From 5a0297ea2dedfc6f3d3fb2f8e9ab0fb4937711f9 Mon Sep 17 00:00:00 2001 From: tmpz23 <28760271+tmpz23@users.noreply.github.com> Date: Sat, 18 Dec 2021 11:58:21 +0100 Subject: [PATCH] Create gcmtool.py Tool for unpack and pack GCM/ISO files. This tool don't save random bytes written in non-mapped DVD intervals that's why the resulting ISO file will be different from initial ISO --- gcmtool.py | 214 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 214 insertions(+) create mode 100644 gcmtool.py diff --git a/gcmtool.py b/gcmtool.py new file mode 100644 index 0000000..71aceaa --- /dev/null +++ b/gcmtool.py @@ -0,0 +1,214 @@ +#!/usr/bin/env python3 +from pathlib import Path + + +__version__ = "0.0.1" +__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 logging ; add extension check ; add --verbose ; 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): + 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) + + print( 0x2440 + apploader_size ) + print("fst.bin :", int.from_bytes(bootbin_data[0x424:0x428],"big", signed=False), int.from_bytes(bootbin_data[0x428:0x42c],"big", signed=False)) + + iso_file.seek( int.from_bytes(bootbin_data[0x424:0x428],"big", signed=False) ) + fstbin_data = iso_file.read( int.from_bytes(bootbin_data[0x428:0x42c],"big", signed=False) ) + + 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) + bootdol_data = dolheader_data + iso_file.read( dol.getDolLen( dolheader_data ) - 0x100 ) + print("dol :", dol_offset, dol.getDolLen( dolheader_data )) + base_path = Path(f"{bootbin_data[:4].decode('utf-8')}-{int.from_bytes(bootbin_data[6:7], 'little', signed=False):02}") + 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 : + bootbin_file.write(bootbin_data) + bi2bin_file.write(bi2bin_data) + fstbin_file.write(fstbin_data) + apploaderimg_file.write(apploaderimg_data) + 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) ) + print("file :", fileoffset, filesize) + 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 : + 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!") + 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) + 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) + print(fileoffset, filesize) + + with (currentdir_path / name).open("rb") as new_file: + 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('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__': + args = get_argparser().parse_args() + + p_input = Path(args.input_path) + p_output = Path(args.output_path) + + gcm = GCM() + + if args.pack: + logging.info("### Pack") + if(p_output == Path(".")): + p_output = Path(p_input.with_suffix(".iso")) + gcm.pack( p_input, p_output ) + elif args.unpack: + logging.info("### Unpack") + if(p_output == Path(".")): + p_output = Path(p_input.name) + gcm.unpack( p_input, p_output )