| #!/usr/bin/env python |
| # 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. |
| |
| from __future__ import print_function |
| from sys import argv, exit, stderr |
| from argparse import ArgumentParser, FileType, Action |
| from os import fstat |
| from struct import pack |
| from hashlib import sha1 |
| import sys |
| import re |
| |
| 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(args): |
| BOOT_MAGIC = 'ANDROID!'.encode() |
| args.output.write(pack('8s', BOOT_MAGIC)) |
| args.output.write(pack('10I', |
| filesize(args.kernel), # size in bytes |
| args.base + args.kernel_offset, # physical load addr |
| filesize(args.ramdisk), # size in bytes |
| args.base + args.ramdisk_offset, # physical load addr |
| filesize(args.second), # size in bytes |
| args.base + args.second_offset, # physical load addr |
| args.base + args.tags_offset, # physical addr for kernel tags |
| args.pagesize, # flash page size we assume |
| args.header_version, # version of bootimage header |
| (args.os_version << 11) | args.os_patch_level)) # os version and patch level |
| args.output.write(pack('16s', args.board.encode())) # asciiz product name |
| args.output.write(pack('512s', args.cmdline[:512].encode())) |
| |
| 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) |
| |
| img_id = pack('32s', sha.digest()) |
| |
| args.output.write(img_id) |
| args.output.write(pack('1024s', args.cmdline[512:].encode())) |
| |
| if args.header_version > 0: |
| args.output.write(pack('I', filesize(args.recovery_dtbo))) # size in bytes |
| if args.recovery_dtbo: |
| args.output.write(pack('Q', get_recovery_dtbo_offset(args))) # recovery dtbo offset |
| else: |
| args.output.write(pack('Q', 0)) # Will be set to 0 for devices without a recovery dtbo |
| args.output.write(pack('I', args.output.tell() + 4)) # size of boot header |
| |
| pad_file(args.output, args.pagesize) |
| return img_id |
| |
| |
| class ValidateStrLenAction(Action): |
| def __init__(self, option_strings, dest, nargs=None, **kwargs): |
| if 'maxlen' not in kwargs: |
| raise ValueError('maxlen must be set') |
| self.maxlen = int(kwargs['maxlen']) |
| del kwargs['maxlen'] |
| super(ValidateStrLenAction, self).__init__(option_strings, dest, **kwargs) |
| |
| def __call__(self, parser, namespace, values, option_string=None): |
| if len(values) > self.maxlen: |
| raise ValueError('String argument too long: max {0:d}, got {1:d}'. |
| format(self.maxlen, len(values))) |
| setattr(namespace, self.dest, values) |
| |
| |
| 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 y >= 0 and y < 128 |
| assert m > 0 and m <= 12 |
| return (y << 4) | m |
| return 0 |
| |
| def parse_cmdline(): |
| parser = ArgumentParser() |
| parser.add_argument('--kernel', help='path to the kernel', type=FileType('rb'), |
| required=True) |
| parser.add_argument('--ramdisk', help='path to the ramdisk', type=FileType('rb')) |
| parser.add_argument('--second', help='path to the 2nd bootloader', type=FileType('rb')) |
| recovery_dtbo_group = parser.add_mutually_exclusive_group() |
| recovery_dtbo_group.add_argument('--recovery_dtbo', help='path to the recovery DTBO', type=FileType('rb')) |
| recovery_dtbo_group.add_argument('--recovery_acpio', help='path to the recovery ACPIO', |
| type=FileType('rb'), metavar='RECOVERY_ACPIO', dest='recovery_dtbo') |
| parser.add_argument('--cmdline', help='extra arguments to be passed on the ' |
| 'kernel command line', default='', action=ValidateStrLenAction, maxlen=1536) |
| parser.add_argument('--base', help='base address', type=parse_int, default=0x10000000) |
| parser.add_argument('--kernel_offset', help='kernel offset', type=parse_int, default=0x00008000) |
| parser.add_argument('--ramdisk_offset', help='ramdisk offset', type=parse_int, default=0x01000000) |
| parser.add_argument('--second_offset', help='2nd bootloader offset', type=parse_int, |
| default=0x00f00000) |
| parser.add_argument('--os_version', help='operating system version', type=parse_os_version, |
| default=0) |
| parser.add_argument('--os_patch_level', help='operating system patch level', |
| type=parse_os_patch_level, default=0) |
| parser.add_argument('--tags_offset', help='tags offset', type=parse_int, default=0x00000100) |
| parser.add_argument('--board', help='board name', default='', action=ValidateStrLenAction, |
| maxlen=16) |
| parser.add_argument('--pagesize', help='page size', type=parse_int, |
| choices=[2**i for i in range(11,15)], default=2048) |
| parser.add_argument('--id', help='print the image ID on standard output', |
| action='store_true') |
| parser.add_argument('--header_version', help='boot image header version', type=parse_int, default=0) |
| parser.add_argument('-o', '--output', help='output file name', type=FileType('wb'), |
| required=True) |
| return parser.parse_args() |
| |
| |
| def write_data(args): |
| write_padded_file(args.output, args.kernel, args.pagesize) |
| write_padded_file(args.output, args.ramdisk, args.pagesize) |
| write_padded_file(args.output, args.second, args.pagesize) |
| |
| if args.header_version > 0: |
| write_padded_file(args.output, args.recovery_dtbo, args.pagesize) |
| |
| def main(): |
| args = parse_cmdline() |
| img_id = write_header(args) |
| write_data(args) |
| if args.id: |
| if isinstance(img_id, str): |
| # Python 2's struct.pack returns a string, but py3 returns bytes. |
| img_id = [ord(x) for x in img_id] |
| print('0x' + ''.join('{:02x}'.format(c) for c in img_id)) |
| |
| if __name__ == '__main__': |
| main() |
