pm-reverse-engineering / papermario_source

This is the source repository for work on decompiling Paper Mario for the Nintendo 64.

Summary of information known

The 2008 Intelligent Systems FTP leak revealed the company used gcc 2.8.1 and binutils 2.9.1 to compile ROMs for the Nintendo 64, with some custom patches.

The patches from the FTP are reproduced here exactly, and they can be applied using the Linux gunzip and patch tools.

As these compilers are very dated, changes in C standards makes them uncompilable by default on modern compilers.

While we don't have a way to compile these in their entirety yet, miscpatches.diff contains two patches that allow cc1 to be built, and so we can compile C into .s (ASM source) files.

Ideally we would then also use the Intelligent Systems binutils to assemble these into .o (object) files, but we don't yet have a method of building this version yet. Until we do, we can use modern binutils to assemble code and hope for accuracy.

Building source for comparison

If you don't want to build gcc yourself, the pipeline for a working cc1 has been set up in the repository Dockerfile. You can either build this Dockerfile yourself, or use the pre-built container on the Docker Hub using:

docker run -it gorialis/is-gcc:latest

Once gcc 2.8.1 is built, you can use it in combination with binutils to generate ASM binary that can be compared to routines in the game ROM:

cpp yourcode.c | gcc-2.8.1/cc1 -o yourcode.s -fomit-frame-pointer -mips2 -O2
mips-linux-gnu-as yourcode.s -o yourcode.o -mips2 -O2
mips-linux-gnu-objdump -dr yourcode.o

This shows the annotated instructions with the binary in hex, so you can compare it to the ROM.