mirror of
https://github.com/platomav/BIOSUtilities.git
synced 2025-05-13 06:34:42 -04:00
b174ce40e6
Added Apple EFI EFI Image Identifier new argument -q Improved Apple EFI EFI Image Identifier detection flow Improved Apple EFI Package Extractor file parsing flow Improved file vs link detection and read access control Improved common switches handling of 7-Zip decompressor Improved non-PATH external executable dependencies names Fixed requirement instruction misalignments at the README
160 lines
6.2 KiB
Python
160 lines
6.2 KiB
Python
#!/usr/bin/env python3 -B
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# coding=utf-8
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"""
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Apple EFI IM4P
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Apple EFI IM4P Splitter
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Copyright (C) 2018-2024 Plato Mavropoulos
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"""
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import os
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from re import Match
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from typing import Final
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from biosutilities.common.paths import make_dirs, path_stem
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from biosutilities.common.patterns import PAT_APPLE_IM4P, PAT_INTEL_FD
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from biosutilities.common.system import printer
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from biosutilities.common.templates import BIOSUtility
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from biosutilities.common.texts import file_to_bytes
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class AppleEfiIm4pSplit(BIOSUtility):
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""" Apple EFI IM4P Splitter """
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TITLE: str = 'Apple EFI IM4P Splitter'
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# Intel Flash Descriptor Component Sizes (2MB, 4MB, 8MB, 16MB and 32MB)
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IFD_COMP_LEN: Final[dict[int, int]] = {2: 0x200000, 3: 0x400000, 4: 0x800000, 5: 0x1000000, 6: 0x2000000}
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def check_format(self, input_object: str | bytes | bytearray) -> bool:
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""" Check if input is Apple EFI IM4P image """
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if isinstance(input_object, str) and not input_object.lower().endswith('.im4p'):
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return False
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input_buffer: bytes = file_to_bytes(in_object=input_object)
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if PAT_APPLE_IM4P.search(string=input_buffer) and PAT_INTEL_FD.search(string=input_buffer):
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return True
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return False
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def parse_format(self, input_object: str | bytes | bytearray, extract_path: str, padding: int = 0) -> bool:
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""" Parse & Split Apple EFI IM4P image """
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parse_success: bool = True
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input_buffer: bytes = file_to_bytes(in_object=input_object)
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make_dirs(in_path=extract_path, delete=True)
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# Detect IM4P EFI pattern
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im4p_match: Match[bytes] | None = PAT_APPLE_IM4P.search(string=input_buffer)
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if not im4p_match:
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return False
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# After IM4P mefi (0x15), multi EFI payloads have _MEFIBIN (0x100) but is difficult to RE w/o varying samples.
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# However, _MEFIBIN is not required for splitting SPI images due to Intel Flash Descriptor Components Density.
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# IM4P mefi payload start offset
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mefi_data_bgn: int = im4p_match.start() + input_buffer[im4p_match.start() - 0x1]
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# IM4P mefi payload size
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mefi_data_len: int = int.from_bytes(bytes=input_buffer[im4p_match.end() + 0x5:im4p_match.end() + 0x9],
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byteorder='big')
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# Check if mefi is followed by _MEFIBIN
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mefibin_exist: bool = input_buffer[mefi_data_bgn:mefi_data_bgn + 0x8] == b'_MEFIBIN'
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# Actual multi EFI payloads start after _MEFIBIN
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efi_data_bgn: int = mefi_data_bgn + 0x100 if mefibin_exist else mefi_data_bgn
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# Actual multi EFI payloads size without _MEFIBIN
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efi_data_len: int = mefi_data_len - 0x100 if mefibin_exist else mefi_data_len
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# Adjust input file buffer to actual multi EFI payloads data
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input_buffer = input_buffer[efi_data_bgn:efi_data_bgn + efi_data_len]
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# Parse Intel Flash Descriptor pattern matches
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for ifd in PAT_INTEL_FD.finditer(string=input_buffer):
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# Component Base Address from FD start (ICH8-ICH10 = 1, IBX = 2, CPT+ = 3)
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ifd_flmap0_fcba: int = input_buffer[ifd.start() + 0x4] * 0x10
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# I/O Controller Hub (ICH)
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if ifd_flmap0_fcba == 0x10:
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# At ICH, Flash Descriptor starts at 0x0
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ifd_bgn_subtruct: int = 0x0
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# 0xBC for [0xAC] + 0xFF * 16 sanity check
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ifd_end_subtruct: int = 0xBC
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# Platform Controller Hub (PCH)
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else:
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# At PCH, Flash Descriptor starts at 0x10
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ifd_bgn_subtruct = 0x10
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# 0xBC for [0xAC] + 0xFF * 16 sanity check
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ifd_end_subtruct = 0xBC
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# Actual Flash Descriptor Start Offset
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ifd_match_start: int = ifd.start() - ifd_bgn_subtruct
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# Actual Flash Descriptor End Offset
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ifd_match_end: int = ifd.end() - ifd_end_subtruct
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# Calculate Intel Flash Descriptor Flash Component Total Size
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# Component Count (00 = 1, 01 = 2)
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ifd_flmap0_nc: int = ((int.from_bytes(bytes=input_buffer[ifd_match_end:ifd_match_end + 0x4],
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byteorder='little') >> 8) & 3) + 1
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# PCH/ICH Strap Length (ME 2-8 & TXE 0-2 & SPS 1-2 <= 0x12, ME 9+ & TXE 3+ & SPS 3+ >= 0x13)
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ifd_flmap1_isl: int = input_buffer[ifd_match_end + 0x7]
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# Component Density Byte (ME 2-8 & TXE 0-2 & SPS 1-2 = 0:5, ME 9+ & TXE 3+ & SPS 3+ = 0:7)
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ifd_comp_den: int = input_buffer[ifd_match_start + ifd_flmap0_fcba]
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# Component 1 Density Bits (ME 2-8 & TXE 0-2 & SPS 1-2 = 3, ME 9+ & TXE 3+ & SPS 3+ = 4)
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ifd_comp_1_bitwise: int = 0xF if ifd_flmap1_isl >= 0x13 else 0x7
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# Component 2 Density Bits (ME 2-8 & TXE 0-2 & SPS 1-2 = 3, ME 9+ & TXE 3+ & SPS 3+ = 4)
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ifd_comp_2_bitwise: int = 0x4 if ifd_flmap1_isl >= 0x13 else 0x3
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# Component 1 Density (FCBA > C0DEN)
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ifd_comp_all_size: int = self.IFD_COMP_LEN[ifd_comp_den & ifd_comp_1_bitwise]
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# Component 2 Density (FCBA > C1DEN)
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if ifd_flmap0_nc == 2:
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ifd_comp_all_size += self.IFD_COMP_LEN[ifd_comp_den >> ifd_comp_2_bitwise]
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ifd_data_bgn: int = ifd_match_start
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ifd_data_end: int = ifd_data_bgn + ifd_comp_all_size
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ifd_data_txt: str = f'0x{ifd_data_bgn:07X}-0x{ifd_data_end:07X}'
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output_data: bytes = input_buffer[ifd_data_bgn:ifd_data_end]
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output_size: int = len(output_data)
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output_name: str = path_stem(in_path=input_object) if isinstance(input_object, str) else 'Part'
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output_path: str = os.path.join(extract_path, f'{output_name}_[{ifd_data_txt}].fd')
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with open(file=output_path, mode='wb') as output_image:
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output_image.write(output_data)
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printer(message=f'Split Apple EFI image at {ifd_data_txt}!', padding=padding)
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if output_size != ifd_comp_all_size:
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printer(message=f'Error: Bad image size 0x{output_size:07X}, expected 0x{ifd_comp_all_size:07X}!',
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padding=padding + 4)
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parse_success = False
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return parse_success
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if __name__ == '__main__':
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AppleEfiIm4pSplit().run_utility()
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