Spyro 2: Ripto's Rage! Decompilation

A decompilation project for the second game in the Spyro the Dragon series, Spyro 2: Ripto's Rage!.

This project aims to produce code that will build to an executable which byte-for-byte matches the one used in the final game.

Version Info

The final NTSC build of the game is used in this project:

• Region: NTSC-U
• Revision: 0
• Product code: SCUS-94425

Project Structure

• asm/: disassembly for non-matching code, and code originally written in assembly.
• include/: include headers for source code, and headers used by disassembly tools.
• src/: decompiled source code.
• tools/: contains utilities for building the game.

PSYQ

Placing the PYSQ headers in psyq/include is required to compile and build, tested using the 4.7 headers.

Building

To make it easier to setup the MIPS toolchain, a docker image is provided. Executing docker_env.sh starts a container in interactive mode with the Dockerfile image, which comes with modern mipsel- gcc and binutils. For the source code, a much older compiler will be used, gcc2.7.2-mipsel.

After starting the container, executing make all will create the main executable, named PSX.EXE, in the /build folder, and overlays in /build/wad.

To speed up the build process, you can use make -j followed by the number of threads you want to use, such as make all -j6.

The overlays will be output to /build/wad, the naming convention matches the Spyro 2 template of wadtool.

This project only concerns the game's code, not the data files.

A tool such as wadtool is needed to rebuild the WAD.WAD file, you can use it for extracting and rebuilding. For creating the CD image, I would recommend mkpsxiso because it's modern and capable of recreating the image perfectly. You can use dumpsxiso to extract the contents of the original image.

I have also included a pair of shell scripts prepare_cd.sh and build_cd.sh which use the aforementioned wadtool and mkpsxiso to extract the contents of a disc image, produce a build config file, extract the WAD.WAD file, copy the built overlay files across, rebuild the WAD, and recreate the disc image.

Contribution Policy

Contributions are greatly appreciated, and this is not a project that I will be able to do all by myself. How you choose to contribute is left up to the contributor, but I ask a few things for you to consider before submitting a pull request:

• Where possible, try to align with the naming schemes and code style with the spyro-1 project, as longer-term all three repositories will be as aligned as possible.
• Please do not co-author commits using an AI agent. Agent context files will not be accepted into the main repository.
• Please ensure that the executable and all overlays are matching before submitting a pull request.

All PRs will be subject to scrutiny before being accepted, and it may take some time before I am able to review them. Please bear with me when a request is made!

Acknowledgements

• splat and its various example projects
• spimdisasm disassembler used by splat
• maspsx
• decomp.me, a very handy tool for matching functions
• Altro50 and his Spyro 1 decomp
• Hwd405 and their Spyro 3 decomp

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