- Rust 97.7%
- Python 2.3%
Add --rom PATH --window with optional bounded --frames execution. Capture from BIOS boot, pump native events between bounded machine slices, retain frames during STOP, and sample keypad input for wake-up. Share final machine reports with terminal mode. Add an original file-exportable input ROM, controller and CLI regressions, and opt-in native window tests. Document controls, frame limits, STOP behavior, and compatibility limits. Verified on Darwin arm64: debug/release workspace and core tests, Clippy, rustdoc, native ROM diagnostics, all ten demo smoke tests, and a 60-frame release ROM run. |
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|---|---|---|
| crates | ||
| docs | ||
| .envrc | ||
| .gitignore | ||
| AGENTS.md | ||
| Cargo.lock | ||
| Cargo.toml | ||
| CLAUDE.md | ||
| flake.lock | ||
| flake.nix | ||
| README.md | ||
gameboy-rust
Game Boy family emulation in Rust, written from scratch. The Game Boy Advance (GBA) is the first and currently only system.
This cannot run Pokémon Emerald or other commercial games yet. It is an emulator foundation: an ARM7TDMI interpreter, memory bus, timers, DMA, Mode 0–5 video, and an original BIOS replacement. The included demos run original ARM test programs through the emulated hardware. Raw ROM files can run in terminal sessions or a window with keyboard input. Audio and saves are not implemented.
Layout
| Crate | Purpose |
|---|---|
crates/gba-core |
Platform-independent GBA emulator. No external Rust dependencies. |
crates/gba-demos |
Original test programs that drive the core. |
crates/desktop |
Native window frontend on minifb. Builds the gameboy-rust executable. |
Quick start
macOS on Apple Silicon is the verified platform. Install Nix (with flakes) and direnv, then:
direnv allow .
direnv exec . cargo run --locked --release -- --tile-demo
direnv exec . cargo test --locked
Arrows scroll, Q rotates, W zooms, Z flips, X changes priority, Enter resets, and Escape exits.
Run direnv exec . cargo run --locked -- --help to list all modes.
For original ROM files, use --rom path/to/original.gba --window, or --steps 100000 instead of --window for terminal diagnostics.
See cartridge loading for limits and report meanings.
Documentation
| Document | Contents |
|---|---|
| docs/status.md | What works today, deliberate limits, and next steps |
| docs/demos.md | Every demo, its command, and its controls |
| docs/development.md | Nix, direnv, and macOS build notes |
| docs/testing.md | Validation commands and what the test suites cover |
| docs/architecture.md | Crate boundaries and a file-by-file map |
| docs/hardware/cpu.md | ARM/Thumb execution rules, modes, exceptions, and timing |
| docs/hardware/cartridge.md | ROM loading, window/input controls, original ROM generator, and diagnostics |
| docs/hardware/bios.md | The original BIOS replacement and each supported service |
| docs/hardware/timers-irq.md | Timers, interrupt registers, HALT/STOP, and power control |
| docs/hardware/dma.md | DMA channels, triggers, and timing |
| docs/hardware/display-timing.md | Display clock, status, IRQs, and scanline capture |
| docs/hardware/video.md | Backgrounds, sprites, mosaic, windows, color effects, and input |
| docs/references.md | External hardware references and emulator sources consulted |
Coding agents should start with AGENTS.md.
Legal
All demo content and the BIOS replacement are original. No Nintendo code or assets are included. Only use game ROMs that you may lawfully use. Do not commit game ROMs, BIOS files, or game assets.