mirror of
https://github.com/platomav/BIOSUtilities.git
synced 2025-05-13 06:34:42 -04:00
d8e23f9ef3
New "package" flow, arguments now provided during utility call (README) New "main" flow, using old "run_utility" method of BIOSUtility (README) Removed "run_utility" and "show_version" methods from base BIOSUtility Removed argparse argument parsing logic from base BIOSUtility class Removed notion of "pause" (i.e. user action) from BIOSUtility logic Adjusted the README with usage info for "main" and "package" flows
156 lines
6 KiB
Python
156 lines
6 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) -> bool:
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""" Check if input is Apple EFI IM4P image """
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if isinstance(self.input_object, str) and not self.input_object.lower().endswith('.im4p'):
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return False
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input_buffer: bytes = file_to_bytes(in_object=self.input_object)
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if PAT_APPLE_IM4P.search(input_buffer) and PAT_INTEL_FD.search(input_buffer):
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return True
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return False
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def parse_format(self) -> 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=self.input_object)
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make_dirs(in_path=self.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(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(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(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(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=self.input_object) if isinstance(self.input_object, str) else 'Part'
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output_path: str = os.path.join(self.extract_path, f'{output_name}_[{ifd_data_txt}].fd')
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with open(output_path, '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=self.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=self.padding + 4)
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parse_success = False
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return parse_success
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