| #!/usr/bin/env python3 |
| # |
| # Copyright 2015, The Android Open Source Project |
| # |
| # Licensed under the Apache License, Version 2.0 (the "License"); |
| # you may not use this file except in compliance with the License. |
| # You may obtain a copy of the License at |
| # |
| # http://www.apache.org/licenses/LICENSE-2.0 |
| # |
| # Unless required by applicable law or agreed to in writing, software |
| # distributed under the License is distributed on an "AS IS" BASIS, |
| # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| # See the License for the specific language governing permissions and |
| # limitations under the License. |
| """Creates the boot image.""" |
| from argparse import (ArgumentParser, ArgumentTypeError, |
| FileType, RawDescriptionHelpFormatter) |
| from hashlib import sha1 |
| from os import fstat |
| from struct import pack |
| import array |
| import collections |
| import os |
| import re |
| import subprocess |
| import tempfile |
| # Constant and structure definition is in |
| # system/tools/mkbootimg/include/bootimg/bootimg.h |
| BOOT_MAGIC = 'ANDROID!' |
| BOOT_MAGIC_SIZE = 8 |
| BOOT_NAME_SIZE = 16 |
| BOOT_ARGS_SIZE = 512 |
| BOOT_EXTRA_ARGS_SIZE = 1024 |
| BOOT_IMAGE_HEADER_V1_SIZE = 1648 |
| BOOT_IMAGE_HEADER_V2_SIZE = 1660 |
| BOOT_IMAGE_HEADER_V3_SIZE = 1580 |
| BOOT_IMAGE_HEADER_V3_PAGESIZE = 4096 |
| BOOT_IMAGE_HEADER_V4_SIZE = 1584 |
| BOOT_IMAGE_V4_SIGNATURE_SIZE = 4096 |
| VENDOR_BOOT_MAGIC = 'VNDRBOOT' |
| VENDOR_BOOT_MAGIC_SIZE = 8 |
| VENDOR_BOOT_NAME_SIZE = BOOT_NAME_SIZE |
| VENDOR_BOOT_ARGS_SIZE = 2048 |
| VENDOR_BOOT_IMAGE_HEADER_V3_SIZE = 2112 |
| VENDOR_BOOT_IMAGE_HEADER_V4_SIZE = 2128 |
| VENDOR_RAMDISK_TYPE_NONE = 0 |
| VENDOR_RAMDISK_TYPE_PLATFORM = 1 |
| VENDOR_RAMDISK_TYPE_RECOVERY = 2 |
| VENDOR_RAMDISK_TYPE_DLKM = 3 |
| VENDOR_RAMDISK_NAME_SIZE = 32 |
| VENDOR_RAMDISK_TABLE_ENTRY_BOARD_ID_SIZE = 16 |
| VENDOR_RAMDISK_TABLE_ENTRY_V4_SIZE = 108 |
| # Names with special meaning, mustn't be specified in --ramdisk_name. |
| VENDOR_RAMDISK_NAME_BLOCKLIST = {b'default'} |
| PARSER_ARGUMENT_VENDOR_RAMDISK_FRAGMENT = '--vendor_ramdisk_fragment' |
| def filesize(f): |
| if f is None: |
| return 0 |
| try: |
| return fstat(f.fileno()).st_size |
| except OSError: |
| return 0 |
| def update_sha(sha, f): |
| if f: |
| sha.update(f.read()) |
| f.seek(0) |
| sha.update(pack('I', filesize(f))) |
| else: |
| sha.update(pack('I', 0)) |
| def pad_file(f, padding): |
| pad = (padding - (f.tell() & (padding - 1))) & (padding - 1) |
| f.write(pack(str(pad) + 'x')) |
| def get_number_of_pages(image_size, page_size): |
| """calculates the number of pages required for the image""" |
| return (image_size + page_size - 1) // page_size |
| def get_recovery_dtbo_offset(args): |
| """calculates the offset of recovery_dtbo image in the boot image""" |
| num_header_pages = 1 # header occupies a page |
| num_kernel_pages = get_number_of_pages(filesize(args.kernel), args.pagesize) |
| num_ramdisk_pages = get_number_of_pages(filesize(args.ramdisk), |
| args.pagesize) |
| num_second_pages = get_number_of_pages(filesize(args.second), args.pagesize) |
| dtbo_offset = args.pagesize * (num_header_pages + num_kernel_pages + |
| num_ramdisk_pages + num_second_pages) |
| return dtbo_offset |
| def write_header_v3_and_above(args): |
| if args.header_version > 3: |
| boot_header_size = BOOT_IMAGE_HEADER_V4_SIZE |
| else: |
| boot_header_size = BOOT_IMAGE_HEADER_V3_SIZE |
| args.output.write(pack(f'{BOOT_MAGIC_SIZE}s', BOOT_MAGIC.encode())) |
| # kernel size in bytes |
| args.output.write(pack('I', filesize(args.kernel))) |
| # ramdisk size in bytes |
| args.output.write(pack('I', filesize(args.ramdisk))) |
| # os version and patch level |
| args.output.write(pack('I', (args.os_version << 11) | args.os_patch_level)) |
| args.output.write(pack('I', boot_header_size)) |
| # reserved |
| args.output.write(pack('4I', 0, 0, 0, 0)) |
| # version of boot image header |
| args.output.write(pack('I', args.header_version)) |
| args.output.write(pack(f'{BOOT_ARGS_SIZE + BOOT_EXTRA_ARGS_SIZE}s', |
| args.cmdline)) |
| if args.header_version >= 4: |
| # The signature used to verify boot image v4. |
| args.output.write(pack('I', BOOT_IMAGE_V4_SIGNATURE_SIZE)) |
| pad_file(args.output, BOOT_IMAGE_HEADER_V3_PAGESIZE) |
| def write_vendor_boot_header(args): |
| if filesize(args.dtb) == 0: |
| raise ValueError('DTB image must not be empty.') |
| if args.header_version > 3: |
| vendor_ramdisk_size = args.vendor_ramdisk_total_size |
| vendor_boot_header_size = VENDOR_BOOT_IMAGE_HEADER_V4_SIZE |
| else: |
| vendor_ramdisk_size = filesize(args.vendor_ramdisk) |
| vendor_boot_header_size = VENDOR_BOOT_IMAGE_HEADER_V3_SIZE |
| args.vendor_boot.write(pack(f'{VENDOR_BOOT_MAGIC_SIZE}s', |
| VENDOR_BOOT_MAGIC.encode())) |
| # version of boot image header |
| args.vendor_boot.write(pack('I', args.header_version)) |
| # flash page size |
| args.vendor_boot.write(pack('I', args.pagesize)) |
| # kernel physical load address |
| args.vendor_boot.write(pack('I', args.base + args.kernel_offset)) |
| # ramdisk physical load address |
| args.vendor_boot.write(pack('I', args.base + args.ramdisk_offset)) |
| # ramdisk size in bytes |
| args.vendor_boot.write(pack('I', vendor_ramdisk_size)) |
| args.vendor_boot.write(pack(f'{VENDOR_BOOT_ARGS_SIZE}s', |
| args.vendor_cmdline)) |
| # kernel tags physical load address |
| args.vendor_boot.write(pack('I', args.base + args.tags_offset)) |
| # asciiz product name |
| args.vendor_boot.write(pack(f'{VENDOR_BOOT_NAME_SIZE}s', args.board)) |
| # header size in bytes |
| args.vendor_boot.write(pack('I', vendor_boot_header_size)) |
| # dtb size in bytes |
| args.vendor_boot.write(pack('I', filesize(args.dtb))) |
| # dtb physical load address |
| args.vendor_boot.write(pack('Q', args.base + args.dtb_offset)) |
| if args.header_version > 3: |
| vendor_ramdisk_table_size = (args.vendor_ramdisk_table_entry_num * |
| VENDOR_RAMDISK_TABLE_ENTRY_V4_SIZE) |
| # vendor ramdisk table size in bytes |
| args.vendor_boot.write(pack('I', vendor_ramdisk_table_size)) |
| # number of vendor ramdisk table entries |
| args.vendor_boot.write(pack('I', args.vendor_ramdisk_table_entry_num)) |
| # vendor ramdisk table entry size in bytes |
| args.vendor_boot.write(pack('I', VENDOR_RAMDISK_TABLE_ENTRY_V4_SIZE)) |
| # bootconfig section size in bytes |
| args.vendor_boot.write(pack('I', filesize(args.vendor_bootconfig))) |
| pad_file(args.vendor_boot, args.pagesize) |
| def write_header(args): |
| if args.header_version > 4: |
| raise ValueError( |
| f'Boot header version {args.header_version} not supported') |
| if args.header_version in {3, 4}: |
| return write_header_v3_and_above(args) |
| ramdisk_load_address = ((args.base + args.ramdisk_offset) |
| if filesize(args.ramdisk) > 0 else 0) |
| second_load_address = ((args.base + args.second_offset) |
| if filesize(args.second) > 0 else 0) |
| args.output.write(pack(f'{BOOT_MAGIC_SIZE}s', BOOT_MAGIC.encode())) |
| # kernel size in bytes |
| args.output.write(pack('I', filesize(args.kernel))) |
| # kernel physical load address |
| args.output.write(pack('I', args.base + args.kernel_offset)) |
| # ramdisk size in bytes |
| args.output.write(pack('I', filesize(args.ramdisk))) |
| # ramdisk physical load address |
| args.output.write(pack('I', ramdisk_load_address)) |
| # second bootloader size in bytes |
| args.output.write(pack('I', filesize(args.second))) |
| # second bootloader physical load address |
| args.output.write(pack('I', second_load_address)) |
| # kernel tags physical load address |
| args.output.write(pack('I', args.base + args.tags_offset)) |
| # flash page size |
| args.output.write(pack('I', args.pagesize)) |
| # version of boot image header |
| args.output.write(pack('I', args.header_version)) |
| # os version and patch level |
| args.output.write(pack('I', (args.os_version << 11) | args.os_patch_level)) |
| # asciiz product name |
| args.output.write(pack(f'{BOOT_NAME_SIZE}s', args.board)) |
| args.output.write(pack(f'{BOOT_ARGS_SIZE}s', args.cmdline)) |
| sha = sha1() |
| update_sha(sha, args.kernel) |
| update_sha(sha, args.ramdisk) |
| update_sha(sha, args.second) |
| if args.header_version > 0: |
| update_sha(sha, args.recovery_dtbo) |
| if args.header_version > 1: |
| update_sha(sha, args.dtb) |
| img_id = pack('32s', sha.digest()) |
| args.output.write(img_id) |
| args.output.write(pack(f'{BOOT_EXTRA_ARGS_SIZE}s', args.extra_cmdline)) |
| if args.header_version > 0: |
| if args.recovery_dtbo: |
| # recovery dtbo size in bytes |
| args.output.write(pack('I', filesize(args.recovery_dtbo))) |
| # recovert dtbo offset in the boot image |
| args.output.write(pack('Q', get_recovery_dtbo_offset(args))) |
| else: |
| # Set to zero if no recovery dtbo |
| args.output.write(pack('I', 0)) |
| args.output.write(pack('Q', 0)) |
| # Populate boot image header size for header versions 1 and 2. |
| if args.header_version == 1: |
| args.output.write(pack('I', BOOT_IMAGE_HEADER_V1_SIZE)) |
| elif args.header_version == 2: |
| args.output.write(pack('I', BOOT_IMAGE_HEADER_V2_SIZE)) |
| if args.header_version > 1: |
| if filesize(args.dtb) == 0: |
| raise ValueError('DTB image must not be empty.') |
| # dtb size in bytes |
| args.output.write(pack('I', filesize(args.dtb))) |
| # dtb physical load address |
| args.output.write(pack('Q', args.base + args.dtb_offset)) |
| pad_file(args.output, args.pagesize) |
| return img_id |
| class AsciizBytes: |
| """Parses a string and encodes it as an asciiz bytes object. |
| >>> AsciizBytes(bufsize=4)('foo') |
| b'foo\\x00' |
| >>> AsciizBytes(bufsize=4)('foob') |
| Traceback (most recent call last): |
| ... |
| argparse.ArgumentTypeError: Encoded asciiz length exceeded: max 4, got 5 |
| """ |
| def __init__(self, bufsize): |
| self.bufsize = bufsize |
| def __call__(self, arg): |
| arg_bytes = arg.encode() + b'\x00' |
| if len(arg_bytes) > self.bufsize: |
| raise ArgumentTypeError( |
| 'Encoded asciiz length exceeded: ' |
| f'max {self.bufsize}, got {len(arg_bytes)}') |
| return arg_bytes |
| class VendorRamdiskTableBuilder: |
| """Vendor ramdisk table builder. |
| Attributes: |
| entries: A list of VendorRamdiskTableEntry namedtuple. |
| ramdisk_total_size: Total size in bytes of all ramdisks in the table. |
| """ |
| VendorRamdiskTableEntry = collections.namedtuple( # pylint: disable=invalid-name |
| 'VendorRamdiskTableEntry', |
| ['ramdisk_path', 'ramdisk_size', 'ramdisk_offset', 'ramdisk_type', |
| 'ramdisk_name', 'board_id']) |
| def __init__(self): |
| self.entries = [] |
| self.ramdisk_total_size = 0 |
| self.ramdisk_names = set() |
| def add_entry(self, ramdisk_path, ramdisk_type, ramdisk_name, board_id): |
| # Strip any trailing null for simple comparison. |
| stripped_ramdisk_name = ramdisk_name.rstrip(b'\x00') |
| if stripped_ramdisk_name in VENDOR_RAMDISK_NAME_BLOCKLIST: |
| raise ValueError( |
| f'Banned vendor ramdisk name: {stripped_ramdisk_name}') |
| if stripped_ramdisk_name in self.ramdisk_names: |
| raise ValueError( |
| f'Duplicated vendor ramdisk name: {stripped_ramdisk_name}') |
| self.ramdisk_names.add(stripped_ramdisk_name) |
| if board_id is None: |
| board_id = array.array( |
| 'I', [0] * VENDOR_RAMDISK_TABLE_ENTRY_BOARD_ID_SIZE) |
| else: |
| board_id = array.array('I', board_id) |
| if len(board_id) != VENDOR_RAMDISK_TABLE_ENTRY_BOARD_ID_SIZE: |
| raise ValueError('board_id size must be ' |
| f'{VENDOR_RAMDISK_TABLE_ENTRY_BOARD_ID_SIZE}') |
| with open(ramdisk_path, 'rb') as f: |
| ramdisk_size = filesize(f) |
| self.entries.append(self.VendorRamdiskTableEntry( |
| ramdisk_path, ramdisk_size, self.ramdisk_total_size, ramdisk_type, |
| ramdisk_name, board_id)) |
| self.ramdisk_total_size += ramdisk_size |
| def write_ramdisks_padded(self, fout, alignment): |
| for entry in self.entries: |
| with open(entry.ramdisk_path, 'rb') as f: |
| fout.write(f.read()) |
| pad_file(fout, alignment) |
| def write_entries_padded(self, fout, alignment): |
| for entry in self.entries: |
| fout.write(pack('I', entry.ramdisk_size)) |
| fout.write(pack('I', entry.ramdisk_offset)) |
| fout.write(pack('I', entry.ramdisk_type)) |
| fout.write(pack(f'{VENDOR_RAMDISK_NAME_SIZE}s', |
| entry.ramdisk_name)) |
| fout.write(entry.board_id) |
| pad_file(fout, alignment) |
| def write_padded_file(f_out, f_in, padding): |
| if f_in is None: |
| return |
| f_out.write(f_in.read()) |
| pad_file(f_out, padding) |
| def parse_int(x): |
| return int(x, 0) |
| def parse_os_version(x): |
| match = re.search(r'^(\d{1,3})(?:\.(\d{1,3})(?:\.(\d{1,3}))?)?', x) |
| if match: |
| a = int(match.group(1)) |
| b = c = 0 |
| if match.lastindex >= 2: |
| b = int(match.group(2)) |
| if match.lastindex == 3: |
| c = int(match.group(3)) |
| # 7 bits allocated for each field |
| assert a < 128 |
| assert b < 128 |
| assert c < 128 |
| return (a << 14) | (b << 7) | c |
| return 0 |
| def parse_os_patch_level(x): |
| match = re.search(r'^(\d{4})-(\d{2})(?:-(\d{2}))?', x) |
| if match: |
| y = int(match.group(1)) - 2000 |
| m = int(match.group(2)) |
| # 7 bits allocated for the year, 4 bits for the month |
| assert 0 <= y < 128 |
| assert 0 < m <= 12 |
| return (y << 4) | m |
| return 0 |
| def parse_vendor_ramdisk_type(x): |
| type_dict = { |
| 'none': VENDOR_RAMDISK_TYPE_NONE, |
| 'platform': VENDOR_RAMDISK_TYPE_PLATFORM, |
| 'recovery': VENDOR_RAMDISK_TYPE_RECOVERY, |
| 'dlkm': VENDOR_RAMDISK_TYPE_DLKM, |
| } |
| if x.lower() in type_dict: |
| return type_dict[x.lower()] |
| return parse_int(x) |
| def get_vendor_boot_v4_usage(): |
| return """vendor boot version 4 arguments: |
| --ramdisk_type {none,platform,recovery,dlkm} |
| specify the type of the ramdisk |
| --ramdisk_name NAME |
| specify the name of the ramdisk |
| --board_id{0..15} NUMBER |
| specify the value of the board_id vector, defaults to 0 |
| --vendor_ramdisk_fragment VENDOR_RAMDISK_FILE |
| path to the vendor ramdisk file |
| These options can be specified multiple times, where each vendor ramdisk |
| option group ends with a --vendor_ramdisk_fragment option. |
| Each option group appends an additional ramdisk to the vendor boot image. |
| """ |
| def parse_vendor_ramdisk_args(args, args_list): |
| """Parses vendor ramdisk specific arguments. |
| Args: |
| args: An argparse.Namespace object. Parsed results are stored into this |
| object. |
| args_list: A list of argument strings to be parsed. |
| Returns: |
| A list argument strings that are not parsed by this method. |
| """ |
| parser = ArgumentParser(add_help=False) |
| parser.add_argument('--ramdisk_type', type=parse_vendor_ramdisk_type, |
| default=VENDOR_RAMDISK_TYPE_NONE) |
| parser.add_argument('--ramdisk_name', |
| type=AsciizBytes(bufsize=VENDOR_RAMDISK_NAME_SIZE), |
| required=True) |
| for i in range(VENDOR_RAMDISK_TABLE_ENTRY_BOARD_ID_SIZE): |
| parser.add_argument(f'--board_id{i}', type=parse_int, default=0) |
| parser.add_argument(PARSER_ARGUMENT_VENDOR_RAMDISK_FRAGMENT, required=True) |
| unknown_args = [] |
| vendor_ramdisk_table_builder = VendorRamdiskTableBuilder() |
| if args.vendor_ramdisk is not None: |
| vendor_ramdisk_table_builder.add_entry( |
| args.vendor_ramdisk.name, VENDOR_RAMDISK_TYPE_PLATFORM, b'', None) |
| while PARSER_ARGUMENT_VENDOR_RAMDISK_FRAGMENT in args_list: |
| idx = args_list.index(PARSER_ARGUMENT_VENDOR_RAMDISK_FRAGMENT) + 2 |
| vendor_ramdisk_args = args_list[:idx] |
| args_list = args_list[idx:] |
| ramdisk_args, extra_args = parser.parse_known_args(vendor_ramdisk_args) |
| ramdisk_args_dict = vars(ramdisk_args) |
| unknown_args.extend(extra_args) |
| ramdisk_path = ramdisk_args.vendor_ramdisk_fragment |
| ramdisk_type = ramdisk_args.ramdisk_type |
| ramdisk_name = ramdisk_args.ramdisk_name |
| board_id = [ramdisk_args_dict[f'board_id{i}'] |
| for i in range(VENDOR_RAMDISK_TABLE_ENTRY_BOARD_ID_SIZE)] |
| vendor_ramdisk_table_builder.add_entry(ramdisk_path, ramdisk_type, |
| ramdisk_name, board_id) |
| if len(args_list) > 0: |
| unknown_args.extend(args_list) |
| args.vendor_ramdisk_total_size = (vendor_ramdisk_table_builder |
| .ramdisk_total_size) |
| args.vendor_ramdisk_table_entry_num = len(vendor_ramdisk_table_builder |
| .entries) |
| args.vendor_ramdisk_table_builder = vendor_ramdisk_table_builder |
| return unknown_args |
| def parse_cmdline(): |
| version_parser = ArgumentParser(add_help=False) |
| version_parser.add_argument('--header_version', type=parse_int, default=0) |
| if version_parser.parse_known_args()[0].header_version < 3: |
| # For boot header v0 to v2, the kernel commandline field is split into |
| # two fields, cmdline and extra_cmdline. Both fields are asciiz strings, |
| # so we minus one here to ensure the encoded string plus the |
| # null-terminator can fit in the buffer size. |
| cmdline_size = BOOT_ARGS_SIZE + BOOT_EXTRA_ARGS_SIZE - 1 |
| else: |
| cmdline_size = BOOT_ARGS_SIZE + BOOT_EXTRA_ARGS_SIZE |
| parser = ArgumentParser(formatter_class=RawDescriptionHelpFormatter, |
| epilog=get_vendor_boot_v4_usage()) |
| parser.add_argument('--kernel', type=FileType('rb'), |
| help='path to the kernel') |
| parser.add_argument('--ramdisk', type=FileType('rb'), |
| help='path to the ramdisk') |
| parser.add_argument('--second', type=FileType('rb'), |
| help='path to the second bootloader') |
| parser.add_argument('--dtb', type=FileType('rb'), help='path to the dtb') |
| dtbo_group = parser.add_mutually_exclusive_group() |
| dtbo_group.add_argument('--recovery_dtbo', type=FileType('rb'), |
| help='path to the recovery DTBO') |
| dtbo_group.add_argument('--recovery_acpio', type=FileType('rb'), |
| metavar='RECOVERY_ACPIO', dest='recovery_dtbo', |
| help='path to the recovery ACPIO') |
| parser.add_argument('--cmdline', type=AsciizBytes(bufsize=cmdline_size), |
| default='', help='kernel command line arguments') |
| parser.add_argument('--vendor_cmdline', |
| type=AsciizBytes(bufsize=VENDOR_BOOT_ARGS_SIZE), |
| default='', |
| help='vendor boot kernel command line arguments') |
| parser.add_argument('--base', type=parse_int, default=0x10000000, |
| help='base address') |
| parser.add_argument('--kernel_offset', type=parse_int, default=0x00008000, |
| help='kernel offset') |
| parser.add_argument('--ramdisk_offset', type=parse_int, default=0x01000000, |
| help='ramdisk offset') |
| parser.add_argument('--second_offset', type=parse_int, default=0x00f00000, |
| help='second bootloader offset') |
| parser.add_argument('--dtb_offset', type=parse_int, default=0x01f00000, |
| help='dtb offset') |
| parser.add_argument('--os_version', type=parse_os_version, default=0, |
| help='operating system version') |
| parser.add_argument('--os_patch_level', type=parse_os_patch_level, |
| default=0, help='operating system patch level') |
| parser.add_argument('--tags_offset', type=parse_int, default=0x00000100, |
| help='tags offset') |
| parser.add_argument('--board', type=AsciizBytes(bufsize=BOOT_NAME_SIZE), |
| default='', help='board name') |
| parser.add_argument('--pagesize', type=parse_int, |
| choices=[2**i for i in range(11, 15)], default=2048, |
| help='page size') |
| parser.add_argument('--id', action='store_true', |
| help='print the image ID on standard output') |
| parser.add_argument('--header_version', type=parse_int, default=0, |
| help='boot image header version') |
| parser.add_argument('-o', '--output', type=FileType('wb'), |
| help='output file name') |
| parser.add_argument('--gki_signing_algorithm', |
| help='GKI signing algorithm to use') |
| parser.add_argument('--gki_signing_key', |
| help='path to RSA private key file') |
| parser.add_argument('--gki_signing_signature_args', |
| help='other hash arguments passed to avbtool') |
| parser.add_argument('--gki_signing_avbtool_path', |
| help='path to avbtool for boot signature generation') |
| parser.add_argument('--vendor_boot', type=FileType('wb'), |
| help='vendor boot output file name') |
| parser.add_argument('--vendor_ramdisk', type=FileType('rb'), |
| help='path to the vendor ramdisk') |
| parser.add_argument('--vendor_bootconfig', type=FileType('rb'), |
| help='path to the vendor bootconfig file') |
| args, extra_args = parser.parse_known_args() |
| if args.vendor_boot is not None and args.header_version > 3: |
| extra_args = parse_vendor_ramdisk_args(args, extra_args) |
| if len(extra_args) > 0: |
| raise ValueError(f'Unrecognized arguments: {extra_args}') |
| if args.header_version < 3: |
| args.extra_cmdline = args.cmdline[BOOT_ARGS_SIZE-1:] |
| args.cmdline = args.cmdline[:BOOT_ARGS_SIZE-1] + b'\x00' |
| assert len(args.cmdline) <= BOOT_ARGS_SIZE |
| assert len(args.extra_cmdline) <= BOOT_EXTRA_ARGS_SIZE |
| return args |
| def add_boot_image_signature(args, pagesize): |
| """Adds the boot image signature. |
| Note that the signature will only be verified in VTS to ensure a |
| generic boot.img is used. It will not be used by the device |
| bootloader at boot time. The bootloader should only verify |
| the boot vbmeta at the end of the boot partition (or in the top-level |
| vbmeta partition) via the Android Verified Boot process, when the |
| device boots. |
| """ |
| args.output.flush() # Flush the buffer for signature calculation. |
| # Appends zeros if the signing key is not specified. |
| if not args.gki_signing_key or not args.gki_signing_algorithm: |
| zeros = b'\x00' * BOOT_IMAGE_V4_SIGNATURE_SIZE |
| args.output.write(zeros) |
| pad_file(args.output, pagesize) |
| return |
| avbtool = 'avbtool' # Used from otatools.zip or Android build env. |
| # We need to specify the path of avbtool in build/core/Makefile. |
| # Because avbtool is not guaranteed to be in $PATH there. |
| if args.gki_signing_avbtool_path: |
| avbtool = args.gki_signing_avbtool_path |
| # Need to specify a value of --partition_size for avbtool to work. |
| # We use 64 MB below, but avbtool will not resize the boot image to |
| # this size because --do_not_append_vbmeta_image is also specified. |
| avbtool_cmd = [ |
| avbtool, 'add_hash_footer', |
| '--partition_name', 'boot', |
| '--partition_size', str(64 * 1024 * 1024), |
| '--image', args.output.name, |
| '--algorithm', args.gki_signing_algorithm, |
| '--key', args.gki_signing_key, |
| '--salt', 'd00df00d'] # TODO: use a hash of kernel/ramdisk as the salt. |
| # Additional arguments passed to avbtool. |
| if args.gki_signing_signature_args: |
| avbtool_cmd += args.gki_signing_signature_args.split() |
| # Outputs the signed vbmeta to a separate file, then append to boot.img |
| # as the boot signature. |
| with tempfile.TemporaryDirectory() as temp_out_dir: |
| boot_signature_output = os.path.join(temp_out_dir, 'boot_signature') |
| avbtool_cmd += ['--do_not_append_vbmeta_image', |
| '--output_vbmeta_image', boot_signature_output] |
| subprocess.check_call(avbtool_cmd) |
| with open(boot_signature_output, 'rb') as boot_signature: |
| if filesize(boot_signature) > BOOT_IMAGE_V4_SIGNATURE_SIZE: |
| raise ValueError( |
| f'boot sigature size is > {BOOT_IMAGE_V4_SIGNATURE_SIZE}') |
| write_padded_file(args.output, boot_signature, pagesize) |
| def write_data(args, pagesize): |
| write_padded_file(args.output, args.kernel, pagesize) |
| write_padded_file(args.output, args.ramdisk, pagesize) |
| write_padded_file(args.output, args.second, pagesize) |
| if args.header_version > 0 and args.header_version < 3: |
| write_padded_file(args.output, args.recovery_dtbo, pagesize) |
| if args.header_version == 2: |
| write_padded_file(args.output, args.dtb, pagesize) |
| if args.header_version >= 4: |
| add_boot_image_signature(args, pagesize) |
| def write_vendor_boot_data(args): |
| if args.header_version > 3: |
| builder = args.vendor_ramdisk_table_builder |
| builder.write_ramdisks_padded(args.vendor_boot, args.pagesize) |
| write_padded_file(args.vendor_boot, args.dtb, args.pagesize) |
| builder.write_entries_padded(args.vendor_boot, args.pagesize) |
| write_padded_file(args.vendor_boot, args.vendor_bootconfig, |
| args.pagesize) |
| else: |
| write_padded_file(args.vendor_boot, args.vendor_ramdisk, args.pagesize) |
| write_padded_file(args.vendor_boot, args.dtb, args.pagesize) |
| def main(): |
| args = parse_cmdline() |
| if args.vendor_boot is not None: |
| if args.header_version not in {3, 4}: |
| raise ValueError( |
| '--vendor_boot not compatible with given header version') |
| if args.header_version == 3 and args.vendor_ramdisk is None: |
| raise ValueError('--vendor_ramdisk missing or invalid') |
| write_vendor_boot_header(args) |
| write_vendor_boot_data(args) |
| if args.output is not None: |
| if args.second is not None and args.header_version > 2: |
| raise ValueError( |
| '--second not compatible with given header version') |
| img_id = write_header(args) |
| if args.header_version > 2: |
| write_data(args, BOOT_IMAGE_HEADER_V3_PAGESIZE) |
| else: |
| write_data(args, args.pagesize) |
| if args.id and img_id is not None: |
| print('0x' + ''.join(f'{octet:02x}' for octet in img_id)) |
| if __name__ == '__main__': |
| main() |