ZBA (working title)

A Game Boy Advance Emulator written in Zig ⚡!

Scope

I'm hardly the first to write a Game Boy Advance Emulator nor will I be the last. This project isn't going to compete with the GOATs like mGBA or NanoBoyAdvance. There aren't any interesting ideas either like in DSHBA.

This is a simple (read: incomplete) for-fun long-term project. I hope to get "mostly there", which to me means that I'm not missing any major hardware features and the set of possible improvements would be in memory timing or in UI/UX. With respect to that goal, here's what's outstanding:

TODO

• Affine Sprites
• Windowing (see this branch)
• Audio Resampler (Having issues with SDL2's)
• Refactoring for easy-ish perf boosts

Usage

ZBA supports both a CLI and a GUI. If running from the terminal, try using zba --help to see what you can do. If you want to use the GUI, feel free to just run zba without any arguments.

ZBA does not feature any BIOS HLE, so providing one will be necessary if a ROM makes use of it. Need one? Why not try using the open-source Cult-Of-GBA BIOS written by fleroviux and DenSinH?

Finally it's worth noting that ZBA uses a TOML config file it'll store in your OS's data directory. See example.toml to learn about the defaults and what exactly you can mess around with.

Compiling

Most recently built on Zig v0.11.0-dev.3395+1e7dcaa3a

Dependencies

Dependency	Source
known-folders	https://github.com/ziglibs/known-folders
nfd-zig	https://github.com/fabioarnold/nfd-zig
SDL.zig	https://github.com/MasterQ32/SDL.zig
tomlz	https://github.com/mattyhall/tomlz
zba-gdbstub	https://github.com/paoda/zba-gdbstub
zba-util	https://git.musuka.dev/paoda/zba-util
zgui	https://github.com/michal-z/zig-gamedev/tree/main/libs/zgui
zig-clap	https://github.com/Hejsil/zig-clap
zig-datetime	https://github.com/frmdstryr/zig-datetime
bitfield.zig	https://github.com/FlorenceOS/Florence
gl.zig	https://github.com/MasterQ32/zig-opengl

Use git submodule update --init from the project root to pull the git relevant git submodules

Be sure to provide SDL2 using:

• Linux: Your distro's package manager
• macOS: ¯\_(ツ)_/¯ (try this formula?)
• Windows: vcpkg (install sdl2:x64-windows)

SDL.zig will provide a helpful compile error if the zig compiler is unable to find SDL2.

Once you've got all the dependencies, execute zig build -Doptimize=ReleaseSafe. The executable will be under zig-out/bin and the shared libraries (if enabled) under zig-out/lib. If working with shared libraries on windows, be sure to add all artifacts to the same directory. On Unix, you'll want to make use of LD_PRELOAD.

Controls

Key	Button		Key	Button
A	L		S	R
X	A		Z	B
Return	Start		RShift	Select
Arrow Keys	D-Pad

Tests

GBA Tests	jsmolka	gba_tests	destoer
arm.gba, thumb.gba	PASS	cond_invalid.gba	PASS
memory.gba, bios.gba	PASS	dma_priority.gba	PASS
flash64.gba, flash128.gba	PASS	hello_world.gba	PASS
sram.gba	PASS	if_ack.gba	PASS
none.gba	PASS	line_timing.gba	FAIL
hello.gba, shades.gba, stripes.gba	PASS	lyc_midline.gba	FAIL
nes.gba	PASS	window_midframe.gba	FAIL

GBARoms	DenSinH	GBA Test Collection	ladystarbreeze
eeprom-test, flash-test	PASS	retAddr.gba	PASS
midikey2freq	PASS	helloWorld.gba	PASS
swi-tests-random	FAIL	helloAudio.gba	PASS

FuzzARM	DenSinH	arm7wrestler GBA Fixed	destoer
main.gba	PASS	armwrestler-gba-fixed.gba	PASS

Resources

• GBATEK
• TONC
• ARM Architecture Reference Manual
• ARM7TDMI Data Sheet