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)
• Immediate Mode GUI (see this branch)
• Refactoring for easy-ish perf boosts

Usage

As it currently exists, ZBA is run from the terminal. In your console of choice, type ./zba --help to see what you can do.

I typically find myself typing ./zba -b ./bin/bios.bin ./bin/test/suite.gba to see how badly my "cool new feature" broke everything else.

Need a BIOS? 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.

Tests

GBA Tests	jsmolka
arm.gba, thumb.gba	PASS
memory.gba, bios.gba	PASS
flash64.gba, flash128.gba	PASS
sram.gba	PASS
none.gba	PASS
hello.gba, shades.gba, stripes.gba	PASS
nes.gba	PASS

GBARoms	DenSinH
eeprom-test, flash-test	PASS
midikey2freq	PASS
swi-tests-random	FAIL

gba_tests	destoer
cond_invalid.gba	PASS
dma_priority.gba	PASS
hello_world.gba	PASS
if_ack.gba	PASS
line_timing.gba	FAIL
lyc_midline.gba	FAIL
window_midframe.gba	FAIL

GBA Test Collection	ladystarbreeze
retAddr.gba	PASS
helloWorld.gba	PASS
helloAudio.gba	PASS

FuzzARM	DenSinH
main.gba	PASS

arm7wrestler GBA Fixed	destoer
armwrestler-gba-fixed.gba	PASS

Resources

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

Compiling

Most recently built on Zig v0.11.0-dev.1580+a5b34a61a

Dependencies

Dependency	Source
SDL.zig	https://github.com/MasterQ32/SDL.zig
known-folders	https://github.com/ziglibs/known-folders
nfd-zig	https://github.com/fabioarnold/nfd-zig
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
zig-toml	https://github.com/aeronavery/zig-toml
bitfields.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 is located at zig-out/bin/.

Controls

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