Create gcmtool.py

gcmtool/gcmtool.py

@@ -0,0 +1,538 @@
+#!/usr/bin/env python3
+from pathlib import Path
+import logging
+
+
+__version__ = "0.1.0"
+__author__ = "rigodron, algoflash, GGLinnk"
+__license__ = "MIT"
+__status__ = "developpement"
+
+
+def align_offset(offset:int, align:int):
+    if offset % align != 0:
+        offset += align - (offset % align)
+    return offset
+
+
+class Fst:
+    TYPE_FILE = 0
+    TYPE_DIR = 1
+
+
+class Node:
+    __id = None
+    __name = None
+    __name_offset = None
+    def __init__(self, name:str):
+        self.__name = name
+    def id(self):             return self.__id
+    def name(self):           return self.__name
+    def name_offset(self):    return self.__name_offset
+    def set_id(self, id:int): self.__id = id
+    def set_name_offset(self, name_offset:int): self.__name_offset = name_offset
+
+
+class File(Node):
+    __type = Fst.TYPE_FILE
+    __size = None
+    __offset = None
+    def __init__(self, name:str, size:int):
+        super().__init__(name)
+        self.__size = size
+    def __str__(self):
+        return f"{self.id()};{self.name()};{self.size()};{self.offset()};{self.name_offset()}"
+    def type(self):                   return self.__type
+    def size(self):                   return self.__size
+    def offset(self):                 return self.__offset
+    def set_offset(self, offset:int): self.__offset = offset 
+    def format(self):
+        return self.type().to_bytes(1, "big") + self.name_offset().to_bytes(3, "big") + self.offset().to_bytes(4, "big") + self.size().to_bytes(4, "big")
+
+
+class Folder(Node):
+    __type = Fst.TYPE_DIR
+    __parent = None
+    __next_dir = None
+    __childs = None
+    def __init__(self, name:str, parent:Node):
+        super().__init__(name)
+        self.__parent = parent
+        self.__childs = []
+    def __str__(self):
+        return f"{self.id()};{self.name()};{self.next_dir()};{self.name_offset()}"
+    def type(self):                   return self.__type
+    def parent(self):                 return self.__parent
+    def next_dir(self):               return self.__next_dir
+    def childs(self):                 return self.__childs
+    def set_next_dir(self, next_dir): self.__next_dir = next_dir
+    # Search child by name an return existing if found or new if not existing
+    def add_child(self, node:Node):
+        for child in self.__childs:
+            if node.name() == child.name():
+                return child
+        self.__childs.append(node)
+        return node
+    def format(self):
+        return self.type().to_bytes(1, "big") + self.name_offset().to_bytes(3, "big") + self.parent().id().to_bytes(4, "big") + self.next_dir().to_bytes(4, "big")
+
+
+class FstTree(Fst):
+    __root_path_length = None
+    __root_node = None
+    __current_id = 0
+    __current_file_offset = None
+    __align = None
+    __fst_block = None
+    __name_block = None
+    __nameblock_length = None # Used to find min file_offset when fst is at the end of the iso beginning
+    def __init__(self, root_path:Path, fst_offset:int, align:int = 4):
+        self.__root_path_length = len(root_path.parts)
+        self.__root_node = Folder(root_path.name, None)
+        self.__align = align
+        self.__name_block = b""
+        self.__fst_block = b""
+        self.__nameblock_length = 0
+        self.__current_file_offset = fst_offset
+    def __str__(self):
+        return self.__to_str(self.__root_node)
+    def __to_str(self, node:Node, depth=0):
+        result = (depth * "    ") + str(node) +"\n"
+        if node.type() == FstTree.TYPE_DIR:
+            for child in node.childs():
+                result += self.__to_str(child, depth+1)
+        return result
+    # Needed to know where we can begin to write files
+    def __get_fst_length(self):
+        self.__generate_nameblock_length()
+        return align_offset(self.__count_childs(self.__root_node)*12 + 12 + self.__nameblock_length, self.__align)
+    def __generate_nameblock_length(self, node:Node = None):
+        if node is None:
+            node = self.__root_node
+        else:
+            self.__nameblock_length += len(node.name()) + 1
+        if node.type() == FstTree.TYPE_DIR:
+            for child in node.childs():
+                self.__generate_nameblock_length(child)
+    def __prepare(self, node:Node = None):
+        name_offset = 0
+        if node is None:
+            node = self.__root_node
+        else:
+            name_offset = len(self.__name_block)
+            self.__name_block += node.name().encode("utf-8")+b"\x00"
+        node.set_name_offset(name_offset)
+        node.set_id(self.__current_id)
+        self.__current_id += 1
+        
+        if node.type() == FstTree.TYPE_DIR:
+            node.set_next_dir(self.__current_id + self.__count_childs(node))
+            if node == self.__root_node:
+                self.__fst_block = b"\x01\x00\x00\x00\x00\x00\x00\x00" + node.next_dir().to_bytes(4, "big")
+            else:
+                self.__fst_block += node.format()
+            for child in node.childs():
+                self.__prepare(child)
+        else:
+            node.set_offset(self.__current_file_offset)
+            self.__fst_block += node.format()
+            self.__current_file_offset = align_offset(self.__current_file_offset + node.size(), self.__align)
+    def __count_childs(self, node:Folder):
+        count = 0
+        for child in node.childs():
+            if child.type() == FstTree.TYPE_DIR:
+                count += self.__count_childs(child)
+        return count + len(node.childs())
+    def add_node_by_path(self, node_path:Path):
+        parent = self.__root_node
+        node = None
+        for i in range(self.__root_path_length, len(node_path.parts)-1):
+            node = Folder(node_path.parts[i], parent)
+            parent = parent.add_child(node)
+        if node_path.is_file():
+            node = File(node_path.name, node_path.stat().st_size)
+        else:
+            node = Folder(node_path.name, parent)
+        parent.add_child(node)
+    def generate_fst(self):
+        self.__current_file_offset += self.__get_fst_length()
+        self.__prepare()
+        return self.__fst_block + self.__name_block
+
+
+class BootBin:
+    LEN = 0x440
+    DOLOFFSET_OFFSET = 0x420
+    FSTOFFSET_OFFSET = 0x424
+    FSTLEN_OFFSET = 0x428
+    MAXFSTLEN_OFFSET = 0x42c
+    __data = None
+    def __init__(self, data:bytes):
+        self.__data = bytearray(data)
+    def data(self): return self.__data
+    def dvd_magic(self):
+        return self.__data[0x1c:0x20]
+    def fstbin_offset(self):
+        return int.from_bytes(self.__data[BootBin.FSTOFFSET_OFFSET:BootBin.FSTOFFSET_OFFSET+4],"big", signed=False)
+    def fstbin_len(self):
+        return int.from_bytes(self.__data[BootBin.FSTLEN_OFFSET:BootBin.FSTLEN_OFFSET+4],"big", signed=False)
+    def dol_offset(self):
+        return int.from_bytes(self.__data[BootBin.DOLOFFSET_OFFSET:BootBin.DOLOFFSET_OFFSET+4],"big", signed=False)
+    def game_code(self):
+        return self.__data[:4].decode('utf-8')
+    def disc_number(self):
+        return int.from_bytes(self.__data[6:7], 'big', signed=False)
+    def set_dol_offset(self, offset:int):
+        self.__data[BootBin.DOLOFFSET_OFFSET:BootBin.DOLOFFSET_OFFSET+4] = offset.to_bytes(4, "big")
+    def set_fst_offset(self, offset:int):
+        self.__data[BootBin.FSTOFFSET_OFFSET:BootBin.FSTOFFSET_OFFSET+4] = offset.to_bytes(4, "big")
+    def set_fst_len(self, size:int):
+        self.__data[BootBin.FSTLEN_OFFSET:BootBin.FSTLEN_OFFSET+4] = size.to_bytes(4, "big")
+    def set_max_fst_len(self, size:int):
+        self.__data[BootBin.MAXFSTLEN_OFFSET:BootBin.MAXFSTLEN_OFFSET+4] = size.to_bytes(4, "big")
+
+
+class Dol:
+    HEADER_LEN = 0x100
+    HEADER_SECTIONLENTABLE_OFFSET = 0x90
+    # Get total length using the sum of the 18 sections length and dol header length
+    def get_dol_len(self, dolheader_data:bytes):
+        dol_len = Dol.HEADER_LEN
+        for i in range(18):
+            dol_len += int.from_bytes(dolheader_data[Dol.HEADER_SECTIONLENTABLE_OFFSET+i*4:Dol.HEADER_SECTIONLENTABLE_OFFSET+(i+1)*4], "big", signed=False)
+        return dol_len
+
+
+# https://sudonull.com/post/68549-Gamecube-file-system-device
+class Gcm:
+    BI2BIN_LEN = 0x2000
+    APPLOADER_HEADER_LEN = 0x20
+    APPLOADER_OFFSET = 0x2440
+    APPLOADERSIZE_OFFSET = 0x2454
+    DVD_MAGIC = b"\xC2\x33\x9F\x3D"
+    def unpack(self, iso_path:Path, folder_path:Path):
+        with iso_path.open("rb") as iso_file:
+            bootbin = BootBin(iso_file.read(BootBin.LEN))
+            if bootbin.dvd_magic() != Gcm.DVD_MAGIC:
+                raise Exception("Error - Invalid DVD format - this tool is for ISO/GCM files")
+
+            bi2bin_data = iso_file.read(Gcm.BI2BIN_LEN)
+
+            iso_file.seek(Gcm.APPLOADERSIZE_OFFSET)
+            size = int.from_bytes(iso_file.read(4), "big", signed=False)
+            trailerSize = int.from_bytes(iso_file.read(4), "big", signed=False)
+            
+            apploader_size = Gcm.APPLOADER_HEADER_LEN + size + trailerSize
+            
+            iso_file.seek(Gcm.APPLOADER_OFFSET)
+            apploaderimg_data = iso_file.read(apploader_size)
+
+            fstbin_offset = bootbin.fstbin_offset()
+            fstbin_len = bootbin.fstbin_len()
+            iso_file.seek( fstbin_offset )
+            fstbin_data = iso_file.read( fstbin_len )
+
+            dol_offset = bootbin.dol_offset()
+            iso_file.seek( dol_offset )
+            dol = Dol()
+            dolheader_data = iso_file.read(Dol.HEADER_LEN)
+            dol_len = dol.get_dol_len( dolheader_data )
+            bootdol_data = dolheader_data + iso_file.read( dol_len - Dol.HEADER_LEN )
+
+            if folder_path == Path("."):
+                folder_path = Path(f"{bootbin.game_code()}-{bootbin.disc_number():02}")
+            if folder_path.is_dir():
+                raise Exception(f"Error - \"{folder_path}\" already exist. Remove this folder or use another name for the unpack folder.")
+            
+            logging.info(f"unpacking \"{iso_path}\" in \"{folder_path}\"")
+            sys_path = folder_path / "sys"
+            sys_path.mkdir(parents=True)
+
+            logging.debug(f"{iso_path}(0x0:0x{BootBin.LEN:x}) -> {sys_path / 'boot.bin'}")
+            (sys_path / "boot.bin").write_bytes(bootbin.data())
+            logging.debug(f"{iso_path}(0x440:0x{Gcm.APPLOADER_OFFSET:x}) -> {sys_path / 'bi2.bin'}")
+            (sys_path / "bi2.bin" ).write_bytes(bi2bin_data)
+            logging.debug(f"{iso_path}(0x{Gcm.APPLOADER_OFFSET:x}:0x{Gcm.APPLOADER_OFFSET + apploader_size:x} -> {sys_path / 'apploader.img'}")
+            (sys_path / "apploader.img").write_bytes(apploaderimg_data)
+            logging.debug(f"{iso_path}(0x{fstbin_offset:x}:0x{fstbin_offset + fstbin_len:x}) -> {sys_path / 'fst.bin'}")
+            (sys_path / "fst.bin").write_bytes(fstbin_data)
+            logging.debug(f"{iso_path}(0x{dol_offset:x}:0x{dol_offset + dol_len:x}) -> {sys_path / 'boot.dol'}")
+            (sys_path / "boot.dol").write_bytes(bootdol_data)
+
+            root_path = folder_path / "root"
+            root_path.mkdir()
+            
+            # And now we parse FST data to unpack all files in the GCM iso file
+            dir_id_path = {0: root_path}
+            currentdir_path = root_path
+
+            # root: id=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 id reach next dir
+            nextdir_arr = [ nextdir ]
+
+            for id in range(1, base_names // 12):
+                i = id * 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 id == nextdir_arr[-1]:
+                    currentdir_path = currentdir_path.parent
+                    nextdir_arr.pop()
+
+                if file_type == FstTree.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_id_path[parentdir] / name
+                    dir_id_path[id] = 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)
+
+                    iso_file.seek(fileoffset)
+                    (currentdir_path / name).write_bytes( 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 is None:
+            iso_path = folder_path.parent / Path(folder_path.name).with_suffix(".iso")
+        if iso_path.is_file():
+            raise Exception(f"Error - {iso_path} already exist. Remove this file or use another GCM file name.")
+
+        with iso_path.open("wb") as iso_file:
+            sys_path = folder_path / "sys"
+            logging.debug(f"{sys_path / 'boot.bin'}      -> {iso_path}(0x0:0x{BootBin.LEN:x})")
+            logging.debug(f"{sys_path / 'bi2.bin'}       -> {iso_path}(0x{BootBin.LEN:x}:0x{Gcm.APPLOADER_OFFSET:x})")
+            logging.debug(f"{sys_path / 'apploader.img'} -> {iso_path}(0x{Gcm.APPLOADER_OFFSET:x}:0x{Gcm.APPLOADER_OFFSET + (sys_path / 'apploader.img').stat().st_size:x}")
+            
+            bootbin = BootBin((sys_path / "boot.bin").read_bytes())
+            iso_file.write(bootbin.data())
+            iso_file.write((sys_path / "bi2.bin").read_bytes())
+            iso_file.write((sys_path / "apploader.img").read_bytes())
+
+            fstbin_offset = bootbin.fstbin_offset()
+            fstbin_len = bootbin.fstbin_len()
+            if (sys_path / "fst.bin").stat().st_size != fstbin_len:
+                raise Exception(f"Error - Invalid fst.bin size in boot.bin offset 0x{BootBin.FSTLEN_OFFSET:x}:0x{BootBin.FSTLEN_OFFSET+4:x}!")
+            logging.debug(f"{sys_path / 'fst.bin'}       -> {iso_path}(0x{fstbin_offset:x}:0x{fstbin_offset + fstbin_len:x})")
+            iso_file.seek( fstbin_offset )
+            fstbin_data = (sys_path / "fst.bin").read_bytes()
+            iso_file.write( fstbin_data )
+            
+            dol_offset = bootbin.dol_offset()
+            logging.debug(f"{sys_path / 'boot.dol'}      -> {iso_path}(0x{dol_offset:x}:0x{dol_offset + (sys_path / 'boot.dol').stat().st_size:x})")
+            iso_file.seek( dol_offset )
+            iso_file.write( (sys_path / "boot.dol").read_bytes() )
+
+            # Now parse fst.bin for writing files in the iso
+            dir_id_path = {0: folder_path / "root"}
+            currentdir_path = folder_path / "root"
+
+            # root: id=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 id reach next dir
+            nextdir_arr = [ nextdir ]
+
+            # Check if there is new / removed files or dirs in the root folder
+            if nextdir - 1 != len(list(currentdir_path.glob("**/*"))):
+                raise Exception(f"Error - Invalid file count inside {currentdir_path}. Use --rebuild-fst to update the FST before packing.")
+
+            for id in range(1, base_names // 12):
+                i = id * 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 id == nextdir_arr[-1]:
+                    currentdir_path = currentdir_path.parent
+                    nextdir_arr.pop()
+
+                if file_type == FstTree.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_id_path[parentdir] / name
+                    dir_id_path[id] = currentdir_path
+                    currentdir_path.mkdir(exist_ok=True)
+                else:
+                    file_offset = int.from_bytes(fstbin_data[i+4:i+8], "big", signed=False)
+                    file_len   = int.from_bytes(fstbin_data[i+8:i+12], "big", signed=False)
+
+                    if (currentdir_path / name).stat().st_size != file_len:
+                        raise Exception(f"Error - Invalid file size: {currentdir_path / name} - use --rebuild-fst before packing files in the iso.")
+                    logging.debug(f"{currentdir_path / name} -> {iso_path}(0x{file_offset:x}:0x{file_offset + file_len:x})")
+                    iso_file.seek(file_offset)
+                    iso_file.write( (currentdir_path / name).read_bytes() )
+    def rebuild_fst(self, folder_path:Path, align:int):
+        root_path = folder_path / "root"
+        sys_path = folder_path / "sys"
+
+        dol_offset = align_offset(Gcm.APPLOADER_OFFSET + (sys_path / "apploader.img").stat().st_size, align)
+        logging.info(f"Patching {Path('sys/boot.bin')} offset 0x{BootBin.DOLOFFSET_OFFSET:x} with new dol offset (0x{dol_offset:x})")
+        bootbin = BootBin((sys_path / "boot.bin").read_bytes())
+        bootbin.set_dol_offset(dol_offset)
+        
+        fst_offset = align_offset(dol_offset + (sys_path / "boot.dol").stat().st_size, align)
+        logging.info(f"Patching {Path('sys/boot.bin')} offset 0x{BootBin.FSTOFFSET_OFFSET:x} with new FST offset (0x{fst_offset:x})")
+        bootbin.set_fst_offset(fst_offset)
+        
+        fst_tree = FstTree(root_path, fst_offset, align=align)
+
+        # Sorting paths approach original fst sort, but in original fst specials chars are after and not before chars
+        path_list = sorted([path for path in root_path.glob('**/*')], key=lambda s:Path(str(s).upper()))
+        for path in path_list:
+            fst_tree.add_node_by_path(path)
+        logging.debug(fst_tree)
+
+        fst_path = sys_path / "fst.bin"
+
+        logging.info(f"Writing fst in {Path('sys/fst.bin')}")
+        fst_path.write_bytes( fst_tree.generate_fst() )
+
+        fst_size = fst_path.stat().st_size
+        logging.info(f"Patching {Path('sys/boot.bin')} offset 0x{BootBin.FSTLEN_OFFSET:x} with new FST size (0x{fst_size:x})")
+        bootbin.set_fst_len(fst_size)
+        logging.info(f"Patching {Path('sys/boot.bin')} offset 0x{BootBin.MAXFSTLEN_OFFSET:x} with new FST max size (0x{fst_size:x})")
+        bootbin.set_max_fst_len(fst_size)
+
+        (sys_path / "boot.bin").write_bytes(bootbin.data())
+    def __get_sys_from_folder(self, file_path:Path):
+        sys_path = file_path / "sys"
+        bootbin = BootBin((sys_path / "boot.bin").read_bytes())
+        apploader_size = (sys_path / "apploader.img").stat().st_size
+        dol_len = (sys_path / "boot.dol").stat().st_size
+        fstbin_data = (sys_path / "fst.bin").read_bytes()
+        return (bootbin, apploader_size, dol_len, fstbin_data)
+    def __get_sys_from_file(self, file_path:Path):
+        bootbin = None
+        apploader_size = None
+        dol_len = None
+        fstbin_data = None
+        with file_path.open("rb") as iso_file:
+            bootbin = BootBin(iso_file.read(BootBin.LEN))
+            iso_file.seek(Gcm.APPLOADERSIZE_OFFSET)
+            apploader_size = Gcm.APPLOADER_HEADER_LEN + int.from_bytes(iso_file.read(4), "big", signed=False) + int.from_bytes(iso_file.read(4), "big", signed=False)
+
+            dol = Dol()
+            iso_file.seek( bootbin.dol_offset() )
+            dol_len = dol.get_dol_len( iso_file.read(Dol.HEADER_LEN) )
+            iso_file.seek( bootbin.fstbin_offset() )
+            fstbin_data = iso_file.read(bootbin.fstbin_len())
+        return (bootbin, apploader_size, dol_len, fstbin_data)
+    def stats(self, path:Path, align:int = 4):
+        (bootbin, apploader_size, dol_len, fstbin_data) = self.__get_sys_from_folder(path) if path.is_dir() else self.__get_sys_from_file(path)
+
+        # Begin offset - end offset - length - name
+        mapping_lists = [
+            [0, BootBin.LEN, f"{BootBin.LEN:08x}", "boot.bin"],
+            [0x440, Gcm.APPLOADER_OFFSET, f"{Gcm.BI2BIN_LEN:08x}", "bi2.bin"],
+            [Gcm.APPLOADER_OFFSET, Gcm.APPLOADER_OFFSET + apploader_size, f"{apploader_size:08x}", "apploader.img"],
+            [bootbin.fstbin_offset(), bootbin.fstbin_offset() + bootbin.fstbin_len(), f"{bootbin.fstbin_len():08x}", "fst.bin"],
+            [bootbin.dol_offset(), bootbin.dol_offset() + dol_len, f"{dol_len:08x}", "boot.dol"]]
+
+        dir_id_path = {0: Path(".")}
+        currentdir_path = Path(".")
+
+        # root: id=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 id reach next dir
+        nextdir_arr = [ nextdir ]
+
+        for id in range(1, base_names // 12):
+            i = id * 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 id == nextdir_arr[-1]:
+                currentdir_path = currentdir_path.parent
+                nextdir_arr.pop()
+
+            if file_type == FstTree.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_id_path[parentdir] / name
+                dir_id_path[id] = currentdir_path
+            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)
+                mapping_lists.append( [fileoffset, fileoffset + filesize, f"{filesize:08x}", str(currentdir_path / name)] )
+
+        mapping_lists.sort(key=lambda x: x[0])
+
+        empty_space_tuples = []
+        last_offset = 0
+        for i in range(len(mapping_lists)):
+            if last_offset < mapping_lists[i][0]:
+                empty_space_tuples.append( (f"{last_offset:08x}", f"{mapping_lists[i][0]:08x}", f"{mapping_lists[i][0] - last_offset:08x}", "") )
+            elif last_offset > mapping_lists[i][0]:
+                raise Exception(f"Error - Bad align ({align})! Offsets collision.")
+            last_offset = align_offset(mapping_lists[i][1], align)
+            mapping_lists[i][0] = f"{mapping_lists[i][0]:08x}"
+            mapping_lists[i][1] = f"{mapping_lists[i][1]:08x}"
+
+        print(f"# Stats for \"{path}\":")
+        self.__print("Global memory mapping:", mapping_lists)
+        self.__print(f"Empty spaces (align={align}):", empty_space_tuples)
+    def __print(self, title:str, lines_tuples):#, columns:list = list(range(3))):
+        stats_buffer = "#"*70+f"\n# {title}\n"+"#"*70+"\n| b offset | e offset | length   | Name\n|"+"-"*69+"\n"
+        for line in lines_tuples:
+            stats_buffer += "| "+" | ".join(line)+"\n"
+        print(stats_buffer, end='')
+
+
+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('-a', '--align', type=int, help='-a=10: alignment of files in the GCM ISO (default value is 4)', default=4)
+    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")
+    group.add_argument('-s', '--stats', action='store_true', help="-s source_iso.iso or source_folder: Get stats about GCM, FST, memory, lengths and offsets.")
+    group.add_argument('-r', '--rebuild-fst', action='store_true', help="-r game_folder: Rebuild the game_folder/sys/fst.bin using files in game_folder/root")
+    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 in new GCM iso")
+        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 iso in new folder")
+        gcm.unpack(p_input, p_output)
+    elif args.stats:
+        gcm.stats(p_input)
+    elif args.rebuild_fst:
+        logging.info("### Rebuilding FST and patching boot.bin")
+        if args.align < 1:
+            raise Exception("Error - Align must be > 0.")
+        logging.info(f"Using alignment: {args.align}")
+        gcm.rebuild_fst(p_input, args.align)