Harvest Moon 64 Recomp

A recompilation/modding project for Harvest Moon 64 using the N64 recompilation toolchain.

This repository contains the mod source, build files, headers, and configuration needed to build a .nrm mod for Harvest Moon 64 Recomp.

Writing mods

This project uses the N64 recomp modding framework. Mods can hook or patch existing game functions with RECOMP_HOOK, RECOMP_HOOK_RETURN, and RECOMP_PATCH.

Use this repository as the place for Harvest Moon 64-specific patches, quality-of-life changes, renderer fixes, gameplay tweaks, and configuration-driven options.

Tools

You'll need to install clang and make to build the mod.

• On Windows, using Chocolatey to install both is recommended. The packages are llvm and make.
  • LLVM 19.1.0 does not support MIPS correctly for this workflow. LLVM/Clang 18.1.8 is recommended.
  • With Chocolatey, you can install that version with --version 18.1.8, or you can download the LLVM 18.1.8 release directly.
• On Linux, install clang, make, and lld through your distro's package manager.
  • On Debian/Ubuntu-based distros, the linker package is usually lld.
• On macOS, install llvm and make through Homebrew.
  • Apple Clang will not work because this build needs a MIPS target.

On Linux and macOS, make sure the zip utility is also installed.

You'll also need RecompModTool from the N64Recomp releases. You can also build it yourself from the N64Recomp repository.

Building

• Run make to build the mod code.
  • You can pass a job count, such as make -j8, to build faster.
• Run RecompModTool with mod.toml as the first argument and the build directory as the second argument:

RecompModTool mod.toml build

This will produce the mod's .nrm file in the build folder.

On macOS, you may need to specify the Homebrew LLVM tools manually:

CC=/opt/homebrew/opt/llvm/bin/clang LD=/opt/homebrew/opt/llvm/bin/ld.lld make

Updating Harvest Moon 64 symbols or headers

If the Harvest Moon 64 recomp/decompilation symbols change, the mod may need updated symbol files or headers.

General process:

• Build the matching Harvest Moon 64 ELF or symbol source used by the recomp project.
• Build N64Recomp and copy the N64Recomp executable to the root of this repository if needed.
• Generate or update the symbol files used by this mod.
• Update the corresponding headers and function names referenced by the mod source.
• Rebuild the mod.

If RecompModTool fails because a patched function does not exist in the original ROM, the function name may have changed. Find the function at the same address in the updated map or symbol file, then update the hook or patch name in the mod source.