] = 0;
@@ -39,15 +59,15 @@ bool init_gpu () {
     mbox[12] = 0x00048005;
     mbox[13] = 4;
     mbox[14] = 0;
-    mbox[15] = 24;
+    mbox[15] = 32;
     mbox[16] = 0;
     mbox[17] = 0;
     mbox[18] = 0;
     mbox[19] = 0;
     
     
-    int_dump (sizeof (mbox), (unsigned int *) mbox);
-    hex_dump (sizeof (mbox), (unsigned int *) mbox);
+    int_dump ((unsigned int *) mbox);
+    hex_dump ((unsigned int *) mbox);
     
     // 28-bit address (MSB) and 4-bit value (LSB)
     unsigned int outgoing = ((unsigned int) ((long) mbox) & ~0xF) | (PROPERTY_ARM_VC & 0xF);
@@ -67,8 +87,8 @@ bool init_gpu () {
         
         // Is it a reply to our message?
         if (outgoing == incoming) {
-            int_dump (sizeof (mbox), (unsigned int *) mbox);
-            hex_dump (sizeof (mbox), (unsigned int *) mbox);
+            int_dump ((unsigned int *) mbox);
+            hex_dump ((unsigned int *) mbox);
             
             if (mbox[1] != MBOX_SUCCESS) {
                 return false;
@@ -76,7 +96,6 @@ bool init_gpu () {
             break;
         }
     }
-    */
     
     mbox[0] = 32;
     mbox[1] = 0;
@@ -87,11 +106,11 @@ bool init_gpu () {
     mbox[6] = 0;
     mbox[7] = 0;
     
-    int_dump (sizeof (mbox), (unsigned int *) mbox);
-    hex_dump (sizeof (mbox), (unsigned int *) mbox);
+    int_dump ((unsigned int *) mbox);
+    hex_dump ((unsigned int *) mbox);
     
     // 28-bit address (MSB) and 4-bit value (LSB)
-    unsigned int outgoing = ((unsigned int) ((long) mbox) & ~0xF) | (PROPERTY_ARM_VC & 0xF);
+    outgoing = ((unsigned int) ((long) mbox) & ~0xF) | (PROPERTY_ARM_VC & 0xF);
     
     // Wait until we can write
     while (get32 (MBOX0 + MBOX_STATUS) & MBOX_FULL);
@@ -103,12 +122,12 @@ bool init_gpu () {
         // Is there a reply?
         while (get32 (MBOX0 + MBOX_STATUS) & MBOX_EMPTY);
         
-        unsigned int incoming = get32 (MBOX0 + MBOX_READ);
+        incoming = get32 (MBOX0 + MBOX_READ);
         
         // Is it a reply to our message?
         if (outgoing == incoming) {
-            int_dump (sizeof (mbox), (unsigned int *) mbox);
-            hex_dump (sizeof (mbox), (unsigned int *) mbox);
+            int_dump ((unsigned int *) mbox);
+            hex_dump ((unsigned int *) mbox);
             
             if (mbox[1] != MBOX_SUCCESS) {
                 return false;
@@ -118,7 +137,8 @@ bool init_gpu () {
     }
     
     
-    fb = * (ptr_t * ) (mbox + 5 * 4);
+    fb = (color * ) (
+    long) (mbox[5] & 0x3FFFFFFF);
     return true;
     
     // for (int i = 0; i < 20; i++) {
@@ -145,6 +165,37 @@ bool init_gpu () {
     // fb = * ((ptr_t * ) (buffer + 20));
 }
 
-ptr_t get_fb () {
+void draw () {
+    printf ("\n");
+    color black = {0, 0, 0, 0xFF};
+    color red = {0, 0, 0xFF, 0xFF};
+    color blue = {0xff, 0, 0, 0xFF};
+    color green = {0, 0xff, 0, 0xFF};
+    color yellow = {0, 0xff, 0xFF, 0xFF};
+    color cyan = {0xff, 0xff, 0, 0xff};
+    
+    fb[0] = red;
+    fb[1] = yellow;
+    fb[16] = blue;
+    fb[17] = cyan;
+
+//    for (int i = 0; i < 1024;) {
+//        fb[i] = black;
+//        fb[()] = red;
+//        delay (100000);
+//        printf ("\r%d    ", i);
+//        printf ("\ri: %d;   %p     ", i, * (unsigned int *) & c);
+//    }
+
+//    while (1) {
+//        for (int i = 0; i < 1024; i++) {
+//            ((unsigned int *) fb)[i] = c++;
+//            printf ("\r%p", c);
+//            delay (100);
+//        }
+//    }
+}
+
+color * get_fb () {
     return fb;
 }
\ No newline at end of file
diff --git a/thorn/src/kernel/kernel.c b/thorn/src/kernel/kernel.c
index 9b9e170..eecf8e9 100644
--- a/thorn/src/kernel/kernel.c
+++ b/thorn/src/kernel/kernel.c
@@ -59,26 +59,26 @@ void kernel_process () {
 
 void kernel_main (int processor_id) {
     
-    static unsigned int current_processor = 0;
+    static volatile unsigned int current_processor = 0;
     
     if (processor_id == 0) {
         uart_init ();
         init_printf (0, putc);
-//        irq_vector_init ();
-//        timer_init ();
-//        enable_interrupt_controller ();
-//        enable_irq ();
+        irq_vector_init ();
+        timer_init ();
+        enable_interrupt_controller ();
+        enable_irq ();
 //        task_init ();
-
+        
         LOG("Logging works");
         
         printf ("Initialising Framebuffer...\r\n");
         int gpu_status = init_gpu ();
-        if (! gpu_status) {
+        if (!gpu_status) {
             printf ("Error while initialising Framebuffer\r\n");
         } else {
             unsigned long fb = get_fb ();
-            if (! fb) {
+            if (!fb) {
                 printf ("Error: Invalid Framebuffer received\r\n");
             } else {
                 printf ("Received framebuffer: %p\r\n", fb);
@@ -91,9 +91,12 @@ void kernel_main (int processor_id) {
     printf ("Hello, from processor %d\n\r", processor_id);
     
     current_processor++;
+    
+    if (processor_id == 0) {
+        while (current_processor != 3);
+        
+        draw ();
 
-//    if (processor_id == 0) {
-//        while (current_processor != 4);
 //        int res = copy_process (PF_KTHREAD, (unsigned long) & kernel_process, 0, 0);
 //        if (res < 0) {
 //            printf ("error while starting kernel process");
@@ -103,5 +106,8 @@ void kernel_main (int processor_id) {
 //        while (1) {
 //            schedule ();
 //        }
-//    }
+    }
+    
+    LOG("DONE PRINTING");
+    while (1);
 }
diff --git a/thorn/src/kernel/mailbox.c b/thorn/src/kernel/mailbox.c
index e26d3e1..cf86e08 100644
--- a/thorn/src/kernel/mailbox.c
+++ b/thorn/src/kernel/mailbox.c
@@ -33,7 +33,7 @@ bool mailbox_request (unsigned int data_ptr, channel_t channel) {
     
     char * buffer[100];
     sprintf (buffer, "Returning response code: operation %s",
-            (property->response == MBOX_SUCCESS) ? "succeeded" : "failed");
+             (property->response == MBOX_SUCCESS) ? "succeeded" : "failed");
     LOG (buffer);
     // Return the message's response code
     return property->response == MBOX_SUCCESS;
@@ -52,8 +52,6 @@ unsigned int mailbox_write_msg (unsigned int message[], mbox_tag_t * tags, int t
     // write struct size to message:
     msg->struct_size = struct_size;
     
-    int_dump (struct_size, (unsigned int *) msg);
-    
     // return number of bytes written, for reference
     return struct_size;
 }

From 515428164d095f342597f61ba413fe16d9cd24d6 Mon Sep 17 00:00:00 2001
From: Aaron Alef <aaron.alef@code.berlin>
Date: Thu, 14 Oct 2021 15:06:34 +0200
Subject: [PATCH 16/61] WIP

---
 thorn/src/common/gpu.c    | 43 +++++++++++++++++++++------------------
 thorn/src/kernel/kernel.c |  2 +-
 2 files changed, 24 insertions(+), 21 deletions(-)

diff --git a/thorn/src/common/gpu.c b/thorn/src/common/gpu.c
index 21f0fd3..2eadd1d 100644
--- a/thorn/src/common/gpu.c
+++ b/thorn/src/common/gpu.c
@@ -48,12 +48,12 @@ bool init_gpu () {
     mbox[1] = 0;
     mbox[2] = 0x00048003;
     mbox[3] = 8;
-    mbox[4] = 0;
+    mbox[4] = 8;
     mbox[5] = 1920;
     mbox[6] = 1080;
     mbox[7] = 0x00048004;
     mbox[8] = 8;
-    mbox[9] = 0;
+    mbox[9] = 8;
     mbox[10] = 640;
     mbox[11] = 480;
     mbox[12] = 0x00048005;
@@ -174,26 +174,29 @@ void draw () {
     color yellow = {0, 0xff, 0xFF, 0xFF};
     color cyan = {0xff, 0xff, 0, 0xff};
     
-    fb[0] = red;
-    fb[1] = yellow;
-    fb[16] = blue;
-    fb[17] = cyan;
-
-//    for (int i = 0; i < 1024;) {
-//        fb[i] = black;
-//        fb[()] = red;
-//        delay (100000);
-//        printf ("\r%d    ", i);
-//        printf ("\ri: %d;   %p     ", i, * (unsigned int *) & c);
-//    }
+    char index[] = {0, 1, 16, 17};
+    
+    byte_t c[] = {0xff, 0xff, 0xff, 0};
+    color colour = * (color *) c;
+    unsigned int c_int = * (unsigned int *) c;
+    while (1) {
+        for (int i = 0; i < 4; i++) {
+            c_int = c_int ? 0 : 0xFFFFFF;
+            fb[index[i]] = colour;
+        }
+        delay (30000);
 
-//    while (1) {
-//        for (int i = 0; i < 1024; i++) {
-//            ((unsigned int *) fb)[i] = c++;
-//            printf ("\r%p", c);
-//            delay (100);
+//        for (int i = 0; i < 4; i++) {
+//            for (int ci = 0; ci < 3; ci++) {
+//                for (int ind = 0; ind < 256; ind++) {
+//                    c[ci] = ind;
+//                    c[(ci + 1) % 3] = 255 - ind;
+//                    fb[index[i]] = * (color *) c;
+//                    delay (100);
+//                }
+//            }
 //        }
-//    }
+    }
 }
 
 color * get_fb () {
diff --git a/thorn/src/kernel/kernel.c b/thorn/src/kernel/kernel.c
index eecf8e9..9b77044 100644
--- a/thorn/src/kernel/kernel.c
+++ b/thorn/src/kernel/kernel.c
@@ -106,8 +106,8 @@ void kernel_main (int processor_id) {
 //        while (1) {
 //            schedule ();
 //        }
+        LOG("DONE PRINTING");
     }
     
-    LOG("DONE PRINTING");
     while (1);
 }

From 5fee6532b9540d7bc4c4b3a4274d1af9323af099 Mon Sep 17 00:00:00 2001
From: Aaron Alef <aaron.alef@code.berlin>
Date: Thu, 14 Oct 2021 16:00:06 +0200
Subject: [PATCH 17/61] feat(gpu): fix screen size and print RAINBOW

---
 thorn/include/common/gpu.h |  10 ++--
 thorn/src/common/gpu.c     | 107 ++++++++++++-------------------------
 2 files changed, 38 insertions(+), 79 deletions(-)

diff --git a/thorn/include/common/gpu.h b/thorn/include/common/gpu.h
index ce78bd6..b867bcc 100644
--- a/thorn/include/common/gpu.h
+++ b/thorn/include/common/gpu.h
@@ -13,16 +13,16 @@
 // https://jsandler18.github.io/extra/prop-channel.html
 
 #define GPU_SCREEN_WIDTH   1920
-#define GPU_SCREEN_HEIGHT  1280
+#define GPU_SCREEN_HEIGHT  1080
 
-#define GPU_VIRTUAL_WIDTH  1920
-#define GPU_VIRTUAL_HEIGHT 1280
+#define GPU_VIRTUAL_WIDTH  GPU_SCREEN_WIDTH
+#define GPU_VIRTUAL_HEIGHT GPU_SCREEN_HEIGHT
 
-#define GPU_COLOUR_DEPTH   24
+#define GPU_COLOUR_DEPTH   32
 
 #define GPU_MAX_MSG_SIZE 64
 
-static volatile unsigned int __attribute__((aligned(16))) mbox[20];
+static volatile unsigned int __attribute__((aligned(16))) mbox[24];
 
 
 static volatile unsigned int buffer[GPU_MAX_MSG_SIZE] __attribute__((aligned(16)));
diff --git a/thorn/src/common/gpu.c b/thorn/src/common/gpu.c
index 2eadd1d..c98793e 100644
--- a/thorn/src/common/gpu.c
+++ b/thorn/src/common/gpu.c
@@ -44,26 +44,30 @@ bool init_gpu () {
 //    colour_depth->response = 0;
 //    colour_depth->buffer = (byte_t * ) & colour_depth_buffer;
     
-    mbox[0] = 80;
+    mbox[0] = 96;
     mbox[1] = 0;
     mbox[2] = 0x00048003;
     mbox[3] = 8;
     mbox[4] = 8;
-    mbox[5] = 1920;
-    mbox[6] = 1080;
+    mbox[5] = GPU_SCREEN_WIDTH;
+    mbox[6] = GPU_SCREEN_HEIGHT;
     mbox[7] = 0x00048004;
     mbox[8] = 8;
     mbox[9] = 8;
-    mbox[10] = 640;
-    mbox[11] = 480;
+    mbox[10] = GPU_VIRTUAL_WIDTH;
+    mbox[11] = GPU_VIRTUAL_HEIGHT;
     mbox[12] = 0x00048005;
     mbox[13] = 4;
     mbox[14] = 0;
-    mbox[15] = 32;
-    mbox[16] = 0;
-    mbox[17] = 0;
+    mbox[15] = GPU_COLOUR_DEPTH;
+    mbox[16] = 0x00040001;
+    mbox[17] = 8;
     mbox[18] = 0;
-    mbox[19] = 0;
+    mbox[19] = 16;
+    mbox[20] = 0;
+    mbox[21] = 0;
+    mbox[22] = 0;
+    mbox[23] = 0;
     
     
     int_dump ((unsigned int *) mbox);
@@ -97,48 +101,12 @@ bool init_gpu () {
         }
     }
     
-    mbox[0] = 32;
-    mbox[1] = 0;
-    mbox[2] = 0x00040001;
-    mbox[3] = 8;
-    mbox[4] = 0;
-    mbox[5] = 16;
-    mbox[6] = 0;
-    mbox[7] = 0;
     
     int_dump ((unsigned int *) mbox);
     hex_dump ((unsigned int *) mbox);
     
-    // 28-bit address (MSB) and 4-bit value (LSB)
-    outgoing = ((unsigned int) ((long) mbox) & ~0xF) | (PROPERTY_ARM_VC & 0xF);
-    
-    // Wait until we can write
-    while (get32 (MBOX0 + MBOX_STATUS) & MBOX_FULL);
-    
-    // Write the address of our buffer to the mailbox with the channel appended
-    put32 (MBOX0 + MBOX_WRITE, outgoing);
-    
-    while (1) {
-        // Is there a reply?
-        while (get32 (MBOX0 + MBOX_STATUS) & MBOX_EMPTY);
-        
-        incoming = get32 (MBOX0 + MBOX_READ);
-        
-        // Is it a reply to our message?
-        if (outgoing == incoming) {
-            int_dump ((unsigned int *) mbox);
-            hex_dump ((unsigned int *) mbox);
-            
-            if (mbox[1] != MBOX_SUCCESS) {
-                return false;
-            }
-            break;
-        }
-    }
-    
-    
     fb = (color * ) (
-    long) (mbox[5] & 0x3FFFFFFF);
+    long) (mbox[19] & 0x3FFFFFFF);
     return true;
     
     // for (int i = 0; i < 20; i++) {
@@ -167,35 +135,26 @@ bool init_gpu () {
 
 void draw () {
     printf ("\n");
-    color black = {0, 0, 0, 0xFF};
-    color red = {0, 0, 0xFF, 0xFF};
-    color blue = {0xff, 0, 0, 0xFF};
-    color green = {0, 0xff, 0, 0xFF};
-    color yellow = {0, 0xff, 0xFF, 0xFF};
-    color cyan = {0xff, 0xff, 0, 0xff};
-    
-    char index[] = {0, 1, 16, 17};
-    
-    byte_t c[] = {0xff, 0xff, 0xff, 0};
-    color colour = * (color *) c;
-    unsigned int c_int = * (unsigned int *) c;
-    while (1) {
-        for (int i = 0; i < 4; i++) {
-            c_int = c_int ? 0 : 0xFFFFFF;
-            fb[index[i]] = colour;
+    
+    color rainbow[] = {
+            {0x80, 0x00, 0xff, 0},
+            {0x00, 0x00, 0xff, 0},
+            {0x00, 0x80, 0xff, 0},
+            {0x00, 0xff, 0xff, 0},
+            {0x00, 0xff, 0x80, 0},
+            {0x00, 0xff, 0x00, 0},
+            {0x80, 0xff, 0x00, 0},
+            {0xff, 0xff, 0x00, 0},
+            {0xff, 0x80, 0x00, 0},
+            {0xff, 0x00, 0x00, 0},
+            {0xff, 0x00, 0x80, 0}
+    };
+    
+    color c = {0, 0, 0, 0};
+    for (int x = 0; x < GPU_SCREEN_WIDTH; x++) {
+        for (int y = 0; y < GPU_SCREEN_HEIGHT; y++) {
+            fb[y * GPU_SCREEN_WIDTH + x] = rainbow[x / (GPU_SCREEN_WIDTH / (sizeof (rainbow) / sizeof (color)))];
         }
-        delay (30000);
-
-//        for (int i = 0; i < 4; i++) {
-//            for (int ci = 0; ci < 3; ci++) {
-//                for (int ind = 0; ind < 256; ind++) {
-//                    c[ci] = ind;
-//                    c[(ci + 1) % 3] = 255 - ind;
-//                    fb[index[i]] = * (color *) c;
-//                    delay (100);
-//                }
-//            }
-//        }
     }
 }
 

From 520a3da9cc35267924ec81ace9a57827e718a3bf Mon Sep 17 00:00:00 2001
From: Aaron Alef <aaron.alef@code.berlin>
Date: Thu, 14 Oct 2021 16:41:18 +0200
Subject: [PATCH 18/61] refactor(gpu): clean up unused code and add comments

---
 thorn/include/common/gpu.h |  12 +---
 thorn/src/common/gpu.c     | 139 ++++++++++++-------------------------
 2 files changed, 45 insertions(+), 106 deletions(-)

diff --git a/thorn/include/common/gpu.h b/thorn/include/common/gpu.h
index b867bcc..15a01ce 100644
--- a/thorn/include/common/gpu.h
+++ b/thorn/include/common/gpu.h
@@ -20,13 +20,6 @@
 
 #define GPU_COLOUR_DEPTH   32
 
-#define GPU_MAX_MSG_SIZE 64
-
-static volatile unsigned int __attribute__((aligned(16))) mbox[24];
-
-
-static volatile unsigned int buffer[GPU_MAX_MSG_SIZE] __attribute__((aligned(16)));
-
 typedef struct {
     byte_t blue;
     byte_t green;
@@ -34,13 +27,12 @@ typedef struct {
     byte_t alpha;
 } color;
 
-extern unsigned int const _vgapal[];
-extern color const * vgapal;
-
+static volatile unsigned int __attribute__((aligned(16))) mbox[2048];
 
 // framebuffer
 static color * fb;
 
+
 bool init_gpu (void);
 
 void draw (void);
diff --git a/thorn/src/common/gpu.c b/thorn/src/common/gpu.c
index c98793e..75bea0f 100644
--- a/thorn/src/common/gpu.c
+++ b/thorn/src/common/gpu.c
@@ -1,73 +1,37 @@
 #include "common/gpu.h"
 
-unsigned int const _vgapal[] = {
-        0x000000,
-        0x0000AA,
-        0x00AA00,
-        0x00AAAA,
-        0xAA0000,
-        0xAA00AA,
-        0xAA5500,
-        0xAAAAAA,
-        0x555555,
-        0x5555FF,
-        0x55FF55,
-        0x55FFFF,
-        0xFF5555,
-        0xFF55FF,
-        0xFFFF55,
-        0xFFFFFF
-};
-
-color const * vgapal = (color * ) & _vgapal;
-
 bool init_gpu () {
-//    unsigned int tag_buffer[24];
-//    mbox_tag_t * screen_size = (mbox_tag_t *) tag_buffer;
-//    unsigned int screen_buffer[] = {GPU_SCREEN_WIDTH, GPU_SCREEN_HEIGHT};
-//    screen_size->identity = GPU_SET_SCREEN_SIZE;
-//    screen_size->buffer_size = 8;
-//    screen_size->response = 0;
-//    screen_size->buffer = (byte_t *) screen_buffer;
-//
-//    mbox_tag_t * virtual_size = (mbox_tag_t * ) (tag_buffer + sizeof (mbox_tag_t));
-//    unsigned int virtual_buffer[] = {GPU_VIRTUAL_WIDTH, GPU_VIRTUAL_HEIGHT};
-//    virtual_size->identity = GPU_SET_VIRTUAL_SIZE;
-//    virtual_size->buffer_size = 8;
-//    virtual_size->response = 0;
-//    virtual_size->buffer = (byte_t *) virtual_buffer;
-//
-//    mbox_tag_t * colour_depth = (mbox_tag_t * ) (tag_buffer + 2 * sizeof (mbox_tag_t));
-//    unsigned int colour_depth_buffer = GPU_COLOUR_DEPTH;
-//    colour_depth->identity = GPU_SET_COLOUR_DEPTH;
-//    colour_depth->buffer_size = 4;
-//    colour_depth->response = 0;
-//    colour_depth->buffer = (byte_t * ) & colour_depth_buffer;
-    
-    mbox[0] = 96;
-    mbox[1] = 0;
-    mbox[2] = 0x00048003;
-    mbox[3] = 8;
-    mbox[4] = 8;
-    mbox[5] = GPU_SCREEN_WIDTH;
-    mbox[6] = GPU_SCREEN_HEIGHT;
-    mbox[7] = 0x00048004;
-    mbox[8] = 8;
-    mbox[9] = 8;
-    mbox[10] = GPU_VIRTUAL_WIDTH;
-    mbox[11] = GPU_VIRTUAL_HEIGHT;
-    mbox[12] = 0x00048005;
-    mbox[13] = 4;
-    mbox[14] = 0;
-    mbox[15] = GPU_COLOUR_DEPTH;
-    mbox[16] = 0x00040001;
-    mbox[17] = 8;
-    mbox[18] = 0;
-    mbox[19] = 16;
-    mbox[20] = 0;
-    mbox[21] = 0;
-    mbox[22] = 0;
-    mbox[23] = 0;
+    int c = 0;
+    mbox[++c] = 0;                      // Response - will be 0x80000000 for SUCCESS or 0x80000001 for FAILURE
+    
+    mbox[++c] = 0x00048003;             // Tag to set physical display width / height
+    mbox[++c] = 8;                      // Size of value buffer
+    mbox[++c] = 0;                      // Response & value buffer size written will be written here
+    mbox[++c] = GPU_SCREEN_WIDTH;       // Set physical screen width    |  Overwritten by actual width
+    mbox[++c] = GPU_SCREEN_HEIGHT;      // Set physical screen height   |  Overwritten by actual height
+    
+    mbox[++c] = 0x00048004;             // Tag to set virtual display width / height
+    mbox[++c] = 8;                      // Size of value buffer
+    mbox[++c] = 0;                      // Response & value buffer size written will be written here
+    mbox[++c] = GPU_VIRTUAL_WIDTH;      // Set virtual screen width     |  Overwritten by actual virtual width
+    mbox[++c] = GPU_VIRTUAL_HEIGHT;     // Set virtual screen height    |  Overwritten by actual virtual height
+    
+    mbox[++c] = 0x00048005;             // Tag to set pixel depth
+    mbox[++c] = 4;                      // Size of value buffer
+    mbox[++c] = 0;                      // Response & value buffer size written will be written here
+    mbox[++c] = GPU_COLOUR_DEPTH;       // Set colour depth             |  Overwritten by actual colour depth
+    
+    mbox[++c] = 0x00040001;             // Tag to allocate framebuffer
+    mbox[++c] = 8;                      // Size of value buffer
+    mbox[++c] = 0;                      // Response & value buffer size will be written here
+    mbox[++c] = 16;                     // Buffer alignment             |  Overwritten by pointer to framebuffer
+    mbox[++c] = 0;                      // Unused - will be overwritten |  Overwritten by size of framebuffer
+    
+    mbox[++c] = 0;                      // End tag
+    mbox[++c] = 0;                      // Padding
+    mbox[++c] = 0;                      // Padding
+    
+    mbox[0] = 4 * c;                    // Write message size at the beginning of the buffer
     
     
     int_dump ((unsigned int *) mbox);
@@ -101,36 +65,12 @@ bool init_gpu () {
         }
     }
     
-    
     int_dump ((unsigned int *) mbox);
     hex_dump ((unsigned int *) mbox);
     
     fb = (color * ) (
     long) (mbox[19] & 0x3FFFFFFF);
     return true;
-    
-    // for (int i = 0; i < 20; i++) {
-    //     printf("%d ", tag_buffer[i]);
-    // }
-    
-    // printf ("Preparing screen configuration request...\r\n");
-    // mailbox_write_msg (buffer, (mbox_tag_t *) tag_buffer, 3);
-    // printf ("Sending screen configuration request...\r\n");
-    // if (! mailbox_request ((unsigned int) mbox, PROPERTY_ARM_VC)) return false;
-    
-    // byte_t alignment[] = {16};
-    // volatile mbox_tag_t request_fb = {
-    //         GPU_REQUEST_FRAMEBUFFER,
-    //         8,
-    //         0,
-    //         alignment,
-    // };
-    // printf ("Preparing framebuffer request...\r\n");
-    // mailbox_write_msg ((unsigned int) buffer, & request_fb, 1);
-    // printf ("Requesting framebuffer...\r\n");
-    // if (! mailbox_request ((unsigned int) buffer, PROPERTY_ARM_VC)) return false;
-    
-    // fb = * ((ptr_t * ) (buffer + 20));
 }
 
 void draw () {
@@ -147,13 +87,20 @@ void draw () {
             {0xff, 0xff, 0x00, 0},
             {0xff, 0x80, 0x00, 0},
             {0xff, 0x00, 0x00, 0},
-            {0xff, 0x00, 0x80, 0}
+            {0xff, 0x00, 0x80, 0},
+            {0xff, 0x00, 0xff, 0}
     };
     
-    color c = {0, 0, 0, 0};
-    for (int x = 0; x < GPU_SCREEN_WIDTH; x++) {
-        for (int y = 0; y < GPU_SCREEN_HEIGHT; y++) {
-            fb[y * GPU_SCREEN_WIDTH + x] = rainbow[x / (GPU_SCREEN_WIDTH / (sizeof (rainbow) / sizeof (color)))];
+    int rb_size = sizeof (rainbow) / sizeof (color);
+    int divisor = GPU_SCREEN_WIDTH / rb_size;
+    
+    while (1) {
+        for (int offset = 0; offset < rb_size; offset++) {
+            for (int x = 0; x < GPU_SCREEN_WIDTH - GPU_SCREEN_WIDTH % rb_size; x++) {
+                for (int y = 0; y < GPU_SCREEN_HEIGHT; y++) {
+                    fb[y * GPU_SCREEN_WIDTH + x] = rainbow[(x / divisor + offset) % rb_size];
+                }
+            }
         }
     }
 }

From 8c67b8f2be0e84118decd80a77efc70c24553a9d Mon Sep 17 00:00:00 2001
From: Aaron Alef <aaron.alef@code.berlin>
Date: Thu, 14 Oct 2021 17:01:53 +0200
Subject: [PATCH 19/61] feat(gpu): use physical dimensions read as virtual size

---
 thorn/include/common/gpu.h | 12 ++++---
 thorn/src/common/gpu.c     | 74 +++++++++++++++++++++-----------------
 2 files changed, 49 insertions(+), 37 deletions(-)

diff --git a/thorn/include/common/gpu.h b/thorn/include/common/gpu.h
index 15a01ce..f7a25ff 100644
--- a/thorn/include/common/gpu.h
+++ b/thorn/include/common/gpu.h
@@ -12,13 +12,15 @@
 // Reference:
 // https://jsandler18.github.io/extra/prop-channel.html
 
-#define GPU_SCREEN_WIDTH   1920
-#define GPU_SCREEN_HEIGHT  1080
+#define GPU_SCREEN_WIDTH    1920
+#define GPU_SCREEN_HEIGHT   1080
 
-#define GPU_VIRTUAL_WIDTH  GPU_SCREEN_WIDTH
-#define GPU_VIRTUAL_HEIGHT GPU_SCREEN_HEIGHT
+#define GPU_VIRTUAL_WIDTH   GPU_SCREEN_WIDTH
+#define GPU_VIRTUAL_HEIGHT  GPU_SCREEN_HEIGHT
 
-#define GPU_COLOUR_DEPTH   32
+#define GPU_COLOUR_DEPTH    32
+
+#define VC_SDRAM_OFFSET     0x3FFFFFFF
 
 typedef struct {
     byte_t blue;
diff --git a/thorn/src/common/gpu.c b/thorn/src/common/gpu.c
index 75bea0f..dcdfd39 100644
--- a/thorn/src/common/gpu.c
+++ b/thorn/src/common/gpu.c
@@ -1,38 +1,48 @@
 #include "common/gpu.h"
 
 bool init_gpu () {
-    int c = 0;
-    mbox[++c] = 0;                      // Response - will be 0x80000000 for SUCCESS or 0x80000001 for FAILURE
-    
-    mbox[++c] = 0x00048003;             // Tag to set physical display width / height
-    mbox[++c] = 8;                      // Size of value buffer
-    mbox[++c] = 0;                      // Response & value buffer size written will be written here
-    mbox[++c] = GPU_SCREEN_WIDTH;       // Set physical screen width    |  Overwritten by actual width
-    mbox[++c] = GPU_SCREEN_HEIGHT;      // Set physical screen height   |  Overwritten by actual height
-    
-    mbox[++c] = 0x00048004;             // Tag to set virtual display width / height
-    mbox[++c] = 8;                      // Size of value buffer
-    mbox[++c] = 0;                      // Response & value buffer size written will be written here
-    mbox[++c] = GPU_VIRTUAL_WIDTH;      // Set virtual screen width     |  Overwritten by actual virtual width
-    mbox[++c] = GPU_VIRTUAL_HEIGHT;     // Set virtual screen height    |  Overwritten by actual virtual height
-    
-    mbox[++c] = 0x00048005;             // Tag to set pixel depth
-    mbox[++c] = 4;                      // Size of value buffer
-    mbox[++c] = 0;                      // Response & value buffer size written will be written here
-    mbox[++c] = GPU_COLOUR_DEPTH;       // Set colour depth             |  Overwritten by actual colour depth
-    
-    mbox[++c] = 0x00040001;             // Tag to allocate framebuffer
-    mbox[++c] = 8;                      // Size of value buffer
-    mbox[++c] = 0;                      // Response & value buffer size will be written here
-    mbox[++c] = 16;                     // Buffer alignment             |  Overwritten by pointer to framebuffer
-    mbox[++c] = 0;                      // Unused - will be overwritten |  Overwritten by size of framebuffer
-    
-    mbox[++c] = 0;                      // End tag
-    mbox[++c] = 0;                      // Padding
-    mbox[++c] = 0;                      // Padding
-    
-    mbox[0] = 4 * c;                    // Write message size at the beginning of the buffer
+    {                                       // First message: read physical dimensions
+        int c = 0;                          // Message size; increment while we write
+        mbox[++c] = 0;                      // Response - will be 0x80000000 for SUCCESS or 0x80000001 for FAILURE
+        
+        mbox[++c] = 0x00040003;             // Tag to get physical display width / height
+        mbox[++c] = 8;                      // Size of value buffer
+        mbox[++c] = 0;                      // Response & value buffer size written will be written here
+        mbox[++c] = GPU_SCREEN_WIDTH;       // Get physical screen width    |  Overwritten by actual width
+        mbox[++c] = GPU_SCREEN_HEIGHT;      // Get physical screen height   |  Overwritten by actual height
+        
+        mbox[0] = 4 * c;                    // Write message size at the beginning of the buffer
+    }
     
+    byte_t index_framebuffer;
+    {
+        int c = 0;                          // Message size; increment while we write
+        mbox[++c] = 0;                      // Response - will be 0x80000000 for SUCCESS or 0x80000001 for FAILURE
+        
+        mbox[++c] = 0x00048004;             // Tag to set virtual display width / height
+        mbox[++c] = 8;                      // Size of value buffer
+        mbox[++c] = 0;                      // Response & value buffer size written will be written here
+        mbox[++c];//GPU_SCREEN_WIDTH;       // Set virtual screen width     |  Overwritten by actual virtual width
+        mbox[++c];//GPU_SCREEN_HEIGHT;      // Set virtual screen height    |  Overwritten by actual virtual height
+        
+        mbox[++c] = 0x00048005;             // Tag to set pixel depth
+        mbox[++c] = 4;                      // Size of value buffer
+        mbox[++c] = 0;                      // Response & value buffer size written will be written here
+        mbox[++c] = GPU_COLOUR_DEPTH;       // Set colour depth             |  Overwritten by actual colour depth
+        
+        mbox[++c] = 0x00040001;             // Tag to allocate framebuffer
+        mbox[++c] = 8;                      // Size of value buffer
+        mbox[++c] = 0;                      // Response & value buffer size will be written here
+        mbox[++c] = 16;                     // Buffer alignment             |  Overwritten by pointer to framebuffer
+        index_framebuffer = c;
+        mbox[++c] = 0;                      // Unused - will be overwritten |  Overwritten by size of framebuffer
+        
+        mbox[++c] = 0;                      // End tag
+        mbox[++c] = 0;                      // Padding
+        mbox[++c] = 0;                      // Padding
+        
+        mbox[0] = 4 * c;                    // Write message size at the beginning of the buffer
+    }
     
     int_dump ((unsigned int *) mbox);
     hex_dump ((unsigned int *) mbox);
@@ -69,7 +79,7 @@ bool init_gpu () {
     hex_dump ((unsigned int *) mbox);
     
     fb = (color * ) (
-    long) (mbox[19] & 0x3FFFFFFF);
+    long) (mbox[index_framebuffer] & VC_SDRAM_OFFSET);
     return true;
 }
 

From d1bbd1de1a8c2cb375c16650084d457d18efb110 Mon Sep 17 00:00:00 2001
From: Aaron Alef <aaron.alef@code.berlin>
Date: Thu, 14 Oct 2021 17:20:10 +0200
Subject: [PATCH 20/61] feat(gpu): update screensaver

---
 thorn/src/common/gpu.c | 17 ++++++++++++++---
 1 file changed, 14 insertions(+), 3 deletions(-)

diff --git a/thorn/src/common/gpu.c b/thorn/src/common/gpu.c
index dcdfd39..9c8fbc6 100644
--- a/thorn/src/common/gpu.c
+++ b/thorn/src/common/gpu.c
@@ -102,13 +102,24 @@ void draw () {
     };
     
     int rb_size = sizeof (rainbow) / sizeof (color);
-    int divisor = GPU_SCREEN_WIDTH / rb_size;
+    int divisor;
     
     while (1) {
         for (int offset = 0; offset < rb_size; offset++) {
-            for (int x = 0; x < GPU_SCREEN_WIDTH - GPU_SCREEN_WIDTH % rb_size; x++) {
+            divisor = GPU_SCREEN_WIDTH / rb_size;
+            for (int x = 0; x < GPU_SCREEN_WIDTH - GPU_SCREEN_WIDTH % divisor; x++) {
                 for (int y = 0; y < GPU_SCREEN_HEIGHT; y++) {
-                    fb[y * GPU_SCREEN_WIDTH + x] = rainbow[(x / divisor + offset) % rb_size];
+                    fb[y * GPU_SCREEN_WIDTH + x].red ^= rainbow[(x / divisor + offset) % rb_size].red;
+                    fb[y * GPU_SCREEN_WIDTH + x].green ^= rainbow[(x / divisor + offset) % rb_size].green;
+                    fb[y * GPU_SCREEN_WIDTH + x].blue ^= rainbow[(x / divisor + offset) % rb_size].blue;
+                }
+            }
+            divisor = GPU_SCREEN_HEIGHT / rb_size;
+            for (int y = 0; y < GPU_SCREEN_HEIGHT - GPU_SCREEN_HEIGHT % divisor; y++) {
+                for (int x = 0; x < GPU_SCREEN_WIDTH; x++) {
+                    fb[y * GPU_SCREEN_WIDTH + x].red ^= rainbow[(y / divisor + offset) % rb_size].red;
+                    fb[y * GPU_SCREEN_WIDTH + x].green ^= rainbow[(y / divisor + offset) % rb_size].green;
+                    fb[y * GPU_SCREEN_WIDTH + x].blue ^= rainbow[(y / divisor + offset) % rb_size].blue;
                 }
             }
         }

From 32b473d97e15c3de49e5adf6774eb1f8c2923ba2 Mon Sep 17 00:00:00 2001
From: Aaron Alef <aaron.alef@code.berlin>
Date: Thu, 14 Oct 2021 17:48:16 +0200
Subject: [PATCH 21/61] feat(gpu): read out physical dims to use for virtual
 dims

---
 thorn/include/common/debug.h   |   2 +-
 thorn/include/kernel/mailbox.h |  23 +-------
 thorn/src/common/gpu.c         |  53 ++++-------------
 thorn/src/kernel/mailbox.c     | 104 +++++++++++----------------------
 4 files changed, 50 insertions(+), 132 deletions(-)

diff --git a/thorn/include/common/debug.h b/thorn/include/common/debug.h
index 552b19d..d5c9c9b 100644
--- a/thorn/include/common/debug.h
+++ b/thorn/include/common/debug.h
@@ -9,7 +9,7 @@
 
 void print_hex (unsigned char dec);
 
-void byte_dump (byte_t * array);
+void hex_dump (byte_t * array);
 
 void int_dump (unsigned int * array);
 
diff --git a/thorn/include/kernel/mailbox.h b/thorn/include/kernel/mailbox.h
index 8ef3619..16075ca 100644
--- a/thorn/include/kernel/mailbox.h
+++ b/thorn/include/kernel/mailbox.h
@@ -10,6 +10,8 @@
 #include "common/debug.h"
 #include "common/logging.h"
 
+#define DUMP_BUFFER true
+
 // Documentation:
 // https://github.com/raspberrypi/firmware/wiki/Mailbox-property-interface
 
@@ -28,30 +30,11 @@ typedef enum {
 
 
 typedef struct {
-    unsigned int data: 28;      // most significant bits contain shared memory address
+    unsigned int data: 28;  // most significant bits contain shared memory address
     channel_t channel: 4;   // least four significant bits contain channel
 } mbox_message_t;
 
-typedef struct {
-    unsigned int identity;
-    unsigned int buffer_size;
-    unsigned int response;
-    byte_t * buffer;
-} mbox_tag_t;
-
-typedef struct {
-    unsigned int struct_size;
-    unsigned int response;
-    mbox_tag_t * tags;
-} mbox_property_t;
-
 // Send message and check responses
 bool mailbox_request (unsigned int data_ptr, channel_t channel);
 
-// Returns total size written
-unsigned int mailbox_write_msg (unsigned int message[], mbox_tag_t * tags, int tags_count);
-
-// Returns total size written
-unsigned int mailbox_write_tags (mbox_tag_t * dest, mbox_tag_t * src, int tags_count);
-
 #endif //_ROSE_K_MAILBOX_H
\ No newline at end of file
diff --git a/thorn/src/common/gpu.c b/thorn/src/common/gpu.c
index 9c8fbc6..5526113 100644
--- a/thorn/src/common/gpu.c
+++ b/thorn/src/common/gpu.c
@@ -6,15 +6,17 @@ bool init_gpu () {
         mbox[++c] = 0;                      // Response - will be 0x80000000 for SUCCESS or 0x80000001 for FAILURE
         
         mbox[++c] = 0x00040003;             // Tag to get physical display width / height
-        mbox[++c] = 8;                      // Size of value buffer
+        mbox[++c] = 0;                      // Size of value buffer
         mbox[++c] = 0;                      // Response & value buffer size written will be written here
-        mbox[++c] = GPU_SCREEN_WIDTH;       // Get physical screen width    |  Overwritten by actual width
-        mbox[++c] = GPU_SCREEN_HEIGHT;      // Get physical screen height   |  Overwritten by actual height
+        mbox[++c] = 0;                      // Get physical screen width    |  Overwritten by actual width
+        mbox[++c] = 0;                      // Get physical screen height   |  Overwritten by actual height
         
-        mbox[0] = 4 * c;                    // Write message size at the beginning of the buffer
+        mbox[0] = 4 * ++c;                    // Write message size at the beginning of the buffer
+        
+        // If reading physical screen dimension fails exit function
+        if (!mailbox_request (mbox, PROPERTY_ARM_VC)) return false;
     }
     
-    byte_t index_framebuffer;
     {
         int c = 0;                          // Message size; increment while we write
         mbox[++c] = 0;                      // Response - will be 0x80000000 for SUCCESS or 0x80000001 for FAILURE
@@ -34,7 +36,7 @@ bool init_gpu () {
         mbox[++c] = 8;                      // Size of value buffer
         mbox[++c] = 0;                      // Response & value buffer size will be written here
         mbox[++c] = 16;                     // Buffer alignment             |  Overwritten by pointer to framebuffer
-        index_framebuffer = c;
+        byte_t index_framebuffer = c;
         mbox[++c] = 0;                      // Unused - will be overwritten |  Overwritten by size of framebuffer
         
         mbox[++c] = 0;                      // End tag
@@ -42,44 +44,13 @@ bool init_gpu () {
         mbox[++c] = 0;                      // Padding
         
         mbox[0] = 4 * c;                    // Write message size at the beginning of the buffer
-    }
-    
-    int_dump ((unsigned int *) mbox);
-    hex_dump ((unsigned int *) mbox);
-    
-    // 28-bit address (MSB) and 4-bit value (LSB)
-    unsigned int outgoing = ((unsigned int) ((long) mbox) & ~0xF) | (PROPERTY_ARM_VC & 0xF);
-    
-    // Wait until we can write
-    while (get32 (MBOX0 + MBOX_STATUS) & MBOX_FULL);
-    
-    // Write the address of our buffer to the mailbox with the channel appended
-    put32 (MBOX0 + MBOX_WRITE, outgoing);
-    
-    unsigned int incoming;
-    while (1) {
-        // Is there a reply?
-        while (get32 (MBOX0 + MBOX_STATUS) & MBOX_EMPTY);
         
-        incoming = get32 (MBOX0 + MBOX_READ);
+        // If message failed exit
+        if (!mailbox_request (mbox, PROPERTY_ARM_VC)) return false;
         
-        // Is it a reply to our message?
-        if (outgoing == incoming) {
-            int_dump ((unsigned int *) mbox);
-            hex_dump ((unsigned int *) mbox);
-            
-            if (mbox[1] != MBOX_SUCCESS) {
-                return false;
-            }
-            break;
-        }
+        // Since message succeeded, update the frame buffer
+        fb = (color * ) (mbox[index_framebuffer] & VC_SDRAM_OFFSET);
     }
-    
-    int_dump ((unsigned int *) mbox);
-    hex_dump ((unsigned int *) mbox);
-    
-    fb = (color * ) (
-    long) (mbox[index_framebuffer] & VC_SDRAM_OFFSET);
     return true;
 }
 
diff --git a/thorn/src/kernel/mailbox.c b/thorn/src/kernel/mailbox.c
index cf86e08..81e153d 100644
--- a/thorn/src/kernel/mailbox.c
+++ b/thorn/src/kernel/mailbox.c
@@ -1,83 +1,47 @@
 #include "kernel/mailbox.h"
 
 bool mailbox_request (unsigned int data_ptr, channel_t channel) {
-    mbox_message_t msg;
-    unsigned int * msg_ptr = (unsigned int *) & msg;
-    unsigned int check;
+    unsigned int * buffer = (unsigned int *) (long) data_ptr;
     
-    * msg_ptr = data_ptr;
-    msg.channel = channel;
-    
-    LOG ("Waiting for empty write buffer GPU...");
-    while ((MBOX0 + MBOX_STATUS) & MBOX_WRITE_FULL);
-    
-    LOG ("Writing to GPU...");
-    put32 (MBOX0 + MBOX_WRITE, * msg_ptr);
-    
-    LOG ("Reading response...");
-    do {
-        // Wait until there's a message
-        LOG ("Waiting for any message...");
-        while ((MBOX0 + MBOX_STATUS) & MBOX_READ_EMPTY);
-        
-        LOG ("Check message");
-        check = get32 (MBOX0 + MBOX_READ);
-        
-        LOG ("Check channel");
-        // Check if it's the response to our message
-    } while (* msg_ptr == check);
-    
-    LOG ("Read pointer to property response");
-    // Get the pointer to the property request message
-    mbox_property_t * property = (mbox_property_t * ) ((unsigned long) (* msg_ptr & ~0xFF));
-    
-    char * buffer[100];
-    sprintf (buffer, "Returning response code: operation %s",
-             (property->response == MBOX_SUCCESS) ? "succeeded" : "failed");
-    LOG (buffer);
-    // Return the message's response code
-    return property->response == MBOX_SUCCESS;
-}
-
-unsigned int mailbox_write_msg (unsigned int message[], mbox_tag_t * tags, int tags_count) {
-    mbox_property_t * msg = (mbox_property_t * ) & message;
+    if (DUMP_BUFFER) {
+        int_dump ((byte_t *) buffer);
+        hex_dump ((unsigned int *) (long) buffer);
+    }
     
-    // Add tags to message:
-    unsigned int struct_size = 2 * sizeof (unsigned int);
-    struct_size += mailbox_write_tags ((mbox_tag_t * ) (message + struct_size), tags, tags_count);
+    // 28-bit address (MSB) and 4-bit value (LSB)
+    unsigned int outgoing = ((unsigned int) ((long) data_ptr) & ~0xF) | (channel & 0xF);
     
-    // Add end tag and 16 byte-aligned padding:
-    struct_size += (struct_size % 16) ? 32 - (struct_size % 16) : 16;
+    // Wait until we can write
+    while (get32 (MBOX0 + MBOX_STATUS) & MBOX_FULL);
     
-    // write struct size to message:
-    msg->struct_size = struct_size;
+    // Write the address of our buffer to the mailbox with the channel appended
+    put32 (MBOX0 + MBOX_WRITE, outgoing);
     
-    // return number of bytes written, for reference
-    return struct_size;
-}
-
-unsigned int mailbox_write_tags (mbox_tag_t * dest, mbox_tag_t * src, int tags_count) {
-    unsigned int written = 0;
-    for (int i = 0; i < tags_count; i++) {
-        dest += written;
+    unsigned int incoming;
+    while (1) {
+        // Is there a reply?
+        while (get32 (MBOX0 + MBOX_STATUS) & MBOX_EMPTY);
         
-        unsigned int buffer_size = src->buffer_size;
+        incoming = get32 (MBOX0 + MBOX_READ);
         
-        dest->identity = src->identity;
-        dest->buffer_size = buffer_size;
-        dest->response = 0;
-        
-        for (unsigned int i = 0; i < buffer_size; i++) {
-            dest->buffer[written] = src->buffer[written];
+        // Is it a reply to our message?
+        if (outgoing == incoming) {
+            if (buffer[1] != MBOX_SUCCESS) {
+                if (DUMP_BUFFER) {
+                    int_dump ((byte_t *) buffer);
+                    hex_dump ((unsigned int *) buffer);
+                }
+                
+                return false;
+            }
+            break;
         }
-        written += 3 * sizeof (unsigned int) + buffer_size;
-        put32 ((unsigned int) (dest + written), 0);
-        
-        written += sizeof (unsigned int);
-        put32 ((unsigned int) (dest + written), 0);
-        
-        written += (written % 16) ? 16 - (written % 16) : 0;
     }
     
-    return written;
-}
\ No newline at end of file
+    if (DUMP_BUFFER) {
+        int_dump ((byte_t *) buffer);
+        hex_dump ((unsigned int *) buffer);
+    }
+    
+    return true;
+}

From 9712af459a8d3dcd4848d5034b8c6bb7544cf02a Mon Sep 17 00:00:00 2001
From: Aaron Alef <aaron.alef@code.berlin>
Date: Thu, 14 Oct 2021 17:53:52 +0200
Subject: [PATCH 22/61] refactor(gpu): allow overriding screen dims read from
 GPU

---
 thorn/include/common/gpu.h |  7 +++++--
 thorn/src/common/gpu.c     | 24 +++++++++++++++++++-----
 2 files changed, 24 insertions(+), 7 deletions(-)

diff --git a/thorn/include/common/gpu.h b/thorn/include/common/gpu.h
index f7a25ff..ce23aba 100644
--- a/thorn/include/common/gpu.h
+++ b/thorn/include/common/gpu.h
@@ -12,8 +12,11 @@
 // Reference:
 // https://jsandler18.github.io/extra/prop-channel.html
 
-#define GPU_SCREEN_WIDTH    1920
-#define GPU_SCREEN_HEIGHT   1080
+// Uncomment to override physical / virtual screen size with the values defined below
+//#define GPU_OVERRIDE_PHYSICAL_SCREEN
+
+#define GPU_SCREEN_WIDTH    1920                // Width used if Override is enabled
+#define GPU_SCREEN_HEIGHT   1080                // Height used if Override is enabled
 
 #define GPU_VIRTUAL_WIDTH   GPU_SCREEN_WIDTH
 #define GPU_VIRTUAL_HEIGHT  GPU_SCREEN_HEIGHT
diff --git a/thorn/src/common/gpu.c b/thorn/src/common/gpu.c
index 5526113..929d81d 100644
--- a/thorn/src/common/gpu.c
+++ b/thorn/src/common/gpu.c
@@ -20,12 +20,26 @@ bool init_gpu () {
     {
         int c = 0;                          // Message size; increment while we write
         mbox[++c] = 0;                      // Response - will be 0x80000000 for SUCCESS or 0x80000001 for FAILURE
+
+#ifdef GPU_OVERRIDE_PHYSICAL_SCREEN
+        mbox[++c] = 0x00048003;             // Tag to set virtual display width / height
+        mbox[++c] = 8;                      // Size of value buffer
+        mbox[++c] = 0;                      // Response & value buffer size written will be written here
+        mbox[++c] = GPU_SCREEN_WIDTH;       // Set virtual screen width     |  Overwritten by actual virtual width
+        mbox[++c] = GPU_SCREEN_HEIGHT;      // Set virtual screen height    |  Overwritten by actual virtual height
         
         mbox[++c] = 0x00048004;             // Tag to set virtual display width / height
         mbox[++c] = 8;                      // Size of value buffer
         mbox[++c] = 0;                      // Response & value buffer size written will be written here
-        mbox[++c];//GPU_SCREEN_WIDTH;       // Set virtual screen width     |  Overwritten by actual virtual width
-        mbox[++c];//GPU_SCREEN_HEIGHT;      // Set virtual screen height    |  Overwritten by actual virtual height
+        mbox[++c] = GPU_VIRTUAL_WIDTH;      // Set virtual screen width     |  Overwritten by actual virtual width
+        mbox[++c] = GPU_VIRTUAL_HEIGHT;     // Set virtual screen height    |  Overwritten by actual virtual height
+#else
+        mbox[++c] = 0x00048004;             // Tag to set virtual display width / height
+        mbox[++c] = 8;                      // Size of value buffer
+        mbox[++c] = 0;                      // Response & value buffer size written will be written here
+        mbox[++c];//GPU_SCREEN_WIDTH;       // Keep virtual screen width    |  Overwritten by actual virtual width
+        mbox[++c];//GPU_SCREEN_HEIGHT;      // Keep virtual screen height   |  Overwritten by actual virtual height
+#endif
         
         mbox[++c] = 0x00048005;             // Tag to set pixel depth
         mbox[++c] = 4;                      // Size of value buffer
@@ -43,7 +57,7 @@ bool init_gpu () {
         mbox[++c] = 0;                      // Padding
         mbox[++c] = 0;                      // Padding
         
-        mbox[0] = 4 * c;                    // Write message size at the beginning of the buffer
+        mbox[0] = 4 * ++c;                    // Write message size at the beginning of the buffer
         
         // If message failed exit
         if (!mailbox_request (mbox, PROPERTY_ARM_VC)) return false;
@@ -58,6 +72,7 @@ void draw () {
     printf ("\n");
     
     color rainbow[] = {
+            {0xff, 0x00, 0xff, 0},
             {0x80, 0x00, 0xff, 0},
             {0x00, 0x00, 0xff, 0},
             {0x00, 0x80, 0xff, 0},
@@ -68,8 +83,7 @@ void draw () {
             {0xff, 0xff, 0x00, 0},
             {0xff, 0x80, 0x00, 0},
             {0xff, 0x00, 0x00, 0},
-            {0xff, 0x00, 0x80, 0},
-            {0xff, 0x00, 0xff, 0}
+            {0xff, 0x00, 0x80, 0}
     };
     
     int rb_size = sizeof (rainbow) / sizeof (color);

From 16b5d6debe1e2e98d886916c9458fe750a4ffb2f Mon Sep 17 00:00:00 2001
From: Aaron Alef <aaron.alef@code.berlin>
Date: Thu, 14 Oct 2021 18:25:00 +0200
Subject: [PATCH 23/61] feat(gpu): request pitch

NOTE: received pitch is always 0!
---
 thorn/include/common/gpu.h |  2 +-
 thorn/src/common/gpu.c     | 28 ++++++++++++++++++++++++++--
 2 files changed, 27 insertions(+), 3 deletions(-)

diff --git a/thorn/include/common/gpu.h b/thorn/include/common/gpu.h
index ce23aba..7046c7c 100644
--- a/thorn/include/common/gpu.h
+++ b/thorn/include/common/gpu.h
@@ -13,7 +13,7 @@
 // https://jsandler18.github.io/extra/prop-channel.html
 
 // Uncomment to override physical / virtual screen size with the values defined below
-//#define GPU_OVERRIDE_PHYSICAL_SCREEN
+#define GPU_OVERRIDE_PHYSICAL_SCREEN
 
 #define GPU_SCREEN_WIDTH    1920                // Width used if Override is enabled
 #define GPU_SCREEN_HEIGHT   1080                // Height used if Override is enabled
diff --git a/thorn/src/common/gpu.c b/thorn/src/common/gpu.c
index 929d81d..a77a73a 100644
--- a/thorn/src/common/gpu.c
+++ b/thorn/src/common/gpu.c
@@ -11,7 +11,9 @@ bool init_gpu () {
         mbox[++c] = 0;                      // Get physical screen width    |  Overwritten by actual width
         mbox[++c] = 0;                      // Get physical screen height   |  Overwritten by actual height
         
-        mbox[0] = 4 * ++c;                    // Write message size at the beginning of the buffer
+        mbox[++c] = 0;                      // End tag
+        
+        mbox[0] = (4 * ++c);                // Write message size at the beginning of the buffer
         
         // If reading physical screen dimension fails exit function
         if (!mailbox_request (mbox, PROPERTY_ARM_VC)) return false;
@@ -56,8 +58,9 @@ bool init_gpu () {
         mbox[++c] = 0;                      // End tag
         mbox[++c] = 0;                      // Padding
         mbox[++c] = 0;                      // Padding
+        mbox[++c] = 0;                      // Padding
         
-        mbox[0] = 4 * ++c;                    // Write message size at the beginning of the buffer
+        mbox[0] = (4 * ++c);                // Write message size at the beginning of the buffer
         
         // If message failed exit
         if (!mailbox_request (mbox, PROPERTY_ARM_VC)) return false;
@@ -65,6 +68,27 @@ bool init_gpu () {
         // Since message succeeded, update the frame buffer
         fb = (color * ) (mbox[index_framebuffer] & VC_SDRAM_OFFSET);
     }
+    {                                       // Third message: read pitch (in bytes per line)
+        int c = 0;                          // Message size; increment while we write
+        mbox[++c] = 0;                      // Response - will be 0x80000000 for SUCCESS or 0x80000001 for FAILURE
+        
+        mbox[++c] = 0x00040008;             // Tag to get pitch
+        mbox[++c] = 0;                      // Size of value buffer
+        mbox[++c] = 0;                      // Response & value buffer size written will be written here
+        mbox[++c] = 0;                      // Pitch will be written here
+        int index_pitch = c;
+        
+        mbox[++c] = 0;                      // End tag
+        mbox[++c] = 0;                      // Padding
+        
+        mbox[0] = (4 * ++c);                // Write message size at the beginning of the buffer
+        
+        // If message failed exit
+        if (!mailbox_request (mbox, PROPERTY_ARM_VC)) return false;
+        if (mbox[index_pitch]) {printf ("\r\nGot pitch: %d\r\n", mbox[index_pitch]);}
+        else {printf ("\r\nPitch received as 0\r\n");}
+    }
+    
     return true;
 }
 

From 8e0be78ce5f2183e525ddf6aa06ad22001065c14 Mon Sep 17 00:00:00 2001
From: Aaron Alef <aaron.alef@code.berlin>
Date: Thu, 14 Oct 2021 18:27:54 +0200
Subject: [PATCH 24/61] fix(debug): fix int dump printing too many integers

---
 thorn/src/common/debug.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/thorn/src/common/debug.c b/thorn/src/common/debug.c
index ca910cb..5d61ef7 100644
--- a/thorn/src/common/debug.c
+++ b/thorn/src/common/debug.c
@@ -21,7 +21,7 @@ void hex_dump (byte_t * array) {
 }
 
 void int_dump (unsigned int * array) {
-    for (int i = 0; i < * array; i++) {
+    for (int i = 0; i < * array / 4; i++) {
         printf ("%d ", array[i]);
     }
     printf ("\r\n");

From 2bdbc94d89c4911c67f4def998dba7ef422a1d15 Mon Sep 17 00:00:00 2001
From: Aaron Alef <aaron.alef@code.berlin>
Date: Thu, 14 Oct 2021 18:30:12 +0200
Subject: [PATCH 25/61] refactor(debug): make output more understandable

---
 thorn/src/common/gpu.c     | 2 +-
 thorn/src/kernel/mailbox.c | 3 +++
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/thorn/src/common/gpu.c b/thorn/src/common/gpu.c
index a77a73a..4e964a2 100644
--- a/thorn/src/common/gpu.c
+++ b/thorn/src/common/gpu.c
@@ -86,7 +86,7 @@ bool init_gpu () {
         // If message failed exit
         if (!mailbox_request (mbox, PROPERTY_ARM_VC)) return false;
         if (mbox[index_pitch]) {printf ("\r\nGot pitch: %d\r\n", mbox[index_pitch]);}
-        else {printf ("\r\nPitch received as 0\r\n");}
+        else {printf ("\r\nPitch is 0?!\r\n");}
     }
     
     return true;
diff --git a/thorn/src/kernel/mailbox.c b/thorn/src/kernel/mailbox.c
index 81e153d..503711f 100644
--- a/thorn/src/kernel/mailbox.c
+++ b/thorn/src/kernel/mailbox.c
@@ -4,6 +4,7 @@ bool mailbox_request (unsigned int data_ptr, channel_t channel) {
     unsigned int * buffer = (unsigned int *) (long) data_ptr;
     
     if (DUMP_BUFFER) {
+        LOG ("Dumping message buffer before sending:");
         int_dump ((byte_t *) buffer);
         hex_dump ((unsigned int *) (long) buffer);
     }
@@ -28,6 +29,7 @@ bool mailbox_request (unsigned int data_ptr, channel_t channel) {
         if (outgoing == incoming) {
             if (buffer[1] != MBOX_SUCCESS) {
                 if (DUMP_BUFFER) {
+                    LOG ("Dumping failed message buffer:");
                     int_dump ((byte_t *) buffer);
                     hex_dump ((unsigned int *) buffer);
                 }
@@ -39,6 +41,7 @@ bool mailbox_request (unsigned int data_ptr, channel_t channel) {
     }
     
     if (DUMP_BUFFER) {
+        LOG ("Dumping successful message buffer:");
         int_dump ((byte_t *) buffer);
         hex_dump ((unsigned int *) buffer);
     }

From 6037e7cef2a30cd1e4fed2b37f9041cd5050167b Mon Sep 17 00:00:00 2001
From: Aaron Alef <aaron.alef@code.berlin>
Date: Fri, 15 Oct 2021 12:17:29 +0200
Subject: [PATCH 26/61] feat(gpu): double rainbow resolution

---
 thorn/src/common/gpu.c | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/thorn/src/common/gpu.c b/thorn/src/common/gpu.c
index 4e964a2..7e7640d 100644
--- a/thorn/src/common/gpu.c
+++ b/thorn/src/common/gpu.c
@@ -97,17 +97,29 @@ void draw () {
     
     color rainbow[] = {
             {0xff, 0x00, 0xff, 0},
+            {0xc0, 0x00, 0xff, 0},
             {0x80, 0x00, 0xff, 0},
+            {0x40, 0x00, 0xff, 0},
             {0x00, 0x00, 0xff, 0},
+            {0x00, 0x40, 0xff, 0},
             {0x00, 0x80, 0xff, 0},
+            {0x00, 0xc0, 0xff, 0},
             {0x00, 0xff, 0xff, 0},
+            {0x00, 0xff, 0xc0, 0},
             {0x00, 0xff, 0x80, 0},
+            {0x00, 0xff, 0x40, 0},
             {0x00, 0xff, 0x00, 0},
+            {0x40, 0xff, 0x00, 0},
             {0x80, 0xff, 0x00, 0},
+            {0xc0, 0xff, 0x00, 0},
             {0xff, 0xff, 0x00, 0},
+            {0xff, 0xc0, 0x00, 0},
             {0xff, 0x80, 0x00, 0},
+            {0xff, 0x40, 0x00, 0},
             {0xff, 0x00, 0x00, 0},
-            {0xff, 0x00, 0x80, 0}
+            {0xff, 0x00, 0x40, 0},
+            {0xff, 0x00, 0x80, 0},
+            {0xff, 0x00, 0xc0, 0}
     };
     
     int rb_size = sizeof (rainbow) / sizeof (color);

From 890343a8f266667c699a243053ebee580445fe15 Mon Sep 17 00:00:00 2001
From: Aaron Alef <aaron.alef@code.berlin>
Date: Fri, 15 Oct 2021 14:23:49 +0200
Subject: [PATCH 27/61] feat(gpu): display a continuous rainbow pattern

---
 thorn/include/common/gpu.h     |  2 -
 thorn/include/common/rainbow.h | 20 ++++++++++
 thorn/include/kernel/mailbox.h |  2 +-
 thorn/include/kernel/mm.h      |  2 +-
 thorn/src/common/gpu.c         | 55 ---------------------------
 thorn/src/common/rainbow.c     | 69 ++++++++++++++++++++++++++++++++++
 thorn/src/kernel/kernel.c      |  1 +
 7 files changed, 92 insertions(+), 59 deletions(-)
 create mode 100644 thorn/include/common/rainbow.h
 create mode 100644 thorn/src/common/rainbow.c

diff --git a/thorn/include/common/gpu.h b/thorn/include/common/gpu.h
index 7046c7c..9fca21a 100644
--- a/thorn/include/common/gpu.h
+++ b/thorn/include/common/gpu.h
@@ -40,8 +40,6 @@ static color * fb;
 
 bool init_gpu (void);
 
-void draw (void);
-
 color * get_fb (void);
 
 
diff --git a/thorn/include/common/rainbow.h b/thorn/include/common/rainbow.h
new file mode 100644
index 0000000..518009c
--- /dev/null
+++ b/thorn/include/common/rainbow.h
@@ -0,0 +1,20 @@
+#ifndef _ROSE_RAINBOW_H
+#define _ROSE_RAINBOW_H
+
+#include "common/gpu.h"
+
+#define SIZE_OF_RAINBOW 950
+#define OFFSET_STEPS 19
+#define OFFSET_FACTOR (SIZE_OF_RAINBOW / OFFSET_STEPS)
+
+static color rainbow[SIZE_OF_RAINBOW];
+
+static unsigned int const RB_SIZE = SIZE_OF_RAINBOW;
+
+void draw (void);
+
+void populate_rainbow (void);
+
+int write_color_to_rainbow (unsigned char red, unsigned char green, unsigned char blue);
+
+#endif //_ROSE_RAINBOW_H
\ No newline at end of file
diff --git a/thorn/include/kernel/mailbox.h b/thorn/include/kernel/mailbox.h
index 16075ca..bb8645a 100644
--- a/thorn/include/kernel/mailbox.h
+++ b/thorn/include/kernel/mailbox.h
@@ -10,7 +10,7 @@
 #include "common/debug.h"
 #include "common/logging.h"
 
-#define DUMP_BUFFER true
+#define DUMP_BUFFER false
 
 // Documentation:
 // https://github.com/raspberrypi/firmware/wiki/Mailbox-property-interface
diff --git a/thorn/include/kernel/mm.h b/thorn/include/kernel/mm.h
index 0be2178..718f88a 100644
--- a/thorn/include/kernel/mm.h
+++ b/thorn/include/kernel/mm.h
@@ -12,7 +12,7 @@
 #define SECTION_SIZE        (1 << SECTION_SHIFT)
 
 #define LOW_MEMORY          (2 * SECTION_SIZE)
-#define HIGH_MEMORY         0x60000000
+#define HIGH_MEMORY         0x70000000
 
 #define PAGING_MEMORY       (HIGH_MEMORY - LOW_MEMORY)
 #define PAGING_PAGES        (PAGING_MEMORY/PAGE_SIZE)
diff --git a/thorn/src/common/gpu.c b/thorn/src/common/gpu.c
index 7e7640d..10fc41a 100644
--- a/thorn/src/common/gpu.c
+++ b/thorn/src/common/gpu.c
@@ -92,61 +92,6 @@ bool init_gpu () {
     return true;
 }
 
-void draw () {
-    printf ("\n");
-    
-    color rainbow[] = {
-            {0xff, 0x00, 0xff, 0},
-            {0xc0, 0x00, 0xff, 0},
-            {0x80, 0x00, 0xff, 0},
-            {0x40, 0x00, 0xff, 0},
-            {0x00, 0x00, 0xff, 0},
-            {0x00, 0x40, 0xff, 0},
-            {0x00, 0x80, 0xff, 0},
-            {0x00, 0xc0, 0xff, 0},
-            {0x00, 0xff, 0xff, 0},
-            {0x00, 0xff, 0xc0, 0},
-            {0x00, 0xff, 0x80, 0},
-            {0x00, 0xff, 0x40, 0},
-            {0x00, 0xff, 0x00, 0},
-            {0x40, 0xff, 0x00, 0},
-            {0x80, 0xff, 0x00, 0},
-            {0xc0, 0xff, 0x00, 0},
-            {0xff, 0xff, 0x00, 0},
-            {0xff, 0xc0, 0x00, 0},
-            {0xff, 0x80, 0x00, 0},
-            {0xff, 0x40, 0x00, 0},
-            {0xff, 0x00, 0x00, 0},
-            {0xff, 0x00, 0x40, 0},
-            {0xff, 0x00, 0x80, 0},
-            {0xff, 0x00, 0xc0, 0}
-    };
-    
-    int rb_size = sizeof (rainbow) / sizeof (color);
-    int divisor;
-    
-    while (1) {
-        for (int offset = 0; offset < rb_size; offset++) {
-            divisor = GPU_SCREEN_WIDTH / rb_size;
-            for (int x = 0; x < GPU_SCREEN_WIDTH - GPU_SCREEN_WIDTH % divisor; x++) {
-                for (int y = 0; y < GPU_SCREEN_HEIGHT; y++) {
-                    fb[y * GPU_SCREEN_WIDTH + x].red ^= rainbow[(x / divisor + offset) % rb_size].red;
-                    fb[y * GPU_SCREEN_WIDTH + x].green ^= rainbow[(x / divisor + offset) % rb_size].green;
-                    fb[y * GPU_SCREEN_WIDTH + x].blue ^= rainbow[(x / divisor + offset) % rb_size].blue;
-                }
-            }
-            divisor = GPU_SCREEN_HEIGHT / rb_size;
-            for (int y = 0; y < GPU_SCREEN_HEIGHT - GPU_SCREEN_HEIGHT % divisor; y++) {
-                for (int x = 0; x < GPU_SCREEN_WIDTH; x++) {
-                    fb[y * GPU_SCREEN_WIDTH + x].red ^= rainbow[(y / divisor + offset) % rb_size].red;
-                    fb[y * GPU_SCREEN_WIDTH + x].green ^= rainbow[(y / divisor + offset) % rb_size].green;
-                    fb[y * GPU_SCREEN_WIDTH + x].blue ^= rainbow[(y / divisor + offset) % rb_size].blue;
-                }
-            }
-        }
-    }
-}
-
 color * get_fb () {
     return fb;
 }
\ No newline at end of file
diff --git a/thorn/src/common/rainbow.c b/thorn/src/common/rainbow.c
new file mode 100644
index 0000000..874f187
--- /dev/null
+++ b/thorn/src/common/rainbow.c
@@ -0,0 +1,69 @@
+#include "common/rainbow.h"
+
+void draw () {
+    populate_rainbow ();
+    
+    unsigned int const X_DIVISOR = GPU_SCREEN_WIDTH / RB_SIZE;
+    unsigned int const Y_DIVISOR = GPU_SCREEN_HEIGHT / RB_SIZE;
+    
+    unsigned int * rainbow_i = (unsigned int *) rainbow;
+    unsigned int * fb_i = (unsigned int *) get_fb ();
+    
+    color current = rainbow[0];
+    unsigned int current_i = * (unsigned int *) & current;
+    
+    while (1) {
+        for (int offset = 0; offset < OFFSET_STEPS; offset++) {
+            for (int x = 0; x < GPU_SCREEN_WIDTH - GPU_SCREEN_WIDTH % X_DIVISOR; x++) {
+                for (int y = 0; y < GPU_SCREEN_HEIGHT; y++) {
+                    fb_i[y * GPU_SCREEN_WIDTH + x] ^= rainbow_i[(x / X_DIVISOR + OFFSET_FACTOR * offset) % RB_SIZE];
+                }
+            }
+            for (int y = 0; y < GPU_SCREEN_HEIGHT - GPU_SCREEN_HEIGHT % Y_DIVISOR; y++) {
+                for (int x = 0; x < GPU_SCREEN_WIDTH; x++) {
+                    fb_i[y * GPU_SCREEN_WIDTH + x] ^= rainbow_i[(y / Y_DIVISOR + OFFSET_FACTOR * offset) % RB_SIZE];
+                }
+            }
+        }
+    }
+}
+
+void populate_rainbow () {
+    unsigned char red = 0xFF;
+    unsigned char green = 0x00;
+    unsigned char blue = 0xFF;
+    
+    do { // purple to red
+        write_color_to_rainbow (red, green, blue);
+    } while (blue -= 4 > 3);
+    
+    do { // red to yellow
+        write_color_to_rainbow (red, green += 4, blue);
+    } while (green < 252);
+    
+    do { // yellow to green
+        write_color_to_rainbow (red, green, blue);
+    } while (red -= 4 > 3);
+    
+    do { // green to cyan
+        write_color_to_rainbow (red, green, blue += 4);
+    } while (blue < 252);
+    
+    do { // cyan to blue
+        write_color_to_rainbow (red, green, blue);
+    } while (green -= 4 > 3);
+    
+    do { // blue to purple
+        write_color_to_rainbow (red += 4, green, blue);
+    } while (red < 252);
+    
+}
+
+int write_color_to_rainbow (unsigned char red, unsigned char green, unsigned char blue) {
+    static int index = 0;
+    rainbow[index].red = red;
+    rainbow[index].green = green;
+    rainbow[index].blue = blue;
+    printf ("%d ", index);
+    return ++index;
+}
diff --git a/thorn/src/kernel/kernel.c b/thorn/src/kernel/kernel.c
index 9b77044..c0d4045 100644
--- a/thorn/src/kernel/kernel.c
+++ b/thorn/src/kernel/kernel.c
@@ -9,6 +9,7 @@
 #include "kernel/fork.h"
 #include "kernel/sys.h"
 #include "common/logging.h"
+#include "common/rainbow.h"
 
 void user_process1 (char * array) {
     char buf[2] = {0};

From bbf67055ed2d317b3e8069edd115485d74ab8f36 Mon Sep 17 00:00:00 2001
From: Aaron Alef <aaron.alef@code.berlin>
Date: Fri, 15 Oct 2021 14:36:39 +0200
Subject: [PATCH 28/61] feat(colour): switch to discrete rainbow again

---
 thorn/include/common/rainbow.h | 36 ++++++++++++++++-------
 thorn/src/common/rainbow.c     | 54 ++++------------------------------
 2 files changed, 31 insertions(+), 59 deletions(-)

diff --git a/thorn/include/common/rainbow.h b/thorn/include/common/rainbow.h
index 518009c..5abc049 100644
--- a/thorn/include/common/rainbow.h
+++ b/thorn/include/common/rainbow.h
@@ -3,18 +3,34 @@
 
 #include "common/gpu.h"
 
-#define SIZE_OF_RAINBOW 950
-#define OFFSET_STEPS 19
-#define OFFSET_FACTOR (SIZE_OF_RAINBOW / OFFSET_STEPS)
+static color const RAINBOW[] = {
+        {0xff, 0x00, 0xff, 0},
+        {0xc0, 0x00, 0xff, 0},
+        {0x80, 0x00, 0xff, 0},
+        {0x40, 0x00, 0xff, 0},
+        {0x00, 0x00, 0xff, 0},
+        {0x00, 0x40, 0xff, 0},
+        {0x00, 0x80, 0xff, 0},
+        {0x00, 0xc0, 0xff, 0},
+        {0x00, 0xff, 0xff, 0},
+        {0x00, 0xff, 0xc0, 0},
+        {0x00, 0xff, 0x80, 0},
+        {0x00, 0xff, 0x40, 0},
+        {0x00, 0xff, 0x00, 0},
+        {0x40, 0xff, 0x00, 0},
+        {0x80, 0xff, 0x00, 0},
+        {0xc0, 0xff, 0x00, 0},
+        {0xff, 0xff, 0x00, 0},
+        {0xff, 0xc0, 0x00, 0},
+        {0xff, 0x80, 0x00, 0},
+        {0xff, 0x40, 0x00, 0},
+        {0xff, 0x00, 0x00, 0},
+        {0xff, 0x00, 0x40, 0},
+        {0xff, 0x00, 0x80, 0},
+        {0xff, 0x00, 0xc0, 0}
+};
 
-static color rainbow[SIZE_OF_RAINBOW];
-
-static unsigned int const RB_SIZE = SIZE_OF_RAINBOW;
 
 void draw (void);
 
-void populate_rainbow (void);
-
-int write_color_to_rainbow (unsigned char red, unsigned char green, unsigned char blue);
-
 #endif //_ROSE_RAINBOW_H
\ No newline at end of file
diff --git a/thorn/src/common/rainbow.c b/thorn/src/common/rainbow.c
index 874f187..5fbd75a 100644
--- a/thorn/src/common/rainbow.c
+++ b/thorn/src/common/rainbow.c
@@ -1,69 +1,25 @@
 #include "common/rainbow.h"
 
 void draw () {
-    populate_rainbow ();
-    
+    unsigned int const RB_SIZE = sizeof (RAINBOW) / sizeof (color);
     unsigned int const X_DIVISOR = GPU_SCREEN_WIDTH / RB_SIZE;
     unsigned int const Y_DIVISOR = GPU_SCREEN_HEIGHT / RB_SIZE;
     
-    unsigned int * rainbow_i = (unsigned int *) rainbow;
+    unsigned int * rainbow_i = (unsigned int *) RAINBOW;
     unsigned int * fb_i = (unsigned int *) get_fb ();
     
-    color current = rainbow[0];
-    unsigned int current_i = * (unsigned int *) & current;
-    
     while (1) {
-        for (int offset = 0; offset < OFFSET_STEPS; offset++) {
+        for (int offset = 0; offset < RB_SIZE; offset++) {
             for (int x = 0; x < GPU_SCREEN_WIDTH - GPU_SCREEN_WIDTH % X_DIVISOR; x++) {
                 for (int y = 0; y < GPU_SCREEN_HEIGHT; y++) {
-                    fb_i[y * GPU_SCREEN_WIDTH + x] ^= rainbow_i[(x / X_DIVISOR + OFFSET_FACTOR * offset) % RB_SIZE];
+                    fb_i[y * GPU_SCREEN_WIDTH + x] ^= rainbow_i[(x / X_DIVISOR + offset) % RB_SIZE];
                 }
             }
             for (int y = 0; y < GPU_SCREEN_HEIGHT - GPU_SCREEN_HEIGHT % Y_DIVISOR; y++) {
                 for (int x = 0; x < GPU_SCREEN_WIDTH; x++) {
-                    fb_i[y * GPU_SCREEN_WIDTH + x] ^= rainbow_i[(y / Y_DIVISOR + OFFSET_FACTOR * offset) % RB_SIZE];
+                    fb_i[y * GPU_SCREEN_WIDTH + x] ^= rainbow_i[(y / Y_DIVISOR + offset) % RB_SIZE];
                 }
             }
         }
     }
 }
-
-void populate_rainbow () {
-    unsigned char red = 0xFF;
-    unsigned char green = 0x00;
-    unsigned char blue = 0xFF;
-    
-    do { // purple to red
-        write_color_to_rainbow (red, green, blue);
-    } while (blue -= 4 > 3);
-    
-    do { // red to yellow
-        write_color_to_rainbow (red, green += 4, blue);
-    } while (green < 252);
-    
-    do { // yellow to green
-        write_color_to_rainbow (red, green, blue);
-    } while (red -= 4 > 3);
-    
-    do { // green to cyan
-        write_color_to_rainbow (red, green, blue += 4);
-    } while (blue < 252);
-    
-    do { // cyan to blue
-        write_color_to_rainbow (red, green, blue);
-    } while (green -= 4 > 3);
-    
-    do { // blue to purple
-        write_color_to_rainbow (red += 4, green, blue);
-    } while (red < 252);
-    
-}
-
-int write_color_to_rainbow (unsigned char red, unsigned char green, unsigned char blue) {
-    static int index = 0;
-    rainbow[index].red = red;
-    rainbow[index].green = green;
-    rainbow[index].blue = blue;
-    printf ("%d ", index);
-    return ++index;
-}

From 9faf4e35eeb5b7f624aae132b4b015c35288d6cb Mon Sep 17 00:00:00 2001
From: Aaron Alef <aaron.alef@code.berlin>
Date: Fri, 15 Oct 2021 15:02:46 +0200
Subject: [PATCH 29/61] feat(gpu): store fb related data in fb_info struct

* Get framebuffer with `get_fb ()`
* Get framebuffer info struct with `get_fb_info ()`

NOTE: Pitch doesn't seem to work; it always gets set to 0
---
 thorn/include/common/gpu.h |  14 +++-
 thorn/src/common/gpu.c     | 147 ++++++++++++++++++++-----------------
 thorn/src/kernel/kernel.c  |   2 +-
 3 files changed, 93 insertions(+), 70 deletions(-)

diff --git a/thorn/include/common/gpu.h b/thorn/include/common/gpu.h
index 9fca21a..c6ee8a2 100644
--- a/thorn/include/common/gpu.h
+++ b/thorn/include/common/gpu.h
@@ -32,15 +32,23 @@ typedef struct {
     byte_t alpha;
 } color;
 
-static volatile unsigned int __attribute__((aligned(16))) mbox[2048];
+typedef struct {
+    color * fb;
+    unsigned int fb_size;
+    short virtual_width;
+    short virtual_height;
+    short pitch;
+    short colour_depth;
+} fb_info_t;
 
-// framebuffer
-static color * fb;
+static volatile unsigned int __attribute__((aligned(16))) gpu_msg_buffer[128];
 
+static fb_info_t fb_info;
 
 bool init_gpu (void);
 
 color * get_fb (void);
 
+fb_info_t const * get_fb_info (void);
 
 #endif //_ROSE_C_GPU_H
\ No newline at end of file
diff --git a/thorn/src/common/gpu.c b/thorn/src/common/gpu.c
index 10fc41a..a2f8550 100644
--- a/thorn/src/common/gpu.c
+++ b/thorn/src/common/gpu.c
@@ -1,97 +1,112 @@
 #include "common/gpu.h"
 
 bool init_gpu () {
-    {                                       // First message: read physical dimensions
-        int c = 0;                          // Message size; increment while we write
-        mbox[++c] = 0;                      // Response - will be 0x80000000 for SUCCESS or 0x80000001 for FAILURE
+    {                                                // First message: read physical dimensions
+        int c = 0;                                   // Message size; increment while we write
+        gpu_msg_buffer[++c] = 0;                     // Response - will be 0x80000000 for SUCCESS or 0x80000001 for FAILURE
         
-        mbox[++c] = 0x00040003;             // Tag to get physical display width / height
-        mbox[++c] = 0;                      // Size of value buffer
-        mbox[++c] = 0;                      // Response & value buffer size written will be written here
-        mbox[++c] = 0;                      // Get physical screen width    |  Overwritten by actual width
-        mbox[++c] = 0;                      // Get physical screen height   |  Overwritten by actual height
+        gpu_msg_buffer[++c] = 0x00040003;            // Tag to get physical display width / height
+        gpu_msg_buffer[++c] = 0;                     // Size of value buffer
+        gpu_msg_buffer[++c] = 0;                     // Response & value buffer size written will be written here
+        gpu_msg_buffer[++c] = 0;                     // Get physical screen width    |  Overwritten by actual width
+        gpu_msg_buffer[++c] = 0;                     // Get physical screen height   |  Overwritten by actual height
         
-        mbox[++c] = 0;                      // End tag
+        gpu_msg_buffer[++c] = 0;                     // End tag
         
-        mbox[0] = (4 * ++c);                // Write message size at the beginning of the buffer
+        gpu_msg_buffer[0] = (4 * ++c);               // Write message size at the beginning of the buffer
         
         // If reading physical screen dimension fails exit function
-        if (!mailbox_request (mbox, PROPERTY_ARM_VC)) return false;
+        if (!mailbox_request (gpu_msg_buffer, PROPERTY_ARM_VC)) return false;
     }
-    
-    {
-        int c = 0;                          // Message size; increment while we write
-        mbox[++c] = 0;                      // Response - will be 0x80000000 for SUCCESS or 0x80000001 for FAILURE
+    {                                                // Second message: request frame buffer
+        int c = 0;                                   // Message size; increment while we write
+        gpu_msg_buffer[++c] = 0;                     // Response - will be 0x80000000 for SUCCESS or 0x80000001 for FAILURE
 
-#ifdef GPU_OVERRIDE_PHYSICAL_SCREEN
-        mbox[++c] = 0x00048003;             // Tag to set virtual display width / height
-        mbox[++c] = 8;                      // Size of value buffer
-        mbox[++c] = 0;                      // Response & value buffer size written will be written here
-        mbox[++c] = GPU_SCREEN_WIDTH;       // Set virtual screen width     |  Overwritten by actual virtual width
-        mbox[++c] = GPU_SCREEN_HEIGHT;      // Set virtual screen height    |  Overwritten by actual virtual height
-        
-        mbox[++c] = 0x00048004;             // Tag to set virtual display width / height
-        mbox[++c] = 8;                      // Size of value buffer
-        mbox[++c] = 0;                      // Response & value buffer size written will be written here
-        mbox[++c] = GPU_VIRTUAL_WIDTH;      // Set virtual screen width     |  Overwritten by actual virtual width
-        mbox[++c] = GPU_VIRTUAL_HEIGHT;     // Set virtual screen height    |  Overwritten by actual virtual height
+#ifdef GPU_OVERRIDE_PHYSICAL_SCREEN                  // If this is set, update physical /virtual dimensions based on constants
+        gpu_msg_buffer[++c] = 0x00048003;            // Tag to set virtual display width / height
+        gpu_msg_buffer[++c] = 8;                     // Size of value buffer
+        gpu_msg_buffer[++c] = 0;                     // Response & value buffer size written will be written here
+        gpu_msg_buffer[++c] = GPU_SCREEN_WIDTH;      // Set virtual screen width     |  Overwritten by actual virtual width
+        gpu_msg_buffer[++c] = GPU_SCREEN_HEIGHT;     // Set virtual screen height    |  Overwritten by actual virtual height
+        
+        gpu_msg_buffer[++c] = 0x00048004;            // Tag to set virtual display width / height
+        gpu_msg_buffer[++c] = 8;                     // Size of value buffer
+        gpu_msg_buffer[++c] = 0;                     // Response & value buffer size written will be written here
+        gpu_msg_buffer[++c] = GPU_VIRTUAL_WIDTH;     // Set virtual screen width     |  Overwritten by actual virtual width
+        int index_virt_width = c;
+        gpu_msg_buffer[++c] = GPU_VIRTUAL_HEIGHT;    // Set virtual screen height    |  Overwritten by actual virtual height
+        int index_virt_height = c;
 #else
-        mbox[++c] = 0x00048004;             // Tag to set virtual display width / height
-        mbox[++c] = 8;                      // Size of value buffer
-        mbox[++c] = 0;                      // Response & value buffer size written will be written here
-        mbox[++c];//GPU_SCREEN_WIDTH;       // Keep virtual screen width    |  Overwritten by actual virtual width
-        mbox[++c];//GPU_SCREEN_HEIGHT;      // Keep virtual screen height   |  Overwritten by actual virtual height
+        gpu_msg_buffer[++c] = 0x00048004;            // Tag to set virtual display width / height
+        gpu_msg_buffer[++c] = 8;                     // Size of value buffer
+        gpu_msg_buffer[++c] = 0;                     // Response & value buffer size written will be written here
+        gpu_msg_buffer[++c];//GPU_SCREEN_WIDTH;      // Reuse previous width         |  Overwritten by actual virtual width
+        int index_virt_width = c;
+        gpu_msg_buffer[++c];//GPU_SCREEN_HEIGHT;     // Reuse previous height        |  Overwritten by actual virtual height
+        int index_virt_height = c;
 #endif
         
-        mbox[++c] = 0x00048005;             // Tag to set pixel depth
-        mbox[++c] = 4;                      // Size of value buffer
-        mbox[++c] = 0;                      // Response & value buffer size written will be written here
-        mbox[++c] = GPU_COLOUR_DEPTH;       // Set colour depth             |  Overwritten by actual colour depth
+        gpu_msg_buffer[++c] = 0x00048005;            // Tag to set pixel depth
+        gpu_msg_buffer[++c] = 4;                     // Size of value buffer
+        gpu_msg_buffer[++c] = 0;                     // Response & value buffer size written will be written here
+        gpu_msg_buffer[++c] = GPU_COLOUR_DEPTH;      // Set colour depth             |  Overwritten by actual colour depth
         
-        mbox[++c] = 0x00040001;             // Tag to allocate framebuffer
-        mbox[++c] = 8;                      // Size of value buffer
-        mbox[++c] = 0;                      // Response & value buffer size will be written here
-        mbox[++c] = 16;                     // Buffer alignment             |  Overwritten by pointer to framebuffer
-        byte_t index_framebuffer = c;
-        mbox[++c] = 0;                      // Unused - will be overwritten |  Overwritten by size of framebuffer
+        gpu_msg_buffer[++c] = 0x00040001;            // Tag to allocate framebuffer
+        gpu_msg_buffer[++c] = 8;                     // Size of value buffer
+        gpu_msg_buffer[++c] = 0;                     // Response & value buffer size will be written here
+        gpu_msg_buffer[++c] = 16;                    // Buffer alignment             |  Overwritten by pointer to framebuffer
+        int index_framebuffer = c;
+        gpu_msg_buffer[++c] = 0;                     // Unused - will be overwritten |  Overwritten by size of framebuffer
+        int index_fb_size = c;
         
-        mbox[++c] = 0;                      // End tag
-        mbox[++c] = 0;                      // Padding
-        mbox[++c] = 0;                      // Padding
-        mbox[++c] = 0;                      // Padding
+        gpu_msg_buffer[++c] = 0;                     // End tag
+        gpu_msg_buffer[++c] = 0;                     // Padding
+        gpu_msg_buffer[++c] = 0;                     // Padding
+        gpu_msg_buffer[++c] = 0;                     // Padding
         
-        mbox[0] = (4 * ++c);                // Write message size at the beginning of the buffer
+        gpu_msg_buffer[0] = (4 * ++c);               // Write message size at the beginning of the buffer
         
         // If message failed exit
-        if (!mailbox_request (mbox, PROPERTY_ARM_VC)) return false;
+        if (!mailbox_request (gpu_msg_buffer, PROPERTY_ARM_VC)) return false;
         
-        // Since message succeeded, update the frame buffer
-        fb = (color * ) (mbox[index_framebuffer] & VC_SDRAM_OFFSET);
+        // Since message succeeded, update frame buffer and its size
+        fb_info.fb = (color * ) (gpu_msg_buffer[index_framebuffer] & VC_SDRAM_OFFSET);
+        fb_info.fb_size = gpu_msg_buffer[index_fb_size];
     }
-    {                                       // Third message: read pitch (in bytes per line)
-        int c = 0;                          // Message size; increment while we write
-        mbox[++c] = 0;                      // Response - will be 0x80000000 for SUCCESS or 0x80000001 for FAILURE
-        
-        mbox[++c] = 0x00040008;             // Tag to get pitch
-        mbox[++c] = 0;                      // Size of value buffer
-        mbox[++c] = 0;                      // Response & value buffer size written will be written here
-        mbox[++c] = 0;                      // Pitch will be written here
+    {                                                // Third message: read pitch (in bytes per line)
+        int c = 0;                                   // Message size; increment while we write
+        gpu_msg_buffer[++c] = 0;                     // Response - will be 0x80000000 for SUCCESS or 0x80000001 for FAILURE
+        
+        gpu_msg_buffer[++c] = 0x00040008;            // Tag to get pitch
+        gpu_msg_buffer[++c] = 0;                     // Size of value buffer
+        gpu_msg_buffer[++c] = 0;                     // Response & value buffer size written will be written here
+        gpu_msg_buffer[++c] = 0;                     // Pitch will be written here
         int index_pitch = c;
         
-        mbox[++c] = 0;                      // End tag
-        mbox[++c] = 0;                      // Padding
+        gpu_msg_buffer[++c] = 0;                     // End tag
+        gpu_msg_buffer[++c] = 0;                     // Padding
         
-        mbox[0] = (4 * ++c);                // Write message size at the beginning of the buffer
+        gpu_msg_buffer[0] = (4 * ++c);               // Write message size at the beginning of the buffer
         
         // If message failed exit
-        if (!mailbox_request (mbox, PROPERTY_ARM_VC)) return false;
-        if (mbox[index_pitch]) {printf ("\r\nGot pitch: %d\r\n", mbox[index_pitch]);}
-        else {printf ("\r\nPitch is 0?!\r\n");}
+        if (!mailbox_request (gpu_msg_buffer, PROPERTY_ARM_VC)) return false;
+        
+        // Else write pitch appropriately
+        int pitch = gpu_msg_buffer;
+        if (pitch) {
+            printf ("\r\nGot pitch: %d\r\n", pitch);
+        } else {
+            printf ("\r\nPitch is 0?!\r\n");
+        }
+        fb_info.pitch = pitch;
     }
-    
     return true;
 }
 
 color * get_fb () {
-    return fb;
+    return fb_info.fb;
+}
+
+fb_info_t const * get_fb_info () {
+    return & fb_info;
 }
\ No newline at end of file
diff --git a/thorn/src/kernel/kernel.c b/thorn/src/kernel/kernel.c
index c0d4045..d631d68 100644
--- a/thorn/src/kernel/kernel.c
+++ b/thorn/src/kernel/kernel.c
@@ -78,7 +78,7 @@ void kernel_main (int processor_id) {
         if (!gpu_status) {
             printf ("Error while initialising Framebuffer\r\n");
         } else {
-            unsigned long fb = get_fb ();
+            color * fb = get_fb ();
             if (!fb) {
                 printf ("Error: Invalid Framebuffer received\r\n");
             } else {

From 41b9349393624ccceeae332c5f26251bb564c2da Mon Sep 17 00:00:00 2001
From: Aaron Alef <aaron.alef@code.berlin>
Date: Fri, 15 Oct 2021 12:13:13 +0200
Subject: [PATCH 30/61] feat(temperature): continously read temperature

NOTE: always reads 0 as both max and current temperature
---
 thorn/include/common/temperature.h | 34 ++++++++++++++++
 thorn/src/common/temperature.c     | 62 ++++++++++++++++++++++++++++++
 thorn/src/config.txt               |  1 +
 thorn/src/kernel/kernel.c          | 20 ++++++++--
 4 files changed, 114 insertions(+), 3 deletions(-)
 create mode 100644 thorn/include/common/temperature.h
 create mode 100644 thorn/src/common/temperature.c

diff --git a/thorn/include/common/temperature.h b/thorn/include/common/temperature.h
new file mode 100644
index 0000000..5e8d02b
--- /dev/null
+++ b/thorn/include/common/temperature.h
@@ -0,0 +1,34 @@
+#ifndef _ROSE_C_TEMPERATURE_H
+#define _ROSE_C_TEMPERATURE_H
+
+#include "common/stdbool.h"
+#include "kernel/mailbox.h"
+
+// Pin 32 / GPIO 12 (PWM0)
+#define GPIO_FAN 32
+
+// Temperature the system tries to keep. Turns off cooling if it falls below.
+// NOTE: The pi hits a 'soft' limit at 70 °C, reducing clock frequency.
+//       This value is defined in the config.txt and defaults to 60 °C if not set
+#define TEMPERATURE_SHOULD  (45 * 1000)
+#define TEMPERATURE_MAX     (80 * 1000)
+
+#define TEMPERATURE_CHECK_DELAY 20000000
+
+static volatile unsigned int __attribute__((aligned(16))) temperature_request[8];
+
+// Max temperature in degree milliCelsius.
+// USB + Ethernet are designed up to 70 °C but unlikely to overheat.
+// CPU is designed up to 85 °C so 80 is probably a reasonable upper limit.
+// Consider reducing to 70 °C if the workload on the ports increases
+static int max_temperature;
+
+bool init_temperature (void);
+
+void regulate_temperature (void);
+
+int get_max_temperature (void);
+
+int get_temperature (void);
+
+#endif //_ROSE_C_TEMPERATURE_H
\ No newline at end of file
diff --git a/thorn/src/common/temperature.c b/thorn/src/common/temperature.c
new file mode 100644
index 0000000..15516c9
--- /dev/null
+++ b/thorn/src/common/temperature.c
@@ -0,0 +1,62 @@
+#include "common/temperature.h"
+
+bool init_temperature () {
+    {                                                       // Read out maximum temperature
+        int c = 0;                                          // Message size; increment while we write
+        temperature_request[++c] = 0;                       // Response - will be 0x80000000 for SUCCESS or 0x80000001 for FAILURE
+        
+        temperature_request[++c] = 0x0003000a;              // Tag to get maximum temperature
+        temperature_request[++c] = 4;                       // Size of value buffer
+        temperature_request[++c] = 0;                       // Response & value buffer size written will be written here
+        temperature_request[++c] = 0;                       // Temperature (device?) ID, should stay 0
+        temperature_request[++c] = 0;                       // Will be overwritten by maximum temperature
+        int index_max_temperature = c;
+        
+        temperature_request[++c] = 0;                       // End tag
+        
+        temperature_request[0] = (4 * ++c);                 // Write message size at the beginning of the buffer
+        
+        // If reading maximum temperature fails, keep default
+        if (!mailbox_request (temperature_request, PROPERTY_ARM_VC)) return false;
+        // Else update temperature
+        max_temperature = temperature_request[index_max_temperature] ? : TEMPERATURE_MAX;
+        
+        return true;        // TODO: remove
+    }
+    
+    // Start regulate_temperature service here
+}
+
+void regulate_temperature () {
+    static int previous_temperature = TEMPERATURE_SHOULD;
+    int current = get_temperature ();
+    printf ("\rCurrent temperature: %d °C", current / 1000);
+}
+
+int get_max_temperature () {
+    return max_temperature;
+}
+
+int get_temperature () {
+    {                                                       // Read out current temperature
+        int c = 0;                                          // Message size; increment while we write
+        temperature_request[++c] = 0;                       // Response - will be 0x80000000 for SUCCESS or 0x80000001 for FAILURE
+        
+        temperature_request[++c] = 0x00030006;              // Tag to get current temperature
+        temperature_request[++c] = 0;                       // Size of value buffer
+        temperature_request[++c] = 4;                       // Response & value buffer size written will be written here
+        temperature_request[++c] = 0;                       // Temperature (device?) ID, should stay 0
+        temperature_request[++c] = 0;                       // Will be overwritten by current temperature
+        int index_temperature = c;
+        
+        temperature_request[++c] = 0;                       // End tag
+        
+        temperature_request[0] = (4 * ++c);                 // Write message size at the beginning of the buffer
+        
+        // If reading maximum temperature fails, keep default
+        if (!mailbox_request (temperature_request, PROPERTY_ARM_VC)) return -1;
+        // Else update temperature
+        max_temperature = temperature_request[index_temperature] ? : TEMPERATURE_MAX;
+        return temperature_request[index_temperature];
+    }
+}
\ No newline at end of file
diff --git a/thorn/src/config.txt b/thorn/src/config.txt
index 1cb4eed..e187384 100644
--- a/thorn/src/config.txt
+++ b/thorn/src/config.txt
@@ -1,2 +1,3 @@
 enable_uart=1
 dtparam=watchdog=on
+temp_soft_limit=70
\ No newline at end of file
diff --git a/thorn/src/kernel/kernel.c b/thorn/src/kernel/kernel.c
index d631d68..9b5ee99 100644
--- a/thorn/src/kernel/kernel.c
+++ b/thorn/src/kernel/kernel.c
@@ -10,6 +10,7 @@
 #include "kernel/sys.h"
 #include "common/logging.h"
 #include "common/rainbow.h"
+#include "common/temperature.h"
 
 void user_process1 (char * array) {
     char buf[2] = {0};
@@ -58,7 +59,7 @@ void kernel_process () {
 }
 
 
-void kernel_main (int processor_id) {
+_Noreturn void kernel_main (int processor_id) {
     
     static volatile unsigned int current_processor = 0;
     
@@ -69,10 +70,10 @@ void kernel_main (int processor_id) {
         timer_init ();
         enable_interrupt_controller ();
         enable_irq ();
-//        task_init ();
-        
+        task_init ();
         LOG("Logging works");
         
+        // Display
         printf ("Initialising Framebuffer...\r\n");
         int gpu_status = init_gpu ();
         if (!gpu_status) {
@@ -85,6 +86,10 @@ void kernel_main (int processor_id) {
                 printf ("Received framebuffer: %p\r\n", fb);
             }
         }
+        
+        // Temperature
+        printf ("Initialising temperature %s. Max temperature set to %d °C.\r\n",
+                init_temperature () ? "succeeded" : "failed", get_max_temperature () / 1000);
     }
     
     while (processor_id != current_processor);
@@ -110,5 +115,14 @@ void kernel_main (int processor_id) {
         LOG("DONE PRINTING");
     }
     
+    // Use processor 1 for checking temperature
+    if (processor_id == 1) {
+        while (current_processor != 3);
+        while (1) {
+            regulate_temperature ();
+            delay (TEMPERATURE_CHECK_DELAY);
+        }
+    }
+    
     while (1);
 }

From 4ef1d2a0026e61976b356889f9e4a67b44522aab Mon Sep 17 00:00:00 2001
From: Aaron Alef <aaron.alef@code.berlin>
Date: Fri, 15 Oct 2021 15:38:10 +0200
Subject: [PATCH 31/61] fix(temperature): fix message using invalid buffer size

---
 thorn/src/common/temperature.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/thorn/src/common/temperature.c b/thorn/src/common/temperature.c
index 15516c9..edd618d 100644
--- a/thorn/src/common/temperature.c
+++ b/thorn/src/common/temperature.c
@@ -6,7 +6,7 @@ bool init_temperature () {
         temperature_request[++c] = 0;                       // Response - will be 0x80000000 for SUCCESS or 0x80000001 for FAILURE
         
         temperature_request[++c] = 0x0003000a;              // Tag to get maximum temperature
-        temperature_request[++c] = 4;                       // Size of value buffer
+        temperature_request[++c] = 8;                       // Size of value buffer
         temperature_request[++c] = 0;                       // Response & value buffer size written will be written here
         temperature_request[++c] = 0;                       // Temperature (device?) ID, should stay 0
         temperature_request[++c] = 0;                       // Will be overwritten by maximum temperature
@@ -43,7 +43,7 @@ int get_temperature () {
         temperature_request[++c] = 0;                       // Response - will be 0x80000000 for SUCCESS or 0x80000001 for FAILURE
         
         temperature_request[++c] = 0x00030006;              // Tag to get current temperature
-        temperature_request[++c] = 0;                       // Size of value buffer
+        temperature_request[++c] = 8;                       // Size of value buffer
         temperature_request[++c] = 4;                       // Response & value buffer size written will be written here
         temperature_request[++c] = 0;                       // Temperature (device?) ID, should stay 0
         temperature_request[++c] = 0;                       // Will be overwritten by current temperature

From a1338733dc76de128f2a7772296a3c1e208afc71 Mon Sep 17 00:00:00 2001
From: Aaron Alef <aaron.alef@code.berlin>
Date: Fri, 15 Oct 2021 16:33:31 +0200
Subject: [PATCH 32/61] WIP: toggle GPIO pin for fan

---
 thorn/include/common/temperature.h      |  8 ++++---
 thorn/include/kernel/peripherals/gpio.h |  1 +
 thorn/src/common/temperature.c          | 28 ++++++++++++++++++-------
 3 files changed, 27 insertions(+), 10 deletions(-)

diff --git a/thorn/include/common/temperature.h b/thorn/include/common/temperature.h
index 5e8d02b..f473957 100644
--- a/thorn/include/common/temperature.h
+++ b/thorn/include/common/temperature.h
@@ -3,14 +3,14 @@
 
 #include "common/stdbool.h"
 #include "kernel/mailbox.h"
+#include "kernel/peripherals/gpio.h"
 
-// Pin 32 / GPIO 12 (PWM0)
-#define GPIO_FAN 32
+#define GPIO_FAN 18
 
 // Temperature the system tries to keep. Turns off cooling if it falls below.
 // NOTE: The pi hits a 'soft' limit at 70 °C, reducing clock frequency.
 //       This value is defined in the config.txt and defaults to 60 °C if not set
-#define TEMPERATURE_SHOULD  (45 * 1000)
+#define TEMPERATURE_SHOULD  (50 * 1000)
 #define TEMPERATURE_MAX     (80 * 1000)
 
 #define TEMPERATURE_CHECK_DELAY 20000000
@@ -31,4 +31,6 @@ int get_max_temperature (void);
 
 int get_temperature (void);
 
+void set_fan (bool enable);
+
 #endif //_ROSE_C_TEMPERATURE_H
\ No newline at end of file
diff --git a/thorn/include/kernel/peripherals/gpio.h b/thorn/include/kernel/peripherals/gpio.h
index bd31882..8532dd1 100644
--- a/thorn/include/kernel/peripherals/gpio.h
+++ b/thorn/include/kernel/peripherals/gpio.h
@@ -3,6 +3,7 @@
 
 #include "kernel/peripherals/base.h"
 
+#define GPIO_BASE       (PBASE+0x00200000)
 #define GPFSEL1         (PBASE+0x00200004)
 #define GPSET0          (PBASE+0x0020001C)
 #define GPCLR0          (PBASE+0x00200028)
diff --git a/thorn/src/common/temperature.c b/thorn/src/common/temperature.c
index edd618d..908cb64 100644
--- a/thorn/src/common/temperature.c
+++ b/thorn/src/common/temperature.c
@@ -20,17 +20,28 @@ bool init_temperature () {
         if (!mailbox_request (temperature_request, PROPERTY_ARM_VC)) return false;
         // Else update temperature
         max_temperature = temperature_request[index_max_temperature] ? : TEMPERATURE_MAX;
-        
-        return true;        // TODO: remove
     }
     
     // Start regulate_temperature service here
+    return true;
 }
 
 void regulate_temperature () {
-    static int previous_temperature = TEMPERATURE_SHOULD;
+    static int fan = 1;
+    static int previous = TEMPERATURE_SHOULD;
     int current = get_temperature ();
-    printf ("\rCurrent temperature: %d °C", current / 1000);
+    printf ("\rCurrent temperature: %d °C. Change since last iteration: %d °mC    ", current / 1000,
+            (current - previous));
+    
+    if (current < TEMPERATURE_SHOULD) {
+        fan = 0;
+    } else {
+        fan = 1;
+    }
+    
+    set_fan (fan);
+    
+    previous = current;
 }
 
 int get_max_temperature () {
@@ -54,9 +65,12 @@ int get_temperature () {
         temperature_request[0] = (4 * ++c);                 // Write message size at the beginning of the buffer
         
         // If reading maximum temperature fails, keep default
-        if (!mailbox_request (temperature_request, PROPERTY_ARM_VC)) return -1;
-        // Else update temperature
-        max_temperature = temperature_request[index_temperature] ? : TEMPERATURE_MAX;
+        if (!mailbox_request (temperature_request, PROPERTY_ARM_VC)) return max_temperature;
+        // Else return temperature
         return temperature_request[index_temperature];
     }
+}
+
+void set_fan (bool enable) {
+    printf ("set fan %d   \r", enable);
 }
\ No newline at end of file

From b2769b692c3519536f8f90b8764d02d493da53be Mon Sep 17 00:00:00 2001
From: Aaron Alef <aaron.alef@code.berlin>
Date: Wed, 8 Sep 2021 16:48:18 +0200
Subject: [PATCH 33/61] feat(base): include lesson05

NOTE: does not work yet
Current output:
```
61
EnableRegister: ff84110c
Kernel process started. EL 1
, ESR: 1fe00000, address, 1434
```
---
 chainloader/include/kernel/peripherals/mini_uart.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/chainloader/include/kernel/peripherals/mini_uart.h b/chainloader/include/kernel/peripherals/mini_uart.h
index b065deb..44a9554 100644
--- a/chainloader/include/kernel/peripherals/mini_uart.h
+++ b/chainloader/include/kernel/peripherals/mini_uart.h
@@ -1,7 +1,7 @@
 #ifndef _ROSE_K_P_MINI_UART_H
 #define _ROSE_K_P_MINI_UART_H
 
-#include "base.h"
+#include "kernel/peripherals/base.h"
 
 #define SYSTEM_CLOCK_FREQ              500000000
 #define BAUD_RATE_REG(target_baudrate) ((SYSTEM_CLOCK_FREQ / target_baudrate / 8) - 1)

From f9bb2e24bb282527b8ee80f7db2ea9596d885d40 Mon Sep 17 00:00:00 2001
From: Aaron Alef <aaron.alef@code.berlin>
Date: Wed, 8 Sep 2021 17:02:54 +0200
Subject: [PATCH 34/61] feat(io): modify printf to allow %p %P for 0x........
 notation

---
 thorn/src/common/printf.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/thorn/src/common/printf.c b/thorn/src/common/printf.c
index 85627be..4955175 100644
--- a/thorn/src/common/printf.c
+++ b/thorn/src/common/printf.c
@@ -200,6 +200,17 @@ void tfp_format (void * putp, putcf putf, char * fmt, va_list va) {
                         ui2a (va_arg (va, unsigned int), 16, (ch == 'P'), bf);
                     putchw (putp, putf, w, lz, bf);
                     break;
+                case 'p': case 'P':
+                    putf(putp, '0');
+                    putf(putp, 'x');
+#ifdef  PRINTF_LONG_SUPPORT
+                    if (lng)
+                        uli2a(va_arg(va, unsigned long int),16,(ch=='P'),bf);
+                    else
+#endif
+                    ui2a(va_arg(va, unsigned int),16,(ch=='P'),bf);
+                    putchw(putp,putf,w,lz,bf);
+                    break;
                 case '%':
                     putf (putp, ch);
                 default:

From c63598b952d0c1e559abc8bd26ee85cef8822686 Mon Sep 17 00:00:00 2001
From: Aaron Alef <aaron.alef@code.berlin>
Date: Mon, 13 Sep 2021 12:36:19 +0200
Subject: [PATCH 35/61] feat(io): add uart as alternative to mini uart

NOTE: the first uart to be included will be the implementation used
throughout the program
---
 chainloader/include/kernel/peripherals/mini_uart.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/chainloader/include/kernel/peripherals/mini_uart.h b/chainloader/include/kernel/peripherals/mini_uart.h
index 44a9554..b065deb 100644
--- a/chainloader/include/kernel/peripherals/mini_uart.h
+++ b/chainloader/include/kernel/peripherals/mini_uart.h
@@ -1,7 +1,7 @@
 #ifndef _ROSE_K_P_MINI_UART_H
 #define _ROSE_K_P_MINI_UART_H
 
-#include "kernel/peripherals/base.h"
+#include "base.h"
 
 #define SYSTEM_CLOCK_FREQ              500000000
 #define BAUD_RATE_REG(target_baudrate) ((SYSTEM_CLOCK_FREQ / target_baudrate / 8) - 1)

From 260af244c3f0ee07b6ec3d446ab943a8af065477 Mon Sep 17 00:00:00 2001
From: Aaron Alef <aaron.alef@code.berlin>
Date: Fri, 17 Sep 2021 10:34:09 +0200
Subject: [PATCH 36/61] style(io): rename hdmi to gpu

---
 thorn/include/kernel/peripherals/gpu.h |  4 +---
 thorn/src/kernel/kernel.c              | 13 +++++++------
 2 files changed, 8 insertions(+), 9 deletions(-)

diff --git a/thorn/include/kernel/peripherals/gpu.h b/thorn/include/kernel/peripherals/gpu.h
index 5677fad..2408fba 100644
--- a/thorn/include/kernel/peripherals/gpu.h
+++ b/thorn/include/kernel/peripherals/gpu.h
@@ -7,6 +7,4 @@
 #define GPU_SET_VIRTUAL_SIZE    0x48004
 #define GPU_SET_COLOUR_DEPTH    0x48005
 
-#endif//_ROSE_K_P_GPU_H
-
-/* Copyright (C) 2020 Aaron Alef */
\ No newline at end of file
+#endif//_ROSE_K_P_GPU_H
\ No newline at end of file
diff --git a/thorn/src/kernel/kernel.c b/thorn/src/kernel/kernel.c
index c766c27..46a4431 100644
--- a/thorn/src/kernel/kernel.c
+++ b/thorn/src/kernel/kernel.c
@@ -59,12 +59,13 @@ void kernel_process () {
 
 void kernel_init (void) {
     uart_init ();
-    init_printf (0, putc);
-    irq_vector_init ();
-    timer_init ();
-    enable_interrupt_controller ();
-    enable_irq ();
-    task_init ();
+    init_gpu ();
+        init_printf (0, putc);
+        irq_vector_init ();
+        timer_init ();
+        enable_interrupt_controller ();
+        enable_irq ();
+        task_init ();
 
     printf ("Initialising Framebuffer...\r\n");
     int gpu_status = init_gpu ();

From d2a4e3e0c382a69568bab817a82cf14778d3a853 Mon Sep 17 00:00:00 2001
From: Aaron Alef <aaron.alef@code.berlin>
Date: Fri, 17 Sep 2021 13:02:55 +0200
Subject: [PATCH 37/61] feat(io): add mailbox send and read functions
 [untested]

---
 chainloader/src/mailbox.c                  | 65 ++++++++++++++++++++++
 thorn/include/kernel/peripherals/mailbox.h | 10 ----
 thorn/src/kernel/mailbox.c                 |  4 +-
 3 files changed, 67 insertions(+), 12 deletions(-)
 create mode 100644 chainloader/src/mailbox.c

diff --git a/chainloader/src/mailbox.c b/chainloader/src/mailbox.c
new file mode 100644
index 0000000..cf12e56
--- /dev/null
+++ b/chainloader/src/mailbox.c
@@ -0,0 +1,65 @@
+#include "kernel/mailbox.h"
+
+void mailbox_send (unsigned int data, channel_t channel) {
+    mbox_message_t msg = {data, channel};
+    
+    while ((MBOX1 + MBOX_STATUS) & MBOX_WRITE_FULL);
+    put32 (MBOX1 + MBOX_WRITE, * (unsigned int *) & msg);
+}
+
+unsigned int mailbox_read (channel_t channel) {
+    unsigned int value;
+    
+    do {
+        // Wait until there's a message
+        while ((MBOX0 + MBOX_STATUS) & MBOX_READ_EMPTY);
+        
+        value = get32 (MBOX0 + MBOX_READ);
+        
+        // Wait until the channel matches (lest four significant bits)
+    } while ((value & 0xF) != channel);
+    
+    // Return most significant bits (actual address)
+    return value >> 4;
+}
+
+unsigned int mailbox_send_tags (channel_t channel, mbox_tag_t * tags) {
+    mbox_property_t * msg = (mbox_property_t *) get_free_page ();
+    
+    // Add tags to message:
+    unsigned int struct_size = 2 * sizeof (unsigned int);
+    struct_size += mailbox_write_tags ((mbox_tag_t * ) (msg + struct_size), tags);
+    
+    // Add end tag and 16 byte-aligned padding:
+    struct_size += (struct_size % 16) ? 32 - (struct_size % 16) : 16;
+    
+    // write struct size to message:
+    msg->struct_size = struct_size;
+    
+    mailbox_send ((unsigned int) msg, channel);
+    return msg;
+}
+
+unsigned int mailbox_write_tags (mbox_tag_t * dest, mbox_tag_t * src) {
+    unsigned int written = 0;
+    while (src->identity) {
+        dest += written;
+        
+        unsigned int buffer_size = src->buffer_size;
+        
+        dest->identity = src->identity;
+        dest->buffer_size = buffer_size;
+        dest->response = 0;
+        
+        
+        for (unsigned int i = 0; i < buffer_size; i ++) {
+            dest->buffer[written] = src->buffer[written];
+        }
+        written += 3 * sizeof (unsigned int) + buffer_size;
+        put32 (dest + written, 0);
+        written += sizeof (unsigned int);
+        put32 (dest + written, 0);
+        written += (written % 16) ? 16 - (written % 16) : 0;
+    }
+    return written;
+}
diff --git a/thorn/include/kernel/peripherals/mailbox.h b/thorn/include/kernel/peripherals/mailbox.h
index bdef5b5..37f664c 100644
--- a/thorn/include/kernel/peripherals/mailbox.h
+++ b/thorn/include/kernel/peripherals/mailbox.h
@@ -16,14 +16,4 @@
 
 #define MBOX_SUCCESS 0x80000000
 
-enum {
-    VIDEOCORE_MBOX = (PBASE + 0x0000B880),
-    MBOX_POLL      = (VIDEOCORE_MBOX + 0x10),
-    MBOX_SENDER    = (VIDEOCORE_MBOX + 0x14),
-    MBOX_CONFIG    = (VIDEOCORE_MBOX + 0x1C),
-    MBOX_RESPONSE  = 0x80000000,
-    MBOX_FULL      = 0x80000000,
-    MBOX_EMPTY     = 0x40000000
-};
-
 #endif//_ROSE_K_P_MAILBOX_H
\ No newline at end of file
diff --git a/thorn/src/kernel/mailbox.c b/thorn/src/kernel/mailbox.c
index a5684b0..a744c50 100644
--- a/thorn/src/kernel/mailbox.c
+++ b/thorn/src/kernel/mailbox.c
@@ -13,7 +13,7 @@ bool mailbox_request (volatile unsigned int * data_ptr, channel_t channel) {
     unsigned int outgoing = ((unsigned int) ((long) data_ptr) & ~0xF) | (channel & 0xF);
 
     // Wait until we can write
-    while (get32 (MBOX0 + MBOX_STATUS) & MBOX_FULL)
+    while (get32 (MBOX0 + MBOX_STATUS) & MBOX_WRITE_FULL)
         ;
 
     // Write the address of our buffer to the mailbox with the channel appended
@@ -22,7 +22,7 @@ bool mailbox_request (volatile unsigned int * data_ptr, channel_t channel) {
     unsigned int incoming;
     while (1) {
         // Is there a reply?
-        while (get32 (MBOX0 + MBOX_STATUS) & MBOX_EMPTY)
+        while (get32 (MBOX0 + MBOX_STATUS) & MBOX_READ_EMPTY)
             ;
 
         incoming = get32 (MBOX0 + MBOX_READ);

From 0561c129f5f5f3945bda06aafa914e84646901aa Mon Sep 17 00:00:00 2001
From: Aaron Alef <aaron.alef@code.berlin>
Date: Fri, 17 Sep 2021 14:03:05 +0200
Subject: [PATCH 38/61] feat(io): initialise framebuffer [not working]

NOTE: Absolutely Not Working
---
 thorn/src/kernel/kernel.c | 19 ++++++++++++-------
 1 file changed, 12 insertions(+), 7 deletions(-)

diff --git a/thorn/src/kernel/kernel.c b/thorn/src/kernel/kernel.c
index 46a4431..7a1cb37 100644
--- a/thorn/src/kernel/kernel.c
+++ b/thorn/src/kernel/kernel.c
@@ -59,13 +59,12 @@ void kernel_process () {
 
 void kernel_init (void) {
     uart_init ();
-    init_gpu ();
-        init_printf (0, putc);
-        irq_vector_init ();
-        timer_init ();
-        enable_interrupt_controller ();
-        enable_irq ();
-        task_init ();
+    init_printf (0, putc);
+    irq_vector_init ();
+    timer_init ();
+    enable_interrupt_controller ();
+    enable_irq ();
+    task_init ();
 
     printf ("Initialising Framebuffer...\r\n");
     int gpu_status = init_gpu ();
@@ -90,6 +89,12 @@ void kernel_main (int processor_id) {
 
     if (processor_id == 0) {
         kernel_init ();
+
+        if (! init_gpu ()) {
+            printf ("Error while initialising framebuffer\r\n");
+        } else {
+            get_fb ();
+        }
     }
 
     while (processor_id != current_processor)

From fb44629c19bccb8627461fdc965536c75013807d Mon Sep 17 00:00:00 2001
From: Aaron Alef <aaron.alef@code.berlin>
Date: Tue, 21 Sep 2021 10:02:07 +0200
Subject: [PATCH 39/61] fix(mb): added missing left shift

---
 chainloader/src/mailbox.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/chainloader/src/mailbox.c b/chainloader/src/mailbox.c
index cf12e56..f0c8e93 100644
--- a/chainloader/src/mailbox.c
+++ b/chainloader/src/mailbox.c
@@ -20,7 +20,7 @@ unsigned int mailbox_read (channel_t channel) {
     } while ((value & 0xF) != channel);
     
     // Return most significant bits (actual address)
-    return value >> 4;
+    return ((value >> 4) << 4);
 }
 
 unsigned int mailbox_send_tags (channel_t channel, mbox_tag_t * tags) {

From 24d89f842a24f8c1e9f5a3c0f6f6482565ea134f Mon Sep 17 00:00:00 2001
From: Aaron Alef <aaron.alef@code.berlin>
Date: Tue, 21 Sep 2021 11:55:39 +0200
Subject: [PATCH 40/61] refactor(io): rewrite mailbox and adapt gpu init to it

NOTE: doesn't work yet - produces

```
Type SYNC_INVALID_EL1h, ESR: 0x96000040, address, 0x81044Type
```
---
 chainloader/src/mailbox.c | 44 +++++++++++++++++++++------------------
 1 file changed, 24 insertions(+), 20 deletions(-)

diff --git a/chainloader/src/mailbox.c b/chainloader/src/mailbox.c
index f0c8e93..0ce766c 100644
--- a/chainloader/src/mailbox.c
+++ b/chainloader/src/mailbox.c
@@ -1,34 +1,38 @@
 #include "kernel/mailbox.h"
 
-void mailbox_send (unsigned int data, channel_t channel) {
-    mbox_message_t msg = {data, channel};
+bool mailbox_request (unsigned int data_ptr, channel_t channel) {
+    mbox_message_t msg;
+    unsigned int * msg_ptr = (unsigned int *) & msg;
+    unsigned int check;
     
-    while ((MBOX1 + MBOX_STATUS) & MBOX_WRITE_FULL);
-    put32 (MBOX1 + MBOX_WRITE, * (unsigned int *) & msg);
-}
-
-unsigned int mailbox_read (channel_t channel) {
-    unsigned int value;
+    * msg_ptr = data_ptr;
+    msg.channel = channel;
+    
+    while ((MBOX0 + MBOX_STATUS) & MBOX_WRITE_FULL);
+    put32 (MBOX0 + MBOX_WRITE, * msg_ptr);
     
     do {
         // Wait until there's a message
         while ((MBOX0 + MBOX_STATUS) & MBOX_READ_EMPTY);
         
-        value = get32 (MBOX0 + MBOX_READ);
+        check = get32 (MBOX0 + MBOX_READ);
         
-        // Wait until the channel matches (lest four significant bits)
-    } while ((value & 0xF) != channel);
+        // Check if it's the response to our message
+    } while (* msg_ptr == check);
+    
+    // Get the pointer to the property request message
+    mbox_property_t * property = (mbox_property_t * ) ((unsigned long) (* msg_ptr & ~ 0xFF));
     
-    // Return most significant bits (actual address)
-    return ((value >> 4) << 4);
+    // Return the message's response code
+    return property->response == MBOX_SUCCESS;
 }
 
-unsigned int mailbox_send_tags (channel_t channel, mbox_tag_t * tags) {
-    mbox_property_t * msg = (mbox_property_t *) get_free_page ();
+unsigned int mailbox_write_msg (unsigned int message[], mbox_tag_t * tags) {
+    mbox_property_t * msg = (mbox_property_t * ) & message;
     
     // Add tags to message:
     unsigned int struct_size = 2 * sizeof (unsigned int);
-    struct_size += mailbox_write_tags ((mbox_tag_t * ) (msg + struct_size), tags);
+    struct_size += mailbox_write_tags ((mbox_tag_t * ) (message + struct_size), tags);
     
     // Add end tag and 16 byte-aligned padding:
     struct_size += (struct_size % 16) ? 32 - (struct_size % 16) : 16;
@@ -36,8 +40,8 @@ unsigned int mailbox_send_tags (channel_t channel, mbox_tag_t * tags) {
     // write struct size to message:
     msg->struct_size = struct_size;
     
-    mailbox_send ((unsigned int) msg, channel);
-    return msg;
+    // return number of bytes written, for reference
+    return struct_size;
 }
 
 unsigned int mailbox_write_tags (mbox_tag_t * dest, mbox_tag_t * src) {
@@ -56,9 +60,9 @@ unsigned int mailbox_write_tags (mbox_tag_t * dest, mbox_tag_t * src) {
             dest->buffer[written] = src->buffer[written];
         }
         written += 3 * sizeof (unsigned int) + buffer_size;
-        put32 (dest + written, 0);
+        put32 ((unsigned int) (dest + written), 0);
         written += sizeof (unsigned int);
-        put32 (dest + written, 0);
+        put32 ((unsigned int) (dest + written), 0);
         written += (written % 16) ? 16 - (written % 16) : 0;
     }
     return written;

From 57f1f23688cb6c87e5791703104f09f8320bda12 Mon Sep 17 00:00:00 2001
From: Aaron Alef <aaron.alef@code.berlin>
Date: Tue, 21 Sep 2021 13:08:04 +0200
Subject: [PATCH 41/61] WIP: add debug showing program gets stuck waiting for
 configuration

---
 chainloader/src/mailbox.c      | 25 ++++++++++++++++++++-----
 thorn/include/common/logging.h |  9 ++++-----
 thorn/src/common/printf.c      | 33 ++++++++++++++-------------------
 thorn/src/kernel/kernel.c      | 13 ++++++++++---
 4 files changed, 48 insertions(+), 32 deletions(-)

diff --git a/chainloader/src/mailbox.c b/chainloader/src/mailbox.c
index 0ce766c..ee5b8b7 100644
--- a/chainloader/src/mailbox.c
+++ b/chainloader/src/mailbox.c
@@ -8,31 +8,42 @@ bool mailbox_request (unsigned int data_ptr, channel_t channel) {
     * msg_ptr = data_ptr;
     msg.channel = channel;
     
+    LOG ("Waiting for empty write buffer GPU...");
     while ((MBOX0 + MBOX_STATUS) & MBOX_WRITE_FULL);
+    LOG ("Writing to GPU...");
     put32 (MBOX0 + MBOX_WRITE, * msg_ptr);
     
+    LOG ("Reading response...");
     do {
         // Wait until there's a message
+        LOG ("Waiting for any message...");
         while ((MBOX0 + MBOX_STATUS) & MBOX_READ_EMPTY);
         
+        LOG ("Check message");
         check = get32 (MBOX0 + MBOX_READ);
         
+        LOG ("Check channel");
         // Check if it's the response to our message
     } while (* msg_ptr == check);
     
+    LOG ("Read pointer to property response");
     // Get the pointer to the property request message
     mbox_property_t * property = (mbox_property_t * ) ((unsigned long) (* msg_ptr & ~ 0xFF));
     
+    char * buffer[100];
+    sprinf (buffer, "Returning response code: operation %s",
+            (property->response == MBOX_SUCCESS) ? "succeeded" : "failed");
+    LOG (buffer);
     // Return the message's response code
     return property->response == MBOX_SUCCESS;
 }
 
-unsigned int mailbox_write_msg (unsigned int message[], mbox_tag_t * tags) {
+unsigned int mailbox_write_msg (unsigned int message[], mbox_tag_t * tags, int tags_count) {
     mbox_property_t * msg = (mbox_property_t * ) & message;
     
     // Add tags to message:
     unsigned int struct_size = 2 * sizeof (unsigned int);
-    struct_size += mailbox_write_tags ((mbox_tag_t * ) (message + struct_size), tags);
+    struct_size += mailbox_write_tags ((mbox_tag_t * ) (message + struct_size), tags, tags_count);
     
     // Add end tag and 16 byte-aligned padding:
     struct_size += (struct_size % 16) ? 32 - (struct_size % 16) : 16;
@@ -40,13 +51,15 @@ unsigned int mailbox_write_msg (unsigned int message[], mbox_tag_t * tags) {
     // write struct size to message:
     msg->struct_size = struct_size;
     
+    int_dump (struct_size, (unsigned int *) msg);
+    
     // return number of bytes written, for reference
     return struct_size;
 }
 
-unsigned int mailbox_write_tags (mbox_tag_t * dest, mbox_tag_t * src) {
+unsigned int mailbox_write_tags (mbox_tag_t * dest, mbox_tag_t * src, int tags_count) {
     unsigned int written = 0;
-    while (src->identity) {
+    for (int i = 0; i < tags_count; i ++) {
         dest += written;
         
         unsigned int buffer_size = src->buffer_size;
@@ -55,15 +68,17 @@ unsigned int mailbox_write_tags (mbox_tag_t * dest, mbox_tag_t * src) {
         dest->buffer_size = buffer_size;
         dest->response = 0;
         
-        
         for (unsigned int i = 0; i < buffer_size; i ++) {
             dest->buffer[written] = src->buffer[written];
         }
         written += 3 * sizeof (unsigned int) + buffer_size;
         put32 ((unsigned int) (dest + written), 0);
+        
         written += sizeof (unsigned int);
         put32 ((unsigned int) (dest + written), 0);
+        
         written += (written % 16) ? 16 - (written % 16) : 0;
     }
+    
     return written;
 }
diff --git a/thorn/include/common/logging.h b/thorn/include/common/logging.h
index fa4db93..710659d 100644
--- a/thorn/include/common/logging.h
+++ b/thorn/include/common/logging.h
@@ -3,11 +3,10 @@
 
 #include "common/printf.h"
 
-#define LOG(msg)                                                           \
-    do {                                                                   \
-        static int __counter__ = 0;                                        \
-        printf (__FILE__ ":%d:[%d] %s\r\n", __LINE__, __counter__++, msg); \
-    } while (0)
+#define LOG(msg)                                                           \do {                                           \
+    static int __counter__ = 0;                                        \
+    printf(__FILE__":%d:[%d] %s\r\n", __LINE__, __counter__++, msg);   \
+} while (0)
 
 #define ASSERT(expr)                  \
     do {                              \
diff --git a/thorn/src/common/printf.c b/thorn/src/common/printf.c
index 4955175..059ee24 100644
--- a/thorn/src/common/printf.c
+++ b/thorn/src/common/printf.c
@@ -158,7 +158,8 @@ void tfp_format (void * putp, putcf putf, char * fmt, va_list va) {
                         uli2a (va_arg (va, unsigned long int), 10, 0, bf);
                     else
 #endif
-                        ui2a (va_arg (va, unsigned int), 10, 0, bf);
+                    ui2a (va_arg (va,
+                                  unsigned int), 10, 0, bf);
                     putchw (putp, putf, w, lz, bf);
                     break;
                 }
@@ -168,7 +169,8 @@ void tfp_format (void * putp, putcf putf, char * fmt, va_list va) {
                         li2a (va_arg (va, unsigned long int), bf);
                     else
 #endif
-                        i2a (va_arg (va, int), bf);
+                    i2a (va_arg (va,
+                                 int), bf);
                     putchw (putp, putf, w, lz, bf);
                     break;
                 }
@@ -179,14 +181,17 @@ void tfp_format (void * putp, putcf putf, char * fmt, va_list va) {
                         uli2a (va_arg (va, unsigned long int), 16, (ch == 'X'), bf);
                     else
 #endif
-                        ui2a (va_arg (va, unsigned int), 16, (ch == 'X'), bf);
+                    ui2a (va_arg (va,
+                                  unsigned int), 16, (ch == 'X'), bf);
                     putchw (putp, putf, w, lz, bf);
                     break;
-                case 'c':
-                    putf (putp, (char) (va_arg (va, int)));
+                case 'c' :
+                    putf (putp, (char) (va_arg (va,
+                                                int)));
                     break;
-                case 's':
-                    putchw (putp, putf, w, 0, va_arg (va, char *));
+                case 's' :
+                    putchw (putp, putf, w, 0, va_arg (va,
+                                                      char*));
                     break;
                 case 'p':
                 case 'P':
@@ -197,20 +202,10 @@ void tfp_format (void * putp, putcf putf, char * fmt, va_list va) {
                         uli2a (va_arg (va, unsigned long int), 16, (ch == 'P'), bf);
                     else
 #endif
-                        ui2a (va_arg (va, unsigned int), 16, (ch == 'P'), bf);
+                    ui2a (va_arg (va,
+                                  unsigned int), 16, (ch == 'P'), bf);
                     putchw (putp, putf, w, lz, bf);
                     break;
-                case 'p': case 'P':
-                    putf(putp, '0');
-                    putf(putp, 'x');
-#ifdef  PRINTF_LONG_SUPPORT
-                    if (lng)
-                        uli2a(va_arg(va, unsigned long int),16,(ch=='P'),bf);
-                    else
-#endif
-                    ui2a(va_arg(va, unsigned int),16,(ch=='P'),bf);
-                    putchw(putp,putf,w,lz,bf);
-                    break;
                 case '%':
                     putf (putp, ch);
                 default:
diff --git a/thorn/src/kernel/kernel.c b/thorn/src/kernel/kernel.c
index 7a1cb37..5821a44 100644
--- a/thorn/src/kernel/kernel.c
+++ b/thorn/src/kernel/kernel.c
@@ -90,10 +90,17 @@ void kernel_main (int processor_id) {
     if (processor_id == 0) {
         kernel_init ();
 
-        if (! init_gpu ()) {
-            printf ("Error while initialising framebuffer\r\n");
+        printf ("Initialising Framebuffer...\r\n");
+        int gpu_status = init_gpu ();
+        if (! gpu_status) {
+            printf ("Error while initialising Framebuffer\r\n");
         } else {
-            get_fb ();
+            unsigned long fb = get_fb ();
+            if (! fb) {
+                printf ("Error: Invalid Framebuffer received\r\n");
+            } else {
+                printf ("Received framebuffer: %p\r\n", fb);
+            }
         }
     }
 

From 47a56965f3fb89f94d978fdfd096577ab3998857 Mon Sep 17 00:00:00 2001
From: Aaron Alef <aaron.alef@code.berlin>
Date: Thu, 14 Oct 2021 12:25:49 +0200
Subject: [PATCH 42/61] feat(gpu): hardcode printing of four pixels

---
 thorn/src/kernel/kernel.c | 14 --------------
 1 file changed, 14 deletions(-)

diff --git a/thorn/src/kernel/kernel.c b/thorn/src/kernel/kernel.c
index 5821a44..07811f7 100644
--- a/thorn/src/kernel/kernel.c
+++ b/thorn/src/kernel/kernel.c
@@ -86,22 +86,8 @@ void kernel_init (void) {
 void kernel_main (int processor_id) {
 
     static volatile unsigned int current_processor = 0;
-
     if (processor_id == 0) {
         kernel_init ();
-
-        printf ("Initialising Framebuffer...\r\n");
-        int gpu_status = init_gpu ();
-        if (! gpu_status) {
-            printf ("Error while initialising Framebuffer\r\n");
-        } else {
-            unsigned long fb = get_fb ();
-            if (! fb) {
-                printf ("Error: Invalid Framebuffer received\r\n");
-            } else {
-                printf ("Received framebuffer: %p\r\n", fb);
-            }
-        }
     }
 
     while (processor_id != current_processor)

From 94e05492c7d7a509a592f49b889b80bc1ff43aad Mon Sep 17 00:00:00 2001
From: BMG93 <brenden.gammill@code.berlin>
Date: Thu, 14 Oct 2021 19:57:54 +0200
Subject: [PATCH 43/61] Bitmap font : WIP currently not rendering any pixels on
 screen

---
 thorn/include/common/font.h    | 139 +++++++++++++++++++++++++++++++++
 thorn/include/common/gpu.h     |   6 +-
 thorn/include/common/logging.h |  11 +--
 thorn/include/common/rainbow.h |   2 +-
 thorn/include/common/screen.h  |  21 ++---
 thorn/src/common/gpu.c         |  10 +--
 thorn/src/common/rainbow.c     |   2 +-
 thorn/src/common/screen.c      |  55 +++----------
 thorn/src/kernel/kernel.c      |   2 +-
 9 files changed, 170 insertions(+), 78 deletions(-)
 create mode 100644 thorn/include/common/font.h

diff --git a/thorn/include/common/font.h b/thorn/include/common/font.h
new file mode 100644
index 0000000..1210bbb
--- /dev/null
+++ b/thorn/include/common/font.h
@@ -0,0 +1,139 @@
+#ifndef _ROSE_C_FONT_H
+#define _ROSE_C_FONT_H
+
+#define FONT_SIZE 8
+/* From https://github.com/dhepper/font8x8/blob/master/font8x8_block.h */
+const unsigned long long int * font(int c) {
+	static const char f[128][FONT_SIZE] = {
+		{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},   // U+0000 (nul)
+		{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},   // U+0001
+		{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},   // U+0002
+		{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},   // U+0003
+		{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},   // U+0004
+		{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},   // U+0005
+		{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},   // U+0006
+		{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},   // U+0007
+		{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},   // U+0008
+		{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},   // U+0009
+		{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},   // U+000A
+		{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},   // U+000B
+		{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},   // U+000C
+		{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},   // U+000D
+		{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},   // U+000E
+		{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},   // U+000F
+		{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},   // U+0010
+		{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},   // U+0011
+		{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},   // U+0012
+		{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},   // U+0013
+		{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},   // U+0014
+		{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},   // U+0015
+		{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},   // U+0016
+		{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},   // U+0017
+		{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},   // U+0018
+		{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},   // U+0019
+		{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},   // U+001A
+		{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},   // U+001B
+		{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},   // U+001C
+		{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},   // U+001D
+		{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},   // U+001E
+		{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},   // U+001F
+		{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},   // U+0020 (space)
+		{ 0x18, 0x3C, 0x3C, 0x18, 0x18, 0x00, 0x18, 0x00},   // U+0021 (!)
+		{ 0x36, 0x36, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},   // U+0022 (")
+		{ 0x36, 0x36, 0x7F, 0x36, 0x7F, 0x36, 0x36, 0x00},   // U+0023 (#)
+		{ 0x0C, 0x3E, 0x03, 0x1E, 0x30, 0x1F, 0x0C, 0x00},   // U+0024 ($)
+		{ 0x00, 0x63, 0x33, 0x18, 0x0C, 0x66, 0x63, 0x00},   // U+0025 (%)
+		{ 0x1C, 0x36, 0x1C, 0x6E, 0x3B, 0x33, 0x6E, 0x00},   // U+0026 (&)
+		{ 0x06, 0x06, 0x03, 0x00, 0x00, 0x00, 0x00, 0x00},   // U+0027 (')
+		{ 0x18, 0x0C, 0x06, 0x06, 0x06, 0x0C, 0x18, 0x00},   // U+0028 (()
+		{ 0x06, 0x0C, 0x18, 0x18, 0x18, 0x0C, 0x06, 0x00},   // U+0029 ())
+		{ 0x00, 0x66, 0x3C, 0xFF, 0x3C, 0x66, 0x00, 0x00},   // U+002A (*)
+		{ 0x00, 0x0C, 0x0C, 0x3F, 0x0C, 0x0C, 0x00, 0x00},   // U+002B (+)
+		{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x0C, 0x0C, 0x06},   // U+002C (,)
+		{ 0x00, 0x00, 0x00, 0x3F, 0x00, 0x00, 0x00, 0x00},   // U+002D (-)
+		{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x0C, 0x0C, 0x00},   // U+002E (.)
+		{ 0x60, 0x30, 0x18, 0x0C, 0x06, 0x03, 0x01, 0x00},   // U+002F (/)
+		{ 0x3E, 0x63, 0x73, 0x7B, 0x6F, 0x67, 0x3E, 0x00},   // U+0030 (0)
+		{ 0x0C, 0x0E, 0x0C, 0x0C, 0x0C, 0x0C, 0x3F, 0x00},   // U+0031 (1)
+		{ 0x1E, 0x33, 0x30, 0x1C, 0x06, 0x33, 0x3F, 0x00},   // U+0032 (2)
+		{ 0x1E, 0x33, 0x30, 0x1C, 0x30, 0x33, 0x1E, 0x00},   // U+0033 (3)
+		{ 0x38, 0x3C, 0x36, 0x33, 0x7F, 0x30, 0x78, 0x00},   // U+0034 (4)
+		{ 0x3F, 0x03, 0x1F, 0x30, 0x30, 0x33, 0x1E, 0x00},   // U+0035 (5)
+		{ 0x1C, 0x06, 0x03, 0x1F, 0x33, 0x33, 0x1E, 0x00},   // U+0036 (6)
+		{ 0x3F, 0x33, 0x30, 0x18, 0x0C, 0x0C, 0x0C, 0x00},   // U+0037 (7)
+		{ 0x1E, 0x33, 0x33, 0x1E, 0x33, 0x33, 0x1E, 0x00},   // U+0038 (8)
+		{ 0x1E, 0x33, 0x33, 0x3E, 0x30, 0x18, 0x0E, 0x00},   // U+0039 (9)
+		{ 0x00, 0x0C, 0x0C, 0x00, 0x00, 0x0C, 0x0C, 0x00},   // U+003A (:)
+		{ 0x00, 0x0C, 0x0C, 0x00, 0x00, 0x0C, 0x0C, 0x06},   // U+003B (//)
+		{ 0x18, 0x0C, 0x06, 0x03, 0x06, 0x0C, 0x18, 0x00},   // U+003C (<)
+		{ 0x00, 0x00, 0x3F, 0x00, 0x00, 0x3F, 0x00, 0x00},   // U+003D (=)
+		{ 0x06, 0x0C, 0x18, 0x30, 0x18, 0x0C, 0x06, 0x00},   // U+003E (>)
+		{ 0x1E, 0x33, 0x30, 0x18, 0x0C, 0x00, 0x0C, 0x00},   // U+003F (?)
+		{ 0x3E, 0x63, 0x7B, 0x7B, 0x7B, 0x03, 0x1E, 0x00},   // U+0040 (@)
+		{ 0x0C, 0x1E, 0x33, 0x33, 0x3F, 0x33, 0x33, 0x00},   // U+0041 (A)
+		{ 0x3F, 0x66, 0x66, 0x3E, 0x66, 0x66, 0x3F, 0x00},   // U+0042 (B)
+		{ 0x3C, 0x66, 0x03, 0x03, 0x03, 0x66, 0x3C, 0x00},   // U+0043 (C)
+		{ 0x1F, 0x36, 0x66, 0x66, 0x66, 0x36, 0x1F, 0x00},   // U+0044 (D)
+		{ 0x7F, 0x46, 0x16, 0x1E, 0x16, 0x46, 0x7F, 0x00},   // U+0045 (E)
+		{ 0x7F, 0x46, 0x16, 0x1E, 0x16, 0x06, 0x0F, 0x00},   // U+0046 (F)
+		{ 0x3C, 0x66, 0x03, 0x03, 0x73, 0x66, 0x7C, 0x00},   // U+0047 (G)
+		{ 0x33, 0x33, 0x33, 0x3F, 0x33, 0x33, 0x33, 0x00},   // U+0048 (H)
+		{ 0x1E, 0x0C, 0x0C, 0x0C, 0x0C, 0x0C, 0x1E, 0x00},   // U+0049 (I)
+		{ 0x78, 0x30, 0x30, 0x30, 0x33, 0x33, 0x1E, 0x00},   // U+004A (J)
+		{ 0x67, 0x66, 0x36, 0x1E, 0x36, 0x66, 0x67, 0x00},   // U+004B (K)
+		{ 0x0F, 0x06, 0x06, 0x06, 0x46, 0x66, 0x7F, 0x00},   // U+004C (L)
+		{ 0x63, 0x77, 0x7F, 0x7F, 0x6B, 0x63, 0x63, 0x00},   // U+004D (M)
+		{ 0x63, 0x67, 0x6F, 0x7B, 0x73, 0x63, 0x63, 0x00},   // U+004E (N)
+		{ 0x1C, 0x36, 0x63, 0x63, 0x63, 0x36, 0x1C, 0x00},   // U+004F (O)
+		{ 0x3F, 0x66, 0x66, 0x3E, 0x06, 0x06, 0x0F, 0x00},   // U+0050 (P)
+		{ 0x1E, 0x33, 0x33, 0x33, 0x3B, 0x1E, 0x38, 0x00},   // U+0051 (Q)
+		{ 0x3F, 0x66, 0x66, 0x3E, 0x36, 0x66, 0x67, 0x00},   // U+0052 (R)
+		{ 0x1E, 0x33, 0x07, 0x0E, 0x38, 0x33, 0x1E, 0x00},   // U+0053 (S)
+		{ 0x3F, 0x2D, 0x0C, 0x0C, 0x0C, 0x0C, 0x1E, 0x00},   // U+0054 (T)
+		{ 0x33, 0x33, 0x33, 0x33, 0x33, 0x33, 0x3F, 0x00},   // U+0055 (U)
+		{ 0x33, 0x33, 0x33, 0x33, 0x33, 0x1E, 0x0C, 0x00},   // U+0056 (V)
+		{ 0x63, 0x63, 0x63, 0x6B, 0x7F, 0x77, 0x63, 0x00},   // U+0057 (W)
+		{ 0x63, 0x63, 0x36, 0x1C, 0x1C, 0x36, 0x63, 0x00},   // U+0058 (X)
+		{ 0x33, 0x33, 0x33, 0x1E, 0x0C, 0x0C, 0x1E, 0x00},   // U+0059 (Y)
+		{ 0x7F, 0x63, 0x31, 0x18, 0x4C, 0x66, 0x7F, 0x00},   // U+005A (Z)
+		{ 0x1E, 0x06, 0x06, 0x06, 0x06, 0x06, 0x1E, 0x00},   // U+005B ([)
+		{ 0x03, 0x06, 0x0C, 0x18, 0x30, 0x60, 0x40, 0x00},   // U+005C (\)
+		{ 0x1E, 0x18, 0x18, 0x18, 0x18, 0x18, 0x1E, 0x00},   // U+005D (])
+		{ 0x08, 0x1C, 0x36, 0x63, 0x00, 0x00, 0x00, 0x00},   // U+005E (^)
+		{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xFF},   // U+005F (_)
+		{ 0x0C, 0x0C, 0x18, 0x00, 0x00, 0x00, 0x00, 0x00},   // U+0060 (`)
+		{ 0x00, 0x00, 0x1E, 0x30, 0x3E, 0x33, 0x6E, 0x00},   // U+0061 (a)
+		{ 0x07, 0x06, 0x06, 0x3E, 0x66, 0x66, 0x3B, 0x00},   // U+0062 (b)
+		{ 0x00, 0x00, 0x1E, 0x33, 0x03, 0x33, 0x1E, 0x00},   // U+0063 (c)
+		{ 0x38, 0x30, 0x30, 0x3e, 0x33, 0x33, 0x6E, 0x00},   // U+0064 (d)
+		{ 0x00, 0x00, 0x1E, 0x33, 0x3f, 0x03, 0x1E, 0x00},   // U+0065 (e)
+		{ 0x1C, 0x36, 0x06, 0x0f, 0x06, 0x06, 0x0F, 0x00},   // U+0066 (f)
+		{ 0x00, 0x00, 0x6E, 0x33, 0x33, 0x3E, 0x30, 0x1F},   // U+0067 (g)
+		{ 0x07, 0x06, 0x36, 0x6E, 0x66, 0x66, 0x67, 0x00},   // U+0068 (h)
+		{ 0x0C, 0x00, 0x0E, 0x0C, 0x0C, 0x0C, 0x1E, 0x00},   // U+0069 (i)
+		{ 0x30, 0x00, 0x30, 0x30, 0x30, 0x33, 0x33, 0x1E},   // U+006A (j)
+		{ 0x07, 0x06, 0x66, 0x36, 0x1E, 0x36, 0x67, 0x00},   // U+006B (k)
+		{ 0x0E, 0x0C, 0x0C, 0x0C, 0x0C, 0x0C, 0x1E, 0x00},   // U+006C (l)
+		{ 0x00, 0x00, 0x33, 0x7F, 0x7F, 0x6B, 0x63, 0x00},   // U+006D (m)
+		{ 0x00, 0x00, 0x1F, 0x33, 0x33, 0x33, 0x33, 0x00},   // U+006E (n)
+		{ 0x00, 0x00, 0x1E, 0x33, 0x33, 0x33, 0x1E, 0x00},   // U+006F (o)
+		{ 0x00, 0x00, 0x3B, 0x66, 0x66, 0x3E, 0x06, 0x0F},   // U+0070 (p)
+		{ 0x00, 0x00, 0x6E, 0x33, 0x33, 0x3E, 0x30, 0x78},   // U+0071 (q)
+		{ 0x00, 0x00, 0x3B, 0x6E, 0x66, 0x06, 0x0F, 0x00},   // U+0072 (r)
+		{ 0x00, 0x00, 0x3E, 0x03, 0x1E, 0x30, 0x1F, 0x00},   // U+0073 (s)
+		{ 0x08, 0x0C, 0x3E, 0x0C, 0x0C, 0x2C, 0x18, 0x00},   // U+0074 (t)
+		{ 0x00, 0x00, 0x33, 0x33, 0x33, 0x33, 0x6E, 0x00},   // U+0075 (u)
+		{ 0x00, 0x00, 0x33, 0x33, 0x33, 0x1E, 0x0C, 0x00},   // U+0076 (v)
+		{ 0x00, 0x00, 0x63, 0x6B, 0x7F, 0x7F, 0x36, 0x00},   // U+0077 (w)
+		{ 0x00, 0x00, 0x63, 0x36, 0x1C, 0x36, 0x63, 0x00},   // U+0078 (x)
+		{ 0x00, 0x00, 0x33, 0x33, 0x33, 0x3E, 0x30, 0x1F},   // U+0079 (y)
+		{ 0x00, 0x00, 0x3F, 0x19, 0x0C, 0x26, 0x3F, 0x00},   // U+007A (z)
+		{ 0x38, 0x0C, 0x0C, 0x07, 0x0C, 0x0C, 0x38, 0x00},   // U+007B ({)
+		{ 0x18, 0x18, 0x18, 0x00, 0x18, 0x18, 0x18, 0x00},   // U+007C (|)
+		{ 0x07, 0x0C, 0x0C, 0x38, 0x0C, 0x0C, 0x07, 0x00},   // U+007D (})
+		{ 0x6E, 0x3B, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},   // U+007E (~)
+		{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00} // U+007F
+	};
+	return (unsigned long long int *)f[c];
+}
+#endif
diff --git a/thorn/include/common/gpu.h b/thorn/include/common/gpu.h
index dadc67b..de01056 100644
--- a/thorn/include/common/gpu.h
+++ b/thorn/include/common/gpu.h
@@ -30,10 +30,10 @@ typedef struct {
     byte_t green;
     byte_t red;
     byte_t alpha;
-} color;
+} color_t;
 
 typedef struct {
-    color *      fb;
+    color_t *    fb;
     unsigned int fb_size;
     short        virtual_width;
     short        virtual_height;
@@ -47,7 +47,7 @@ static fb_info_t fb_info;
 
 bool init_gpu (void);
 
-color * get_fb (void);
+color_t * get_fb (void);
 
 fb_info_t const * get_fb_info (void);
 
diff --git a/thorn/include/common/logging.h b/thorn/include/common/logging.h
index 710659d..a58da93 100644
--- a/thorn/include/common/logging.h
+++ b/thorn/include/common/logging.h
@@ -3,14 +3,15 @@
 
 #include "common/printf.h"
 
-#define LOG(msg)                                                           \do {                                           \
-    static int __counter__ = 0;                                        \
-    printf(__FILE__":%d:[%d] %s\r\n", __LINE__, __counter__++, msg);   \
-} while (0)
+#define LOG(msg)                                                           \
+    do {                                                                   \
+        static int __counter__ = 0;                                        \
+        printf (__FILE__ ":%d:[%d] %s\r\n", __LINE__, __counter__++, msg); \
+    } while (0)
 
 #define ASSERT(expr)                  \
     do {                              \
-        if (!(expr))                  \
+        if (! (expr))                 \
             LOG ("Assertion failed"); \
     } while (0)
 
diff --git a/thorn/include/common/rainbow.h b/thorn/include/common/rainbow.h
index b8ae654..0389940 100644
--- a/thorn/include/common/rainbow.h
+++ b/thorn/include/common/rainbow.h
@@ -3,7 +3,7 @@
 
 #include "common/gpu.h"
 
-static color const RAINBOW[] = {
+static color_t const RAINBOW[] = {
         {0xff, 0x00, 0xff, 0},
         {0xc0, 0x00, 0xff, 0},
         {0x80, 0x00, 0xff, 0},
diff --git a/thorn/include/common/screen.h b/thorn/include/common/screen.h
index 8da1800..ab4b68a 100644
--- a/thorn/include/common/screen.h
+++ b/thorn/include/common/screen.h
@@ -1,21 +1,10 @@
 #ifndef _ROSE_C_SCREEN_H
 #define _ROSE_C_SCREEN_H
+#include "common/font.h"
+#include "common/gpu.h"
 
-#include "common/printf.h"
+void printc(char c);
 
-#define HEIGHT 79
-#define WIDTH  317
+void drawpx (unsigned int x, unsigned int y, color_t color);
 
-static char screen[HEIGHT * WIDTH];
-
-void clear_screen ();
-
-void draw_border ();
-
-void draw_screen ();
-
-char get_pixel (int x, int y);
-
-char set_pixel (int x, int y, char c);
-
-#endif//_ROSE_C_SCREEN_H
\ No newline at end of file
+#endif //_ROSE_C_SCREEN_H
\ No newline at end of file
diff --git a/thorn/src/common/gpu.c b/thorn/src/common/gpu.c
index 2b31913..b86af19 100644
--- a/thorn/src/common/gpu.c
+++ b/thorn/src/common/gpu.c
@@ -16,7 +16,7 @@ bool init_gpu () {
         gpu_msg_buffer[0] = (4 * ++c);// Write message size at the beginning of the buffer
 
         // If reading physical screen dimension fails exit function
-        if (!mailbox_request (gpu_msg_buffer, PROPERTY_ARM_VC))
+        if (! mailbox_request (gpu_msg_buffer, PROPERTY_ARM_VC))
             return false;
     }
     {                           // Second message: request frame buffer
@@ -64,11 +64,11 @@ bool init_gpu () {
         gpu_msg_buffer[0] = (4 * ++c);// Write message size at the beginning of the buffer
 
         // If message failed exit
-        if (!mailbox_request (gpu_msg_buffer, PROPERTY_ARM_VC))
+        if (! mailbox_request (gpu_msg_buffer, PROPERTY_ARM_VC))
             return false;
 
         // Since message succeeded, update frame buffer and its size
-        fb_info.fb      = (color *) (long) (gpu_msg_buffer[index_framebuffer] & VC_SDRAM_OFFSET);
+        fb_info.fb      = (color_t *) (long) (gpu_msg_buffer[index_framebuffer] & VC_SDRAM_OFFSET);
         fb_info.fb_size = gpu_msg_buffer[index_fb_size];
     }
     {                           // Third message: read pitch (in bytes per line)
@@ -87,7 +87,7 @@ bool init_gpu () {
         gpu_msg_buffer[0] = (4 * ++c);// Write message size at the beginning of the buffer
 
         // If message failed exit
-        if (!mailbox_request (gpu_msg_buffer, PROPERTY_ARM_VC))
+        if (! mailbox_request (gpu_msg_buffer, PROPERTY_ARM_VC))
             return false;
 
         // Else write pitch appropriately
@@ -96,7 +96,7 @@ bool init_gpu () {
     return true;
 }
 
-color * get_fb () {
+color_t * get_fb () {
     return fb_info.fb;
 }
 
diff --git a/thorn/src/common/rainbow.c b/thorn/src/common/rainbow.c
index 7efb05e..16e000f 100644
--- a/thorn/src/common/rainbow.c
+++ b/thorn/src/common/rainbow.c
@@ -1,7 +1,7 @@
 #include "common/rainbow.h"
 
 void draw () {
-    unsigned int const RB_SIZE   = sizeof (RAINBOW) / sizeof (color);
+    unsigned int const RB_SIZE   = sizeof (RAINBOW) / sizeof (color_t);
     unsigned int const X_DIVISOR = GPU_SCREEN_WIDTH / RB_SIZE;
     unsigned int const Y_DIVISOR = GPU_SCREEN_HEIGHT / RB_SIZE;
 
diff --git a/thorn/src/common/screen.c b/thorn/src/common/screen.c
index 937b091..a01d33d 100644
--- a/thorn/src/common/screen.c
+++ b/thorn/src/common/screen.c
@@ -1,47 +1,10 @@
 #include "common/screen.h"
-
-void clear_screen () {
-    for (int i = 0; i < HEIGHT; i++) {
-        printf ("\n");
-    }
-}
-
-void draw_border () {
-    for (int y = 0; y < HEIGHT; y++) {
-        for (int x = 0; x < WIDTH; x++) {
-            char c;
-            if (y == 0 || y == HEIGHT - 1) {
-                if (x == 0 || x == WIDTH - 1) {
-                    c = '+';
-                } else {
-                    c = '-';
-                }
-            } else {
-                if (x == 0 || x == WIDTH - 1) {
-                    c = '|';
-                } else {
-                    c = ' ';
-                }
-            }
-            printf ("%c", c);
-            set_pixel (x, y, c);
-        }
-    }
-}
-
-void draw_screen () {
-    for (int y = 0; y < HEIGHT; y++) {
-        for (int x = 0; x < WIDTH; x++) {
-            printf ("%c", get_pixel (x, y));
-        }
-        printf ("\r\n");
-    }
-}
-
-char get_pixel (int x, int y) {
-    return screen[x + WIDTH * y];
-}
-
-char set_pixel (int x, int y, char c) {
-    return screen[x + WIDTH * y] = c;
-}
+#define FB_PITCH GPU_COLOUR_DEPTH * GPU_SCREEN_WIDTH
+//static color_t * fb = get_fb();
+void printc(char c){
+};
+
+void drawpx (unsigned int x, unsigned int y, color_t color){
+    unsigned long int location = get_fb() + y * FB_PITCH + x * GPU_COLOUR_DEPTH;
+    get_fb()[location] = color;
+};
\ No newline at end of file
diff --git a/thorn/src/kernel/kernel.c b/thorn/src/kernel/kernel.c
index 07811f7..6244a1e 100644
--- a/thorn/src/kernel/kernel.c
+++ b/thorn/src/kernel/kernel.c
@@ -71,7 +71,7 @@ void kernel_init (void) {
     if (! gpu_status) {
         printf ("Error while initialising Framebuffer\r\n");
     } else {
-        color * fb = get_fb ();
+        color_t * fb = get_fb ();
         if (! fb) {
             printf ("Error: Invalid Framebuffer received\r\n");
         } else {

From dd73b5158f857caa815c776e3aef2d200307c6c9 Mon Sep 17 00:00:00 2001
From: Max Streitberger <max.streitberger@gmail.com>
Date: Thu, 21 Oct 2021 10:51:48 +0200
Subject: [PATCH 44/61] fix(bitmap): remove get_fb() from pixel location

---
 thorn/src/common/screen.c | 13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/thorn/src/common/screen.c b/thorn/src/common/screen.c
index a01d33d..1566aa4 100644
--- a/thorn/src/common/screen.c
+++ b/thorn/src/common/screen.c
@@ -1,10 +1,9 @@
 #include "common/screen.h"
-#define FB_PITCH GPU_COLOUR_DEPTH * GPU_SCREEN_WIDTH
-//static color_t * fb = get_fb();
-void printc(char c){
-};
+#define FB_PITCH GPU_COLOUR_DEPTH *GPU_SCREEN_WIDTH
+// static color_t * fb = get_fb();
+void printc(char c){};
 
-void drawpx (unsigned int x, unsigned int y, color_t color){
-    unsigned long int location = get_fb() + y * FB_PITCH + x * GPU_COLOUR_DEPTH;
-    get_fb()[location] = color;
+void drawpx(unsigned int x, unsigned int y, color_t color) {
+  unsigned long int location = y * FB_PITCH + x * GPU_COLOUR_DEPTH;
+  get_fb()[location] = color;
 };
\ No newline at end of file

From 4120e92100585c79d4bae7041ed403f52c6ba410 Mon Sep 17 00:00:00 2001
From: Max Streitberger <max.streitberger@gmail.com>
Date: Thu, 21 Oct 2021 12:45:26 +0200
Subject: [PATCH 45/61] feat(bitmap): WIP

---
 thorn/include/common/font.h   | 137 +----------------------------
 thorn/include/common/screen.h |   4 +
 thorn/src/common/gpu.c        |  34 +++++---
 thorn/src/common/screen.c     | 159 ++++++++++++++++++++++++++++++++--
 thorn/src/kernel/kernel.c     |  37 +++++---
 5 files changed, 207 insertions(+), 164 deletions(-)

diff --git a/thorn/include/common/font.h b/thorn/include/common/font.h
index 1210bbb..de1ef9e 100644
--- a/thorn/include/common/font.h
+++ b/thorn/include/common/font.h
@@ -2,138 +2,7 @@
 #define _ROSE_C_FONT_H
 
 #define FONT_SIZE 8
-/* From https://github.com/dhepper/font8x8/blob/master/font8x8_block.h */
-const unsigned long long int * font(int c) {
-	static const char f[128][FONT_SIZE] = {
-		{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},   // U+0000 (nul)
-		{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},   // U+0001
-		{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},   // U+0002
-		{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},   // U+0003
-		{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},   // U+0004
-		{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},   // U+0005
-		{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},   // U+0006
-		{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},   // U+0007
-		{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},   // U+0008
-		{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},   // U+0009
-		{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},   // U+000A
-		{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},   // U+000B
-		{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},   // U+000C
-		{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},   // U+000D
-		{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},   // U+000E
-		{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},   // U+000F
-		{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},   // U+0010
-		{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},   // U+0011
-		{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},   // U+0012
-		{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},   // U+0013
-		{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},   // U+0014
-		{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},   // U+0015
-		{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},   // U+0016
-		{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},   // U+0017
-		{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},   // U+0018
-		{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},   // U+0019
-		{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},   // U+001A
-		{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},   // U+001B
-		{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},   // U+001C
-		{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},   // U+001D
-		{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},   // U+001E
-		{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},   // U+001F
-		{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},   // U+0020 (space)
-		{ 0x18, 0x3C, 0x3C, 0x18, 0x18, 0x00, 0x18, 0x00},   // U+0021 (!)
-		{ 0x36, 0x36, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},   // U+0022 (")
-		{ 0x36, 0x36, 0x7F, 0x36, 0x7F, 0x36, 0x36, 0x00},   // U+0023 (#)
-		{ 0x0C, 0x3E, 0x03, 0x1E, 0x30, 0x1F, 0x0C, 0x00},   // U+0024 ($)
-		{ 0x00, 0x63, 0x33, 0x18, 0x0C, 0x66, 0x63, 0x00},   // U+0025 (%)
-		{ 0x1C, 0x36, 0x1C, 0x6E, 0x3B, 0x33, 0x6E, 0x00},   // U+0026 (&)
-		{ 0x06, 0x06, 0x03, 0x00, 0x00, 0x00, 0x00, 0x00},   // U+0027 (')
-		{ 0x18, 0x0C, 0x06, 0x06, 0x06, 0x0C, 0x18, 0x00},   // U+0028 (()
-		{ 0x06, 0x0C, 0x18, 0x18, 0x18, 0x0C, 0x06, 0x00},   // U+0029 ())
-		{ 0x00, 0x66, 0x3C, 0xFF, 0x3C, 0x66, 0x00, 0x00},   // U+002A (*)
-		{ 0x00, 0x0C, 0x0C, 0x3F, 0x0C, 0x0C, 0x00, 0x00},   // U+002B (+)
-		{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x0C, 0x0C, 0x06},   // U+002C (,)
-		{ 0x00, 0x00, 0x00, 0x3F, 0x00, 0x00, 0x00, 0x00},   // U+002D (-)
-		{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x0C, 0x0C, 0x00},   // U+002E (.)
-		{ 0x60, 0x30, 0x18, 0x0C, 0x06, 0x03, 0x01, 0x00},   // U+002F (/)
-		{ 0x3E, 0x63, 0x73, 0x7B, 0x6F, 0x67, 0x3E, 0x00},   // U+0030 (0)
-		{ 0x0C, 0x0E, 0x0C, 0x0C, 0x0C, 0x0C, 0x3F, 0x00},   // U+0031 (1)
-		{ 0x1E, 0x33, 0x30, 0x1C, 0x06, 0x33, 0x3F, 0x00},   // U+0032 (2)
-		{ 0x1E, 0x33, 0x30, 0x1C, 0x30, 0x33, 0x1E, 0x00},   // U+0033 (3)
-		{ 0x38, 0x3C, 0x36, 0x33, 0x7F, 0x30, 0x78, 0x00},   // U+0034 (4)
-		{ 0x3F, 0x03, 0x1F, 0x30, 0x30, 0x33, 0x1E, 0x00},   // U+0035 (5)
-		{ 0x1C, 0x06, 0x03, 0x1F, 0x33, 0x33, 0x1E, 0x00},   // U+0036 (6)
-		{ 0x3F, 0x33, 0x30, 0x18, 0x0C, 0x0C, 0x0C, 0x00},   // U+0037 (7)
-		{ 0x1E, 0x33, 0x33, 0x1E, 0x33, 0x33, 0x1E, 0x00},   // U+0038 (8)
-		{ 0x1E, 0x33, 0x33, 0x3E, 0x30, 0x18, 0x0E, 0x00},   // U+0039 (9)
-		{ 0x00, 0x0C, 0x0C, 0x00, 0x00, 0x0C, 0x0C, 0x00},   // U+003A (:)
-		{ 0x00, 0x0C, 0x0C, 0x00, 0x00, 0x0C, 0x0C, 0x06},   // U+003B (//)
-		{ 0x18, 0x0C, 0x06, 0x03, 0x06, 0x0C, 0x18, 0x00},   // U+003C (<)
-		{ 0x00, 0x00, 0x3F, 0x00, 0x00, 0x3F, 0x00, 0x00},   // U+003D (=)
-		{ 0x06, 0x0C, 0x18, 0x30, 0x18, 0x0C, 0x06, 0x00},   // U+003E (>)
-		{ 0x1E, 0x33, 0x30, 0x18, 0x0C, 0x00, 0x0C, 0x00},   // U+003F (?)
-		{ 0x3E, 0x63, 0x7B, 0x7B, 0x7B, 0x03, 0x1E, 0x00},   // U+0040 (@)
-		{ 0x0C, 0x1E, 0x33, 0x33, 0x3F, 0x33, 0x33, 0x00},   // U+0041 (A)
-		{ 0x3F, 0x66, 0x66, 0x3E, 0x66, 0x66, 0x3F, 0x00},   // U+0042 (B)
-		{ 0x3C, 0x66, 0x03, 0x03, 0x03, 0x66, 0x3C, 0x00},   // U+0043 (C)
-		{ 0x1F, 0x36, 0x66, 0x66, 0x66, 0x36, 0x1F, 0x00},   // U+0044 (D)
-		{ 0x7F, 0x46, 0x16, 0x1E, 0x16, 0x46, 0x7F, 0x00},   // U+0045 (E)
-		{ 0x7F, 0x46, 0x16, 0x1E, 0x16, 0x06, 0x0F, 0x00},   // U+0046 (F)
-		{ 0x3C, 0x66, 0x03, 0x03, 0x73, 0x66, 0x7C, 0x00},   // U+0047 (G)
-		{ 0x33, 0x33, 0x33, 0x3F, 0x33, 0x33, 0x33, 0x00},   // U+0048 (H)
-		{ 0x1E, 0x0C, 0x0C, 0x0C, 0x0C, 0x0C, 0x1E, 0x00},   // U+0049 (I)
-		{ 0x78, 0x30, 0x30, 0x30, 0x33, 0x33, 0x1E, 0x00},   // U+004A (J)
-		{ 0x67, 0x66, 0x36, 0x1E, 0x36, 0x66, 0x67, 0x00},   // U+004B (K)
-		{ 0x0F, 0x06, 0x06, 0x06, 0x46, 0x66, 0x7F, 0x00},   // U+004C (L)
-		{ 0x63, 0x77, 0x7F, 0x7F, 0x6B, 0x63, 0x63, 0x00},   // U+004D (M)
-		{ 0x63, 0x67, 0x6F, 0x7B, 0x73, 0x63, 0x63, 0x00},   // U+004E (N)
-		{ 0x1C, 0x36, 0x63, 0x63, 0x63, 0x36, 0x1C, 0x00},   // U+004F (O)
-		{ 0x3F, 0x66, 0x66, 0x3E, 0x06, 0x06, 0x0F, 0x00},   // U+0050 (P)
-		{ 0x1E, 0x33, 0x33, 0x33, 0x3B, 0x1E, 0x38, 0x00},   // U+0051 (Q)
-		{ 0x3F, 0x66, 0x66, 0x3E, 0x36, 0x66, 0x67, 0x00},   // U+0052 (R)
-		{ 0x1E, 0x33, 0x07, 0x0E, 0x38, 0x33, 0x1E, 0x00},   // U+0053 (S)
-		{ 0x3F, 0x2D, 0x0C, 0x0C, 0x0C, 0x0C, 0x1E, 0x00},   // U+0054 (T)
-		{ 0x33, 0x33, 0x33, 0x33, 0x33, 0x33, 0x3F, 0x00},   // U+0055 (U)
-		{ 0x33, 0x33, 0x33, 0x33, 0x33, 0x1E, 0x0C, 0x00},   // U+0056 (V)
-		{ 0x63, 0x63, 0x63, 0x6B, 0x7F, 0x77, 0x63, 0x00},   // U+0057 (W)
-		{ 0x63, 0x63, 0x36, 0x1C, 0x1C, 0x36, 0x63, 0x00},   // U+0058 (X)
-		{ 0x33, 0x33, 0x33, 0x1E, 0x0C, 0x0C, 0x1E, 0x00},   // U+0059 (Y)
-		{ 0x7F, 0x63, 0x31, 0x18, 0x4C, 0x66, 0x7F, 0x00},   // U+005A (Z)
-		{ 0x1E, 0x06, 0x06, 0x06, 0x06, 0x06, 0x1E, 0x00},   // U+005B ([)
-		{ 0x03, 0x06, 0x0C, 0x18, 0x30, 0x60, 0x40, 0x00},   // U+005C (\)
-		{ 0x1E, 0x18, 0x18, 0x18, 0x18, 0x18, 0x1E, 0x00},   // U+005D (])
-		{ 0x08, 0x1C, 0x36, 0x63, 0x00, 0x00, 0x00, 0x00},   // U+005E (^)
-		{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xFF},   // U+005F (_)
-		{ 0x0C, 0x0C, 0x18, 0x00, 0x00, 0x00, 0x00, 0x00},   // U+0060 (`)
-		{ 0x00, 0x00, 0x1E, 0x30, 0x3E, 0x33, 0x6E, 0x00},   // U+0061 (a)
-		{ 0x07, 0x06, 0x06, 0x3E, 0x66, 0x66, 0x3B, 0x00},   // U+0062 (b)
-		{ 0x00, 0x00, 0x1E, 0x33, 0x03, 0x33, 0x1E, 0x00},   // U+0063 (c)
-		{ 0x38, 0x30, 0x30, 0x3e, 0x33, 0x33, 0x6E, 0x00},   // U+0064 (d)
-		{ 0x00, 0x00, 0x1E, 0x33, 0x3f, 0x03, 0x1E, 0x00},   // U+0065 (e)
-		{ 0x1C, 0x36, 0x06, 0x0f, 0x06, 0x06, 0x0F, 0x00},   // U+0066 (f)
-		{ 0x00, 0x00, 0x6E, 0x33, 0x33, 0x3E, 0x30, 0x1F},   // U+0067 (g)
-		{ 0x07, 0x06, 0x36, 0x6E, 0x66, 0x66, 0x67, 0x00},   // U+0068 (h)
-		{ 0x0C, 0x00, 0x0E, 0x0C, 0x0C, 0x0C, 0x1E, 0x00},   // U+0069 (i)
-		{ 0x30, 0x00, 0x30, 0x30, 0x30, 0x33, 0x33, 0x1E},   // U+006A (j)
-		{ 0x07, 0x06, 0x66, 0x36, 0x1E, 0x36, 0x67, 0x00},   // U+006B (k)
-		{ 0x0E, 0x0C, 0x0C, 0x0C, 0x0C, 0x0C, 0x1E, 0x00},   // U+006C (l)
-		{ 0x00, 0x00, 0x33, 0x7F, 0x7F, 0x6B, 0x63, 0x00},   // U+006D (m)
-		{ 0x00, 0x00, 0x1F, 0x33, 0x33, 0x33, 0x33, 0x00},   // U+006E (n)
-		{ 0x00, 0x00, 0x1E, 0x33, 0x33, 0x33, 0x1E, 0x00},   // U+006F (o)
-		{ 0x00, 0x00, 0x3B, 0x66, 0x66, 0x3E, 0x06, 0x0F},   // U+0070 (p)
-		{ 0x00, 0x00, 0x6E, 0x33, 0x33, 0x3E, 0x30, 0x78},   // U+0071 (q)
-		{ 0x00, 0x00, 0x3B, 0x6E, 0x66, 0x06, 0x0F, 0x00},   // U+0072 (r)
-		{ 0x00, 0x00, 0x3E, 0x03, 0x1E, 0x30, 0x1F, 0x00},   // U+0073 (s)
-		{ 0x08, 0x0C, 0x3E, 0x0C, 0x0C, 0x2C, 0x18, 0x00},   // U+0074 (t)
-		{ 0x00, 0x00, 0x33, 0x33, 0x33, 0x33, 0x6E, 0x00},   // U+0075 (u)
-		{ 0x00, 0x00, 0x33, 0x33, 0x33, 0x1E, 0x0C, 0x00},   // U+0076 (v)
-		{ 0x00, 0x00, 0x63, 0x6B, 0x7F, 0x7F, 0x36, 0x00},   // U+0077 (w)
-		{ 0x00, 0x00, 0x63, 0x36, 0x1C, 0x36, 0x63, 0x00},   // U+0078 (x)
-		{ 0x00, 0x00, 0x33, 0x33, 0x33, 0x3E, 0x30, 0x1F},   // U+0079 (y)
-		{ 0x00, 0x00, 0x3F, 0x19, 0x0C, 0x26, 0x3F, 0x00},   // U+007A (z)
-		{ 0x38, 0x0C, 0x0C, 0x07, 0x0C, 0x0C, 0x38, 0x00},   // U+007B ({)
-		{ 0x18, 0x18, 0x18, 0x00, 0x18, 0x18, 0x18, 0x00},   // U+007C (|)
-		{ 0x07, 0x0C, 0x0C, 0x38, 0x0C, 0x0C, 0x07, 0x00},   // U+007D (})
-		{ 0x6E, 0x3B, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},   // U+007E (~)
-		{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00} // U+007F
-	};
-	return (unsigned long long int *)f[c];
-}
+
+const unsigned long long int * font (int c);
+
 #endif
diff --git a/thorn/include/common/screen.h b/thorn/include/common/screen.h
index ab4b68a..6beaf3b 100644
--- a/thorn/include/common/screen.h
+++ b/thorn/include/common/screen.h
@@ -7,4 +7,8 @@ void printc(char c);
 
 void drawpx (unsigned int x, unsigned int y, color_t color);
 
+short get_max_width ();
+short get_max_height ();
+
+
 #endif //_ROSE_C_SCREEN_H
\ No newline at end of file
diff --git a/thorn/src/common/gpu.c b/thorn/src/common/gpu.c
index b86af19..17539a8 100644
--- a/thorn/src/common/gpu.c
+++ b/thorn/src/common/gpu.c
@@ -6,12 +6,11 @@ bool init_gpu () {
         gpu_msg_buffer[++c] = 0;// Response - will be 0x80000000 for SUCCESS or 0x80000001 for FAILURE
 
         gpu_msg_buffer[++c] = 0x00040003;// Tag to get physical display width / height
-        gpu_msg_buffer[++c] = 0;         // Size of value buffer
+        gpu_msg_buffer[++c] = 8;         // Size of value buffer
         gpu_msg_buffer[++c] = 0;         // Response & value buffer size written will be written here
         gpu_msg_buffer[++c] = 0;         // Get physical screen width    |  Overwritten by actual width
         gpu_msg_buffer[++c] = 0;         // Get physical screen height   |  Overwritten by actual height
-
-        gpu_msg_buffer[++c] = 0;// End tag
+        gpu_msg_buffer[++c] = 0;         // End tag
 
         gpu_msg_buffer[0] = (4 * ++c);// Write message size at the beginning of the buffer
 
@@ -24,23 +23,29 @@ bool init_gpu () {
         gpu_msg_buffer[++c] = 0;// Response - will be 0x80000000 for SUCCESS or 0x80000001 for FAILURE
 
 #ifdef GPU_OVERRIDE_PHYSICAL_SCREEN             // If this is set, update physical /virtual dimensions based on constants
-        gpu_msg_buffer[++c] = 0x00048003;       // Tag to set virtual display width / height
+        gpu_msg_buffer[++c]  = 0x00048003;      // Tag to set virtual display width / height
+        gpu_msg_buffer[++c]  = 8;               // Size of value buffer
+        gpu_msg_buffer[++c]  = 0;               // Response & value buffer size written will be written here
+        gpu_msg_buffer[++c]  = GPU_SCREEN_WIDTH;// Set virtual screen width     |  Overwritten by actual virtual width
+        int index_gpu_width  = c;
+        gpu_msg_buffer[++c]  = GPU_SCREEN_HEIGHT;// Set virtual screen height    |  Overwritten by actual virtual height
+        int index_gpu_height = c;
+
+        gpu_msg_buffer[++c] = 0x00048004;       // Tag to set virtual display width / height
         gpu_msg_buffer[++c] = 8;                // Size of value buffer
         gpu_msg_buffer[++c] = 0;                // Response & value buffer size written will be written here
-        gpu_msg_buffer[++c] = GPU_SCREEN_WIDTH; // Set virtual screen width     |  Overwritten by actual virtual width
-        gpu_msg_buffer[++c] = GPU_SCREEN_HEIGHT;// Set virtual screen height    |  Overwritten by actual virtual height
-
-        gpu_msg_buffer[++c] = 0x00048004;        // Tag to set virtual display width / height
-        gpu_msg_buffer[++c] = 8;                 // Size of value buffer
-        gpu_msg_buffer[++c] = 0;                 // Response & value buffer size written will be written here
-        gpu_msg_buffer[++c] = GPU_VIRTUAL_WIDTH; // Set virtual screen width     |  Overwritten by actual virtual width
+        gpu_msg_buffer[++c] = GPU_VIRTUAL_WIDTH;// Set virtual screen width     |  Overwritten by actual virtual width
+        int index_width     = c;
         gpu_msg_buffer[++c] = GPU_VIRTUAL_HEIGHT;// Set virtual screen height    |  Overwritten by actual virtual height
+        int index_height    = c;
 #else
         gpu_msg_buffer[++c] = 0x00048004;// Tag to set virtual display width / height
         gpu_msg_buffer[++c] = 8;         // Size of value buffer
         gpu_msg_buffer[++c] = 0;         // Response & value buffer size written will be written here
         gpu_msg_buffer[++c];             //GPU_SCREEN_WIDTH;      // Reuse previous width         |  Overwritten by actual virtual width
-        gpu_msg_buffer[++c];             //GPU_SCREEN_HEIGHT;     // Reuse previous height        |  Overwritten by actual virtual height
+        int index_width = c;
+        gpu_msg_buffer[++c];//GPU_SCREEN_HEIGHT;     // Reuse previous height        |  Overwritten by actual virtual height
+        int index_height = c;
 #endif
 
         gpu_msg_buffer[++c] = 0x00048005;      // Tag to set pixel depth
@@ -70,6 +75,11 @@ bool init_gpu () {
         // Since message succeeded, update frame buffer and its size
         fb_info.fb      = (color_t *) (long) (gpu_msg_buffer[index_framebuffer] & VC_SDRAM_OFFSET);
         fb_info.fb_size = gpu_msg_buffer[index_fb_size];
+
+        // printf ("PHY_WIDTH: %d, PHY_HEIGHT: %d, VIRT_WIDTH: %d, VIRT_HEIGHT: %d\n\r", gpu_msg_buffer[index_gpu_width], gpu_msg_buffer[index_gpu_height], gpu_msg_buffer[index_width], gpu_msg_buffer[index_height]);
+
+        fb_info.virtual_width  = gpu_msg_buffer[index_width];
+        fb_info.virtual_height = gpu_msg_buffer[index_height];
     }
     {                           // Third message: read pitch (in bytes per line)
         int c               = 0;// Message size; increment while we write
diff --git a/thorn/src/common/screen.c b/thorn/src/common/screen.c
index 1566aa4..9f7520a 100644
--- a/thorn/src/common/screen.c
+++ b/thorn/src/common/screen.c
@@ -1,9 +1,156 @@
 #include "common/screen.h"
-#define FB_PITCH GPU_COLOUR_DEPTH *GPU_SCREEN_WIDTH
+#include "common/font.h"
+#define FB_PITCH GPU_COLOUR_DEPTH * GPU_SCREEN_WIDTH
 // static color_t * fb = get_fb();
-void printc(char c){};
 
-void drawpx(unsigned int x, unsigned int y, color_t color) {
-  unsigned long int location = y * FB_PITCH + x * GPU_COLOUR_DEPTH;
-  get_fb()[location] = color;
-};
\ No newline at end of file
+/* From https://github.com/dhepper/font8x8/blob/master/font8x8_block.h */
+const unsigned long long int * font (int c) {
+    static const char f[128][FONT_SIZE] = {
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+0000 (nul)
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+0001
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+0002
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+0003
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+0004
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+0005
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+0006
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+0007
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+0008
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+0009
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+000A
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+000B
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+000C
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+000D
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+000E
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+000F
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+0010
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+0011
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+0012
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+0013
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+0014
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+0015
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+0016
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+0017
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+0018
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+0019
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+001A
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+001B
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+001C
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+001D
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+001E
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+001F
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+0020 (space)
+            {0x18, 0x3C, 0x3C, 0x18, 0x18, 0x00, 0x18, 0x00},// U+0021 (!)
+            {0x36, 0x36, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+0022 (")
+            {0x36, 0x36, 0x7F, 0x36, 0x7F, 0x36, 0x36, 0x00},// U+0023 (#)
+            {0x0C, 0x3E, 0x03, 0x1E, 0x30, 0x1F, 0x0C, 0x00},// U+0024 ($)
+            {0x00, 0x63, 0x33, 0x18, 0x0C, 0x66, 0x63, 0x00},// U+0025 (%)
+            {0x1C, 0x36, 0x1C, 0x6E, 0x3B, 0x33, 0x6E, 0x00},// U+0026 (&)
+            {0x06, 0x06, 0x03, 0x00, 0x00, 0x00, 0x00, 0x00},// U+0027 (')
+            {0x18, 0x0C, 0x06, 0x06, 0x06, 0x0C, 0x18, 0x00},// U+0028 (()
+            {0x06, 0x0C, 0x18, 0x18, 0x18, 0x0C, 0x06, 0x00},// U+0029 ())
+            {0x00, 0x66, 0x3C, 0xFF, 0x3C, 0x66, 0x00, 0x00},// U+002A (*)
+            {0x00, 0x0C, 0x0C, 0x3F, 0x0C, 0x0C, 0x00, 0x00},// U+002B (+)
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x0C, 0x0C, 0x06},// U+002C (,)
+            {0x00, 0x00, 0x00, 0x3F, 0x00, 0x00, 0x00, 0x00},// U+002D (-)
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x0C, 0x0C, 0x00},// U+002E (.)
+            {0x60, 0x30, 0x18, 0x0C, 0x06, 0x03, 0x01, 0x00},// U+002F (/)
+            {0x3E, 0x63, 0x73, 0x7B, 0x6F, 0x67, 0x3E, 0x00},// U+0030 (0)
+            {0x0C, 0x0E, 0x0C, 0x0C, 0x0C, 0x0C, 0x3F, 0x00},// U+0031 (1)
+            {0x1E, 0x33, 0x30, 0x1C, 0x06, 0x33, 0x3F, 0x00},// U+0032 (2)
+            {0x1E, 0x33, 0x30, 0x1C, 0x30, 0x33, 0x1E, 0x00},// U+0033 (3)
+            {0x38, 0x3C, 0x36, 0x33, 0x7F, 0x30, 0x78, 0x00},// U+0034 (4)
+            {0x3F, 0x03, 0x1F, 0x30, 0x30, 0x33, 0x1E, 0x00},// U+0035 (5)
+            {0x1C, 0x06, 0x03, 0x1F, 0x33, 0x33, 0x1E, 0x00},// U+0036 (6)
+            {0x3F, 0x33, 0x30, 0x18, 0x0C, 0x0C, 0x0C, 0x00},// U+0037 (7)
+            {0x1E, 0x33, 0x33, 0x1E, 0x33, 0x33, 0x1E, 0x00},// U+0038 (8)
+            {0x1E, 0x33, 0x33, 0x3E, 0x30, 0x18, 0x0E, 0x00},// U+0039 (9)
+            {0x00, 0x0C, 0x0C, 0x00, 0x00, 0x0C, 0x0C, 0x00},// U+003A (:)
+            {0x00, 0x0C, 0x0C, 0x00, 0x00, 0x0C, 0x0C, 0x06},// U+003B (//)
+            {0x18, 0x0C, 0x06, 0x03, 0x06, 0x0C, 0x18, 0x00},// U+003C (<)
+            {0x00, 0x00, 0x3F, 0x00, 0x00, 0x3F, 0x00, 0x00},// U+003D (=)
+            {0x06, 0x0C, 0x18, 0x30, 0x18, 0x0C, 0x06, 0x00},// U+003E (>)
+            {0x1E, 0x33, 0x30, 0x18, 0x0C, 0x00, 0x0C, 0x00},// U+003F (?)
+            {0x3E, 0x63, 0x7B, 0x7B, 0x7B, 0x03, 0x1E, 0x00},// U+0040 (@)
+            {0x0C, 0x1E, 0x33, 0x33, 0x3F, 0x33, 0x33, 0x00},// U+0041 (A)
+            {0x3F, 0x66, 0x66, 0x3E, 0x66, 0x66, 0x3F, 0x00},// U+0042 (B)
+            {0x3C, 0x66, 0x03, 0x03, 0x03, 0x66, 0x3C, 0x00},// U+0043 (C)
+            {0x1F, 0x36, 0x66, 0x66, 0x66, 0x36, 0x1F, 0x00},// U+0044 (D)
+            {0x7F, 0x46, 0x16, 0x1E, 0x16, 0x46, 0x7F, 0x00},// U+0045 (E)
+            {0x7F, 0x46, 0x16, 0x1E, 0x16, 0x06, 0x0F, 0x00},// U+0046 (F)
+            {0x3C, 0x66, 0x03, 0x03, 0x73, 0x66, 0x7C, 0x00},// U+0047 (G)
+            {0x33, 0x33, 0x33, 0x3F, 0x33, 0x33, 0x33, 0x00},// U+0048 (H)
+            {0x1E, 0x0C, 0x0C, 0x0C, 0x0C, 0x0C, 0x1E, 0x00},// U+0049 (I)
+            {0x78, 0x30, 0x30, 0x30, 0x33, 0x33, 0x1E, 0x00},// U+004A (J)
+            {0x67, 0x66, 0x36, 0x1E, 0x36, 0x66, 0x67, 0x00},// U+004B (K)
+            {0x0F, 0x06, 0x06, 0x06, 0x46, 0x66, 0x7F, 0x00},// U+004C (L)
+            {0x63, 0x77, 0x7F, 0x7F, 0x6B, 0x63, 0x63, 0x00},// U+004D (M)
+            {0x63, 0x67, 0x6F, 0x7B, 0x73, 0x63, 0x63, 0x00},// U+004E (N)
+            {0x1C, 0x36, 0x63, 0x63, 0x63, 0x36, 0x1C, 0x00},// U+004F (O)
+            {0x3F, 0x66, 0x66, 0x3E, 0x06, 0x06, 0x0F, 0x00},// U+0050 (P)
+            {0x1E, 0x33, 0x33, 0x33, 0x3B, 0x1E, 0x38, 0x00},// U+0051 (Q)
+            {0x3F, 0x66, 0x66, 0x3E, 0x36, 0x66, 0x67, 0x00},// U+0052 (R)
+            {0x1E, 0x33, 0x07, 0x0E, 0x38, 0x33, 0x1E, 0x00},// U+0053 (S)
+            {0x3F, 0x2D, 0x0C, 0x0C, 0x0C, 0x0C, 0x1E, 0x00},// U+0054 (T)
+            {0x33, 0x33, 0x33, 0x33, 0x33, 0x33, 0x3F, 0x00},// U+0055 (U)
+            {0x33, 0x33, 0x33, 0x33, 0x33, 0x1E, 0x0C, 0x00},// U+0056 (V)
+            {0x63, 0x63, 0x63, 0x6B, 0x7F, 0x77, 0x63, 0x00},// U+0057 (W)
+            {0x63, 0x63, 0x36, 0x1C, 0x1C, 0x36, 0x63, 0x00},// U+0058 (X)
+            {0x33, 0x33, 0x33, 0x1E, 0x0C, 0x0C, 0x1E, 0x00},// U+0059 (Y)
+            {0x7F, 0x63, 0x31, 0x18, 0x4C, 0x66, 0x7F, 0x00},// U+005A (Z)
+            {0x1E, 0x06, 0x06, 0x06, 0x06, 0x06, 0x1E, 0x00},// U+005B ([)
+            {0x03, 0x06, 0x0C, 0x18, 0x30, 0x60, 0x40, 0x00},// U+005C (\)
+            {0x1E, 0x18, 0x18, 0x18, 0x18, 0x18, 0x1E, 0x00},// U+005D (])
+            {0x08, 0x1C, 0x36, 0x63, 0x00, 0x00, 0x00, 0x00},// U+005E (^)
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xFF},// U+005F (_)
+            {0x0C, 0x0C, 0x18, 0x00, 0x00, 0x00, 0x00, 0x00},// U+0060 (`)
+            {0x00, 0x00, 0x1E, 0x30, 0x3E, 0x33, 0x6E, 0x00},// U+0061 (a)
+            {0x07, 0x06, 0x06, 0x3E, 0x66, 0x66, 0x3B, 0x00},// U+0062 (b)
+            {0x00, 0x00, 0x1E, 0x33, 0x03, 0x33, 0x1E, 0x00},// U+0063 (c)
+            {0x38, 0x30, 0x30, 0x3e, 0x33, 0x33, 0x6E, 0x00},// U+0064 (d)
+            {0x00, 0x00, 0x1E, 0x33, 0x3f, 0x03, 0x1E, 0x00},// U+0065 (e)
+            {0x1C, 0x36, 0x06, 0x0f, 0x06, 0x06, 0x0F, 0x00},// U+0066 (f)
+            {0x00, 0x00, 0x6E, 0x33, 0x33, 0x3E, 0x30, 0x1F},// U+0067 (g)
+            {0x07, 0x06, 0x36, 0x6E, 0x66, 0x66, 0x67, 0x00},// U+0068 (h)
+            {0x0C, 0x00, 0x0E, 0x0C, 0x0C, 0x0C, 0x1E, 0x00},// U+0069 (i)
+            {0x30, 0x00, 0x30, 0x30, 0x30, 0x33, 0x33, 0x1E},// U+006A (j)
+            {0x07, 0x06, 0x66, 0x36, 0x1E, 0x36, 0x67, 0x00},// U+006B (k)
+            {0x0E, 0x0C, 0x0C, 0x0C, 0x0C, 0x0C, 0x1E, 0x00},// U+006C (l)
+            {0x00, 0x00, 0x33, 0x7F, 0x7F, 0x6B, 0x63, 0x00},// U+006D (m)
+            {0x00, 0x00, 0x1F, 0x33, 0x33, 0x33, 0x33, 0x00},// U+006E (n)
+            {0x00, 0x00, 0x1E, 0x33, 0x33, 0x33, 0x1E, 0x00},// U+006F (o)
+            {0x00, 0x00, 0x3B, 0x66, 0x66, 0x3E, 0x06, 0x0F},// U+0070 (p)
+            {0x00, 0x00, 0x6E, 0x33, 0x33, 0x3E, 0x30, 0x78},// U+0071 (q)
+            {0x00, 0x00, 0x3B, 0x6E, 0x66, 0x06, 0x0F, 0x00},// U+0072 (r)
+            {0x00, 0x00, 0x3E, 0x03, 0x1E, 0x30, 0x1F, 0x00},// U+0073 (s)
+            {0x08, 0x0C, 0x3E, 0x0C, 0x0C, 0x2C, 0x18, 0x00},// U+0074 (t)
+            {0x00, 0x00, 0x33, 0x33, 0x33, 0x33, 0x6E, 0x00},// U+0075 (u)
+            {0x00, 0x00, 0x33, 0x33, 0x33, 0x1E, 0x0C, 0x00},// U+0076 (v)
+            {0x00, 0x00, 0x63, 0x6B, 0x7F, 0x7F, 0x36, 0x00},// U+0077 (w)
+            {0x00, 0x00, 0x63, 0x36, 0x1C, 0x36, 0x63, 0x00},// U+0078 (x)
+            {0x00, 0x00, 0x33, 0x33, 0x33, 0x3E, 0x30, 0x1F},// U+0079 (y)
+            {0x00, 0x00, 0x3F, 0x19, 0x0C, 0x26, 0x3F, 0x00},// U+007A (z)
+            {0x38, 0x0C, 0x0C, 0x07, 0x0C, 0x0C, 0x38, 0x00},// U+007B ({)
+            {0x18, 0x18, 0x18, 0x00, 0x18, 0x18, 0x18, 0x00},// U+007C (|)
+            {0x07, 0x0C, 0x0C, 0x38, 0x0C, 0x0C, 0x07, 0x00},// U+007D (})
+            {0x6E, 0x3B, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+007E (~)
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00} // U+007F
+    };
+    return (unsigned long long int *) f[c];
+}
+
+
+void printc (char c) {};
+
+void drawpx (unsigned int x, unsigned int y, color_t color) {
+    unsigned long int location = y * get_fb_info ()->pitch + x;
+    printf ("X: %d, Y: %d, location: %d\r\n", x, y, location);
+    get_fb ()[location] = color;
+};
+
+short get_max_width () {
+    return get_fb_info ()->virtual_width - 1;
+}
+
+short get_max_height () {
+    return get_fb_info ()->virtual_height - 1;
+}
\ No newline at end of file
diff --git a/thorn/src/kernel/kernel.c b/thorn/src/kernel/kernel.c
index 6244a1e..9d5189f 100644
--- a/thorn/src/kernel/kernel.c
+++ b/thorn/src/kernel/kernel.c
@@ -2,6 +2,7 @@
 #include "common/logging.h"
 #include "common/printf.h"
 #include "common/rainbow.h"
+#include "common/screen.h"
 #include "common/utils.h"
 #include "kernel/fork.h"
 #include "kernel/irq.h"
@@ -50,7 +51,7 @@ void user_process () {
 }
 
 void kernel_process () {
-    printf ("Kernel process started. EL %d\r\n", get_el ());
+    // printf ("Kernel process started. EL %d\r\n", get_el ());
     int err = move_to_user_mode ((unsigned long) &user_process);
     if (err < 0) {
         printf ("Error while moving process to user mode\n\r");
@@ -80,6 +81,14 @@ void kernel_init (void) {
     }
 
     LOG ("Initialisation done");
+
+    printf ("MAX_WIDTH: %d\n\r", get_fb_info ()->virtual_width);
+    printf ("MAX_HEIGHT: %d\n\r", get_fb_info ()->virtual_height);
+
+    printf ("GET_MAX_WIDTH: %d\n\r", get_max_width ());
+    printf ("GET_MAX_HEIGHT: %d\n\r", get_max_height ());
+
+    printf ("PITCH: %d\n\r", get_fb_info ()->pitch);
 }
 
 
@@ -93,32 +102,36 @@ void kernel_main (int processor_id) {
     while (processor_id != current_processor)
         ;
 
-    printf ("Hello, from processor %d\n\r", processor_id);
+    // printf ("Hello, from processor %d\n\r", processor_id);
 
     current_processor++;
     while (current_processor != 3)
         ;
     switch (processor_id) {
         case 0: {
-            int res = copy_process (PF_KTHREAD, (unsigned long) &kernel_process, 0, 0);
-            if (res < 0) {
-                printf ("error while starting kernel process");
-                return;
-            }
+            // int res = copy_process (PF_KTHREAD, (unsigned long) &kernel_process, 0, 0);
+            // if (res < 0) {
+            //     // printf ("error while starting kernel process");
+            //     return;
+            // }
             while (1) {
-                schedule ();
+                // schedule ();
             }
         }
         case 1:
-            if (get_fb ())
-                draw ();
+            if (get_fb ()) {
+                color_t color = {0xff, 0xff, 0xff, 0xff};
+                for (int i = 0; i < 50; i++) {
+                    drawpx (i, i, color);
+                }
+            }
             break;
         case 2:
         case 3:
         default:
-            printf ("Undefined behaviour on processor %d\r\n", processor_id);
+            // printf ("Undefined behaviour on processor %d\r\n", processor_id);
             while (1)
                 ;
     }
-    printf ("Processor %d going out of scope\r\n", processor_id);
+    // printf ("Processor %d going out of scope\r\n", processor_id);
 }

From d2f9e290a873ebf92f3c871c06f3a03d2082dc87 Mon Sep 17 00:00:00 2001
From: Max Streitberger <max.streitberger@gmail.com>
Date: Thu, 21 Oct 2021 12:55:42 +0200
Subject: [PATCH 46/61] fix(bitmap): drawpx

---
 thorn/src/common/screen.c | 2 +-
 thorn/src/kernel/kernel.c | 6 +++++-
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/thorn/src/common/screen.c b/thorn/src/common/screen.c
index 9f7520a..9b88ca5 100644
--- a/thorn/src/common/screen.c
+++ b/thorn/src/common/screen.c
@@ -142,7 +142,7 @@ const unsigned long long int * font (int c) {
 void printc (char c) {};
 
 void drawpx (unsigned int x, unsigned int y, color_t color) {
-    unsigned long int location = y * get_fb_info ()->pitch + x;
+    unsigned long int location = y * (get_fb_info ()->pitch) / sizeof (color_t) + x;
     printf ("X: %d, Y: %d, location: %d\r\n", x, y, location);
     get_fb ()[location] = color;
 };
diff --git a/thorn/src/kernel/kernel.c b/thorn/src/kernel/kernel.c
index 9d5189f..7d06db2 100644
--- a/thorn/src/kernel/kernel.c
+++ b/thorn/src/kernel/kernel.c
@@ -121,9 +121,13 @@ void kernel_main (int processor_id) {
         case 1:
             if (get_fb ()) {
                 color_t color = {0xff, 0xff, 0xff, 0xff};
-                for (int i = 0; i < 50; i++) {
+                for (int i = 0; i < get_max_height (); i++) {
                     drawpx (i, i, color);
                 }
+                drawpx (0, 0, color);
+                drawpx (get_max_width (), 0, color);
+                drawpx (0, get_max_height (), color);
+                drawpx (get_max_width (), get_max_height (), color);
             }
             break;
         case 2:

From 90608fcd040d34e774675682f907a84822201cd0 Mon Sep 17 00:00:00 2001
From: Max Streitberger <max.streitberger@gmail.com>
Date: Thu, 21 Oct 2021 12:56:43 +0200
Subject: [PATCH 47/61] chore(bitmap): remove printf in drawpx

---
 thorn/src/common/screen.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/thorn/src/common/screen.c b/thorn/src/common/screen.c
index 9b88ca5..f16c382 100644
--- a/thorn/src/common/screen.c
+++ b/thorn/src/common/screen.c
@@ -143,8 +143,7 @@ void printc (char c) {};
 
 void drawpx (unsigned int x, unsigned int y, color_t color) {
     unsigned long int location = y * (get_fb_info ()->pitch) / sizeof (color_t) + x;
-    printf ("X: %d, Y: %d, location: %d\r\n", x, y, location);
-    get_fb ()[location] = color;
+    get_fb ()[location]        = color;
 };
 
 short get_max_width () {

From 356c0f78e4c11fc3f26538583080e06fac090aeb Mon Sep 17 00:00:00 2001
From: Max Streitberger <max.streitberger@gmail.com>
Date: Thu, 21 Oct 2021 13:58:46 +0200
Subject: [PATCH 48/61] feat(bitmap): working on printing char

---
 thorn/include/common/font.h |   5 +-
 thorn/src/common/font.c     | 163 ++++++++++++++++++++++++++++++++++++
 thorn/src/common/screen.c   | 141 -------------------------------
 thorn/src/kernel/kernel.c   |   9 +-
 4 files changed, 169 insertions(+), 149 deletions(-)
 create mode 100644 thorn/src/common/font.c

diff --git a/thorn/include/common/font.h b/thorn/include/common/font.h
index de1ef9e..3a2e4e9 100644
--- a/thorn/include/common/font.h
+++ b/thorn/include/common/font.h
@@ -1,8 +1,11 @@
 #ifndef _ROSE_C_FONT_H
 #define _ROSE_C_FONT_H
 
-#define FONT_SIZE 8
+#define FONT_SIZE 8 * 5
+
+#include "common/screen.h"
 
 const unsigned long long int * font (int c);
+void printc_location(char c, unsigned int x, unsigned int y);
 
 #endif
diff --git a/thorn/src/common/font.c b/thorn/src/common/font.c
new file mode 100644
index 0000000..9ed177a
--- /dev/null
+++ b/thorn/src/common/font.c
@@ -0,0 +1,163 @@
+#include "common/font.h"
+
+/* From https://github.com/dhepper/font8x8/blob/master/font8x8_block.h */
+const unsigned long long int * font (int c) {
+    static const char f[128][FONT_SIZE] = {
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+0000 (nul)
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+0001
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+0002
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+0003
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+0004
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+0005
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+0006
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+0007
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+0008
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+0009
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+000A
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+000B
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+000C
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+000D
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+000E
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+000F
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+0010
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+0011
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+0012
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+0013
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+0014
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+0015
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+0016
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+0017
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+0018
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+0019
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+001A
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+001B
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+001C
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+001D
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+001E
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+001F
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+0020 (space)
+            {0x18, 0x3C, 0x3C, 0x18, 0x18, 0x00, 0x18, 0x00},// U+0021 (!)
+            {0x36, 0x36, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+0022 (")
+            {0x36, 0x36, 0x7F, 0x36, 0x7F, 0x36, 0x36, 0x00},// U+0023 (#)
+            {0x0C, 0x3E, 0x03, 0x1E, 0x30, 0x1F, 0x0C, 0x00},// U+0024 ($)
+            {0x00, 0x63, 0x33, 0x18, 0x0C, 0x66, 0x63, 0x00},// U+0025 (%)
+            {0x1C, 0x36, 0x1C, 0x6E, 0x3B, 0x33, 0x6E, 0x00},// U+0026 (&)
+            {0x06, 0x06, 0x03, 0x00, 0x00, 0x00, 0x00, 0x00},// U+0027 (')
+            {0x18, 0x0C, 0x06, 0x06, 0x06, 0x0C, 0x18, 0x00},// U+0028 (()
+            {0x06, 0x0C, 0x18, 0x18, 0x18, 0x0C, 0x06, 0x00},// U+0029 ())
+            {0x00, 0x66, 0x3C, 0xFF, 0x3C, 0x66, 0x00, 0x00},// U+002A (*)
+            {0x00, 0x0C, 0x0C, 0x3F, 0x0C, 0x0C, 0x00, 0x00},// U+002B (+)
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x0C, 0x0C, 0x06},// U+002C (,)
+            {0x00, 0x00, 0x00, 0x3F, 0x00, 0x00, 0x00, 0x00},// U+002D (-)
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x0C, 0x0C, 0x00},// U+002E (.)
+            {0x60, 0x30, 0x18, 0x0C, 0x06, 0x03, 0x01, 0x00},// U+002F (/)
+            {0x3E, 0x63, 0x73, 0x7B, 0x6F, 0x67, 0x3E, 0x00},// U+0030 (0)
+            {0x0C, 0x0E, 0x0C, 0x0C, 0x0C, 0x0C, 0x3F, 0x00},// U+0031 (1)
+            {0x1E, 0x33, 0x30, 0x1C, 0x06, 0x33, 0x3F, 0x00},// U+0032 (2)
+            {0x1E, 0x33, 0x30, 0x1C, 0x30, 0x33, 0x1E, 0x00},// U+0033 (3)
+            {0x38, 0x3C, 0x36, 0x33, 0x7F, 0x30, 0x78, 0x00},// U+0034 (4)
+            {0x3F, 0x03, 0x1F, 0x30, 0x30, 0x33, 0x1E, 0x00},// U+0035 (5)
+            {0x1C, 0x06, 0x03, 0x1F, 0x33, 0x33, 0x1E, 0x00},// U+0036 (6)
+            {0x3F, 0x33, 0x30, 0x18, 0x0C, 0x0C, 0x0C, 0x00},// U+0037 (7)
+            {0x1E, 0x33, 0x33, 0x1E, 0x33, 0x33, 0x1E, 0x00},// U+0038 (8)
+            {0x1E, 0x33, 0x33, 0x3E, 0x30, 0x18, 0x0E, 0x00},// U+0039 (9)
+            {0x00, 0x0C, 0x0C, 0x00, 0x00, 0x0C, 0x0C, 0x00},// U+003A (:)
+            {0x00, 0x0C, 0x0C, 0x00, 0x00, 0x0C, 0x0C, 0x06},// U+003B (//)
+            {0x18, 0x0C, 0x06, 0x03, 0x06, 0x0C, 0x18, 0x00},// U+003C (<)
+            {0x00, 0x00, 0x3F, 0x00, 0x00, 0x3F, 0x00, 0x00},// U+003D (=)
+            {0x06, 0x0C, 0x18, 0x30, 0x18, 0x0C, 0x06, 0x00},// U+003E (>)
+            {0x1E, 0x33, 0x30, 0x18, 0x0C, 0x00, 0x0C, 0x00},// U+003F (?)
+            {0x3E, 0x63, 0x7B, 0x7B, 0x7B, 0x03, 0x1E, 0x00},// U+0040 (@)
+            {0x0C, 0x1E, 0x33, 0x33, 0x3F, 0x33, 0x33, 0x00},// U+0041 (A)
+            {0x3F, 0x66, 0x66, 0x3E, 0x66, 0x66, 0x3F, 0x00},// U+0042 (B)
+            {0x3C, 0x66, 0x03, 0x03, 0x03, 0x66, 0x3C, 0x00},// U+0043 (C)
+            {0x1F, 0x36, 0x66, 0x66, 0x66, 0x36, 0x1F, 0x00},// U+0044 (D)
+            {0x7F, 0x46, 0x16, 0x1E, 0x16, 0x46, 0x7F, 0x00},// U+0045 (E)
+            {0x7F, 0x46, 0x16, 0x1E, 0x16, 0x06, 0x0F, 0x00},// U+0046 (F)
+            {0x3C, 0x66, 0x03, 0x03, 0x73, 0x66, 0x7C, 0x00},// U+0047 (G)
+            {0x33, 0x33, 0x33, 0x3F, 0x33, 0x33, 0x33, 0x00},// U+0048 (H)
+            {0x1E, 0x0C, 0x0C, 0x0C, 0x0C, 0x0C, 0x1E, 0x00},// U+0049 (I)
+            {0x78, 0x30, 0x30, 0x30, 0x33, 0x33, 0x1E, 0x00},// U+004A (J)
+            {0x67, 0x66, 0x36, 0x1E, 0x36, 0x66, 0x67, 0x00},// U+004B (K)
+            {0x0F, 0x06, 0x06, 0x06, 0x46, 0x66, 0x7F, 0x00},// U+004C (L)
+            {0x63, 0x77, 0x7F, 0x7F, 0x6B, 0x63, 0x63, 0x00},// U+004D (M)
+            {0x63, 0x67, 0x6F, 0x7B, 0x73, 0x63, 0x63, 0x00},// U+004E (N)
+            {0x1C, 0x36, 0x63, 0x63, 0x63, 0x36, 0x1C, 0x00},// U+004F (O)
+            {0x3F, 0x66, 0x66, 0x3E, 0x06, 0x06, 0x0F, 0x00},// U+0050 (P)
+            {0x1E, 0x33, 0x33, 0x33, 0x3B, 0x1E, 0x38, 0x00},// U+0051 (Q)
+            {0x3F, 0x66, 0x66, 0x3E, 0x36, 0x66, 0x67, 0x00},// U+0052 (R)
+            {0x1E, 0x33, 0x07, 0x0E, 0x38, 0x33, 0x1E, 0x00},// U+0053 (S)
+            {0x3F, 0x2D, 0x0C, 0x0C, 0x0C, 0x0C, 0x1E, 0x00},// U+0054 (T)
+            {0x33, 0x33, 0x33, 0x33, 0x33, 0x33, 0x3F, 0x00},// U+0055 (U)
+            {0x33, 0x33, 0x33, 0x33, 0x33, 0x1E, 0x0C, 0x00},// U+0056 (V)
+            {0x63, 0x63, 0x63, 0x6B, 0x7F, 0x77, 0x63, 0x00},// U+0057 (W)
+            {0x63, 0x63, 0x36, 0x1C, 0x1C, 0x36, 0x63, 0x00},// U+0058 (X)
+            {0x33, 0x33, 0x33, 0x1E, 0x0C, 0x0C, 0x1E, 0x00},// U+0059 (Y)
+            {0x7F, 0x63, 0x31, 0x18, 0x4C, 0x66, 0x7F, 0x00},// U+005A (Z)
+            {0x1E, 0x06, 0x06, 0x06, 0x06, 0x06, 0x1E, 0x00},// U+005B ([)
+            {0x03, 0x06, 0x0C, 0x18, 0x30, 0x60, 0x40, 0x00},// U+005C (\)
+            {0x1E, 0x18, 0x18, 0x18, 0x18, 0x18, 0x1E, 0x00},// U+005D (])
+            {0x08, 0x1C, 0x36, 0x63, 0x00, 0x00, 0x00, 0x00},// U+005E (^)
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xFF},// U+005F (_)
+            {0x0C, 0x0C, 0x18, 0x00, 0x00, 0x00, 0x00, 0x00},// U+0060 (`)
+            {0x00, 0x00, 0x1E, 0x30, 0x3E, 0x33, 0x6E, 0x00},// U+0061 (a)
+            {0x07, 0x06, 0x06, 0x3E, 0x66, 0x66, 0x3B, 0x00},// U+0062 (b)
+            {0x00, 0x00, 0x1E, 0x33, 0x03, 0x33, 0x1E, 0x00},// U+0063 (c)
+            {0x38, 0x30, 0x30, 0x3e, 0x33, 0x33, 0x6E, 0x00},// U+0064 (d)
+            {0x00, 0x00, 0x1E, 0x33, 0x3f, 0x03, 0x1E, 0x00},// U+0065 (e)
+            {0x1C, 0x36, 0x06, 0x0f, 0x06, 0x06, 0x0F, 0x00},// U+0066 (f)
+            {0x00, 0x00, 0x6E, 0x33, 0x33, 0x3E, 0x30, 0x1F},// U+0067 (g)
+            {0x07, 0x06, 0x36, 0x6E, 0x66, 0x66, 0x67, 0x00},// U+0068 (h)
+            {0x0C, 0x00, 0x0E, 0x0C, 0x0C, 0x0C, 0x1E, 0x00},// U+0069 (i)
+            {0x30, 0x00, 0x30, 0x30, 0x30, 0x33, 0x33, 0x1E},// U+006A (j)
+            {0x07, 0x06, 0x66, 0x36, 0x1E, 0x36, 0x67, 0x00},// U+006B (k)
+            {0x0E, 0x0C, 0x0C, 0x0C, 0x0C, 0x0C, 0x1E, 0x00},// U+006C (l)
+            {0x00, 0x00, 0x33, 0x7F, 0x7F, 0x6B, 0x63, 0x00},// U+006D (m)
+            {0x00, 0x00, 0x1F, 0x33, 0x33, 0x33, 0x33, 0x00},// U+006E (n)
+            {0x00, 0x00, 0x1E, 0x33, 0x33, 0x33, 0x1E, 0x00},// U+006F (o)
+            {0x00, 0x00, 0x3B, 0x66, 0x66, 0x3E, 0x06, 0x0F},// U+0070 (p)
+            {0x00, 0x00, 0x6E, 0x33, 0x33, 0x3E, 0x30, 0x78},// U+0071 (q)
+            {0x00, 0x00, 0x3B, 0x6E, 0x66, 0x06, 0x0F, 0x00},// U+0072 (r)
+            {0x00, 0x00, 0x3E, 0x03, 0x1E, 0x30, 0x1F, 0x00},// U+0073 (s)
+            {0x08, 0x0C, 0x3E, 0x0C, 0x0C, 0x2C, 0x18, 0x00},// U+0074 (t)
+            {0x00, 0x00, 0x33, 0x33, 0x33, 0x33, 0x6E, 0x00},// U+0075 (u)
+            {0x00, 0x00, 0x33, 0x33, 0x33, 0x1E, 0x0C, 0x00},// U+0076 (v)
+            {0x00, 0x00, 0x63, 0x6B, 0x7F, 0x7F, 0x36, 0x00},// U+0077 (w)
+            {0x00, 0x00, 0x63, 0x36, 0x1C, 0x36, 0x63, 0x00},// U+0078 (x)
+            {0x00, 0x00, 0x33, 0x33, 0x33, 0x3E, 0x30, 0x1F},// U+0079 (y)
+            {0x00, 0x00, 0x3F, 0x19, 0x0C, 0x26, 0x3F, 0x00},// U+007A (z)
+            {0x38, 0x0C, 0x0C, 0x07, 0x0C, 0x0C, 0x38, 0x00},// U+007B ({)
+            {0x18, 0x18, 0x18, 0x00, 0x18, 0x18, 0x18, 0x00},// U+007C (|)
+            {0x07, 0x0C, 0x0C, 0x38, 0x0C, 0x0C, 0x07, 0x00},// U+007D (})
+            {0x6E, 0x3B, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+007E (~)
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00} // U+007F
+    };
+    return (unsigned long long int *) f[c];
+}
+
+void printc (char c) {
+
+    // for (int i = 0; i < FONT_SIZE; i++) {
+
+    //   unsigned int y = ?;
+    //   unsigned int x = ?;
+    //   drawpx();
+    // }
+};
+
+void printc_location(char c, unsigned int x, unsigned int y) {
+    color_t bg = {0x0, 0x0, 0x0, 0x0};
+    color_t fg = {0xff, 0xff, 0xff, 0xff};
+    unsigned long long int * bitmap = font(c);
+    for (int i = 0; i < FONT_SIZE; i++) {
+        for (int j = 0; j < FONT_SIZE; j++) {
+            bool is_on = bitmap[i] & (1 << FONT_SIZE - j - 1);
+            
+            for (int k = 0; k < 5; k++) {
+                for (int h = 0; h < 5; h++) {
+                    drawpx(((x*k) + i), ((y*h) + j), is_on ? fg : bg);
+                }
+            }
+        }
+    }
+}
\ No newline at end of file
diff --git a/thorn/src/common/screen.c b/thorn/src/common/screen.c
index f16c382..f410612 100644
--- a/thorn/src/common/screen.c
+++ b/thorn/src/common/screen.c
@@ -1,145 +1,4 @@
 #include "common/screen.h"
-#include "common/font.h"
-#define FB_PITCH GPU_COLOUR_DEPTH * GPU_SCREEN_WIDTH
-// static color_t * fb = get_fb();
-
-/* From https://github.com/dhepper/font8x8/blob/master/font8x8_block.h */
-const unsigned long long int * font (int c) {
-    static const char f[128][FONT_SIZE] = {
-            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+0000 (nul)
-            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+0001
-            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+0002
-            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+0003
-            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+0004
-            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+0005
-            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+0006
-            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+0007
-            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+0008
-            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+0009
-            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+000A
-            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+000B
-            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+000C
-            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+000D
-            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+000E
-            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+000F
-            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+0010
-            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+0011
-            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+0012
-            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+0013
-            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+0014
-            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+0015
-            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+0016
-            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+0017
-            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+0018
-            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+0019
-            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+001A
-            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+001B
-            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+001C
-            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+001D
-            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+001E
-            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+001F
-            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+0020 (space)
-            {0x18, 0x3C, 0x3C, 0x18, 0x18, 0x00, 0x18, 0x00},// U+0021 (!)
-            {0x36, 0x36, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+0022 (")
-            {0x36, 0x36, 0x7F, 0x36, 0x7F, 0x36, 0x36, 0x00},// U+0023 (#)
-            {0x0C, 0x3E, 0x03, 0x1E, 0x30, 0x1F, 0x0C, 0x00},// U+0024 ($)
-            {0x00, 0x63, 0x33, 0x18, 0x0C, 0x66, 0x63, 0x00},// U+0025 (%)
-            {0x1C, 0x36, 0x1C, 0x6E, 0x3B, 0x33, 0x6E, 0x00},// U+0026 (&)
-            {0x06, 0x06, 0x03, 0x00, 0x00, 0x00, 0x00, 0x00},// U+0027 (')
-            {0x18, 0x0C, 0x06, 0x06, 0x06, 0x0C, 0x18, 0x00},// U+0028 (()
-            {0x06, 0x0C, 0x18, 0x18, 0x18, 0x0C, 0x06, 0x00},// U+0029 ())
-            {0x00, 0x66, 0x3C, 0xFF, 0x3C, 0x66, 0x00, 0x00},// U+002A (*)
-            {0x00, 0x0C, 0x0C, 0x3F, 0x0C, 0x0C, 0x00, 0x00},// U+002B (+)
-            {0x00, 0x00, 0x00, 0x00, 0x00, 0x0C, 0x0C, 0x06},// U+002C (,)
-            {0x00, 0x00, 0x00, 0x3F, 0x00, 0x00, 0x00, 0x00},// U+002D (-)
-            {0x00, 0x00, 0x00, 0x00, 0x00, 0x0C, 0x0C, 0x00},// U+002E (.)
-            {0x60, 0x30, 0x18, 0x0C, 0x06, 0x03, 0x01, 0x00},// U+002F (/)
-            {0x3E, 0x63, 0x73, 0x7B, 0x6F, 0x67, 0x3E, 0x00},// U+0030 (0)
-            {0x0C, 0x0E, 0x0C, 0x0C, 0x0C, 0x0C, 0x3F, 0x00},// U+0031 (1)
-            {0x1E, 0x33, 0x30, 0x1C, 0x06, 0x33, 0x3F, 0x00},// U+0032 (2)
-            {0x1E, 0x33, 0x30, 0x1C, 0x30, 0x33, 0x1E, 0x00},// U+0033 (3)
-            {0x38, 0x3C, 0x36, 0x33, 0x7F, 0x30, 0x78, 0x00},// U+0034 (4)
-            {0x3F, 0x03, 0x1F, 0x30, 0x30, 0x33, 0x1E, 0x00},// U+0035 (5)
-            {0x1C, 0x06, 0x03, 0x1F, 0x33, 0x33, 0x1E, 0x00},// U+0036 (6)
-            {0x3F, 0x33, 0x30, 0x18, 0x0C, 0x0C, 0x0C, 0x00},// U+0037 (7)
-            {0x1E, 0x33, 0x33, 0x1E, 0x33, 0x33, 0x1E, 0x00},// U+0038 (8)
-            {0x1E, 0x33, 0x33, 0x3E, 0x30, 0x18, 0x0E, 0x00},// U+0039 (9)
-            {0x00, 0x0C, 0x0C, 0x00, 0x00, 0x0C, 0x0C, 0x00},// U+003A (:)
-            {0x00, 0x0C, 0x0C, 0x00, 0x00, 0x0C, 0x0C, 0x06},// U+003B (//)
-            {0x18, 0x0C, 0x06, 0x03, 0x06, 0x0C, 0x18, 0x00},// U+003C (<)
-            {0x00, 0x00, 0x3F, 0x00, 0x00, 0x3F, 0x00, 0x00},// U+003D (=)
-            {0x06, 0x0C, 0x18, 0x30, 0x18, 0x0C, 0x06, 0x00},// U+003E (>)
-            {0x1E, 0x33, 0x30, 0x18, 0x0C, 0x00, 0x0C, 0x00},// U+003F (?)
-            {0x3E, 0x63, 0x7B, 0x7B, 0x7B, 0x03, 0x1E, 0x00},// U+0040 (@)
-            {0x0C, 0x1E, 0x33, 0x33, 0x3F, 0x33, 0x33, 0x00},// U+0041 (A)
-            {0x3F, 0x66, 0x66, 0x3E, 0x66, 0x66, 0x3F, 0x00},// U+0042 (B)
-            {0x3C, 0x66, 0x03, 0x03, 0x03, 0x66, 0x3C, 0x00},// U+0043 (C)
-            {0x1F, 0x36, 0x66, 0x66, 0x66, 0x36, 0x1F, 0x00},// U+0044 (D)
-            {0x7F, 0x46, 0x16, 0x1E, 0x16, 0x46, 0x7F, 0x00},// U+0045 (E)
-            {0x7F, 0x46, 0x16, 0x1E, 0x16, 0x06, 0x0F, 0x00},// U+0046 (F)
-            {0x3C, 0x66, 0x03, 0x03, 0x73, 0x66, 0x7C, 0x00},// U+0047 (G)
-            {0x33, 0x33, 0x33, 0x3F, 0x33, 0x33, 0x33, 0x00},// U+0048 (H)
-            {0x1E, 0x0C, 0x0C, 0x0C, 0x0C, 0x0C, 0x1E, 0x00},// U+0049 (I)
-            {0x78, 0x30, 0x30, 0x30, 0x33, 0x33, 0x1E, 0x00},// U+004A (J)
-            {0x67, 0x66, 0x36, 0x1E, 0x36, 0x66, 0x67, 0x00},// U+004B (K)
-            {0x0F, 0x06, 0x06, 0x06, 0x46, 0x66, 0x7F, 0x00},// U+004C (L)
-            {0x63, 0x77, 0x7F, 0x7F, 0x6B, 0x63, 0x63, 0x00},// U+004D (M)
-            {0x63, 0x67, 0x6F, 0x7B, 0x73, 0x63, 0x63, 0x00},// U+004E (N)
-            {0x1C, 0x36, 0x63, 0x63, 0x63, 0x36, 0x1C, 0x00},// U+004F (O)
-            {0x3F, 0x66, 0x66, 0x3E, 0x06, 0x06, 0x0F, 0x00},// U+0050 (P)
-            {0x1E, 0x33, 0x33, 0x33, 0x3B, 0x1E, 0x38, 0x00},// U+0051 (Q)
-            {0x3F, 0x66, 0x66, 0x3E, 0x36, 0x66, 0x67, 0x00},// U+0052 (R)
-            {0x1E, 0x33, 0x07, 0x0E, 0x38, 0x33, 0x1E, 0x00},// U+0053 (S)
-            {0x3F, 0x2D, 0x0C, 0x0C, 0x0C, 0x0C, 0x1E, 0x00},// U+0054 (T)
-            {0x33, 0x33, 0x33, 0x33, 0x33, 0x33, 0x3F, 0x00},// U+0055 (U)
-            {0x33, 0x33, 0x33, 0x33, 0x33, 0x1E, 0x0C, 0x00},// U+0056 (V)
-            {0x63, 0x63, 0x63, 0x6B, 0x7F, 0x77, 0x63, 0x00},// U+0057 (W)
-            {0x63, 0x63, 0x36, 0x1C, 0x1C, 0x36, 0x63, 0x00},// U+0058 (X)
-            {0x33, 0x33, 0x33, 0x1E, 0x0C, 0x0C, 0x1E, 0x00},// U+0059 (Y)
-            {0x7F, 0x63, 0x31, 0x18, 0x4C, 0x66, 0x7F, 0x00},// U+005A (Z)
-            {0x1E, 0x06, 0x06, 0x06, 0x06, 0x06, 0x1E, 0x00},// U+005B ([)
-            {0x03, 0x06, 0x0C, 0x18, 0x30, 0x60, 0x40, 0x00},// U+005C (\)
-            {0x1E, 0x18, 0x18, 0x18, 0x18, 0x18, 0x1E, 0x00},// U+005D (])
-            {0x08, 0x1C, 0x36, 0x63, 0x00, 0x00, 0x00, 0x00},// U+005E (^)
-            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xFF},// U+005F (_)
-            {0x0C, 0x0C, 0x18, 0x00, 0x00, 0x00, 0x00, 0x00},// U+0060 (`)
-            {0x00, 0x00, 0x1E, 0x30, 0x3E, 0x33, 0x6E, 0x00},// U+0061 (a)
-            {0x07, 0x06, 0x06, 0x3E, 0x66, 0x66, 0x3B, 0x00},// U+0062 (b)
-            {0x00, 0x00, 0x1E, 0x33, 0x03, 0x33, 0x1E, 0x00},// U+0063 (c)
-            {0x38, 0x30, 0x30, 0x3e, 0x33, 0x33, 0x6E, 0x00},// U+0064 (d)
-            {0x00, 0x00, 0x1E, 0x33, 0x3f, 0x03, 0x1E, 0x00},// U+0065 (e)
-            {0x1C, 0x36, 0x06, 0x0f, 0x06, 0x06, 0x0F, 0x00},// U+0066 (f)
-            {0x00, 0x00, 0x6E, 0x33, 0x33, 0x3E, 0x30, 0x1F},// U+0067 (g)
-            {0x07, 0x06, 0x36, 0x6E, 0x66, 0x66, 0x67, 0x00},// U+0068 (h)
-            {0x0C, 0x00, 0x0E, 0x0C, 0x0C, 0x0C, 0x1E, 0x00},// U+0069 (i)
-            {0x30, 0x00, 0x30, 0x30, 0x30, 0x33, 0x33, 0x1E},// U+006A (j)
-            {0x07, 0x06, 0x66, 0x36, 0x1E, 0x36, 0x67, 0x00},// U+006B (k)
-            {0x0E, 0x0C, 0x0C, 0x0C, 0x0C, 0x0C, 0x1E, 0x00},// U+006C (l)
-            {0x00, 0x00, 0x33, 0x7F, 0x7F, 0x6B, 0x63, 0x00},// U+006D (m)
-            {0x00, 0x00, 0x1F, 0x33, 0x33, 0x33, 0x33, 0x00},// U+006E (n)
-            {0x00, 0x00, 0x1E, 0x33, 0x33, 0x33, 0x1E, 0x00},// U+006F (o)
-            {0x00, 0x00, 0x3B, 0x66, 0x66, 0x3E, 0x06, 0x0F},// U+0070 (p)
-            {0x00, 0x00, 0x6E, 0x33, 0x33, 0x3E, 0x30, 0x78},// U+0071 (q)
-            {0x00, 0x00, 0x3B, 0x6E, 0x66, 0x06, 0x0F, 0x00},// U+0072 (r)
-            {0x00, 0x00, 0x3E, 0x03, 0x1E, 0x30, 0x1F, 0x00},// U+0073 (s)
-            {0x08, 0x0C, 0x3E, 0x0C, 0x0C, 0x2C, 0x18, 0x00},// U+0074 (t)
-            {0x00, 0x00, 0x33, 0x33, 0x33, 0x33, 0x6E, 0x00},// U+0075 (u)
-            {0x00, 0x00, 0x33, 0x33, 0x33, 0x1E, 0x0C, 0x00},// U+0076 (v)
-            {0x00, 0x00, 0x63, 0x6B, 0x7F, 0x7F, 0x36, 0x00},// U+0077 (w)
-            {0x00, 0x00, 0x63, 0x36, 0x1C, 0x36, 0x63, 0x00},// U+0078 (x)
-            {0x00, 0x00, 0x33, 0x33, 0x33, 0x3E, 0x30, 0x1F},// U+0079 (y)
-            {0x00, 0x00, 0x3F, 0x19, 0x0C, 0x26, 0x3F, 0x00},// U+007A (z)
-            {0x38, 0x0C, 0x0C, 0x07, 0x0C, 0x0C, 0x38, 0x00},// U+007B ({)
-            {0x18, 0x18, 0x18, 0x00, 0x18, 0x18, 0x18, 0x00},// U+007C (|)
-            {0x07, 0x0C, 0x0C, 0x38, 0x0C, 0x0C, 0x07, 0x00},// U+007D (})
-            {0x6E, 0x3B, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+007E (~)
-            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00} // U+007F
-    };
-    return (unsigned long long int *) f[c];
-}
-
-
-void printc (char c) {};
 
 void drawpx (unsigned int x, unsigned int y, color_t color) {
     unsigned long int location = y * (get_fb_info ()->pitch) / sizeof (color_t) + x;
diff --git a/thorn/src/kernel/kernel.c b/thorn/src/kernel/kernel.c
index 7d06db2..ce291df 100644
--- a/thorn/src/kernel/kernel.c
+++ b/thorn/src/kernel/kernel.c
@@ -120,14 +120,9 @@ void kernel_main (int processor_id) {
         }
         case 1:
             if (get_fb ()) {
-                color_t color = {0xff, 0xff, 0xff, 0xff};
-                for (int i = 0; i < get_max_height (); i++) {
-                    drawpx (i, i, color);
+                for (int i = 0; i < 128; i++) {
+                    printc_location(i, i*8, 0);
                 }
-                drawpx (0, 0, color);
-                drawpx (get_max_width (), 0, color);
-                drawpx (0, get_max_height (), color);
-                drawpx (get_max_width (), get_max_height (), color);
             }
             break;
         case 2:

From f0e492eebda81a7e371a019d8191c052689878cc Mon Sep 17 00:00:00 2001
From: Aaron Alef <aaron.alef@code.berlin>
Date: Thu, 21 Oct 2021 15:01:43 +0200
Subject: [PATCH 49/61] feat(font): configure printf to print to screen

---
 thorn/include/common/font.h | 14 ++++++++--
 thorn/src/common/font.c     | 55 +++++++++++++++++++++++--------------
 thorn/src/kernel/kernel.c   | 27 +++++++-----------
 3 files changed, 57 insertions(+), 39 deletions(-)

diff --git a/thorn/include/common/font.h b/thorn/include/common/font.h
index 3a2e4e9..84c1989 100644
--- a/thorn/include/common/font.h
+++ b/thorn/include/common/font.h
@@ -1,11 +1,21 @@
 #ifndef _ROSE_C_FONT_H
 #define _ROSE_C_FONT_H
 
-#define FONT_SIZE 8 * 5
+#define FONT_SIZE   8
+#define FONT_FACTOR 2
+
+// Spacing between lines in pixels
+#define FONT_SPACING 4
 
 #include "common/screen.h"
 
+static int cursor_x = 0;
+static int cursor_y = 0;
+
 const unsigned long long int * font (int c);
-void printc_location(char c, unsigned int x, unsigned int y);
+void                           printc (char c);
+void                           printc_location (char c, unsigned int x, unsigned int y);
+
+void putc_screen (void * p, char c);
 
 #endif
diff --git a/thorn/src/common/font.c b/thorn/src/common/font.c
index 9ed177a..1e721b5 100644
--- a/thorn/src/common/font.c
+++ b/thorn/src/common/font.c
@@ -135,29 +135,44 @@ const unsigned long long int * font (int c) {
     return (unsigned long long int *) f[c];
 }
 
-void printc (char c) {
-
-    // for (int i = 0; i < FONT_SIZE; i++) {
-
-    //   unsigned int y = ?;
-    //   unsigned int x = ?;
-    //   drawpx();
-    // }
-};
-
-void printc_location(char c, unsigned int x, unsigned int y) {
-    color_t bg = {0x0, 0x0, 0x0, 0x0};
-    color_t fg = {0xff, 0xff, 0xff, 0xff};
-    unsigned long long int * bitmap = font(c);
+void printc_location (char c, unsigned int x, unsigned int y) {
+    color_t               bg     = {0x0, 0x0, 0x0, 0xff};
+    color_t               fg     = {0xff, 0xff, 0xff, 0xff};
+    unsigned char const * bitmap = font (c);
     for (int i = 0; i < FONT_SIZE; i++) {
         for (int j = 0; j < FONT_SIZE; j++) {
-            bool is_on = bitmap[i] & (1 << FONT_SIZE - j - 1);
-            
-            for (int k = 0; k < 5; k++) {
-                for (int h = 0; h < 5; h++) {
-                    drawpx(((x*k) + i), ((y*h) + j), is_on ? fg : bg);
+            bool is_on = bitmap[i] & (1 << j);
+
+            int _x, _y;
+            for (int k = 0; k < FONT_FACTOR; k++) {
+                for (int h = 0; h < FONT_FACTOR; h++) {
+                    _x = x + j * FONT_FACTOR + k;
+                    _y = y + i * FONT_FACTOR + h;
+                    drawpx (_x, _y, is_on ? fg : bg);
                 }
             }
         }
     }
-}
\ No newline at end of file
+}
+
+void printc (char c) {
+    printc_location (c, cursor_x, cursor_y);
+    cursor_x += FONT_SIZE * FONT_FACTOR;
+    if (c == '\r') {
+        cursor_x = 0;
+    } else if (c == '\n') {
+        cursor_y += FONT_SIZE * FONT_FACTOR + FONT_SPACING;
+    } else {
+        if (cursor_x >= get_max_width ()) {
+            cursor_x = 0;
+            cursor_y += FONT_SIZE * FONT_FACTOR + FONT_SPACING;
+        }
+    }
+    if (cursor_y >= get_max_height ()) {
+        cursor_y = 0;
+    }
+}
+
+void putc_screen (void * p, char c) {
+    printc (c);
+}
diff --git a/thorn/src/kernel/kernel.c b/thorn/src/kernel/kernel.c
index ce291df..18e88b6 100644
--- a/thorn/src/kernel/kernel.c
+++ b/thorn/src/kernel/kernel.c
@@ -77,18 +77,11 @@ void kernel_init (void) {
             printf ("Error: Invalid Framebuffer received\r\n");
         } else {
             printf ("Received framebuffer: %p\r\n", fb);
+            init_printf (0, putc_screen);
         }
     }
 
     LOG ("Initialisation done");
-
-    printf ("MAX_WIDTH: %d\n\r", get_fb_info ()->virtual_width);
-    printf ("MAX_HEIGHT: %d\n\r", get_fb_info ()->virtual_height);
-
-    printf ("GET_MAX_WIDTH: %d\n\r", get_max_width ());
-    printf ("GET_MAX_HEIGHT: %d\n\r", get_max_height ());
-
-    printf ("PITCH: %d\n\r", get_fb_info ()->pitch);
 }
 
 
@@ -102,27 +95,27 @@ void kernel_main (int processor_id) {
     while (processor_id != current_processor)
         ;
 
-    // printf ("Hello, from processor %d\n\r", processor_id);
+    printf ("Hello, from processor %d\n\r", processor_id);
 
     current_processor++;
     while (current_processor != 3)
         ;
     switch (processor_id) {
         case 0: {
-            // int res = copy_process (PF_KTHREAD, (unsigned long) &kernel_process, 0, 0);
-            // if (res < 0) {
-            //     // printf ("error while starting kernel process");
-            //     return;
-            // }
+            int res = copy_process (PF_KTHREAD, (unsigned long) &kernel_process, 0, 0);
+            if (res < 0) {
+                // printf ("error while starting kernel process");
+                return;
+            }
             while (1) {
                 // schedule ();
             }
         }
         case 1:
+            printf ("Width  resolution: %d\n\r", get_fb_info ()->virtual_width);
+            printf ("Height resolution: %d\n\r", get_fb_info ()->virtual_height);
+            printf ("Frame buffer:      %p\n\r", get_fb ());
             if (get_fb ()) {
-                for (int i = 0; i < 128; i++) {
-                    printc_location(i, i*8, 0);
-                }
             }
             break;
         case 2:

From 069e856dd88d69ab03d018eee3969189efa46a3f Mon Sep 17 00:00:00 2001
From: Aaron Alef <aaron.alef@code.berlin>
Date: Thu, 21 Oct 2021 15:13:19 +0200
Subject: [PATCH 50/61] refactor(font): make printing a bit nicer

Also makes the font grey
---
 thorn/include/common/font.h |  9 +++++++--
 thorn/src/common/font.c     |  8 +++-----
 thorn/src/kernel/kernel.c   | 12 +++++-------
 3 files changed, 15 insertions(+), 14 deletions(-)

diff --git a/thorn/include/common/font.h b/thorn/include/common/font.h
index 84c1989..dda8215 100644
--- a/thorn/include/common/font.h
+++ b/thorn/include/common/font.h
@@ -7,14 +7,19 @@
 // Spacing between lines in pixels
 #define FONT_SPACING 4
 
+#include "common/gpu.h"
 #include "common/screen.h"
 
 static int cursor_x = 0;
 static int cursor_y = 0;
 
+static color_t bg = {0x00, 0x00, 0x00, 0x00};
+static color_t fg = {0xC0, 0xC0, 0xC0, 0x00};
+
 const unsigned long long int * font (int c);
-void                           printc (char c);
-void                           printc_location (char c, unsigned int x, unsigned int y);
+
+void printc (char c);
+void printc_location (char c, unsigned int x, unsigned int y);
 
 void putc_screen (void * p, char c);
 
diff --git a/thorn/src/common/font.c b/thorn/src/common/font.c
index 1e721b5..30dc743 100644
--- a/thorn/src/common/font.c
+++ b/thorn/src/common/font.c
@@ -136,9 +136,7 @@ const unsigned long long int * font (int c) {
 }
 
 void printc_location (char c, unsigned int x, unsigned int y) {
-    color_t               bg     = {0x0, 0x0, 0x0, 0xff};
-    color_t               fg     = {0xff, 0xff, 0xff, 0xff};
-    unsigned char const * bitmap = font (c);
+    unsigned char const * bitmap = (unsigned char const *) font (c);
     for (int i = 0; i < FONT_SIZE; i++) {
         for (int j = 0; j < FONT_SIZE; j++) {
             bool is_on = bitmap[i] & (1 << j);
@@ -163,12 +161,12 @@ void printc (char c) {
     } else if (c == '\n') {
         cursor_y += FONT_SIZE * FONT_FACTOR + FONT_SPACING;
     } else {
-        if (cursor_x >= get_max_width ()) {
+        if (cursor_x + FONT_SIZE + FONT_FACTOR >= get_max_width ()) {
             cursor_x = 0;
             cursor_y += FONT_SIZE * FONT_FACTOR + FONT_SPACING;
         }
     }
-    if (cursor_y >= get_max_height ()) {
+    if (cursor_y + FONT_SIZE + FONT_FACTOR >= get_max_height ()) {
         cursor_y = 0;
     }
 }
diff --git a/thorn/src/kernel/kernel.c b/thorn/src/kernel/kernel.c
index 18e88b6..764402e 100644
--- a/thorn/src/kernel/kernel.c
+++ b/thorn/src/kernel/kernel.c
@@ -72,12 +72,13 @@ void kernel_init (void) {
     if (! gpu_status) {
         printf ("Error while initialising Framebuffer\r\n");
     } else {
-        color_t * fb = get_fb ();
-        if (! fb) {
+        if (! get_fb ()) {
             printf ("Error: Invalid Framebuffer received\r\n");
         } else {
-            printf ("Received framebuffer: %p\r\n", fb);
             init_printf (0, putc_screen);
+            printf ("Frame  buffer:     %p\r\n", get_fb ());
+            printf ("Width  resolution: %d\r\n", get_fb_info ()->virtual_width);
+            printf ("Height resolution: %d\r\n", get_fb_info ()->virtual_height);
         }
     }
 
@@ -108,13 +109,10 @@ void kernel_main (int processor_id) {
                 return;
             }
             while (1) {
-                // schedule ();
+                schedule ();
             }
         }
         case 1:
-            printf ("Width  resolution: %d\n\r", get_fb_info ()->virtual_width);
-            printf ("Height resolution: %d\n\r", get_fb_info ()->virtual_height);
-            printf ("Frame buffer:      %p\n\r", get_fb ());
             if (get_fb ()) {
             }
             break;

From 987ff7d6f0c26961e2b75b5ac6761c9d80aaedc1 Mon Sep 17 00:00:00 2001
From: Aaron Alef <aaron.alef@code.berlin>
Date: Tue, 9 Nov 2021 10:29:16 +0100
Subject: [PATCH 51/61] =?UTF-8?q?feat(fan):=20run=20fan=20while=20temperat?=
 =?UTF-8?q?ure=20is=20above=2050=C2=B0C?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 thorn/include/common/temperature.h |  2 +-
 thorn/src/common/temperature.c     | 33 +++++++++++++++++-------------
 thorn/src/kernel/kernel.c          |  6 +-----
 3 files changed, 21 insertions(+), 20 deletions(-)

diff --git a/thorn/include/common/temperature.h b/thorn/include/common/temperature.h
index 883edbf..9f978b9 100644
--- a/thorn/include/common/temperature.h
+++ b/thorn/include/common/temperature.h
@@ -2,8 +2,8 @@
 #define _ROSE_C_TEMPERATURE_H
 
 #include "common/stdbool.h"
+#include "kernel/gpio.h"
 #include "kernel/mailbox.h"
-#include "kernel/peripherals/gpio.h"
 
 #define GPIO_FAN 18
 
diff --git a/thorn/src/common/temperature.c b/thorn/src/common/temperature.c
index d1abf73..5889e4c 100644
--- a/thorn/src/common/temperature.c
+++ b/thorn/src/common/temperature.c
@@ -1,6 +1,7 @@
 #include "common/temperature.h"
 
 bool init_temperature () {
+    gpio_mode (GPIO_FAN, GPIO_OUTPUT);
     {                                // Read out maximum temperature
         int c                    = 0;// Message size; increment while we write
         temperature_request[++c] = 0;// Response - will be 0x80000000 for SUCCESS or 0x80000001 for FAILURE
@@ -17,7 +18,7 @@ bool init_temperature () {
         temperature_request[0] = (4 * ++c);// Write message size at the beginning of the buffer
 
         // If reading maximum temperature fails, keep default
-        if (! mailbox_request (temperature_request, PROPERTY_ARM_VC))
+        if (!mailbox_request (temperature_request, PROPERTY_ARM_VC))
             return false;
         // Else update temperature
         max_temperature = temperature_request[index_max_temperature] ?: TEMPERATURE_MAX;
@@ -30,19 +31,23 @@ bool init_temperature () {
 void regulate_temperature () {
     static int fan      = 1;
     static int previous = TEMPERATURE_SHOULD;
-    int        current  = get_temperature ();
-    printf ("\rCurrent temperature: %d °C. Change since last iteration: %d °mC    ", current / 1000,
-            (current - previous));
-
-    if (current < TEMPERATURE_SHOULD) {
-        fan = 0;
-    } else {
-        fan = 1;
-    }
+    while (1) {
+        int current = get_temperature ();
+        printf ("\rCurrent temperature: %d °C. Change since last iteration: %d °mC    ", current / 1000,
+                (current - previous));
+
+        if (current < TEMPERATURE_SHOULD) {
+            fan = 0;
+        } else {
+            fan = 1;
+        }
 
-    set_fan (fan);
+        set_fan (fan);
 
-    previous = current;
+        previous = current;
+
+        delay (TEMPERATURE_CHECK_DELAY);
+    }
 }
 
 int get_max_temperature () {
@@ -66,7 +71,7 @@ int get_temperature () {
         temperature_request[0] = (4 * ++c);// Write message size at the beginning of the buffer
 
         // If reading maximum temperature fails, keep default
-        if (! mailbox_request (temperature_request, PROPERTY_ARM_VC))
+        if (!mailbox_request (temperature_request, PROPERTY_ARM_VC))
             return max_temperature;
         // Else return temperature
         return temperature_request[index_temperature];
@@ -74,5 +79,5 @@ int get_temperature () {
 }
 
 void set_fan (bool enable) {
-    printf ("set fan %d   \r", enable);
+    gpio_set (GPIO_FAN, !enable);
 }
\ No newline at end of file
diff --git a/thorn/src/kernel/kernel.c b/thorn/src/kernel/kernel.c
index 70b963b..9d71569 100644
--- a/thorn/src/kernel/kernel.c
+++ b/thorn/src/kernel/kernel.c
@@ -125,16 +125,12 @@ void kernel_main (int processor_id) {
             break;
         }
         case 1:
-            while (1) {
-                regulate_temperature ();
-                delay (TEMPERATURE_CHECK_DELAY);
-            }
+            regulate_temperature ();
             break;
         case 2:
             while (get_fb ()) {
                 // Do screen work here
             }
-            break;
         case 3:
         default:
             while (1) {}

From d93a7ba40378c6902583b698fdf5f71932a62b44 Mon Sep 17 00:00:00 2001
From: Aaron Alef <aaron.alef@code.berlin>
Date: Tue, 9 Nov 2021 10:48:03 +0100
Subject: [PATCH 52/61] feat(fan): regulate fan in kernel process

---
 thorn/include/common/temperature.h | 1 +
 thorn/src/common/temperature.c     | 7 ++++---
 thorn/src/kernel/kernel.c          | 6 ++----
 3 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/thorn/include/common/temperature.h b/thorn/include/common/temperature.h
index 9f978b9..d5b36e0 100644
--- a/thorn/include/common/temperature.h
+++ b/thorn/include/common/temperature.h
@@ -2,6 +2,7 @@
 #define _ROSE_C_TEMPERATURE_H
 
 #include "common/stdbool.h"
+#include "kernel/fork.h"
 #include "kernel/gpio.h"
 #include "kernel/mailbox.h"
 
diff --git a/thorn/src/common/temperature.c b/thorn/src/common/temperature.c
index 5889e4c..ebb1b0c 100644
--- a/thorn/src/common/temperature.c
+++ b/thorn/src/common/temperature.c
@@ -25,6 +25,7 @@ bool init_temperature () {
     }
 
     // Start regulate_temperature service here
+    copy_process (PF_KTHREAD, (unsigned long) &regulate_temperature, 0, 0);
     return true;
 }
 
@@ -36,10 +37,10 @@ void regulate_temperature () {
         printf ("\rCurrent temperature: %d °C. Change since last iteration: %d °mC    ", current / 1000,
                 (current - previous));
 
-        if (current < TEMPERATURE_SHOULD) {
-            fan = 0;
-        } else {
+        if (current >= TEMPERATURE_SHOULD) {
             fan = 1;
+        } else if (current < TEMPERATURE_SHOULD - 2000) {
+            fan = 0;
         }
 
         set_fan (fan);
diff --git a/thorn/src/kernel/kernel.c b/thorn/src/kernel/kernel.c
index 9d71569..63b6cf1 100644
--- a/thorn/src/kernel/kernel.c
+++ b/thorn/src/kernel/kernel.c
@@ -120,17 +120,15 @@ void kernel_main (int processor_id) {
             //                break;
             //            }
             while (1) {
-                //                schedule ();
+                schedule ();
             }
             break;
         }
         case 1:
-            regulate_temperature ();
-            break;
-        case 2:
             while (get_fb ()) {
                 // Do screen work here
             }
+        case 2:
         case 3:
         default:
             while (1) {}

From b7ce1c1a71c07bf90f326b88e6dbf696d223efd8 Mon Sep 17 00:00:00 2001
From: Aaron Alef <aaron.alef@code.berlin>
Date: Tue, 9 Nov 2021 11:46:28 +0100
Subject: [PATCH 53/61] feat(font): replace font with extended ascii font

---
 thorn/include/common/font.h |   6 +-
 thorn/src/common/font.c     | 116 +++++++++++++++++++++++++++++++++---
 2 files changed, 113 insertions(+), 9 deletions(-)

diff --git a/thorn/include/common/font.h b/thorn/include/common/font.h
index b732416..e28b335 100644
--- a/thorn/include/common/font.h
+++ b/thorn/include/common/font.h
@@ -2,7 +2,7 @@
 #define _ROSE_C_FONT_H
 
 #define FONT_SIZE       8
-#define FONT_FACTOR     2
+#define FONT_FACTOR     4
 #define FONT_REAL_WIDTH (FONT_SIZE * FONT_FACTOR)
 
 // Spacing between lines in pixels
@@ -20,6 +20,7 @@
 
 #include "common/gpu.h"
 #include "common/screen.h"
+#include "kernel/mini_uart.h"
 #include "kernel/mm.h"
 
 static point_t cursor = {0, 0};
@@ -29,10 +30,11 @@ static volatile color_t font_normal_fg = {0xC0, 0xC0, 0xC0, 0x00};
 static volatile color_t font_error_fg  = {0x00, 0x00, 0xC0, 0x00};
 static volatile color_t font_fg;
 
-const unsigned long long int * font (int c);
+unsigned char const * font (unsigned char c);
 
 void printc (char c);
 void printc_location (point_t point, char c);
+void prints_location (point_t point, char const * s);
 
 void putc_screen (void * p, char c);
 
diff --git a/thorn/src/common/font.c b/thorn/src/common/font.c
index 86addf5..532bec5 100644
--- a/thorn/src/common/font.c
+++ b/thorn/src/common/font.c
@@ -1,9 +1,9 @@
 #include "common/font.h"
 
 /* From https://github.com/dhepper/font8x8/blob/master/font8x8_block.h */
-const unsigned long long int * font (int c) {
-    static const char f[128][FONT_SIZE] = {
-            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+0000 (nul)
+unsigned char const * font (unsigned char c) {
+    static unsigned char const f[256][FONT_SIZE] = {
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+0000
             {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+0001
             {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+0002
             {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+0003
@@ -62,7 +62,7 @@ const unsigned long long int * font (int c) {
             {0x1E, 0x33, 0x33, 0x1E, 0x33, 0x33, 0x1E, 0x00},// U+0038 (8)
             {0x1E, 0x33, 0x33, 0x3E, 0x30, 0x18, 0x0E, 0x00},// U+0039 (9)
             {0x00, 0x0C, 0x0C, 0x00, 0x00, 0x0C, 0x0C, 0x00},// U+003A (:)
-            {0x00, 0x0C, 0x0C, 0x00, 0x00, 0x0C, 0x0C, 0x06},// U+003B (//)
+            {0x00, 0x0C, 0x0C, 0x00, 0x00, 0x0C, 0x0C, 0x06},// U+003B (;)
             {0x18, 0x0C, 0x06, 0x03, 0x06, 0x0C, 0x18, 0x00},// U+003C (<)
             {0x00, 0x00, 0x3F, 0x00, 0x00, 0x3F, 0x00, 0x00},// U+003D (=)
             {0x06, 0x0C, 0x18, 0x30, 0x18, 0x0C, 0x06, 0x00},// U+003E (>)
@@ -130,13 +130,109 @@ const unsigned long long int * font (int c) {
             {0x18, 0x18, 0x18, 0x00, 0x18, 0x18, 0x18, 0x00},// U+007C (|)
             {0x07, 0x0C, 0x0C, 0x38, 0x0C, 0x0C, 0x07, 0x00},// U+007D (})
             {0x6E, 0x3B, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+007E (~)
-            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00} // U+007F
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},// U+007F
+            {0x1E, 0x33, 0x03, 0x33, 0x1E, 0x18, 0x30, 0x1E},// U+00C7 (C cedille)
+            {0x00, 0x33, 0x00, 0x33, 0x33, 0x33, 0x7E, 0x00},// U+00FC (u umlaut)
+            {0x38, 0x00, 0x1E, 0x33, 0x3F, 0x03, 0x1E, 0x00},// U+00E9 (e aigu)
+            {0x7E, 0xC3, 0x3C, 0x60, 0x7C, 0x66, 0xFC, 0x00},// U+00E2 (a circumflex)
+            {0x33, 0x00, 0x1E, 0x30, 0x3E, 0x33, 0x7E, 0x00},// U+00E4 (a umlaut)
+            {0x07, 0x00, 0x1E, 0x30, 0x3E, 0x33, 0x7E, 0x00},// U+00E0 (a grave)
+            {0x0C, 0x0C, 0x1E, 0x30, 0x3E, 0x33, 0x7E, 0x00},// U+00E5 (a ring)
+            {0x00, 0x00, 0x1E, 0x03, 0x03, 0x1E, 0x30, 0x1C},// U+00E7 (c cedille)
+            {0x7E, 0xC3, 0x3C, 0x66, 0x7E, 0x06, 0x3C, 0x00},// U+00EA (e circumflex)
+            {0x33, 0x00, 0x1E, 0x33, 0x3F, 0x03, 0x1E, 0x00},// U+00EB (e umlaut)
+            {0x07, 0x00, 0x1E, 0x33, 0x3F, 0x03, 0x1E, 0x00},// U+00E8 (e grave)
+            {0x33, 0x00, 0x0E, 0x0C, 0x0C, 0x0C, 0x1E, 0x00},// U+00EF (i umlaut)
+            {0x3E, 0x63, 0x1C, 0x18, 0x18, 0x18, 0x3C, 0x00},// U+00EE (i circumflex)
+            {0x07, 0x00, 0x0E, 0x0C, 0x0C, 0x0C, 0x1E, 0x00},// U+00EC (i grave)
+            {0x63, 0x1C, 0x36, 0x63, 0x7F, 0x63, 0x63, 0x00},// U+00C4 (A umlaut)
+            {0x0C, 0x0C, 0x00, 0x1E, 0x33, 0x3F, 0x33, 0x00},// U+00C5 (A ring)
+            {0x07, 0x00, 0x3F, 0x06, 0x1E, 0x06, 0x3F, 0x00},// U+00C8 (E grave)
+            {0x00, 0x00, 0xFE, 0x30, 0xFE, 0x33, 0xFE, 0x00},// U+00E6 (ae)
+            {0x7C, 0x36, 0x33, 0x7F, 0x33, 0x33, 0x73, 0x00},// U+00C6 (AE)
+            {0x1E, 0x33, 0x00, 0x1E, 0x33, 0x33, 0x1E, 0x00},// U+00F4 (o circumflex)
+            {0x00, 0x33, 0x00, 0x1E, 0x33, 0x33, 0x1E, 0x00},// U+00F6 (o umlaut)
+            {0x00, 0x07, 0x00, 0x1E, 0x33, 0x33, 0x1E, 0x00},// U+00F2 (o grave)
+            {0x1E, 0x33, 0x00, 0x33, 0x33, 0x33, 0x7E, 0x00},// U+00FB (u circumflex)
+            {0x00, 0x07, 0x00, 0x33, 0x33, 0x33, 0x7E, 0x00},// U+00F9 (u grave)
+            {0x00, 0x33, 0x00, 0x33, 0x33, 0x3E, 0x30, 0x1F},// U+00FF (y umlaut)
+            {0xC3, 0x18, 0x3C, 0x66, 0x66, 0x3C, 0x18, 0x00},// U+00D6 (O umlaut)
+            {0x33, 0x00, 0x33, 0x33, 0x33, 0x33, 0x1E, 0x00},// U+00DC (U umlaut)
+            {0x18, 0x18, 0x7E, 0x03, 0x03, 0x7E, 0x18, 0x18},// U+00A2 (dollarcents)
+            {0x1C, 0x36, 0x26, 0x0F, 0x06, 0x67, 0x3F, 0x00},// U+00A3 (pound sterling)
+            {0x33, 0x33, 0x1E, 0x3F, 0x0C, 0x3F, 0x0C, 0x0C},// U+00A5 (yen)
+            {0x7C, 0xC6, 0x1C, 0x36, 0x36, 0x1C, 0x33, 0x1E},// U+00A7 (paragraph)
+            {0x70, 0xD8, 0x18, 0x3C, 0x18, 0x18, 0x1B, 0x0E},// U+0192 (dutch florijn)
+            {0x38, 0x00, 0x1E, 0x30, 0x3E, 0x33, 0x7E, 0x00},// U+00E1 (a aigu)
+            {0x1C, 0x00, 0x0E, 0x0C, 0x0C, 0x0C, 0x1E, 0x00},// U+00ED (i augu)
+            {0x00, 0x38, 0x00, 0x1E, 0x33, 0x33, 0x1E, 0x00},// U+00F3 (o aigu)
+            {0x00, 0x38, 0x00, 0x33, 0x33, 0x33, 0x7E, 0x00},// U+00FA (u aigu)
+            {0x00, 0x1F, 0x00, 0x1F, 0x33, 0x33, 0x33, 0x00},// U+00F1 (n ~)
+            {0x3F, 0x00, 0x33, 0x37, 0x3F, 0x3B, 0x33, 0x00},// U+00D1 (N ~)
+            {0x3C, 0x36, 0x36, 0x7C, 0x00, 0x00, 0x00, 0x00},// U+00AA (superscript a)
+            {0x1C, 0x36, 0x36, 0x1C, 0x00, 0x00, 0x00, 0x00},// U+00BA (superscript 0)
+            {0x0C, 0x00, 0x0C, 0x06, 0x03, 0x33, 0x1E, 0x00},// U+00BF (inverted ?)
+            {0x00, 0x00, 0x00, 0x3F, 0x03, 0x03, 0x00, 0x00},// U+2310 (gun pointing right)
+            {0x00, 0x00, 0x00, 0x3F, 0x30, 0x30, 0x00, 0x00},// U+00AC (gun pointing left)
+            {0xC3, 0x63, 0x33, 0x7B, 0xCC, 0x66, 0x33, 0xF0},// U+00BD (1/2)
+            {0xC3, 0x63, 0x33, 0xBD, 0xEC, 0xF6, 0xF3, 0x03},// U+00BC (1/4)
+            {0x18, 0x18, 0x00, 0x18, 0x18, 0x18, 0x18, 0x00},// U+00A1 (inverted !)
+            {0x00, 0xCC, 0x66, 0x33, 0x66, 0xCC, 0x00, 0x00},// U+00AB (<<)
+            {0x00, 0x33, 0x66, 0xCC, 0x66, 0x33, 0x00, 0x00},// U+00BB (>>)
+            {0x55, 0x00, 0xAA, 0x00, 0x55, 0x00, 0xAA, 0x00},// U+2591 (25% solid)
+            {0x55, 0xAA, 0x55, 0xAA, 0x55, 0xAA, 0x55, 0xAA},// U+2592 (50% solid)
+            {0xFF, 0xAA, 0xFF, 0x55, 0xFF, 0xAA, 0xFF, 0x55},// U+2593 (75% solid)
+            {0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08},// U+2502 (thin vertical)
+            {0x08, 0x08, 0x08, 0x08, 0x0f, 0x08, 0x08, 0x08},// U+2524 (down L, left L, up L)
+            {0x08, 0x08, 0x08, 0x0F, 0x08, 0x0F, 0x08, 0x08},// U+2561 (up L, down L, left D)
+            {0x14, 0x14, 0x14, 0x14, 0x17, 0x14, 0x14, 0x14},// U+2562 (up D, down D, left L)
+            {0x00, 0x00, 0x00, 0x00, 0x1F, 0x14, 0x14, 0x14},// U+2556 (down D, left L)
+            {0x00, 0x00, 0x00, 0x0F, 0x08, 0x0F, 0x08, 0x08},// U+2555 (down L, left D)
+            {0x14, 0x14, 0x14, 0x17, 0x10, 0x17, 0x14, 0x14},// U+2563 (up D, down D, left D)
+            {0x14, 0x14, 0x14, 0x14, 0x14, 0x14, 0x14, 0x14},// U+2551 (double vertical)
+            {0x00, 0x00, 0x00, 0x1F, 0x10, 0x17, 0x14, 0x14},// U+2557 (down D, left D)
+            {0x14, 0x14, 0x14, 0x17, 0x10, 0x1F, 0x00, 0x00},// U+255D (up D, left D)
+            {0x14, 0x14, 0x14, 0x14, 0x1F, 0x00, 0x00, 0x00},// U+255C (up D, left L)
+            {0x08, 0x08, 0x08, 0x0F, 0x08, 0x0F, 0x00, 0x00},// U+255B (up L, left D)
+            {0x00, 0x00, 0x00, 0x00, 0x0f, 0x08, 0x08, 0x08},// U+2510 (down L, left L)
+            {0x08, 0x08, 0x08, 0x08, 0xf8, 0x00, 0x00, 0x00},// U+2514 (up L, right L)
+            {0x08, 0x08, 0x08, 0x08, 0xff, 0x00, 0x00, 0x00},// U+2534 (up L, right L, left L)
+            {0x00, 0x00, 0x00, 0x00, 0xff, 0x08, 0x08, 0x08},// U+252C (down L, right L, left L)
+            {0x08, 0x08, 0x08, 0x08, 0xf8, 0x08, 0x08, 0x08},// U+251C (down L, right L, up L)
+            {0x00, 0x00, 0x00, 0x00, 0xFF, 0x00, 0x00, 0x00},// U+2500 (thin horizontal)
+            {0x08, 0x08, 0x08, 0x08, 0xff, 0x08, 0x08, 0x08},// U+253C (up L, right L, left L, down L)
+            {0x08, 0x08, 0x08, 0xF8, 0x08, 0xF8, 0x08, 0x08},// U+255E (up L, down L, right D)
+            {0x14, 0x14, 0x14, 0x14, 0xF4, 0x14, 0x14, 0x14},// U+255F (up D, down D, right L)
+            {0x14, 0x14, 0x14, 0xF4, 0x04, 0xFC, 0x00, 0x00},// U+255A (up D, right D)
+            {0x00, 0x00, 0x00, 0xFC, 0x04, 0xF4, 0x14, 0x14},// U+2554 (down D, right D)
+            {0x14, 0x14, 0x14, 0xF7, 0x00, 0xFF, 0x00, 0x00},// U+2569 (left D, right D, up D)
+            {0x00, 0x00, 0x00, 0xFF, 0x00, 0xF7, 0x14, 0x14},// U+2566 (left D, right D, down D)
+            {0x14, 0x14, 0x14, 0xF4, 0x04, 0xF4, 0x14, 0x14},// U+2560 (up D, down D, right D)
+            {0x00, 0x00, 0x00, 0xFF, 0x00, 0xFF, 0x00, 0x00},// U+2550 (double horizontal)
+            {0x14, 0x14, 0x14, 0xF7, 0x00, 0xF7, 0x14, 0x14},// U+256C (left D, right D, down D, up D)
+            {0x08, 0x08, 0x08, 0xFF, 0x00, 0xFF, 0x00, 0x00},// U+2567 (left D, right D, up L)
+            {0x14, 0x14, 0x14, 0x14, 0xFF, 0x00, 0x00, 0x00},// U+2568 (left L, right L, up D)
+            {0x00, 0x00, 0x00, 0xFF, 0x00, 0xFF, 0x08, 0x08},// U+2564 (left D, right D, down L)
+            {0x00, 0x00, 0x00, 0x00, 0xFF, 0x14, 0x14, 0x14},// U+2565 (left L, right L, down D)
+            {0x14, 0x14, 0x14, 0x14, 0xFC, 0x00, 0x00, 0x00},// U+2559 (up D, right L)
+            {0x08, 0x08, 0x08, 0xF8, 0x08, 0xF8, 0x00, 0x00},// U+2558 (up L, right D)
+            {0x00, 0x00, 0x00, 0xF8, 0x08, 0xF8, 0x08, 0x08},// U+2552 (down L, right D)
+            {0x00, 0x00, 0x00, 0x00, 0xFC, 0x14, 0x14, 0x14},// U+2553 (down D, right L)
+            {0x14, 0x14, 0x14, 0x14, 0xFF, 0x14, 0x14, 0x14},// U+256B (left L, right L, down D, up D)
+            {0x08, 0x08, 0x08, 0xFF, 0x08, 0xFF, 0x08, 0x08},// U+256A (left D, right D, down L, up L)
+            {0x08, 0x08, 0x08, 0x08, 0x0f, 0x00, 0x00, 0x00},// U+2518 (up L, left L)
+            {0x00, 0x00, 0x00, 0x00, 0xf8, 0x08, 0x08, 0x08},// U+250C (down L, right L)
+            {0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF},// U+2588 (solid)
+            {0x00, 0x00, 0x00, 0x00, 0xFF, 0xFF, 0xFF, 0xFF},// U+2584 (bottom half)
+            {0x0F, 0x0F, 0x0F, 0x0F, 0x0F, 0x0F, 0x0F, 0x0F},// U+258C (left half)
+            {0xF0, 0xF0, 0xF0, 0xF0, 0xF0, 0xF0, 0xF0, 0xF0},// U+2590 (right half)
+            {0xFF, 0xFF, 0xFF, 0xFF, 0x00, 0x00, 0x00, 0x00},// U+2580 (top half)
     };
-    return (unsigned long long int *) f[c];
+    return f[c];
 }
 
 void printc_location (point_t point, char c) {
-    unsigned char const * bitmap = (unsigned char const *) font (c);
+    unsigned char const * bitmap = font (c);
     for (int i = 0; i < FONT_SIZE; i++) {
         for (int j = 0; j < FONT_SIZE; j++) {
             bool is_on = bitmap[i] & (1 << j);
@@ -152,6 +248,12 @@ void printc_location (point_t point, char c) {
         }
     }
 }
+void prints_location (point_t point, char const * s) {
+    while (*s) {
+        printc_location (point, *s++);
+        point.x += FONT_REAL_WIDTH;
+    }
+}
 
 void printc (char c) {
     // Handle special characters, print otherwise

From 08b595db8357456f90df4dd9bd800f1a1159f364 Mon Sep 17 00:00:00 2001
From: Aaron Alef <aaron.alef@code.berlin>
Date: Tue, 9 Nov 2021 12:30:30 +0100
Subject: [PATCH 54/61] =?UTF-8?q?feat(temperature):=20remove=20=C2=B0=20(n?=
 =?UTF-8?q?ot=20working)=20and=20print=20a=20graph=20frame?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 thorn/include/common/font.h        |  2 +-
 thorn/include/common/temperature.h |  4 ++++
 thorn/src/common/font.c            | 23 +++++++++++++++++++++-
 thorn/src/common/temperature.c     | 31 +++++++++++++++++++++---------
 thorn/src/kernel/kernel.c          |  2 +-
 thorn/src/kernel/mini_uart.c       |  4 ++--
 6 files changed, 52 insertions(+), 14 deletions(-)

diff --git a/thorn/include/common/font.h b/thorn/include/common/font.h
index e28b335..b11ad30 100644
--- a/thorn/include/common/font.h
+++ b/thorn/include/common/font.h
@@ -2,7 +2,7 @@
 #define _ROSE_C_FONT_H
 
 #define FONT_SIZE       8
-#define FONT_FACTOR     4
+#define FONT_FACTOR     3
 #define FONT_REAL_WIDTH (FONT_SIZE * FONT_FACTOR)
 
 // Spacing between lines in pixels
diff --git a/thorn/include/common/temperature.h b/thorn/include/common/temperature.h
index d5b36e0..2f5f17f 100644
--- a/thorn/include/common/temperature.h
+++ b/thorn/include/common/temperature.h
@@ -1,6 +1,8 @@
 #ifndef _ROSE_C_TEMPERATURE_H
 #define _ROSE_C_TEMPERATURE_H
 
+#include "common/font.h"
+#include "common/screen.h"
 #include "common/stdbool.h"
 #include "kernel/fork.h"
 #include "kernel/gpio.h"
@@ -34,4 +36,6 @@ int get_temperature (void);
 
 void set_fan (bool enable);
 
+void draw_temp_graph (void);
+
 #endif//_ROSE_C_TEMPERATURE_H
\ No newline at end of file
diff --git a/thorn/src/common/font.c b/thorn/src/common/font.c
index 532bec5..74f4ca7 100644
--- a/thorn/src/common/font.c
+++ b/thorn/src/common/font.c
@@ -227,7 +227,28 @@ unsigned char const * font (unsigned char c) {
             {0x0F, 0x0F, 0x0F, 0x0F, 0x0F, 0x0F, 0x0F, 0x0F},// U+258C (left half)
             {0xF0, 0xF0, 0xF0, 0xF0, 0xF0, 0xF0, 0xF0, 0xF0},// U+2590 (right half)
             {0xFF, 0xFF, 0xFF, 0xFF, 0x00, 0x00, 0x00, 0x00},// U+2580 (top half)
-    };
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},
+            {0x1C, 0x36, 0x36, 0x1C, 0x00, 0x00, 0x00, 0x00},// U+00BA (degree)
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},
+            {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00}};
     return f[c];
 }
 
diff --git a/thorn/src/common/temperature.c b/thorn/src/common/temperature.c
index ebb1b0c..3a7de93 100644
--- a/thorn/src/common/temperature.c
+++ b/thorn/src/common/temperature.c
@@ -30,24 +30,21 @@ bool init_temperature () {
 }
 
 void regulate_temperature () {
-    static int fan      = 1;
     static int previous = TEMPERATURE_SHOULD;
     while (1) {
+        delay (TEMPERATURE_CHECK_DELAY);
         int current = get_temperature ();
-        printf ("\rCurrent temperature: %d °C. Change since last iteration: %d °mC    ", current / 1000,
-                (current - previous));
+        printf ("\rCurrent temperature: %d C. Change since last iteration: %d mC    ", current / 1000,
+                ((current - previous) + 50) / 500 * 500);
 
         if (current >= TEMPERATURE_SHOULD) {
-            fan = 1;
+            set_fan (1);
         } else if (current < TEMPERATURE_SHOULD - 2000) {
-            fan = 0;
+            set_fan (0);
         }
-
-        set_fan (fan);
-
         previous = current;
 
-        delay (TEMPERATURE_CHECK_DELAY);
+        draw_temp_graph ();
     }
 }
 
@@ -81,4 +78,20 @@ int get_temperature () {
 
 void set_fan (bool enable) {
     gpio_set (GPIO_FAN, !enable);
+}
+
+void draw_temp_graph () {
+    // Clear lower half of screen
+    memzero (get_fb () + get_fb_info ()->fb_size / 2, get_fb_info ()->fb_size / 2);
+
+    // Corners of graph
+    point_t OO = {0, get_fb_info ()->virtual_height / 2};
+    point_t OY = {0, get_fb_info ()->virtual_height - 1};
+    point_t XO = {get_fb_info ()->virtual_width - 1, get_fb_info ()->virtual_height / 2};
+    point_t XY = {get_fb_info ()->virtual_width - 1, get_fb_info ()->virtual_height - 1};
+
+    // Draw frame + legend
+    drawrec (OO, XY, (color_t) {0xFF, 0xFF, 0x00, 0});
+    prints_location (OO, "55C");
+    prints_location ((point_t) {OY.x, OY.y - FONT_REAL_WIDTH}, "45C");
 }
\ No newline at end of file
diff --git a/thorn/src/kernel/kernel.c b/thorn/src/kernel/kernel.c
index 63b6cf1..aa9d139 100644
--- a/thorn/src/kernel/kernel.c
+++ b/thorn/src/kernel/kernel.c
@@ -93,7 +93,7 @@ void kernel_init (void) {
         }
     }
     // Temperature
-    printf ("Initialising temperature %s. Max temperature set to %d °C.\r\n",
+    printf ("Initialising temperature %s. Max temperature set to %d C.\r\n",
             init_temperature () ? "succeeded" : "failed", get_max_temperature () / 1000);
     LOG ("Initialisation done");
     ERROR ("I'm important!");
diff --git a/thorn/src/kernel/mini_uart.c b/thorn/src/kernel/mini_uart.c
index 8f6c2bf..44c3174 100644
--- a/thorn/src/kernel/mini_uart.c
+++ b/thorn/src/kernel/mini_uart.c
@@ -29,7 +29,7 @@ void mini_uart_init (void) {
     static volatile bool init_done     = false;
 
     if (init_progress) {
-        while (! init_done)
+        while (!init_done)
             ;
         return;
     }
@@ -71,7 +71,7 @@ void handle_mini_uart_irq (void) {
         case 19:
             toggle_blank_screen ();
         default:
-            mini_uart_send (c_event);
+            printf ("%c", c_event);
     }
 }
 

From e38145fcc3253cb919421b177ee1a0b3a0176010 Mon Sep 17 00:00:00 2001
From: Aaron Alef <aaron.alef@code.berlin>
Date: Tue, 9 Nov 2021 14:51:47 +0100
Subject: [PATCH 55/61] feat(temperature): graph development of temperature

---
 thorn/include/common/screen.h      |  1 +
 thorn/include/common/temperature.h |  7 ++++++-
 thorn/src/common/font.c            |  6 +++---
 thorn/src/common/screen.c          |  8 ++++++++
 thorn/src/common/temperature.c     | 33 ++++++++++++++++++++++--------
 5 files changed, 42 insertions(+), 13 deletions(-)

diff --git a/thorn/include/common/screen.h b/thorn/include/common/screen.h
index 8020bde..4e6a2c5 100644
--- a/thorn/include/common/screen.h
+++ b/thorn/include/common/screen.h
@@ -3,6 +3,7 @@
 
 #include "common/geometry.h"
 #include "common/gpu.h"
+#include "common/logging.h"
 #include "common/math.h"
 #include "common/printf.h"
 
diff --git a/thorn/include/common/temperature.h b/thorn/include/common/temperature.h
index 2f5f17f..8547b77 100644
--- a/thorn/include/common/temperature.h
+++ b/thorn/include/common/temperature.h
@@ -16,10 +16,15 @@
 #define TEMPERATURE_SHOULD (50 * 1000)
 #define TEMPERATURE_MAX    (80 * 1000)
 
-#define TEMPERATURE_CHECK_DELAY 20000000
+#define TEMPERATURE_CHECK_DELAY 10000000
+
+#define TEMPERATURE_POINTS 100
 
 static volatile unsigned int __attribute__ ((aligned (16))) temperature_request[8];
 
+static unsigned int temperatures[TEMPERATURE_POINTS] = {0};
+static unsigned int current_temperature_index        = 0;
+
 // Max temperature in degree milliCelsius.
 // USB + Ethernet are designed up to 70 °C but unlikely to overheat.
 // CPU is designed up to 85 °C so 80 is probably a reasonable upper limit.
diff --git a/thorn/src/common/font.c b/thorn/src/common/font.c
index 74f4ca7..fe134ea 100644
--- a/thorn/src/common/font.c
+++ b/thorn/src/common/font.c
@@ -300,11 +300,11 @@ void printc (char c) {
         cursor.y += FONT_REAL_HEIGHT;
     }
     // If next line would overflow screen height (ignoring line spacing) move to beginning of screen
-    if (cursor.y + FONT_REAL_WIDTH - FONT_SPACING >= get_max_height ()) {
+    if (cursor.y + FONT_REAL_WIDTH - FONT_SPACING > get_max_height () / 2) {
 #ifdef FONT_SCROLLBACK
         cursor.y -= FONT_SB_LINES * FONT_REAL_HEIGHT;
-        unsigned int remove_size = FONT_SB_LINES * FONT_REAL_HEIGHT * get_fb_info ()->pitch;
-        unsigned int scroll_size = get_fb_info ()->fb_size - remove_size;
+        unsigned int remove_size = FONT_SB_LINES * FONT_REAL_HEIGHT * get_fb_info ()->pitch - FONT_SPACING;
+        unsigned int scroll_size = get_fb_info ()->fb_size / 2 - remove_size;
         memcpy ((ptr_t) get_fb (), (ptr_t) get_fb () + remove_size, scroll_size);
         memzero ((ptr_t) get_fb () + scroll_size, remove_size);
 #else
diff --git a/thorn/src/common/screen.c b/thorn/src/common/screen.c
index 801e7c8..dd4670e 100644
--- a/thorn/src/common/screen.c
+++ b/thorn/src/common/screen.c
@@ -8,6 +8,14 @@ void drawpx (point_t p, color_t color) {
 
 // Bresenham's line algorithm
 void drawline (point_t p0, point_t p1, color_t color) {
+    if (p0.x > get_max_width ()
+        || p0.y > get_max_height ()
+        || p1.x > get_max_width ()
+        || p1.y > get_max_height ()) {
+        ERROR ("Couldn't draw line");
+        printf ("Offending points: {%u, %u} - {%u, %u}\r\n", p0.x, p0.y, p1.x, p1.y);
+        return;
+    }
 
     if (p1.y == p0.y) {
         if (p0.x < p1.x)
diff --git a/thorn/src/common/temperature.c b/thorn/src/common/temperature.c
index 3a7de93..2af84ac 100644
--- a/thorn/src/common/temperature.c
+++ b/thorn/src/common/temperature.c
@@ -30,19 +30,19 @@ bool init_temperature () {
 }
 
 void regulate_temperature () {
-    static int previous = TEMPERATURE_SHOULD;
     while (1) {
         delay (TEMPERATURE_CHECK_DELAY);
-        int current = get_temperature ();
+        unsigned int previous                   = temperatures[(current_temperature_index++) % TEMPERATURE_POINTS];
+        temperatures[current_temperature_index] = get_temperature ();
+        unsigned int current                    = temperatures[current_temperature_index];
         printf ("\rCurrent temperature: %d C. Change since last iteration: %d mC    ", current / 1000,
-                ((current - previous) + 50) / 500 * 500);
+                (current - previous + 5050) / 100 * 100 - 5000);
 
         if (current >= TEMPERATURE_SHOULD) {
             set_fan (1);
         } else if (current < TEMPERATURE_SHOULD - 2000) {
             set_fan (0);
         }
-        previous = current;
 
         draw_temp_graph ();
     }
@@ -82,16 +82,31 @@ void set_fan (bool enable) {
 
 void draw_temp_graph () {
     // Clear lower half of screen
-    memzero (get_fb () + get_fb_info ()->fb_size / 2, get_fb_info ()->fb_size / 2);
+    memzero ((unsigned long) get_fb () + get_fb_info ()->fb_size / 2, get_fb_info ()->fb_size / 2);
 
     // Corners of graph
-    point_t OO = {0, get_fb_info ()->virtual_height / 2};
-    point_t OY = {0, get_fb_info ()->virtual_height - 1};
-    point_t XO = {get_fb_info ()->virtual_width - 1, get_fb_info ()->virtual_height / 2};
-    point_t XY = {get_fb_info ()->virtual_width - 1, get_fb_info ()->virtual_height - 1};
+    point_t OO = {0, get_max_height () / 2};
+    point_t OY = {0, get_max_height ()};
+    point_t XO = {get_max_width (), get_max_height () / 2};
+    point_t XY = {get_max_width (), get_max_height ()};
 
     // Draw frame + legend
     drawrec (OO, XY, (color_t) {0xFF, 0xFF, 0x00, 0});
+    drawline_grid ((point_t) {0, get_max_height () / 8 * 6}, (point_t) {get_max_width (), get_max_height () / 4 * 3}, (color_t) {0, 128, 255, 0});
+    drawline_grid ((point_t) {0, get_max_height () / 8 * 7}, (point_t) {get_max_width (), get_max_height () / 4 * 3}, (color_t) {0, 128, 0, 0});
     prints_location (OO, "55C");
     prints_location ((point_t) {OY.x, OY.y - FONT_REAL_WIDTH}, "45C");
+
+    // Draw lines between data points
+    int factor_x  = get_fb_info ()->virtual_width / TEMPERATURE_POINTS;
+    int divisor_y = 10000 / (get_fb_info ()->virtual_height / 2);
+    for (int j = 0; j < TEMPERATURE_POINTS - 1; j++) {
+        unsigned int i0 = (current_temperature_index + j + 1) % TEMPERATURE_POINTS;
+        unsigned int i1 = (i0 + 1) % TEMPERATURE_POINTS;
+        if (!temperatures[i0] || !temperatures[i1])
+            continue;
+        point_t a = {j * factor_x, OO.y + (temperatures[i0] - 45000) / divisor_y};
+        point_t b = {(j + 1) * factor_x, OO.y + (temperatures[i1] - 45000) / divisor_y};
+        drawline (a, b, (color_t) {0, 0, 255, 0});
+    }
 }
\ No newline at end of file

From ec769b1a2d916dafb3691c93f05914d8b88683b1 Mon Sep 17 00:00:00 2001
From: Aaron Alef <aaron.alef@code.berlin>
Date: Tue, 9 Nov 2021 14:53:22 +0100
Subject: [PATCH 56/61] fix(temperature): invert graph

---
 thorn/src/common/temperature.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/thorn/src/common/temperature.c b/thorn/src/common/temperature.c
index 2af84ac..5758b49 100644
--- a/thorn/src/common/temperature.c
+++ b/thorn/src/common/temperature.c
@@ -105,8 +105,8 @@ void draw_temp_graph () {
         unsigned int i1 = (i0 + 1) % TEMPERATURE_POINTS;
         if (!temperatures[i0] || !temperatures[i1])
             continue;
-        point_t a = {j * factor_x, OO.y + (temperatures[i0] - 45000) / divisor_y};
-        point_t b = {(j + 1) * factor_x, OO.y + (temperatures[i1] - 45000) / divisor_y};
+        point_t a = {j * factor_x, OY.y - (temperatures[i0] - 45000) / divisor_y};
+        point_t b = {(j + 1) * factor_x, OY.y - (temperatures[i1] - 45000) / divisor_y};
         drawline (a, b, (color_t) {0, 0, 255, 0});
     }
 }
\ No newline at end of file

From e7d826836c57898c099f3b1a61937b32c15c4ba0 Mon Sep 17 00:00:00 2001
From: Aaron Alef <aaron.alef@code.berlin>
Date: Tue, 9 Nov 2021 14:57:05 +0100
Subject: [PATCH 57/61] feat(fan): turn-off-fan value adjusted to match graph

---
 thorn/include/common/temperature.h | 2 +-
 thorn/src/common/temperature.c     | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/thorn/include/common/temperature.h b/thorn/include/common/temperature.h
index 8547b77..5d8d137 100644
--- a/thorn/include/common/temperature.h
+++ b/thorn/include/common/temperature.h
@@ -16,7 +16,7 @@
 #define TEMPERATURE_SHOULD (50 * 1000)
 #define TEMPERATURE_MAX    (80 * 1000)
 
-#define TEMPERATURE_CHECK_DELAY 10000000
+#define TEMPERATURE_CHECK_DELAY 5000000
 
 #define TEMPERATURE_POINTS 100
 
diff --git a/thorn/src/common/temperature.c b/thorn/src/common/temperature.c
index 5758b49..26c8e58 100644
--- a/thorn/src/common/temperature.c
+++ b/thorn/src/common/temperature.c
@@ -40,7 +40,7 @@ void regulate_temperature () {
 
         if (current >= TEMPERATURE_SHOULD) {
             set_fan (1);
-        } else if (current < TEMPERATURE_SHOULD - 2000) {
+        } else if (current < TEMPERATURE_SHOULD - 2500) {
             set_fan (0);
         }
 

From c50fba009cc76d8c6d6dfa1941ea63fc3e3b1a39 Mon Sep 17 00:00:00 2001
From: Aaron Alef <aaron.alef@code.berlin>
Date: Tue, 9 Nov 2021 15:16:44 +0100
Subject: [PATCH 58/61] refactor(temperature): change graph clearing to not
 clear unused bottom

---
 thorn/src/common/temperature.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/thorn/src/common/temperature.c b/thorn/src/common/temperature.c
index 26c8e58..4faf57d 100644
--- a/thorn/src/common/temperature.c
+++ b/thorn/src/common/temperature.c
@@ -35,8 +35,10 @@ void regulate_temperature () {
         unsigned int previous                   = temperatures[(current_temperature_index++) % TEMPERATURE_POINTS];
         temperatures[current_temperature_index] = get_temperature ();
         unsigned int current                    = temperatures[current_temperature_index];
-        printf ("\rCurrent temperature: %d C. Change since last iteration: %d mC    ", current / 1000,
-                (current - previous + 5050) / 100 * 100 - 5000);
+
+        previous = (previous + 50) / 100 * 100;
+        current  = (previous + 50) / 100 * 100;
+        printf ("\rCurrent temperature: %d,%d C. Change since last iteration: %d mC    ", current / 1000, current % 1000 / 100, current - previous);
 
         if (current >= TEMPERATURE_SHOULD) {
             set_fan (1);
@@ -82,7 +84,7 @@ void set_fan (bool enable) {
 
 void draw_temp_graph () {
     // Clear lower half of screen
-    memzero ((unsigned long) get_fb () + get_fb_info ()->fb_size / 2, get_fb_info ()->fb_size / 2);
+    memzero ((unsigned long) get_fb () + get_fb_info ()->fb_size / 2, get_fb_info ()->fb_size / 2 - get_fb_info ()->pitch * 10);
 
     // Corners of graph
     point_t OO = {0, get_max_height () / 2};

From 41f302654492ef6d74606506f386edcefce50d6d Mon Sep 17 00:00:00 2001
From: Aaron Alef <aaron.alef@code.berlin>
Date: Tue, 9 Nov 2021 15:41:29 +0100
Subject: [PATCH 59/61] style(temperature): use colors to indicate the status
 of the fan

Also, factor out some constants
---
 thorn/include/common/temperature.h |  8 +++++--
 thorn/src/common/temperature.c     | 38 +++++++++++++++++++-----------
 2 files changed, 30 insertions(+), 16 deletions(-)

diff --git a/thorn/include/common/temperature.h b/thorn/include/common/temperature.h
index 5d8d137..524824e 100644
--- a/thorn/include/common/temperature.h
+++ b/thorn/include/common/temperature.h
@@ -13,13 +13,17 @@
 // Temperature the system tries to keep. Turns off cooling if it falls below.
 // NOTE: The pi hits a 'soft' limit at 70 °C, reducing clock frequency.
 //       This value is defined in the config.txt and defaults to 60 °C if not set
-#define TEMPERATURE_SHOULD (50 * 1000)
-#define TEMPERATURE_MAX    (80 * 1000)
+#define TEMPERATURE_FAN_OFF 47500
+#define TEMPERATURE_FAN_ON  50000
+#define TEMPERATURE_MAX     80000
 
 #define TEMPERATURE_CHECK_DELAY 5000000
 
 #define TEMPERATURE_POINTS 100
 
+#define TEMPERATURE_GRAPH_LOW  45000
+#define TEMPERATURE_GRAPH_HIGH 55000
+
 static volatile unsigned int __attribute__ ((aligned (16))) temperature_request[8];
 
 static unsigned int temperatures[TEMPERATURE_POINTS] = {0};
diff --git a/thorn/src/common/temperature.c b/thorn/src/common/temperature.c
index 4faf57d..2780ca3 100644
--- a/thorn/src/common/temperature.c
+++ b/thorn/src/common/temperature.c
@@ -36,16 +36,16 @@ void regulate_temperature () {
         temperatures[current_temperature_index] = get_temperature ();
         unsigned int current                    = temperatures[current_temperature_index];
 
-        previous = (previous + 50) / 100 * 100;
-        current  = (previous + 50) / 100 * 100;
-        printf ("\rCurrent temperature: %d,%d C. Change since last iteration: %d mC    ", current / 1000, current % 1000 / 100, current - previous);
-
-        if (current >= TEMPERATURE_SHOULD) {
+        if (current >= TEMPERATURE_FAN_ON) {
             set_fan (1);
-        } else if (current < TEMPERATURE_SHOULD - 2500) {
+        } else if (current <= TEMPERATURE_FAN_OFF) {
             set_fan (0);
         }
 
+        previous = (previous + 50) / 100 * 100;
+        current  = (current + 50) / 100 * 100;
+        printf ("\rCurrent temperature: %d,%d C. Change since last iteration: %d mC    ", current / 1000, current % 1000 / 100, current - previous);
+
         draw_temp_graph ();
     }
 }
@@ -96,19 +96,29 @@ void draw_temp_graph () {
     drawrec (OO, XY, (color_t) {0xFF, 0xFF, 0x00, 0});
     drawline_grid ((point_t) {0, get_max_height () / 8 * 6}, (point_t) {get_max_width (), get_max_height () / 4 * 3}, (color_t) {0, 128, 255, 0});
     drawline_grid ((point_t) {0, get_max_height () / 8 * 7}, (point_t) {get_max_width (), get_max_height () / 4 * 3}, (color_t) {0, 128, 0, 0});
-    prints_location (OO, "55C");
-    prints_location ((point_t) {OY.x, OY.y - FONT_REAL_WIDTH}, "45C");
+    char buf[5] = {0};
+    sprintf (buf, "%d C", TEMPERATURE_GRAPH_HIGH / 1000);
+    prints_location (OO, buf);
+    sprintf (buf, "%d C", TEMPERATURE_GRAPH_LOW / 1000);
+    prints_location ((point_t) {OY.x, OY.y - FONT_REAL_WIDTH}, buf);
 
     // Draw lines between data points
-    int factor_x  = get_fb_info ()->virtual_width / TEMPERATURE_POINTS;
-    int divisor_y = 10000 / (get_fb_info ()->virtual_height / 2);
-    for (int j = 0; j < TEMPERATURE_POINTS - 1; j++) {
+    color_t const red       = {0, 0, 255, 0};
+    color_t const blue      = {196, 0, 0, 0};
+    color_t       current   = red;
+    int           factor_x  = get_fb_info ()->virtual_width / TEMPERATURE_POINTS;
+    int           divisor_y = (TEMPERATURE_GRAPH_HIGH - TEMPERATURE_GRAPH_LOW) / (get_fb_info ()->virtual_height / 2);
+    for (int j = 0; j < TEMPERATURE_POINTS; j++) {
         unsigned int i0 = (current_temperature_index + j + 1) % TEMPERATURE_POINTS;
         unsigned int i1 = (i0 + 1) % TEMPERATURE_POINTS;
         if (!temperatures[i0] || !temperatures[i1])
             continue;
-        point_t a = {j * factor_x, OY.y - (temperatures[i0] - 45000) / divisor_y};
-        point_t b = {(j + 1) * factor_x, OY.y - (temperatures[i1] - 45000) / divisor_y};
-        drawline (a, b, (color_t) {0, 0, 255, 0});
+        if (temperatures[i0] >= TEMPERATURE_FAN_ON)
+            current = red;
+        else if (temperatures[i0] <= TEMPERATURE_FAN_OFF)
+            current = blue;
+        point_t a = {j * factor_x, OY.y - (temperatures[i0] - TEMPERATURE_GRAPH_LOW) / divisor_y};
+        point_t b = {(j + 1) * factor_x, OY.y - (temperatures[i1] - TEMPERATURE_GRAPH_LOW) / divisor_y};
+        drawline (a, b, current);
     }
 }
\ No newline at end of file

From 32898859994737e9443c196d4f1b6a4cce2d9a97 Mon Sep 17 00:00:00 2001
From: Aaron Alef <aaron.alef@code.berlin>
Date: Thu, 11 Nov 2021 11:23:07 +0100
Subject: [PATCH 60/61] feat(screen): add fillrec, a function filling
 rectangles with color

---
 thorn/include/common/screen.h |  1 +
 thorn/src/common/screen.c     | 18 ++++++++++++++++++
 2 files changed, 19 insertions(+)

diff --git a/thorn/include/common/screen.h b/thorn/include/common/screen.h
index 4e6a2c5..347e1e4 100644
--- a/thorn/include/common/screen.h
+++ b/thorn/include/common/screen.h
@@ -19,6 +19,7 @@ void drawline_grid (point_t p0, point_t p1, color_t color);
 void drawrec (point_t p0, point_t p1, color_t color);
 void drawcircle (point_t p, int radius, color_t color);
 void draw_all_octant_points (point_t p, point_t offset, color_t color);
+void fillrec (point_t pp0, point_t p1, color_t color);
 
 void test_drawing ();
 
diff --git a/thorn/src/common/screen.c b/thorn/src/common/screen.c
index dd4670e..3e3d738 100644
--- a/thorn/src/common/screen.c
+++ b/thorn/src/common/screen.c
@@ -155,6 +155,16 @@ short get_max_height () {
     return get_fb_info ()->virtual_height - 1;
 }
 
+void fillrec (point_t p0, point_t p1, color_t color) {
+    unsigned int startx = p0.x > p1.x ? p1.x : p0.x;
+    unsigned int starty = p0.y > p1.y ? p1.y : p0.y;
+    unsigned int endx   = p0.x < p1.x ? p1.x : p0.x;
+    unsigned int endy   = p0.y < p1.y ? p1.y : p0.y;
+    for (unsigned int i = starty; i <= endy; i++) {
+        drawline_grid ((point_t) {startx, i}, (point_t) {endx, i}, color);
+    }
+}
+
 void test_drawing () {
     color_t white_color  = {0xff, 0xff, 0xff, 0xff};
     color_t blue_color   = {0xff, 0x00, 0x00, 0xff};
@@ -240,4 +250,12 @@ void test_drawing () {
     drawcircle (POINT (1128, 428),
                 50,
                 red_color);
+
+    fillrec (POINT (800, 800),
+             POINT (900, 900),
+             blue_color);
+
+    fillrec (POINT (800, 800),
+             POINT (850, 850),
+             red_color);
 }

From c7a8b98a2292eaeeab92dfc88db5841f987bec6f Mon Sep 17 00:00:00 2001
From: Aaron Alef <aaron.alef@code.berlin>
Date: Thu, 11 Nov 2021 12:53:39 +0100
Subject: [PATCH 61/61] refactor(temperature): make graph less stroboscopic

---
 thorn/include/common/temperature.h |  4 ++--
 thorn/include/kernel/irq.h         |  2 +-
 thorn/include/kernel/timer.h       |  6 ++++++
 thorn/src/common/temperature.c     | 29 +++++++++++++++++++----------
 thorn/src/kernel/entry.S           |  1 +
 thorn/src/kernel/irq.c             |  4 ++--
 thorn/src/kernel/kernel.c          |  2 ++
 thorn/src/kernel/timer.c           |  6 +-----
 8 files changed, 34 insertions(+), 20 deletions(-)

diff --git a/thorn/include/common/temperature.h b/thorn/include/common/temperature.h
index 524824e..6528640 100644
--- a/thorn/include/common/temperature.h
+++ b/thorn/include/common/temperature.h
@@ -17,9 +17,9 @@
 #define TEMPERATURE_FAN_ON  50000
 #define TEMPERATURE_MAX     80000
 
-#define TEMPERATURE_CHECK_DELAY 5000000
+#define TEMPERATURE_CHECK_DELAY 2000
 
-#define TEMPERATURE_POINTS 100
+#define TEMPERATURE_POINTS 200
 
 #define TEMPERATURE_GRAPH_LOW  45000
 #define TEMPERATURE_GRAPH_HIGH 55000
diff --git a/thorn/include/kernel/irq.h b/thorn/include/kernel/irq.h
index d95cc0b..7997206 100644
--- a/thorn/include/kernel/irq.h
+++ b/thorn/include/kernel/irq.h
@@ -13,7 +13,7 @@
 
 void enable_interrupt_controller (void);
 
-void show_invalid_entry_message (int type, ptr_t esr, ptr_t address);
+void show_invalid_entry_message (int type, ptr_t esr, ptr_t address, ptr_t far);
 
 void irq_vector_init (void);
 
diff --git a/thorn/include/kernel/timer.h b/thorn/include/kernel/timer.h
index f5cd0b8..bfc59ce 100644
--- a/thorn/include/kernel/timer.h
+++ b/thorn/include/kernel/timer.h
@@ -1,6 +1,12 @@
 #ifndef _ROSE_K_TIMER_H
 #define _ROSE_K_TIMER_H
 
+#include "common/printf.h"
+#include "common/status_led.h"
+#include "common/utils.h"
+#include "kernel/peripherals/timer.h"
+#include "kernel/sched.h"
+
 void timer_init (void);
 
 void handle_timer_irq (void);
diff --git a/thorn/src/common/temperature.c b/thorn/src/common/temperature.c
index 2780ca3..09f9343 100644
--- a/thorn/src/common/temperature.c
+++ b/thorn/src/common/temperature.c
@@ -32,7 +32,8 @@ bool init_temperature () {
 void regulate_temperature () {
     while (1) {
         delay (TEMPERATURE_CHECK_DELAY);
-        unsigned int previous                   = temperatures[(current_temperature_index++) % TEMPERATURE_POINTS];
+        unsigned int previous                   = temperatures[current_temperature_index];
+        current_temperature_index               = (current_temperature_index + 1) % TEMPERATURE_POINTS;
         temperatures[current_temperature_index] = get_temperature ();
         unsigned int current                    = temperatures[current_temperature_index];
 
@@ -83,31 +84,39 @@ void set_fan (bool enable) {
 }
 
 void draw_temp_graph () {
-    // Clear lower half of screen
-    memzero ((unsigned long) get_fb () + get_fb_info ()->fb_size / 2, get_fb_info ()->fb_size / 2 - get_fb_info ()->pitch * 10);
-
     // Corners of graph
     point_t OO = {0, get_max_height () / 2};
     point_t OY = {0, get_max_height ()};
     point_t XO = {get_max_width (), get_max_height () / 2};
     point_t XY = {get_max_width (), get_max_height ()};
 
-    // Draw frame + legend
-    drawrec (OO, XY, (color_t) {0xFF, 0xFF, 0x00, 0});
-    drawline_grid ((point_t) {0, get_max_height () / 8 * 6}, (point_t) {get_max_width (), get_max_height () / 4 * 3}, (color_t) {0, 128, 255, 0});
-    drawline_grid ((point_t) {0, get_max_height () / 8 * 7}, (point_t) {get_max_width (), get_max_height () / 4 * 3}, (color_t) {0, 128, 0, 0});
+    // Clear lower half of screen
+    unsigned int  pitch = get_fb_info ()->pitch;
+    unsigned int  size  = get_fb_info ()->fb_size;
+    unsigned long fb    = (unsigned long) get_fb ();
+    memzero (fb + size / 8 * 4 - 7 * pitch, size / 4 - 5 * pitch);
+    memzero (fb + size / 8 * 6 - 11 * pitch, size / 8 - 3 * pitch);
+    memzero (fb + size / 8 * 7 - 13 * pitch, size / 8 - 22 * pitch);
+
+    // Draw frame, legend and orientation lines
+    drawline_grid ((point_t) {0, get_max_height () / 8 * 6}, (point_t) {get_max_width (), get_max_height () / 8 * 6}, (color_t) {0, 128, 255, 0});
+    drawline_grid ((point_t) {0, get_max_height () / 8 * 7}, (point_t) {get_max_width (), get_max_height () / 8 * 7}, (color_t) {0, 128, 0, 0});
+
+    drawline_grid ((point_t) {0, get_max_height () / 8 * 4}, (point_t) {get_max_width (), get_max_height () / 8 * 4}, (color_t) {255, 128, 0, 0});
+    drawline_grid ((point_t) {4 * FONT_REAL_WIDTH, get_max_height () / 8 * 8}, (point_t) {get_max_width (), get_max_height () / 8 * 8}, (color_t) {255, 128, 0, 0});
+
     char buf[5] = {0};
     sprintf (buf, "%d C", TEMPERATURE_GRAPH_HIGH / 1000);
-    prints_location (OO, buf);
+    prints_location (POINT (OO.x, OO.y - FONT_REAL_WIDTH - 3), buf);
     sprintf (buf, "%d C", TEMPERATURE_GRAPH_LOW / 1000);
     prints_location ((point_t) {OY.x, OY.y - FONT_REAL_WIDTH}, buf);
 
     // Draw lines between data points
     color_t const red       = {0, 0, 255, 0};
     color_t const blue      = {196, 0, 0, 0};
-    color_t       current   = red;
     int           factor_x  = get_fb_info ()->virtual_width / TEMPERATURE_POINTS;
     int           divisor_y = (TEMPERATURE_GRAPH_HIGH - TEMPERATURE_GRAPH_LOW) / (get_fb_info ()->virtual_height / 2);
+    color_t       current   = red;
     for (int j = 0; j < TEMPERATURE_POINTS; j++) {
         unsigned int i0 = (current_temperature_index + j + 1) % TEMPERATURE_POINTS;
         unsigned int i1 = (i0 + 1) % TEMPERATURE_POINTS;
diff --git a/thorn/src/kernel/entry.S b/thorn/src/kernel/entry.S
index 4f44a25..4fe363a 100644
--- a/thorn/src/kernel/entry.S
+++ b/thorn/src/kernel/entry.S
@@ -7,6 +7,7 @@
 	mov	x0, #\type
 	mrs	x1, esr_el1
 	mrs	x2, elr_el1
+	mrs	x3, far_el1
 	bl	show_invalid_entry_message
 	b	err_hang
 	.endm
diff --git a/thorn/src/kernel/irq.c b/thorn/src/kernel/irq.c
index b893bda..bab9f1f 100644
--- a/thorn/src/kernel/irq.c
+++ b/thorn/src/kernel/irq.c
@@ -19,8 +19,8 @@ void assign_target (unsigned int irq, unsigned int cpu) {
     put32 (targetRegister, get32 (targetRegister) | (1 << 8));
 }
 
-void show_invalid_entry_message (int type, ptr_t esr, ptr_t address) {
-    printf ("Type %s, ESR: %p, address, %p\r\n", entry_error_messages[type], (void *) esr, (void *) address);
+void show_invalid_entry_message (int type, ptr_t esr, ptr_t address, ptr_t far) {
+    printf ("Type %s, ESR: %p, ELR: %p, FAR: %p\r\n", entry_error_messages[type], (void *) esr, (void *) address, (void *) far);
 }
 
 void enable_interrupt_controller () {
diff --git a/thorn/src/kernel/kernel.c b/thorn/src/kernel/kernel.c
index aa9d139..c5af6ec 100644
--- a/thorn/src/kernel/kernel.c
+++ b/thorn/src/kernel/kernel.c
@@ -127,6 +127,8 @@ void kernel_main (int processor_id) {
         case 1:
             while (get_fb ()) {
                 // Do screen work here
+                //                test_drawing ();
+                //                break;
             }
         case 2:
         case 3:
diff --git a/thorn/src/kernel/timer.c b/thorn/src/kernel/timer.c
index 0fe4556..94950df 100644
--- a/thorn/src/kernel/timer.c
+++ b/thorn/src/kernel/timer.c
@@ -1,8 +1,4 @@
-#include "kernel/peripherals/timer.h"
-#include "common/printf.h"
-#include "common/status_led.h"
-#include "common/utils.h"
-#include "kernel/sched.h"
+#include "kernel/timer.h"
 
 const unsigned int interval = 200000;
 unsigned int       curVal   = 0;