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oot/tools/decompress_baserom.py
2024-01-24 10:07:56 -08:00

275 lines
8.3 KiB
Python
Executable file

#!/usr/bin/env python3
# SPDX-FileCopyrightText: © 2024 ZeldaRET
# SPDX-License-Identifier: CC0-1.0
from __future__ import annotations
import hashlib
import io
import struct
from pathlib import Path
import argparse
import crunch64
import ipl3checksum
import zlib
def decompress_zlib(data: bytes) -> bytes:
decomp = zlib.decompressobj(-zlib.MAX_WBITS)
output = bytearray()
output.extend(decomp.decompress(data))
while decomp.unconsumed_tail:
output.extend(decomp.decompress(decomp.unconsumed_tail))
output.extend(decomp.flush())
return bytes(output)
def decompress(data: bytes, is_zlib_compressed: bool) -> bytes:
if is_zlib_compressed:
return decompress_zlib(data)
return crunch64.yaz0.decompress(data)
FILE_TABLE_OFFSET = {
"gc-eu-mq": 0x07170,
"gc-eu-mq-dbg": 0x12F70,
}
VERSIONS_MD5S = {
"gc-eu-mq": "1a438f4235f8038856971c14a798122a",
"gc-eu-mq-dbg": "f0b7f35375f9cc8ca1b2d59d78e35405",
}
def round_up(n, shift):
mod = 1 << shift
return (n + mod - 1) >> shift << shift
def as_word_list(b) -> list[int]:
return [i[0] for i in struct.iter_unpack(">I", b)]
def read_dmadata_entry(file_content: bytearray, addr: int) -> list[int]:
return as_word_list(file_content[addr : addr + 0x10])
def read_dmadata(file_content: bytearray, start) -> list[list[int]]:
dmadata = []
addr = start
entry = read_dmadata_entry(file_content, addr)
i = 0
while any([e != 0 for e in entry]):
dmadata.append(entry)
addr += 0x10
i += 1
entry = read_dmadata_entry(file_content, addr)
return dmadata
def update_crc(decompressed: io.BytesIO) -> io.BytesIO:
print("Recalculating crc...")
calculated_checksum = ipl3checksum.CICKind.CIC_X105.calculateChecksum(
bytes(decompressed.getbuffer())
)
new_crc = struct.pack(f">II", calculated_checksum[0], calculated_checksum[1])
decompressed.seek(0x10)
decompressed.write(new_crc)
return decompressed
def decompress_rom(
file_content: bytearray, dmadata_addr: int, dmadata: list[list[int]], version: str
) -> bytearray:
rom_segments = {} # vrom start : data s.t. len(data) == vrom_end - vrom_start
new_dmadata = bytearray() # new dmadata: {vrom start , vrom end , vrom start , 0}
decompressed = io.BytesIO(b"")
for v_start, v_end, p_start, p_end in dmadata:
if p_start == 0xFFFFFFFF and p_end == 0xFFFFFFFF:
new_dmadata.extend(struct.pack(">IIII", v_start, v_end, p_start, p_end))
continue
if p_end == 0: # uncompressed
rom_segments.update(
{v_start: file_content[p_start : p_start + v_end - v_start]}
)
else: # compressed
rom_segments.update(
{
v_start: decompress(
file_content[p_start:p_end], version in {"ique-cn", "ique-zh"}
)
}
)
new_dmadata.extend(struct.pack(">IIII", v_start, v_end, v_start, 0))
# write rom segments to vaddrs
for vrom_st, data in rom_segments.items():
decompressed.seek(vrom_st)
decompressed.write(data)
# write new dmadata
decompressed.seek(dmadata_addr)
decompressed.write(new_dmadata)
# pad to size
padding_end = round_up(dmadata[-1][1], 14)
decompressed.seek(padding_end - 1)
decompressed.write(bytearray([0]))
# re-calculate crc
return bytearray(update_crc(decompressed).getbuffer())
def get_str_hash(byte_array):
return str(hashlib.md5(byte_array).hexdigest())
def check_existing_rom(rom_path: Path, correct_str_hash: str):
# If the baserom exists and is correct, we don't need to change anything
if rom_path.exists():
if get_str_hash(rom_path.read_bytes()) == correct_str_hash:
return True
return False
def word_swap(file_content: bytearray) -> bytearray:
words = str(int(len(file_content) / 4))
little_byte_format = "<" + words + "I"
big_byte_format = ">" + words + "I"
tmp = struct.unpack_from(little_byte_format, file_content, 0)
struct.pack_into(big_byte_format, file_content, 0, *tmp)
return file_content
def byte_swap(file_content: bytearray) -> bytearray:
halfwords = str(int(len(file_content) / 2))
little_byte_format = "<" + halfwords + "H"
big_byte_format = ">" + halfwords + "H"
tmp = struct.unpack_from(little_byte_format, file_content, 0)
struct.pack_into(big_byte_format, file_content, 0, *tmp)
return file_content
def per_version_fixes(file_content: bytearray, version: str) -> bytearray:
if version == "gc-eu-mq-dbg":
# Strip the overdump
print("Stripping overdump...")
file_content = file_content[0:0x3600000]
# Patch the header
print("Patching header...")
file_content[0x3E] = 0x50
return file_content
def pad_rom(file_content: bytearray, dmadata: list[list[int]]) -> bytearray:
padding_start = round_up(dmadata[-1][1], 12)
padding_end = round_up(dmadata[-1][1], 14)
print(f"Padding from {padding_start:X} to {padding_end:X}...")
for i in range(padding_start, padding_end):
file_content[i] = 0xFF
return file_content
# Determine if we have a ROM file
ROM_FILE_EXTENSIONS = ["z64", "n64", "v64"]
def find_baserom(version: str) -> Path | None:
for rom_file_ext_lower in ROM_FILE_EXTENSIONS:
for rom_file_ext in (rom_file_ext_lower, rom_file_ext_lower.upper()):
rom_file_name_candidate = Path(f"baseroms/{version}/baserom.{rom_file_ext}")
if rom_file_name_candidate.exists():
return rom_file_name_candidate
return None
def main():
description = "Convert a rom that uses dmadata to an uncompressed one."
parser = argparse.ArgumentParser(description=description)
parser.add_argument("version", help="Version of the game to decompress.", choices=list(VERSIONS_MD5S.keys()))
args = parser.parse_args()
version = args.version
uncompressed_path = Path(f"baseroms/{version}/baserom-decompressed.z64")
file_table_offset = FILE_TABLE_OFFSET[version]
correct_str_hash = VERSIONS_MD5S[version]
if check_existing_rom(uncompressed_path, correct_str_hash):
print("Found valid baserom - exiting early")
return
rom_file_name = find_baserom(version)
if rom_file_name is None:
path_list = [
f"baseroms/{version}/baserom.{rom_file_ext}" for rom_file_ext in ROM_FILE_EXTENSIONS
]
print(f"Error: Could not find {','.join(path_list)}.")
exit(1)
# Read in the original ROM
print(f"File '{rom_file_name}' found.")
file_content = bytearray(rom_file_name.read_bytes())
# Check if ROM needs to be byte/word swapped
# Little-endian
if file_content[0] == 0x40:
# Word Swap ROM
print("ROM needs to be word swapped...")
file_content = word_swap(file_content)
print("Word swapping done.")
# Byte-swapped
elif file_content[0] == 0x37:
# Byte Swap ROM
print("ROM needs to be byte swapped...")
file_content = byte_swap(file_content)
print("Byte swapping done.")
file_content = per_version_fixes(file_content, version)
dmadata = read_dmadata(file_content, file_table_offset)
# Decompress
if any(
[
b != 0
for b in file_content[
file_table_offset + 0xAC : file_table_offset + 0xAC + 0x4
]
]
):
print("Decompressing rom...")
file_content = decompress_rom(file_content, file_table_offset, dmadata, version)
file_content = pad_rom(file_content, dmadata)
# Check to see if the ROM is a "vanilla" ROM
str_hash = get_str_hash(file_content)
if str_hash != correct_str_hash:
print(
f"Error: Expected a hash of {correct_str_hash} but got {str_hash}. The baserom has probably been tampered, find a new one"
)
if version == "gc-eu-mq-dbg":
if str_hash == "32fe2770c0f9b1a9cd2a4d449348c1cb":
print(
"The provided baserom is a rom which has been edited with ZeldaEdit and is not suitable for use with decomp. Find a new one."
)
exit(1)
# Write out our new ROM
print(f"Writing new ROM {uncompressed_path}.")
uncompressed_path.write_bytes(file_content)
print("Done!")
if __name__ == "__main__":
main()