Legend of Mana PS1 gets a matching decomp for both NA and JP releases
A new matching decompilation of Legend of Mana on PS1 rebuilds both the NTSC-U and NTSC-J releases back to their original MIPS code. Here's what it means.
Legend of Mana on PlayStation now has a matching decompilation, and it covers both the North American and Japanese releases. The project, celophi/lom-decomp, says both versions are 100% matched. For a hobbyist, the word “matching” is the part that counts. The C source it rebuilds compiles back into the same MIPS machine code that sits on the disc.
The project targets SLUS-01013 (NTSC-U, executable SLUS_010.13) and SLPS-02170 (NTSC-J, executable SLPS_021.70). Every module is fully linked: the main executable plus all 17 overlays, so 18 binaries per version. For the overlays, the check runs the whole round trip. The original .BIN gets decompressed, turned into C, compiled into an ELF, compressed again, and comes out bit-identical. The author calls the compressor check “kind of extraneous, but cool nonetheless.” I’d say that’s the kind of detail that eats weeks of patience.
It’s not a PC port. The repo has no game executable, art, or audio, so you need your own legally obtained copy. The project lists the SHA-1 hashes so you can check your files. It has 35 stars and over a thousand commits. The roadmap still shows cleanup and documentation in progress, and modding plus a source port sit under future work.
How to try it
- Clone the repo with submodules:
git clone --recursive https://github.com/celophi/lom-decomp.git - Copy SLUS_010.13 and the BIN folder into
disc/us/, then check withsha1sum disc/us/SLUS_010.13. - Build the four historical compiler images from the old-gcc submodule, as the README lists.
- Build the dev container:
docker build -t lom-dev -f dockerfiles/dev.dockerfile . - Inside the container, run
make splat, thenmake, thenmake verify-bins.
My take: matching decomps are the slow, boring base layer. Recomp projects like Zelda64Recomp go faster, but they don’t give you readable source that rebuilds the original disc byte for byte. Once this one finishes its cleanup, the question is whether the modding work follows. That’s the part I’ll be watching.
