#!/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 write_header(args): BOOT_MAGIC = 'ANDROID!'.encode() dt_addr = args.tags_addr if 0 == dt_addr: dt_addr = args.base + args.tags_offset 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 dt_addr, # physical addr for kernel tags args.pagesize, # flash page size we assume 0, # future expansion: MUST be 0 (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) img_id = pack('32s', sha.digest()) args.output.write(img_id) args.output.write(pack('1024s', args.cmdline[512:].encode())) 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 = 0 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')) 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('--tags-addr', help='tags addr', type=parse_int, default=0x0) 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('-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) 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()