NeoGF/gcmtool

gcmtool.py

Python3 script for unpack/pack/rebuild GCM/iso file format. This tool can rebuild FileStringTable (FST) of GCM and patch boot.bin with a new apploader.img, boot.dol, add/remove/edit folder and files of the game. MIT License.

User manual

Unpack GCM/iso file source_gcm.iso in the default new folder game_code-DVD_number. If optional_dest_folder is specified we unpack in optional_dest_folder.

gcmtool.py --unpack source_gcm.iso optional_dest_folder

Pack source_folder in the default new GCM/iso file source_folder.iso. If optional_dest_file.iso is specified we pack in optional_dest_file.iso. If one of the files or system files contains length change we have to use --rebuild-fst command before packing.

gcmtool.py --pack source_folder optional_dest_file.iso

Rebuild the FST file system of an unpacked GCM/iso and patch boot.bin for a new apploader, dol, and add/remove/edit of folders and files.

gcmtool.py --rebuild-fst source_folder

Print stats about the GCM/iso file or the unpacked GCM/iso folder. This stats contains informations about full memory mapping sorted by offset (files and system files), get empty spaces informations using optional align -a (default=4).

gcmtool.py --stats path -a 4 

Japanese charset is not handled for now except if you have installed Japanese local.

The original GCM/iso and repack GCM/iso are different most of the time. This is because GCM DVD contains "empty spaces" with data unused (old datas or random datas I don't know). So this datas are useless and loss during unpack.

The sorting of files during FST rebuild is deferent from the original and this is full compatible with the GameCube dol API.

Extracted file tree

root folder contains all files of the unpacked GCM/iso

sys folder contains GCM system files of the game:

• boot.bin
• bi2.bin
• apploader.img
• boot.dol
• fst.bin