This project is made to help with modding the PS1 version of Rayman 1 using the PSX Modding Toolchain. Currently the NTSC and PAL versions are supported by this project, though different mods might only work on specific versions. Included in here are several mods as well as an example. Feel free to submit your own mods through pull requests!
NOTE: This project is still a work in process. As such changes may be made at any point, especially to the exported symbols. Keep this in mind if you're going to work on a mod.
- Download and set up the PSX Modding Toolchain.
- Clone or download this repo and add it to a new folder under
games.
Each mod folder has a MOD.BAT file which allows building the mod and accessing other options from the toolchain.
Every mod will include the files under the include folder. For this project this contains the export.h file which is a header file exported from Ghidra. Symbols are named from the Android version of Rayman 1 and from the PSYQ SDK. If a symbol name is not known then it is prefixed with PS1_ to indicate it uses a custom name.
The resources folder includes additional reusable files which can be copied into and modified for your mods. Usually these are re-implementations of game functions which can then be used to more easily rewrite them.
Currently the NTSC and PAL versions are supported. In the future it is planned to add support for the remaining versions (DemoDemo vol. 3, DemoDemo vol. 6, NTSC-J and Rayman 2 2D prototype). Once they are added they will use separate export.h files and thus any mod that targets them alongside other versions will require conditional compilation based on version. Many functions are however the same across them making it not too difficult to multi-target your mods. In cases were structs are changes many of the fields still remain the same.
To create a mod the easiest to do is to first run the clean command on an existing mod and then copy its folder. The most important thing to keep in mind is to not make your code too big or else it can overwrite existing code in the game.
Generally the easiest way to hook in your code is to extend an existing function by replacing its return instruction with a jump j. Another easy option is to replace a function call jal with your own one and then have your custom function also call the original function.
Once you've added a hook you also need a place to write your custom code. Generally any unused space in the exe will do. One option used in some examples here is to truncate the FntPrint function and overwrite the remaining part of it with your own code.