Silent Hill Decompilation Project

An in-progress decompilation of the 1.1 US release of Silent Hill on the Playstation 1.

Building (Linux)

Install build dependencies

The build process has the following package requirements:

git
build-essential
binutils-mips-linux-gnu
python3
bchunk
7z

Under a Debian-based distribution (or Windows with a Debian-based WSL2 setup), you can install these with the following commands:

sudo apt update
sudo apt install git build-essential binutils-mips-linux-gnu python3 bchunk p7zip-full p7zip-rar

Clone the repository

Clone https://github.com/Vatuu/silent-hill-decomp in whatever directory you wish. Make sure to clone recursively!

git clone --recursive https://github.com/Vatuu/silent-hill-decomp.git
cd silent-hill-decomp

Install Python3 requirements

Run pip3 install -r requirements.txt

Placing the ROM

Obviously, you will need to provide your own rom dump of the game. The required version is the NTSC-U 1.1 Version of Silent Hill. If done correctly, you will end up with a .BIN and .CUE file. Both of these need to be placed inside the rom/image folder, and renamed to SLUS-00707.bin/.cue respectively. SHA1 Hashes:

.cue: 299D08DCB44E7516F394C3DD5BA40690AE33FD22 84 Bytes
.bin: 34278D31D9B9B12B3B5DB5E45BCBE548991ECBC7 616,494,480 Bytes / 587 MiB

Build the code

Run make setup to extract needed assets/code from the bin, if that succeeds, run make to build it. Once build has finished a folder will be produced with the name build, inside this, you will find the output.

Contributing

Contributions are welcome, please read over the contents of docs/ beforehand to learn the conventions used in this project.

If you would like to reserve a function, open a PR with the function or file name(s).

Useful scripts

asm-differ

Before making changes it's recommended to build a clean version of the current matching code, the makefile will then copy the results of this build over to the expected directory.

This will allow asm-differ to be able to compare any future changes against the known-matching version for you.

While asm-differ is running it can also auto-build changes to the function, giving you a live view of how close it currently matches.

asm-differ can be ran by passing an overlay & function name over to it, eg:

python3 tools/asm-differ/diff.py -mwo --overlay bodyprog vcRetMaxTgtMvXzLen

decompile.py

The decompile.py script (from sotn-decomp project) can try to decompile a function for you using m2c and m2ctx, automatically inserting it into the functions .c file.

The script will tell you whether the decompiled function matches or not, for trivial functions it may be able to match straight away, usually it will need some massaging though.
(eg. by adding structures or prototypes of functions called by it into header files beforehand)

decompile.py can be ran by just passing a function name over to it, eg:

python3 tools/decompile.py vcRetMaxTgtMvXzLen

emoose / silent-hill-decomp