arm\asm\emu

A Game Boy emulator written entirely in ARM assemly language.

Why assembly language? Why not.

Cross-assembling

The Makefile is set up for both native building on an ARM platform as well as cross-compling. Pass your favorite cross-compiling prefix to the make invocation with something like CROSS=arm-none-eabi-.

The testing harness can also be invoked on a non-arm platform using QEMU. Specify something like TEST_WRAPPER=qemu-arm during the make test invocation to use QEMU when running tests.

Testing

A test harness has been created which runs a ROM for a given number of cycles and checks a CRC32 of the screen contents against a set value. If the value doesn't match, a capture of the screen is saved as a .bmp file and the process returns non-zero.

At present, only the Blargg tests are targeted. Here are the current passing tests:

cpu_instrs	passing
special	:heavy_check_mark:
interrupts	:heavy_check_mark:
op sp,hl	:heavy_check_mark:
op r,imm	:heavy_check_mark:
op rp	:heavy_check_mark:
ld r,r	:heavy_check_mark:
jr,jp,call,ret,rst	:heavy_check_mark:
misc instrs	:heavy_check_mark:
op r,r	:heavy_check_mark:
bit ops	:heavy_check_mark:
op a,(hl)	:heavy_check_mark:

timing	passing
instr_timing	:heavy_check_mark:
mem_timing	:heavy_check_mark:
mem_timing-2	:heavy_check_mark:

misc	passing
oam_bug causes	:heavy_check_mark:
oam_bug non_causes	:heavy_check_mark:
oam_bug timing_bug	:heavy_check_mark:

Interface

Supported graphics interfaces

• Null
• Linux framebuffer
• Bitmap (capture)

Supported control interfaces

• Null
• Linux evdev

Sound

(not implemented)

License

All code is published under the BSD-3-Clause License. See LICENSE for more information.