gcmod is a tool for extracting the contents of and rebuilding GameCube ROMs, as well as for getting all sorts of useful information about a ROM without ever extracting the contents.

I'm working on adding more features to actually help the modding process go smoother, and eventually, I would like it to also be a powerful tool for creating mods for GameCube games. I'd also like to create a Rust API for all of this at some point, but that's a slightly lower priority right now.

If you don't have Rust installed, you'll need to do that first. I recommend installing it via rustup. gcmod works on macOS and Linux, but there is currently no Windows support. I'd like to add that eventually, but I don't have a Windows machine at the moment.

To install gcmod, download the project and run cargo install in the project's directory. This will place gcmod at ~/.cargo/bin/gcmod, so you will need to make sure ~/.cargo/bin is in your $PATH environment variable.

I plan on adding a better installation method eventually, as well as distributing pre-built binaries.

gcmod --help will give you an overview of the available subcommands.

disasm     Disassemble the main DOL file from a ROM.
extract    Extract a ROM's contents to disk.
help       Prints this message or the help of the given subcommand(s)
info       Display information about the ROM.
rebuild    Rebuilds a ROM.

You can also pass --help after any of these subcommands to see their usage.

$ gcmod info --help
gcmod-info
Display information about the ROM.

USAGE:
    gcmod info [FLAGS] [OPTIONS] <rom_path>

FLAGS:
        --help       Prints help information
    -h, --hex        Displays numbers in hexadecimal.
    -V, --version    Prints version information

OPTIONS:
    -o, --offset <offset>    Print information about whichever section is at the given offset.
    -t, --type <type>        Print a given type of information about the ROM. [possible values: header, dol, fst,
                             apploader, layout]

ARGS:
    <rom_path>

$ gcmod extract melee.iso melee_root
Writing game header...
Writing file system table...
Writing app loader...
Writing DOL header...
1209/1209 files written.
$ gcmod rebuild melee_root melee.iso
1212/1212 files added.

Here's a link to some documentation I'm working on for the GameCube ROM format: GameCube ROM Info (I don't update this very often, I need to stay on top of that...)