scheme->gba

A Scheme compiler targeting ARM assembly and Game Boy Advance. Started on a flight from ORD to SFO using:

• An Incremental Approach to Compiler Construction by Abdulaziz Ghuloum
• tonclib header files (from J Vijn's excellent TONC GBA reference)
• The Racket docs

Currently supports:

• Fixnums
• Immediate constants
• Primitive procedures: add1, sub1, integer->char, char->integer, null?, zero?, not, integer?, boolean?, +, -, *, let (immediate constants only), if, cons, cons?, car, cdr, make-vector, vector?, vector-ref, vector-set!, make-string, string?, string-ref, string-set!
• lambda, funcall, tailcall

Requires devKitPro (formerly devKitARM).

Compiler components

gbacompile.rkt

Emits the assembly prelude (prelude.s) and the result of compiling scheme.rkt with the label scheme_entry (specify a different source file with the -o flag).

compile-program.rkt

Takes an emit function and a Scheme program and compiles it.

gba.rkt, mem-defs.rkt

Contains GBA/memory-specific constants and functions

driver.c

Calls scheme_entry and writes the result to WRAM (address 0x02000000), visible in the VisualBoyAdvance memory viewer.

Utilities

gbasend.rkt

Located in the gbasend folder. Takes a GBA multiboot ROM as an argument and sends it over Link Cable via Raspberry Pi GPIO pins. Requires a Raspberry Pi and GBA Link Cable. I used a $2 cable and jumper wire from a cheap Chinese electronics site; only one end of the Link Cable had the necessary pins for multiboot.

Wiring: RPI GPIO / GBA LINK IO PIN 19/MOSI -> PIN 3/SI PIN 21/MISO -> PIN 2/SO PIN 23/SCLK -> PIN 5/SC PIN 25/GND -> PIN 6/GND

Cable pinout (via HardwareBook): _________ / 6 4 2 \ \_5_ 3 _1_/ (at cable) '-'