Paper Mario

This is a WIP decompilation of Paper Mario (USA). It builds the following ROM:

• papermario.z64 md5: a722f8161ff489943191330bf8416496

Discord: Paper Mario Modding

Setup

You'll need Linux, a Linux VM, or Windows 10 (WSL) to work on this project.

Clone the repository

$ git clone https://github.com/ethteck/papermario.git
$ cd papermario

Install build dependencies

$ ./install.sh

Our install script does not yet support distros other than Ubuntu, Arch, and their derivatives. Please consider contributing to the script if you use another distro!

Base ROM

You'll need a Paper Mario (USA) ROM to work on this project. Copy it into the root directory of the repository with the name baserom.z64.

Install tools and extract ROM

$ make setup

Compile the game

$ make

If you get OK, you're all set! Otherwise, please feel free to reach out to us in our Discord channel.

Contributing

Dependencies

There are a few additional dependencies needed when contributing to this project. You can install them with ./install.sh --extra.

Rebuilding

Setting the PM_HEADER_REBUILD environment variable will cause make to rebuild all .c files whenever a .h file is modified.

$ PM_HEADER_REBUILD=1 make

If you use Visual Studio Code, you can use Run Build Task (Ctrl+Shift+B) to run make. Any errors or warnings generated by the compiler will show up in the Problems tab.

Matching a function

Setup

Once you've created a successful (OK) build, copy build/ to expected/build/:

$ mkdir -p expected
$ cp -r build expected

Roughly converting assembly to C

Decide on a function to match. These can be found in the subdirectories of asm/nonmatchings/. Currently, functions which use float constants, data sections, or jump tables are unmatchable.

Take the relevant .s file and pass it to mips_to_c (web version).

If mips_to_c gives you an error about branch-likely instructions, edit the .s file and rename any branch-likely instructions to their unlikely equivalent (i.e. remove the l suffix). Add a nop after the branches and move the instruction that was originally in the delay slot (directly after the branch instruction) to the start of the target label. Don't commit the edited assembly.

Open up the relevant .c file and replace the function's INCLUDE_ASM macro with the output from mips_to_c. Run the following command to attempt to compile, replacing function_name with the name of the function you're working with:

./diff.py -mwo function_name

Fix any errors and rerun diff.py. This will involve typing the function signature correctly, which you will probably find in Star Rod's library database. See also common_structs.h.

Once a successful build is made, diff.py will show you the difference between the original game's assembly (on the left) and what your C code generated (on the right).

Matching the function

You're on your own now. Get your C code compiling to match the original assembly! diff.py, when running, will automatically recompile your code whenever you save the .c file.

If you use Visual Studio Code, you can use Run Test Task to run diff.py and show you errors and warnings from the compiler inline. You might want to attach Run Test Task to a keybinding, as you'll be using it often.

Formatting and linting

Once your function is matching, you'll want to make a pull request. Before you do that, run the following script to reformat your code. (You can also format specific files with ./format.sh path/to/file.c.)

$ ./format.sh

If format.sh displays any errors, go and fix them. If you can't fix them without breaking the function from matching, append // NOLINT to the offending line.

FAQ

• If you received the following error when running make:

sha1sum -c checksum.sha1
sha1sum: 'papermario.z64'$'\r': No such file or directory
: FAILED open or read
sha1sum: WARNING: 1 listed file could not be read
Makefile:118: recipe for target 'verify' failed
make: *** [verify] Error 1

💡 Solution

This is a Windows line ending issue run git checkout checksum.sha1 to fix it.