NGCRecomp

NGCRecomp is a static recompilation tool for GameCube binaries. The goal of this project is to lift GameCube executable code (.dol and .rel) into a recompilable format using the Capstone disassembly engine.

Currently, the project is in the Experimental Phase, focusing on ISO parsing, DOL header validation, and Entry Point detection.

Project Structure:

src/: Core logic for the recompiler.

boot.c: Entry point for the tool; handles ISO/DOL loading.

external/capstone/: The Capstone Disassembly Engine (v5.0.1) source code.

gamerom.iso: (Not tracked) The base GameCube ROM for analysis.

Current Progress

• ISO Disk Header Parsing: Successfully reading the GCM/GCE format.

• DOL Header Extraction: Parsing text/data section offsets and sizes.

• Big-Endian to Little-Endian Conversion: Manual byte-swapping for Windows/UCRT64 compatibility.

• Entry Point Detection: Targeted at The Wind Waker (USA 1.00) at 0x80003140.

• Section-to-Address Mapping: Translation loop implemented to map RAM addresses to ISO file offsets.

• Instruction Lifting via Capstone:

• Basic Arithmetic (addi, add, li, lis).

• Load/Store Logic (lwz, stw, stwu, stb).

• Logical Operations (or, mr, rlwinm, andi.).

• Control Flow Translation:

• Function Call Lifting (bl to C function calls).

• Conditional Branching (bt, bc to C if/goto).

• Unconditional Jumps (b to C goto).

• Static Block Recovery: (Next Step) Automatically tracing and disassembling full functions until blr.

• Global Pointer / TOC Handling: Mapping r2 and r13 for static data access.

Notice

NGCRecomp is not affiliated with Nintendo in any way. NGCRecomp does not contain any copyrighted assets. You must provide your own .ISO

Building

This project uses CMake 3.12+ and a C compiler (GCC/Clang).

The first step is to build Capstone. From your repo root folder. Enter

cd external/capstone

After that. Enter the following commands in this exact order

mkdir build
cd build
cmake ..
cmake --build .

Once it has finished compiling. Go back to the root folder. And repeat the same build process for building Capstone.

Usage

./NGCRecomp <path_to_game.iso>

Limitations

• Inside the recompiled C code of the game. You will notice some unhandled instructions. This is because not all instructions have been added to decode. But many of them have already been implemented.
• This tool is (obviously) still experimental and is not finished.

Credits & Licensing

• NGCRecomp: Licensed under the MIT License.
• Capstone Engine: This project includes the Capstone disassembly framework, which is licensed under the BSD 3-Clause License.