pureikyubu
EN RU

A work-in-progress Nintendo GameCube emulator

pureikyubu (プレイキューブ) is an emulator of the Nintendo GameCube built to research the hardware of the console and to reverse engineer the technologies the games were made with. The GameCube is a masterpiece of the Nintendo/ArtX engineers — this project is a way to take it apart and understand it.

Release Notes 1.9.1 What changed after 1.6 Source on GitHub

What is new

Release 1.9 is the feature release: an integrated Game Boy Advance and Game Boy, a complete software implementation of the Flipper graphics blocks, a new debugger, an MCP server for LLM agents, a hardware-interface profiler, a headless build and a DSP recompiler — plus the fixes that run the Metroid Prime intro to its title screen and boot Super Mario Sunshine.

New machine

Game Boy Advance and Game Boy

src/gba is a second console written from the public specifications, with a free boot ROM that draws the pureikyubu logo, its own SDL2 front end and its own test harness. pureikyubu --gba game.gba runs a cartridge; pureikyubu game.gbc runs the Game Boy inside it.

Graphics

The software GFX pipeline

The Flipper blocks have a CPU implementation next to the OpenGL one: a real EFB memory array, a real TMEM and a copy engine that writes the XFB the video interface scans out. GFX_PIPELINE switches pipelines on the fly.

Debugging

DebugUI2

A new debugger with its own thread, its own OpenGL window and a session per run. Every panel is the Markdown of a JDI command: thirteen tabs from Gekko to the profiler, plus the GBA and Game Boy machines.

Tooling

The MCP server

pureikyubu --mcp publishes the whole debug interface as Model Context Protocol tools — around 170 of them — so an LLM agent drives the emulator over stdin/stdout.

Diagnostics

HW interface profiler

What the console's channels actually move, per emulated second: the 60x and Splash buses, the PI/CP FIFOs, every DMA engine, the audio mixer input, the GFX primitives and the VI frames — as a table, a PNG or an overlay.

Platform

Headless build and DSP JIT

A windowless console target for benchmarks and MCP runs (with an offscreen OpenGL backend on Windows), a security review behind a small verifier layer, UTF-8 throughout the interface, and a DSP basic-block recompiler that is 1.5–1.8x faster.

Screenshots

Captured from the current development build (release 1.9 line).

The new DebugUI2 debugger with the Gekko registers and memory
The new debuggerEvery panel is the Markdown of a JDI command: the session history and the command line next to the Gekko registers, the disassembly and the physical memory.
Super Mario Sunshine reaching its intro cutscene
Super Mario SunshineBoots, plays its intro FMV and reaches the scene after it, once the cache-management instructions stop faulting on a direct-store segment.
Metroid Fusion on the integrated Game Boy Advance
Metroid FusionThe integrated Game Boy Advance, booted by the emulator's own free boot ROM and drawn at 60 fps.
Soul Calibur II rendered by pureikyubu
Soul Calibur IIA third-party 3D title rendered through the XF/TEV shader pipeline.

Build it

Windows

Open scripts/VS2026/pureikyubu.sln in Visual Studio 2026 and press Build. Debug and Release configurations exist for both the Win32 and the SDL front end.

Linux

CMake + SDL2 build, verified under WSL2 as well:

sudo apt install libglew-dev
git clone https://github.com/emu-russia/pureikyubu.git
cd pureikyubu && git submodule update --init
cd build && cmake .. && make
./pureikyubu pong.dol

The software GFX pipeline

The Flipper graphics subsystem now has a second rendering path: a software (CPU) implementation of the same hardware blocks, written from the GameCube specifications, switchable on the fly through the GFX_PIPELINE configuration variable and drawing through a real EFB memory array whose copy-engine output (the XFB) the video interface scans out.

A scene rendered by the software GFX pipeline

Read the page · По-русски · Wiki · Issue #384

The MCP server

The emulator can run as a local MCP (Model Context Protocol) server: an LLM agent starts it as its own child process and drives the whole debug interface through it — every command of the emulator becomes a tool. Load a disc image, read the Gekko registers, dump main memory, watch the hardware counters, take a screenshot. 

{
  "mcpServers": {
    "pureikyubu": { "command": "pureikyubu_headless", "args": ["--mcp"] }
  }
}

Read the page · По-русски · Wiki · Issue #383

Up next

Release 2.0 will be the next major version, the peripheral release. It is aimed at the console's peripheral devices — the EXI bus and the devices on it (memory cards, the Broadband Adapter, the RTC), the serial interface and the pads, the disk interface and the drive, and the link port the GBA side already has — and it should close out many of the emulator's features, so that the list of what is not implemented yet shrinks to what genuinely does not matter.

After that the project moves into its steady state: planned, methodical improvement — performance work and bug fixing release after release, rather than another feature push. The architecture is in place; what remains is making what is there faster, more exact and more complete. The details are in the 1.9.1 release notes.

Documentation

Release Notes 1.9.1

English release notes · Заметки о релизе на русском · Markdown

Digest since 1.6

English digest · Дайджест на русском

Wiki

Emulator internals: Flipper, GFX, Gekko, Debug UI and the DSP IROM analysis.

Archive

Earlier releases, kept for reference.

Release Notes 1.9

English release notes · Заметки о релизе на русском · Markdown

Release Notes 1.8

English release notes · Заметки о релизе на русском · Markdown

Release Notes 1.7

English release notes · Заметки о релизе на русском · Markdown