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#!/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.
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 = 2108
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()
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