Decodes Gauntlet Legends Dreamcast DISK.ROM and SIZES.ROM files.

Place both your DISK.ROM and SIZES.ROM files into the same directory as the scripts, and run rom_decoder.py. Afterwords you should see a out/ folder. You will also see a not_in_archive.txt, which just contains a list of files that weren't packed into the archive or are just missing. (This is normal.)

SIZES.ROM and DISK.ROM are fairly simple formats. SIZES.ROM contains a total file count, a list of file sizes, offsets (for DISK.ROM) and file paths stored as such:

struct Header{
    uint Count;
}
struct Entry {
    uint Size;
    uint Offset;
    // Relative to the end of entries
    short PathOffsets[4];
};

You then need to loop per each PathOffsets, offset from the end of your Entry list and read the null terminated string. If you reach -1 (or 0xFFFF) in your PathOffsets list then break from the loop.

Once you've read SIZES.ROM, simply load up DISK.ROM. Loop through each Entry, seeking (from the start of the file) to the Offset, and reading until you hit Size.

Some helper functions are from io_scene_abc, at least for the time being! Research and development by Haekb (HeyThereCoffeee)