Legend of Mana PSX Decompilation

A decompilation project for the PlayStation 1 game Legend of Mana, targeting MIPS assembly.

Prerequisites

• Git - For cloning the repository
• Docker Desktop - Required for the build environment (Download here)
• Legend of Mana ROM - Your legally obtained copy of SLUS_010.13

Setup Instructions

1. Clone the Repository

Open a terminal (PowerShell or Command Prompt on Windows) and run:

git clone https://github.com/celophi/lom-decomp.git
cd lom-decomp
git submodule update --init --recursive

This downloads the project and all its dependencies.

2. Add Your Game ROM

Copy your SLUS_010.13 file into the disc folder in the project directory.

3. Build the Compiler Container

The project uses an old PlayStation compiler (gcc-2.8.0) that runs in Docker. Build it with:

docker build -t old-gcc/gcc-2.8.0-psx -f tools/old-gcc/gcc-2.8.0-psx.Dockerfile tools/old-gcc

This step may take several minutes.

4. Build the Development Environment

Build the main development container:

docker build -t lom-dev .

5. Start the Development Environment

Launch the container with your project files mounted:

docker run --rm -ti -v "${PWD}:/lom" lom-dev

You should now be inside the container at a Linux terminal prompt.

6. Split the Game Binary

Inside the container, run the splat tool to extract the game binary into assembly files:

splat split config/SLUS_010.13.yaml

7. Build the Project

Compile the decompiled code:

make clean
make
make bin

The compiled output will be in the build directory as both an ELF executable and a BIN file.

Workflow Summary

After initial setup, your typical workflow is:

1. Start the container: docker run --rm -ti -v "${PWD}:/lom" lom-dev
2. Make your code changes (outside the container, in your editor)
3. Build inside the container: make clean && make && make bin
4. Test the output from the build directory

Troubleshooting

• If Docker commands fail, ensure Docker Desktop is running
• On Windows, use PowerShell or Command Prompt, not Git Bash, for the docker run command
• The ${PWD} variable should automatically expand to your current directory path

Matching

You can use spimdisasm to help with matching after producing a binary:

spimdisasm elfObjDisasm build/slus_010.13.elf output/

Notes

Current esearch points to a Psy-Q SDK version of 4.6 while game functions match somewhere around GCC 2.8.0.