Game Boy family emulation in Rust, written from scratch. GBA first.
  • Rust 97.7%
  • Python 2.3%
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0xrsydn 109c1ffe81 feat(desktop): run ROM files in a window with keypad input
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.
2026-10-05 19:22:13 +07:00
crates feat(desktop): run ROM files in a window with keypad input 2026-10-05 19:22:13 +07:00
docs feat(desktop): run ROM files in a window with keypad input 2026-10-05 19:22:13 +07:00
.envrc chore(dev): bootstrap Rust and Nix environments for Darwin 2026-10-05 12:58:37 +07:00
.gitignore chore(dev): bootstrap Rust and Nix environments for Darwin 2026-10-05 12:58:37 +07:00
AGENTS.md feat(desktop): run ROM files in a window with keypad input 2026-10-05 19:22:13 +07:00
Cargo.lock refactor: split into gameboy-rust workspace with core, demos, and desktop crates 2026-10-05 16:09:46 +07:00
Cargo.toml refactor: split into gameboy-rust workspace with core, demos, and desktop crates 2026-10-05 16:09:46 +07:00
CLAUDE.md docs: split README into docs/ and add AGENTS.md 2026-10-05 16:20:18 +07:00
flake.lock chore(dev): bootstrap Rust and Nix environments for Darwin 2026-10-05 12:58:37 +07:00
flake.nix refactor: split into gameboy-rust workspace with core, demos, and desktop crates 2026-10-05 16:09:46 +07:00
README.md feat(desktop): run ROM files in a window with keypad input 2026-10-05 19:22:13 +07:00

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.

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.