#!/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 argparse import ArgumentParser, FileType, Action from hashlib import sha1 from os import fstat import re from struct import pack BOOT_IMAGE_HEADER_V3_PAGESIZE = 4096 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(args): BOOT_IMAGE_HEADER_V3_SIZE = 1596 BOOT_MAGIC = 'ANDROID!'.encode() args.output.write(pack('8s', BOOT_MAGIC)) args.output.write(pack( '4I', filesize(args.kernel), # kernel size in bytes filesize(args.ramdisk), # ramdisk size in bytes (args.os_version << 11) | args.os_patch_level, # os version and patch level BOOT_IMAGE_HEADER_V3_SIZE)) args.output.write(pack('4I', 0, 0, 0, 0)) # reserved args.output.write(pack('I', args.header_version)) # version of bootimage header args.output.write(pack('1536s', args.cmdline.encode())) pad_file(args.output, BOOT_IMAGE_HEADER_V3_PAGESIZE) def write_vendor_boot_header(args): VENDOR_BOOT_IMAGE_HEADER_V3_SIZE = 2112 BOOT_MAGIC = 'VNDRBOOT'.encode() args.vendor_boot.write(pack('8s', BOOT_MAGIC)) args.vendor_boot.write(pack( '5I', args.header_version, # version of header args.pagesize, # flash page size we assume args.base + args.kernel_offset, # kernel physical load addr args.base + args.ramdisk_offset, # ramdisk physical load addr filesize(args.vendor_ramdisk))) # vendor ramdisk size in bytes args.vendor_boot.write(pack('2048s', args.vendor_cmdline.encode())) args.vendor_boot.write(pack('I', args.base + args.tags_offset)) # physical addr for kernel tags args.vendor_boot.write(pack('16s', args.board.encode())) # asciiz product name args.vendor_boot.write(pack('I', VENDOR_BOOT_IMAGE_HEADER_V3_SIZE)) # header size in bytes if filesize(args.dtb) == 0: raise ValueError("DTB image must not be empty.") args.vendor_boot.write(pack('I', filesize(args.dtb))) # size in bytes args.vendor_boot.write(pack('Q', args.base + args.dtb_offset)) # dtb physical load address pad_file(args.vendor_boot, args.pagesize) def write_header(args): BOOT_IMAGE_HEADER_V1_SIZE = 1648 BOOT_IMAGE_HEADER_V2_SIZE = 1660 BOOT_MAGIC = 'ANDROID!'.encode() if args.header_version > 3: raise ValueError('Boot header version %d not supported' % args.header_version) elif args.header_version == 3: return write_header_v3(args) args.output.write(pack('8s', BOOT_MAGIC)) final_ramdisk_offset = (args.base + args.ramdisk_offset) if filesize(args.ramdisk) > 0 else 0 final_second_offset = (args.base + args.second_offset) if filesize(args.second) > 0 else 0 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 final_ramdisk_offset, # physical load addr filesize(args.second), # size in bytes final_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) 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('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 # 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.") args.output.write(pack('I', filesize(args.dtb))) # size in bytes args.output.write(pack('Q', args.base + args.dtb_offset)) # dtb physical load address 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 0 <= y < 128 assert 0 < 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')) 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')) parser.add_argument('--dtb', help='path to dtb', 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('--vendor_cmdline', help='kernel command line arguments contained in vendor boot', default='', action=ValidateStrLenAction, maxlen=2048) 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('--dtb_offset', help='dtb offset', type=parse_int, default=0x01f00000) 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')) parser.add_argument('--vendor_boot', help='vendor boot output file name', type=FileType('wb')) parser.add_argument('--vendor_ramdisk', help='path to the vendor ramdisk', type=FileType('rb')) return parser.parse_args() 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) def write_vendor_boot_data(args): 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 < 3: raise ValueError('--vendor_boot not compatible with given header version') if 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.kernel is None: raise ValueError('kernel must be supplied when creating a boot image') 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: # Python 2's struct.pack returns a string, but py3 returns bytes. if isinstance(img_id, str): img_id = [ord(x) for x in img_id] print('0x' + ''.join('{:02x}'.format(c) for c in img_id)) if __name__ == '__main__': main()