#!/usr/bin/env python3 from pathlib import Path import logging __version__ = "0.0.3" __author__ = "rigodron, algoflash, GGLinnk" __license__ = "MIT" __status__ = "developpement" DVD_MAGIC = b"\xC2\x33\x9F\x3D" FST_TYPE_FILE = 0 FST_TYPE_DIR = 1 ###################################################################### # Todo : add extension check ; add --disable-ignore # -> test it on random iso and check that it's the same than dolphin extract # -> test it !!!! # Add FST rebuild ; # add info on unused randoms bytes on initial DVD iso file # -> that's why repack iso is different from initial iso ###################################################################### class Dol: # Get total length using the sum of the 18 sections length and dol header length (0x100) def getDolLen(self, dolheader_data:bytes): dol_len = 0x100 for i in range(18): dol_len += int.from_bytes(dolheader_data[0x90+i*4:0x90+(i+1)*4], "big", signed=False) return dol_len # https://sudonull.com/post/68549-Gamecube-file-system-device class GCM: def unpack(self, iso_path:Path, folder_path:Path): with iso_path.open("rb") as iso_file: bootbin_data = iso_file.read(0x440) if bootbin_data[0x1c:0x20] != DVD_MAGIC: raise Exception("Invalid DVD format - this tool is for ISO/GCM files") bi2bin_data = iso_file.read(0x2000) # https://www.gc-forever.com/wiki/index.php?title=Apploader # -> Full apploader size is sum of size and trailerSize, rounded up to 32 bytes. iso_file.seek(0x2454) size = int.from_bytes(iso_file.read(4), "big", signed=False) trailerSize = int.from_bytes(iso_file.read(4), "big", signed=False) # Dolphin Emulator add 32 Null bytes at the end of the extracted apploader.img apploader_size = size + trailerSize + 32 iso_file.seek(0x2440) apploaderimg_data = iso_file.read(apploader_size) fstbin_offset = int.from_bytes(bootbin_data[0x424:0x428],"big", signed=False) fstbin_len = int.from_bytes(bootbin_data[0x428:0x42c],"big", signed=False) iso_file.seek( fstbin_offset ) fstbin_data = iso_file.read( fstbin_len ) dol_offset = int.from_bytes(bootbin_data[0x420:0x424],"big", signed=False) iso_file.seek( dol_offset ) dol = Dol() dolheader_data = iso_file.read(0x100) dol_len = dol.getDolLen( dolheader_data ) bootdol_data = dolheader_data + iso_file.read( dol_len - 0x100 ) if folder_path != Path("."): base_path = folder_path else: base_path = Path(f"{bootbin_data[:4].decode('utf-8')}-{int.from_bytes(bootbin_data[6:7], 'little', signed=False):02}") logging.info(f"unpacking {iso_path} in {base_path}") sys_path = base_path / "sys" sys_path.mkdir(parents=True, exist_ok=True) with (sys_path / "boot.bin").open("wb") as bootbin_file, \ (sys_path / "bi2.bin" ).open("wb") as bi2bin_file, \ (sys_path / "fst.bin").open("wb") as fstbin_file, \ (sys_path / "apploader.img").open("wb") as apploaderimg_file,\ (sys_path / "boot.dol").open("wb") as bootdol_file: logging.debug(f"{iso_path}(0x0:0x440) -> {sys_path / 'boot.bin'}") bootbin_file.write(bootbin_data) logging.debug(f"{iso_path}(0x440:0x2440) -> {sys_path / 'bi2.bin'}") bi2bin_file.write(bi2bin_data) logging.debug(f"{iso_path}(0x2440:0x{0x2440 + apploader_size:x} -> {sys_path / 'apploader.img'}") apploaderimg_file.write(apploaderimg_data) logging.debug(f"{iso_path}(0x{fstbin_offset:x}:0x{fstbin_offset + fstbin_len:x}) -> {sys_path / 'fst.bin'}") fstbin_file.write(fstbin_data) logging.debug(f"{iso_path}(0x{dol_offset:x}:0x{dol_offset + dol_len:x}) -> {sys_path / 'boot.dol'}") bootdol_file.write(bootdol_data) root_path = base_path / "root" root_path.mkdir(exist_ok=True) # And now we parse FST data to unpack all files in the GCM iso file dir_index_path = {0: root_path} currentdir_path = root_path # root: index=0 so nextdir is the end nextdir = int.from_bytes(fstbin_data[8:12], "big", signed=False) # offset of filenames block base_names = nextdir * 12 # go to parent when index reach next dir nextdir_arr = [ nextdir ] for index in range(1, base_names // 12): i = index * 12 file_type = int.from_bytes(fstbin_data[i:i+1], "big", signed=False) name = fstbin_data[base_names + int.from_bytes(fstbin_data[i+1:i+4], "big", signed=False):].split(b"\x00")[0].decode("utf-8") while index == nextdir_arr[-1]: currentdir_path = currentdir_path.parent nextdir_arr.pop() if file_type == FST_TYPE_DIR: nextdir = int.from_bytes(fstbin_data[i+8:i+12], "big", signed=False) parentdir = int.from_bytes(fstbin_data[i+4:i+8], "big", signed=False) nextdir_arr.append( nextdir ) currentdir_path = dir_index_path[parentdir] / name dir_index_path[index] = currentdir_path currentdir_path.mkdir(exist_ok=True) else: fileoffset = int.from_bytes(fstbin_data[i+4:i+8], "big", signed=False) filesize = int.from_bytes(fstbin_data[i+8:i+12], "big", signed=False) with (currentdir_path / name).open("wb") as new_file: iso_file.seek(fileoffset) new_file.write( iso_file.read(filesize) ) logging.debug(f"{iso_path}(0x{fileoffset:x}:0x{fileoffset + filesize:x}) -> {currentdir_path / name}") def pack(self, folder_path:Path, iso_path:Path = None): if iso_path == None: iso_path = folder_path.parent / Path(folder_path.name).with_suffix(".iso") with iso_path.open("wb") as iso_file, \ (folder_path / "sys" / "boot.bin").open("rb") as bootbin_file, \ (folder_path / "sys" / "bi2.bin" ).open("rb") as bi2bin_file, \ (folder_path / "sys" / "fst.bin").open("rb") as fstbin_file, \ (folder_path / "sys" / "apploader.img").open("rb") as apploaderimg_file,\ (folder_path / "sys" / "boot.dol").open("rb") as bootdol_file : logging.debug(f"{folder_path / 'sys' / 'boot.bin'} -> {iso_path}(0x0:0x440)") logging.debug(f"{folder_path / 'sys' / 'bi2.bin'} -> {iso_path}(0x440:0x2440)") logging.debug(f"{folder_path / 'sys' / 'apploader.img'} -> {iso_path}(0x2440:0x{0x2440 + (folder_path / 'sys' / 'apploader.img').stat().st_size:x}") bootbin_data = bootbin_file.read() iso_file.write( bootbin_data ) iso_file.write(bi2bin_file.read()) iso_file.write(apploaderimg_file.read()) fstbin_offset = int.from_bytes(bootbin_data[0x424:0x428],"big", signed=False) fstbin_len = int.from_bytes(bootbin_data[0x428:0x42c],"big", signed=False) if (folder_path / "sys" / "fst.bin").stat().st_size != fstbin_len: raise Exception("Invalid fst.bin size in boot.bin offset 0x428:0x42c!") logging.debug(f"{folder_path / 'sys' / 'fst.bin'} -> {iso_path}(0x{fstbin_offset:x}:0x{fstbin_offset + fstbin_len:x})") iso_file.seek( fstbin_offset ) fstbin_data = fstbin_file.read() iso_file.write( fstbin_data ) dol_offset = int.from_bytes(bootbin_data[0x420:0x424],"big", signed=False) logging.debug(f"{folder_path / 'sys' / 'boot.dol'} -> {iso_path}(0x{dol_offset:x}:0x{dol_offset + (folder_path / 'sys' / 'boot.dol').stat().st_size:x})") iso_file.seek( dol_offset ) iso_file.write( bootdol_file.read() ) # Now parse fst.bin for writing files in the iso dir_index_path = {0: folder_path / "root"} currentdir_path = folder_path / "root" # root: index=0 so nextdir is the end nextdir = int.from_bytes(fstbin_data[8:12], "big", signed=False) # offset of filenames block base_names = nextdir * 12 # go to parent when index reach next dir nextdir_arr = [ nextdir ] for index in range(1, base_names // 12): i = index * 12 file_type = int.from_bytes(fstbin_data[i:i+1], "big", signed=False) name = fstbin_data[base_names + int.from_bytes(fstbin_data[i+1:i+4], "big", signed=False):].split(b"\x00")[0].decode("utf-8") while index == nextdir_arr[-1]: currentdir_path = currentdir_path.parent nextdir_arr.pop() if file_type == FST_TYPE_DIR: nextdir = int.from_bytes(fstbin_data[i+8:i+12], "big", signed=False) parentdir = int.from_bytes(fstbin_data[i+4:i+8], "big", signed=False) nextdir_arr.append( nextdir ) currentdir_path = dir_index_path[parentdir] / name dir_index_path[index] = currentdir_path currentdir_path.mkdir(exist_ok=True) else: fileoffset = int.from_bytes(fstbin_data[i+4:i+8], "big", signed=False) filesize = int.from_bytes(fstbin_data[i+8:i+12], "big", signed=False) with (currentdir_path / name).open("rb") as new_file: logging.debug(f"{currentdir_path / name} -> {iso_path}(0x{fileoffset:x}:0x{fileoffset + filesize:x})") iso_file.seek(fileoffset) iso_file.write( new_file.read(filesize) ) def get_argparser(): import argparse parser = argparse.ArgumentParser(description='ISO/GCM packer & unpacker - [GameCube] v' + __version__) parser.add_argument('--version', action='version', version='%(prog)s ' + __version__) parser.add_argument('-v', '--verbose', action='store_true', help='verbose mode') parser.add_argument('input_path', metavar='INPUT', help='') parser.add_argument('output_path', metavar='OUTPUT', help='', nargs='?', default="") group = parser.add_mutually_exclusive_group(required=True) group.add_argument('-p', '--pack', action='store_true', help="-p source_folder (dest_file.iso) : Pack source_folder in new file source_folder.iso or dest_file.iso if specified") group.add_argument('-u', '--unpack', action='store_true', help='-u source_iso.iso (dest_folder) : Unpack the GCM/ISO in new folder source_iso or dest_folder if specified') return parser if __name__ == '__main__': logging.basicConfig(format='%(levelname)s:%(message)s', level=logging.INFO) args = get_argparser().parse_args() p_input = Path(args.input_path) p_output = Path(args.output_path) gcm = GCM() if args.verbose: logging.getLogger().setLevel(logging.DEBUG) if args.pack: logging.info("### Pack") if(p_output == Path(".")): p_output = Path(p_input.with_suffix(".iso")) logging.info(f"packing folder {p_input} in {p_output}") gcm.pack( p_input, p_output ) elif args.unpack: logging.info("### Unpack") gcm.unpack( p_input, p_output )