Body Harvest N64 Decompilation

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Help is welcome! Message me on discord jaytheham or @gmail.com

Help match existing scratches on decomp.me

A decompilation to C of the N64 game Body Harvest.

Building

Windows (without Docker)

Install 64-bit Python 3.12 (3.11.4 to 3.12 works; some pinned libraries have no Windows wheels for 3.13 or newer) with the Python launcher enabled. This is the only build dependency you need to install yourself; use Git to clone the repository, or download its source ZIP. Windows 10/11 and the included PowerShell and tar.exe are required.

git clone https://github.com/jaytheham/body-harvest-decompilation.git
cd body-harvest-decompilation

Place your US ROM at baserom.us.z64 in the repository root, then run:

.\tools\extract.ps1
.\tools\make.ps1

The first command automatically downloads pinned, SHA256-checked Windows tools and installs the extraction libraries in tools/windows/venv. Nothing is installed globally and no environment activation is needed. Initial setup needs internet access; subsequent extractions and builds work offline. You can also run .\tools\setup.ps1 separately to prepare the tools before supplying the ROM.

A successful matching build prints build/bh.us.z64: OK. Builds are incremental and use up to four workers. Options:

.\tools\make.ps1 -Jobs 4
.\tools\make.ps1 -Rebuild
.\tools\make.ps1 -NonMatching
.\tools\make.ps1 -VerboseBuild

Some existing NON_MATCHING source does not compile; that option reports its source errors. A failed build cannot leave objects from that configuration eligible for reuse in a matching build.

The scripts locate the repository relative to themselves, so they also work when launched from another directory or from a checkout with spaces in its name. If PowerShell blocks scripts, invoke them with powershell -ExecutionPolicy Bypass -File .\tools\extract.ps1 (and similarly for make.ps1); this applies only to that process.

Native builds support both versions; pass -Version eu to both scripts for the EU ROM, which builds into build.eu/. The existing Linux/Docker workflow remains available, including .\tools\extract.ps1 -Docker and .\tools\make.ps1 -Docker for an already running bh-container. Other development scripts such as diff.ps1 still use Docker.

The local tool cache is ignored by Git. To reset setup, remove tools/windows and run the commands again. The compiler is IDO 5.3 v1.2, with Windows binutils v0.10. A standalone MSYS runtime DLL supports IDO, and portable Tiny C builds the repository's RNC tools; no MSYS installation, Bash, Make, WSL, Docker, Visual Studio, or system C compiler is needed.

Linux / WSL

The instructions below assume that you will be using Ubuntu 22.04; either natively, via WSL2, or via Docker. Please check the packages.txt and requirements.txt for the prerequisite Linux and Python packages respectively.

Natively

Clone the repository; note the --recursive flag to fetch submodules at the same time:

git clone --recursive https://github.com/jaytheham/body-harvest-decompilation.git

Navigate into the freshly cloned repo

cd body-harvest-decompilation

Place the US Body Harvest ROM in the root of this repository, name it baserom.us.z64, and then run the first make command to extract the ROM:

make extract

Now build the ROM:

make --jobs

If you did everything correctly, you'll be greeted with the following:

build/bh.us.z64: OK

On Ubuntu 24.04, or wherever clang 16 or newer is on the PATH, the Makefile's syntax check rejects code that IDO accepts. Use gcc for that check instead: make --jobs HOSTCC=gcc "HOSTCC_CHECK_FLAGS=-m32 -D__clang__". The -D__clang__ makes gcc skip the boot assembly block in src.us/core/1050.c, which is guarded with #ifndef __clang__ for IDO alone to read; without it gcc stops there.

Note: Currently need to change the references to func_802D4CD0 in loader.s to func_802D4CD0_18D7E0 Not sure why this one file is problematic. Should be done automatically during extract.

Docker

Clone this repository, place the baserom.us.z64 at its root, and then build the Docker image:

docker build --no-cache -t bh-local .

Run the docker image with:

docker run --name bh-container --rm -ti -v "${PWD}:/bh" bh-local

From here you can run the make extract and make --jobs commands.

Building EU Version

Place baserom.eu.z64 in the root of the repository, and suffix each make command with VERSION=eu (make extract VERSION=eu, then make --jobs VERSION=eu). The EU build uses its own asm.eu, assets.eu and build.eu directories, so both versions can be extracted side by side; a matching build prints build.eu/bh.eu.z64: OK. The EU build also compiles the C files in src.us/core and the overlay files listed in shared_overlay_files.txt (with -DVERSION_EU), so that code is shared by both versions; src.eu holds only the C files that exist in the EU build alone.

Building NON_MATCHING Version

Functions that are not yet a byte-perfect match are wrapped with NON_MATCHING to exclude from the build. In order to build/test the non-matching, pass NON_MATCHING=1 to the make commands. These functions range from actually matched - but require rodata to be configured - through to nowhere close to matching, and may not be functionally equivalent to the target ASM yet.

ROM Versions

There are 2 known ROMs of the game:

Country Code	CRC1/CRC2	ROM SHA1	Version
E - North America	5326696F/FE9A99C3	BBB6666F5014A473747EE4145F036D9FB25D7348	B6.5
P - European	0B58B8CD/B7B291D2	67750E2E7AB46FEDF65A271AB7F4C7AAD92AE355	F2.6

Only US and EU versions were released to the public. If you are in possession of a beta/prototype ROM please contact me!

Repo layout

asm/             ; assembly files split by splat (not checked in)
assets/          ; binary files split by splat (not checked in)
build/           ; build folder (not checked in)
include/
  2.0I/          ; libultra 2.0I headers
lib/libultra.a   ; libultra 2.0I static library
src.us/          ; C source of the US build; src.us/core and the files of shared_overlay_files.txt are also compiled into the EU build
src.eu/          ; C source that exists in the EU build only
tools/
  ido5.3_recomp/ ; static recompilation of IDO 5.3 compiler
  splat_ext      ; custom splat extensions

Tools

• asm-processor; allows GLOBAL_ASM pragma - replacing assembly inside C files
• asm-differ; rapidly diff between source/target assembly
• decomp-permuter; tweaks code, rebuilds, scores; helpful for weird regalloc issues
• ido-static-recomp; no need to use qemu-irix anymore!
• m2c; assembly to C code translator
• rnc_propack_source; open-source compressor/decompressor for RNC file format
• splat; successor to n64split