arch-image-builder/external/mkbootimg.py

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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.
"""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 re
# 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.
boot_signature_size = 0
args.output.write(pack('I', boot_signature_size))
pad_file(args.output, BOOT_IMAGE_HEADER_V3_PAGESIZE)
def write_vendor_boot_header(args):
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(sys_argv=None):
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('--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(sys_argv)
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 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):
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(sys_argv=None):
args = parse_cmdline(sys_argv)
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()