Nemu

A Game Boy (DMG) emulator written in Rust.

This repo contains:

• nemu-core: Core emulation logic as a Rust library + a built-in debugger binary + custom boot ROM source code
• nemu-gui: GUI for running ROMs

Getting Started

Requirements:

• Rust toolchain (duh)
• RGBDS toolchain
• A computer (strongly recommended)

Clone with submodules:

git clone --recurse-submodules https://github.com/Arikatsu/nemu.git

Build the boot ROM:

cd nemu_core/bootrom
./build.sh # OR .\build.ps1 on Windows PowerShell

Run tests:

cargo test -p nemu-core --lib

Run with the debugger:

cargo run -p nemu-core --features debugger

Run with the GUI (supports game saves):

cargo run -p nemu-gui -- <path_to_rom>

Current Status

Features implemented so far:

• Full CPU instruction set and emulation
• Bus and memory mapping (partial, will evolve as more features are implemented)
• Timer
• Interrupt handling
• Debugger
• Background/Window rendering and PPU mode switching
• Sprite rendering
• Joypad input
• Custom Boot ROM (currently only does basic initialization, plan to show my own boot animation later)
• GUI for running ROMs (nemu-gui)
• MBC cartridges
  • ROM only
  • MBC1 (ROM + RAM + BATTERY)
• Serial
• Sound
• Save states

List items may be updated or even changed as development progresses and does not indicate a strict roadmap.

Passing Tests

• Blargg's CPU instruction tests
• Blargg's CPU and Memory instruction timing tests
• dmg-acid2 test ROM

(need to test more lol)

Notes

• The project is still under active development and may contain bugs or incomplete behavior.
• Contributions, bug reports, and feedback are welcome.
• Yes, I have NOT come around to adding the HALT bug yet.