#!/usr/bin/env python
#
# Copyright (C) 2011 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.
"""
Build image output_image_file from input_directory and properties_file.
Usage: build_image input_directory properties_file output_image_file
"""
import os
import os.path
import re
import subprocess
import sys
import commands
import common
import shutil
import tempfile
OPTIONS = common.OPTIONS
FIXED_SALT = "aee087a5be3b982978c923f566a94613496b417f2af592639bc80d141e34dfe7"
def RunCommand(cmd):
"""Echo and run the given command.
Args:
cmd: the command represented as a list of strings.
Returns:
A tuple of the output and the exit code.
"""
print "Running: ", " ".join(cmd)
p = subprocess.Popen(cmd, stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
output, _ = p.communicate()
print "%s" % (output.rstrip(),)
return (output, p.returncode)
def GetVerityTreeSize(partition_size):
cmd = "build_verity_tree -s %d"
cmd %= partition_size
status, output = commands.getstatusoutput(cmd)
if status:
print output
return False, 0
return True, int(output)
def GetVerityMetadataSize(partition_size):
cmd = "system/extras/verity/build_verity_metadata.py -s %d"
cmd %= partition_size
status, output = commands.getstatusoutput(cmd)
if status:
print output
return False, 0
return True, int(output)
def AdjustPartitionSizeForVerity(partition_size):
"""Modifies the provided partition size to account for the verity metadata.
This information is used to size the created image appropriately.
Args:
partition_size: the size of the partition to be verified.
Returns:
The size of the partition adjusted for verity metadata.
"""
success, verity_tree_size = GetVerityTreeSize(partition_size)
if not success:
return 0
success, verity_metadata_size = GetVerityMetadataSize(partition_size)
if not success:
return 0
return partition_size - verity_tree_size - verity_metadata_size
def BuildVerityTree(sparse_image_path, verity_image_path, prop_dict):
cmd = "build_verity_tree -A %s %s %s" % (
FIXED_SALT, sparse_image_path, verity_image_path)
print cmd
status, output = commands.getstatusoutput(cmd)
if status:
print "Could not build verity tree! Error: %s" % output
return False
root, salt = output.split()
prop_dict["verity_root_hash"] = root
prop_dict["verity_salt"] = salt
return True
def BuildVerityMetadata(image_size, verity_metadata_path, root_hash, salt,
block_device, signer_path, key):
cmd_template = (
"system/extras/verity/build_verity_metadata.py %s %s %s %s %s %s %s")
cmd = cmd_template % (image_size, verity_metadata_path, root_hash, salt,
block_device, signer_path, key)
print cmd
status, output = commands.getstatusoutput(cmd)
if status:
print "Could not build verity metadata! Error: %s" % output
return False
return True
def Append2Simg(sparse_image_path, unsparse_image_path, error_message):
"""Appends the unsparse image to the given sparse image.
Args:
sparse_image_path: the path to the (sparse) image
unsparse_image_path: the path to the (unsparse) image
Returns:
True on success, False on failure.
"""
cmd = "append2simg %s %s"
cmd %= (sparse_image_path, unsparse_image_path)
print cmd
status, output = commands.getstatusoutput(cmd)
if status:
print "%s: %s" % (error_message, output)
return False
return True
def BuildVerifiedImage(data_image_path, verity_image_path,
verity_metadata_path):
if not Append2Simg(data_image_path, verity_metadata_path,
"Could not append verity metadata!"):
return False
if not Append2Simg(data_image_path, verity_image_path,
"Could not append verity tree!"):
return False
return True
def UnsparseImage(sparse_image_path, replace=True):
img_dir = os.path.dirname(sparse_image_path)
unsparse_image_path = "unsparse_" + os.path.basename(sparse_image_path)
unsparse_image_path = os.path.join(img_dir, unsparse_image_path)
if os.path.exists(unsparse_image_path):
if replace:
os.unlink(unsparse_image_path)
else:
return True, unsparse_image_path
inflate_command = ["simg2img", sparse_image_path, unsparse_image_path]
(_, exit_code) = RunCommand(inflate_command)
if exit_code != 0:
os.remove(unsparse_image_path)
return False, None
return True, unsparse_image_path
def MakeVerityEnabledImage(out_file, prop_dict):
"""Creates an image that is verifiable using dm-verity.
Args:
out_file: the location to write the verifiable image at
prop_dict: a dictionary of properties required for image creation and
verification
Returns:
True on success, False otherwise.
"""
# get properties
image_size = prop_dict["partition_size"]
block_dev = prop_dict["verity_block_device"]
signer_key = prop_dict["verity_key"] + ".pk8"
if OPTIONS.verity_signer_path is not None:
signer_path = OPTIONS.verity_signer_path + ' '
signer_path += ' '.join(OPTIONS.verity_signer_args)
else:
signer_path = prop_dict["verity_signer_cmd"]
# make a tempdir
tempdir_name = tempfile.mkdtemp(suffix="_verity_images")
# get partial image paths
verity_image_path = os.path.join(tempdir_name, "verity.img")
verity_metadata_path = os.path.join(tempdir_name, "verity_metadata.img")
# build the verity tree and get the root hash and salt
if not BuildVerityTree(out_file, verity_image_path, prop_dict):
shutil.rmtree(tempdir_name, ignore_errors=True)
return False
# build the metadata blocks
root_hash = prop_dict["verity_root_hash"]
salt = prop_dict["verity_salt"]
if not BuildVerityMetadata(image_size, verity_metadata_path, root_hash, salt,
block_dev, signer_path, signer_key):
shutil.rmtree(tempdir_name, ignore_errors=True)
return False
# build the full verified image
if not BuildVerifiedImage(out_file,
verity_image_path,
verity_metadata_path):
shutil.rmtree(tempdir_name, ignore_errors=True)
return False
shutil.rmtree(tempdir_name, ignore_errors=True)
return True
def BuildImage(in_dir, prop_dict, out_file, target_out=None):
"""Build an image to out_file from in_dir with property prop_dict.
Args:
in_dir: path of input directory.
prop_dict: property dictionary.
out_file: path of the output image file.
target_out: path of the product out directory to read device specific FS config files.
Returns:
True iff the image is built successfully.
"""
# system_root_image=true: build a system.img that combines the contents of
# /system and the ramdisk, and can be mounted at the root of the file system.
origin_in = in_dir
fs_config = prop_dict.get("fs_config")
if (prop_dict.get("system_root_image") == "true"
and prop_dict["mount_point"] == "system"):
in_dir = tempfile.mkdtemp()
# Change the mount point to "/"
prop_dict["mount_point"] = "/"
if fs_config:
# We need to merge the fs_config files of system and ramdisk.
fd, merged_fs_config = tempfile.mkstemp(prefix="root_fs_config",
suffix=".txt")
os.close(fd)
with open(merged_fs_config, "w") as fw:
if "ramdisk_fs_config" in prop_dict:
with open(prop_dict["ramdisk_fs_config"]) as fr:
fw.writelines(fr.readlines())
with open(fs_config) as fr:
fw.writelines(fr.readlines())
fs_config = merged_fs_config
build_command = []
fs_type = prop_dict.get("fs_type", "")
run_fsck = False
fs_spans_partition = True
if fs_type.startswith("squash"):
fs_spans_partition = False
is_verity_partition = "verity_block_device" in prop_dict
verity_supported = prop_dict.get("verity") == "true"
# Adjust the partition size to make room for the hashes if this is to be
# verified.
if verity_supported and is_verity_partition and fs_spans_partition:
partition_size = int(prop_dict.get("partition_size"))
adjusted_size = AdjustPartitionSizeForVerity(partition_size)
if not adjusted_size:
return False
prop_dict["partition_size"] = str(adjusted_size)
prop_dict["original_partition_size"] = str(partition_size)
if fs_type.startswith("ext"):
build_command = ["mkuserimg.sh"]
if "extfs_sparse_flag" in prop_dict:
build_command.append(prop_dict["extfs_sparse_flag"])
run_fsck = True
build_command.extend([in_dir, out_file, fs_type,
prop_dict["mount_point"]])
build_command.append(prop_dict["partition_size"])
if "journal_size" in prop_dict:
build_command.extend(["-j", prop_dict["journal_size"]])
if "timestamp" in prop_dict:
build_command.extend(["-T", str(prop_dict["timestamp"])])
if fs_config:
build_command.extend(["-C", fs_config])
if target_out:
build_command.extend(["-D", target_out])
if "block_list" in prop_dict:
build_command.extend(["-B", prop_dict["block_list"]])
build_command.extend(["-L", prop_dict["mount_point"]])
if "selinux_fc" in prop_dict:
build_command.append(prop_dict["selinux_fc"])
elif fs_type.startswith("squash"):
build_command = ["mksquashfsimage.sh"]
build_command.extend([in_dir, out_file])
build_command.extend(["-s"])
build_command.extend(["-m", prop_dict["mount_point"]])
if target_out:
build_command.extend(["-d", target_out])
if "selinux_fc" in prop_dict:
build_command.extend(["-c", prop_dict["selinux_fc"]])
if "squashfs_compressor" in prop_dict:
build_command.extend(["-z", prop_dict["squashfs_compressor"]])
if "squashfs_compressor_opt" in prop_dict:
build_command.extend(["-zo", prop_dict["squashfs_compressor_opt"]])
elif fs_type.startswith("f2fs"):
build_command = ["mkf2fsuserimg.sh"]
build_command.extend([out_file, prop_dict["partition_size"]])
else:
build_command = ["mkyaffs2image", "-f"]
if prop_dict.get("mkyaffs2_extra_flags", None):
build_command.extend(prop_dict["mkyaffs2_extra_flags"].split())
build_command.append(in_dir)
build_command.append(out_file)
if "selinux_fc" in prop_dict:
build_command.append(prop_dict["selinux_fc"])
build_command.append(prop_dict["mount_point"])
if in_dir != origin_in:
# Construct a staging directory of the root file system.
ramdisk_dir = prop_dict.get("ramdisk_dir")
if ramdisk_dir:
shutil.rmtree(in_dir)
shutil.copytree(ramdisk_dir, in_dir, symlinks=True)
staging_system = os.path.join(in_dir, "system")
shutil.rmtree(staging_system, ignore_errors=True)
shutil.copytree(origin_in, staging_system, symlinks=True)
reserved_blocks = prop_dict.get("has_ext4_reserved_blocks") == "true"
ext4fs_output = None
try:
if reserved_blocks and fs_type.startswith("ext4"):
(ext4fs_output, exit_code) = RunCommand(build_command)
else:
(_, exit_code) = RunCommand(build_command)
finally:
if in_dir != origin_in:
# Clean up temporary directories and files.
shutil.rmtree(in_dir, ignore_errors=True)
if fs_config:
os.remove(fs_config)
if exit_code != 0:
return False
# Bug: 21522719, 22023465
# There are some reserved blocks on ext4 FS (lesser of 4096 blocks and 2%).
# We need to deduct those blocks from the available space, since they are
# not writable even with root privilege. It only affects devices using
# file-based OTA and a kernel version of 3.10 or greater (currently just
# sprout).
if reserved_blocks and fs_type.startswith("ext4"):
assert ext4fs_output is not None
ext4fs_stats = re.compile(
r'Created filesystem with .* (?P<used_blocks>[0-9]+)/'
r'(?P<total_blocks>[0-9]+) blocks')
m = ext4fs_stats.match(ext4fs_output.strip().split('\n')[-1])
used_blocks = int(m.groupdict().get('used_blocks'))
total_blocks = int(m.groupdict().get('total_blocks'))
reserved_blocks = min(4096, int(total_blocks * 0.02))
adjusted_blocks = total_blocks - reserved_blocks
if used_blocks > adjusted_blocks:
mount_point = prop_dict.get("mount_point")
print("Error: Not enough room on %s (total: %d blocks, used: %d blocks, "
"reserved: %d blocks, available: %d blocks)" % (
mount_point, total_blocks, used_blocks, reserved_blocks,
adjusted_blocks))
return False
if not fs_spans_partition:
mount_point = prop_dict.get("mount_point")
partition_size = int(prop_dict.get("partition_size"))
image_size = os.stat(out_file).st_size
if image_size > partition_size:
print("Error: %s image size of %d is larger than partition size of "
"%d" % (mount_point, image_size, partition_size))
return False
if verity_supported and is_verity_partition:
if 2 * image_size - AdjustPartitionSizeForVerity(image_size) > partition_size:
print "Error: No more room on %s to fit verity data" % mount_point
return False
prop_dict["original_partition_size"] = prop_dict["partition_size"]
prop_dict["partition_size"] = str(image_size)
# create the verified image if this is to be verified
if verity_supported and is_verity_partition:
if not MakeVerityEnabledImage(out_file, prop_dict):
return False
if run_fsck and prop_dict.get("skip_fsck") != "true":
success, unsparse_image = UnsparseImage(out_file, replace=False)
if not success:
return False
# Run e2fsck on the inflated image file
e2fsck_command = ["e2fsck", "-f", "-n", unsparse_image]
(_, exit_code) = RunCommand(e2fsck_command)
os.remove(unsparse_image)
return exit_code == 0
def ImagePropFromGlobalDict(glob_dict, mount_point):
"""Build an image property dictionary from the global dictionary.
Args:
glob_dict: the global dictionary from the build system.
mount_point: such as "system", "data" etc.
"""
d = {}
if "build.prop" in glob_dict:
bp = glob_dict["build.prop"]
if "ro.build.date.utc" in bp:
d["timestamp"] = bp["ro.build.date.utc"]
def copy_prop(src_p, dest_p):
if src_p in glob_dict:
d[dest_p] = str(glob_dict[src_p])
common_props = (
"extfs_sparse_flag",
"mkyaffs2_extra_flags",
"selinux_fc",
"skip_fsck",
"verity",
"verity_key",
"verity_signer_cmd"
)
for p in common_props:
copy_prop(p, p)
d["mount_point"] = mount_point
if mount_point == "system":
copy_prop("fs_type", "fs_type")
# Copy the generic sysetem fs type first, override with specific one if
# available.
copy_prop("system_fs_type", "fs_type")
copy_prop("system_size", "partition_size")
copy_prop("system_journal_size", "journal_size")
copy_prop("system_verity_block_device", "verity_block_device")
copy_prop("system_root_image", "system_root_image")
copy_prop("ramdisk_dir", "ramdisk_dir")
copy_prop("has_ext4_reserved_blocks", "has_ext4_reserved_blocks")
copy_prop("system_squashfs_compressor", "squashfs_compressor")
copy_prop("system_squashfs_compressor_opt", "squashfs_compressor_opt")
elif mount_point == "data":
# Copy the generic fs type first, override with specific one if available.
copy_prop("fs_type", "fs_type")
copy_prop("userdata_fs_type", "fs_type")
copy_prop("userdata_size", "partition_size")
elif mount_point == "cache":
copy_prop("cache_fs_type", "fs_type")
copy_prop("cache_size", "partition_size")
elif mount_point == "vendor":
copy_prop("vendor_fs_type", "fs_type")
copy_prop("vendor_size", "partition_size")
copy_prop("vendor_journal_size", "journal_size")
copy_prop("vendor_verity_block_device", "verity_block_device")
copy_prop("has_ext4_reserved_blocks", "has_ext4_reserved_blocks")
elif mount_point == "oem":
copy_prop("fs_type", "fs_type")
copy_prop("oem_size", "partition_size")
copy_prop("oem_journal_size", "journal_size")
copy_prop("has_ext4_reserved_blocks", "has_ext4_reserved_blocks")
return d
def LoadGlobalDict(filename):
"""Load "name=value" pairs from filename"""
d = {}
f = open(filename)
for line in f:
line = line.strip()
if not line or line.startswith("#"):
continue
k, v = line.split("=", 1)
d[k] = v
f.close()
return d
def main(argv):
if len(argv) != 4:
print __doc__
sys.exit(1)
in_dir = argv[0]
glob_dict_file = argv[1]
out_file = argv[2]
target_out = argv[3]
glob_dict = LoadGlobalDict(glob_dict_file)
if "mount_point" in glob_dict:
# The caller knows the mount point and provides a dictionay needed by
# BuildImage().
image_properties = glob_dict
else:
image_filename = os.path.basename(out_file)
mount_point = ""
if image_filename == "system.img":
mount_point = "system"
elif image_filename == "userdata.img":
mount_point = "data"
elif image_filename == "cache.img":
mount_point = "cache"
elif image_filename == "vendor.img":
mount_point = "vendor"
elif image_filename == "oem.img":
mount_point = "oem"
else:
print >> sys.stderr, "error: unknown image file name ", image_filename
exit(1)
image_properties = ImagePropFromGlobalDict(glob_dict, mount_point)
if not BuildImage(in_dir, image_properties, out_file, target_out):
print >> sys.stderr, "error: failed to build %s from %s" % (out_file,
in_dir)
exit(1)
if __name__ == '__main__':
main(sys.argv[1:])