mkbootimg: add os_version
Adds operating system version and security patch level to the boot
image header. This change take into use one of the existing unused
fields to preserve compatibility.
Note: All information is packed into a single field, because there
are a lot of existing devices that break if the first unused field
is set to a non-zero value.
Bug: 27498078
Bug: 22914603
Change-Id: I24953129e06019b95014a050e916fe4f5c199286
diff --git a/mkbootimg/bootimg.h b/mkbootimg/bootimg.h
index 5ab6195..60834fe 100644
--- a/mkbootimg/bootimg.h
+++ b/mkbootimg/bootimg.h
@@ -43,7 +43,14 @@
uint32_t tags_addr; /* physical addr for kernel tags */
uint32_t page_size; /* flash page size we assume */
- uint32_t unused[2]; /* future expansion: should be 0 */
+ uint32_t unused; /* reserved for future expansion: MUST be 0 */
+
+ /* operating system version and security patch level; for
+ * version "A.B.C" and patch level "Y-M-D":
+ * ver = A << 14 | B << 7 | C (7 bits for each of A, B, C)
+ * lvl = ((Y - 2000) & 127) << 4 | M (7 bits for Y, 4 bits for M)
+ * os_version = ver << 11 | lvl */
+ uint32_t os_version;
uint8_t name[BOOT_NAME_SIZE]; /* asciiz product name */
diff --git a/mkbootimg/mkbootimg b/mkbootimg/mkbootimg
index f95d703..7b04bcc 100755
--- a/mkbootimg/mkbootimg
+++ b/mkbootimg/mkbootimg
@@ -20,6 +20,7 @@
from struct import pack
from hashlib import sha1
import sys
+import re
def filesize(f):
if f is None:
@@ -47,7 +48,7 @@
def write_header(args):
BOOT_MAGIC = 'ANDROID!'.encode()
args.output.write(pack('8s', BOOT_MAGIC))
- args.output.write(pack('8I',
+ 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
@@ -55,8 +56,9 @@
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.output.write(pack('8x')) # future expansion: should be 0
+ 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()))
@@ -97,6 +99,32 @@
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 = parse_int(match.group(1))
+ b = c = 0
+ if match.lastindex >= 2:
+ b = parse_int(match.group(2))
+ if match.lastindex == 3:
+ c = parse_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 = parse_int(match.group(1)) - 2000
+ m = parse_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()
@@ -111,6 +139,10 @@
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)