• Toast CPU
• Todo

Toast CPU

toast is a 16-bit architecture spec, an emulator, a subscalar FPGA implementation, and an assembler.

Read documents on the architecture, and the application binary interface.

Todo

• Fix assembler to include calling convention and register renamings
• Fix the emulator, create an emulated screen
• Finish VGA text mode (Maybe a smaller VGA text mode font for more lines)
• VGA buffer currently takes up too much of the IO mapped space, maybe consider changing to 0x0000: Address, 0x0001: Value type of memory addressing.
• Implement elementary OS / Basic interpreter
• Extend functionality of assembler
  • Add call macro
• Implement a compiler backend for C->toast compilation
• Add floating point module, maybe a 32-bit variant?
• IRQ and handlers (keyboard driver testing TBD...)
• Implement a rti instruction that allows for more interrupts to occur. Currently, interrupts will nest themselves and cause a ton of issues.
  • rti will also need to restore the status register
  • rti will also stop other interrupts from occuring
• Implement better multi-interrupt support.
• Add Register Banking (Maybe...)
• Implement mult and div in hardware
• Re-implement stack to grow downwards and add addressing with offset load r5 r6 0xA to load @r6 + 10