build_image.py revision cade49ddee44287d1bd5e9688558daf8912f0f9b
1#!/usr/bin/env python 2# 3# Copyright (C) 2011 The Android Open Source Project 4# 5# Licensed under the Apache License, Version 2.0 (the "License"); 6# you may not use this file except in compliance with the License. 7# You may obtain a copy of the License at 8# 9# http://www.apache.org/licenses/LICENSE-2.0 10# 11# Unless required by applicable law or agreed to in writing, software 12# distributed under the License is distributed on an "AS IS" BASIS, 13# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14# See the License for the specific language governing permissions and 15# limitations under the License. 16 17""" 18Build image output_image_file from input_directory and properties_file. 19 20Usage: build_image input_directory properties_file output_image_file 21 22""" 23import os 24import os.path 25import subprocess 26import sys 27import commands 28import shutil 29import tempfile 30 31FIXED_SALT = "aee087a5be3b982978c923f566a94613496b417f2af592639bc80d141e34dfe7" 32 33def RunCommand(cmd): 34 """ Echo and run the given command 35 36 Args: 37 cmd: the command represented as a list of strings. 38 Returns: 39 The exit code. 40 """ 41 print "Running: ", " ".join(cmd) 42 p = subprocess.Popen(cmd) 43 p.communicate() 44 return p.returncode 45 46def GetVerityTreeSize(partition_size): 47 cmd = "build_verity_tree -s %d" 48 cmd %= partition_size 49 status, output = commands.getstatusoutput(cmd) 50 if status: 51 print output 52 return False, 0 53 return True, int(output) 54 55def GetVerityMetadataSize(partition_size): 56 cmd = "system/extras/verity/build_verity_metadata.py -s %d" 57 cmd %= partition_size 58 status, output = commands.getstatusoutput(cmd) 59 if status: 60 print output 61 return False, 0 62 return True, int(output) 63 64def AdjustPartitionSizeForVerity(partition_size): 65 """Modifies the provided partition size to account for the verity metadata. 66 67 This information is used to size the created image appropriately. 68 Args: 69 partition_size: the size of the partition to be verified. 70 Returns: 71 The size of the partition adjusted for verity metadata. 72 """ 73 success, verity_tree_size = GetVerityTreeSize(partition_size) 74 if not success: 75 return 0; 76 success, verity_metadata_size = GetVerityMetadataSize(partition_size) 77 if not success: 78 return 0 79 return partition_size - verity_tree_size - verity_metadata_size 80 81def BuildVerityTree(sparse_image_path, verity_image_path, prop_dict): 82 cmd = ("build_verity_tree -A %s %s %s" % (FIXED_SALT, sparse_image_path, verity_image_path)) 83 print cmd 84 status, output = commands.getstatusoutput(cmd) 85 if status: 86 print "Could not build verity tree! Error: %s" % output 87 return False 88 root, salt = output.split() 89 prop_dict["verity_root_hash"] = root 90 prop_dict["verity_salt"] = salt 91 return True 92 93def BuildVerityMetadata(image_size, verity_metadata_path, root_hash, salt, 94 block_device, signer_path, key): 95 cmd = ("system/extras/verity/build_verity_metadata.py %s %s %s %s %s %s %s" % 96 (image_size, 97 verity_metadata_path, 98 root_hash, 99 salt, 100 block_device, 101 signer_path, 102 key)) 103 print cmd 104 status, output = commands.getstatusoutput(cmd) 105 if status: 106 print "Could not build verity metadata! Error: %s" % output 107 return False 108 return True 109 110def Append2Simg(sparse_image_path, unsparse_image_path, error_message): 111 """Appends the unsparse image to the given sparse image. 112 113 Args: 114 sparse_image_path: the path to the (sparse) image 115 unsparse_image_path: the path to the (unsparse) image 116 Returns: 117 True on success, False on failure. 118 """ 119 cmd = "append2simg %s %s" 120 cmd %= (sparse_image_path, unsparse_image_path) 121 print cmd 122 status, output = commands.getstatusoutput(cmd) 123 if status: 124 print "%s: %s" % (error_message, output) 125 return False 126 return True 127 128def BuildVerifiedImage(data_image_path, verity_image_path, verity_metadata_path): 129 if not Append2Simg(data_image_path, verity_metadata_path, "Could not append verity metadata!"): 130 return False 131 if not Append2Simg(data_image_path, verity_image_path, "Could not append verity tree!"): 132 return False 133 return True 134 135def UnsparseImage(sparse_image_path, replace=True): 136 img_dir = os.path.dirname(sparse_image_path) 137 unsparse_image_path = "unsparse_" + os.path.basename(sparse_image_path) 138 unsparse_image_path = os.path.join(img_dir, unsparse_image_path) 139 if os.path.exists(unsparse_image_path): 140 if replace: 141 os.unlink(unsparse_image_path) 142 else: 143 return True, unsparse_image_path 144 inflate_command = ["simg2img", sparse_image_path, unsparse_image_path] 145 exit_code = RunCommand(inflate_command) 146 if exit_code != 0: 147 os.remove(unsparse_image_path) 148 return False, None 149 return True, unsparse_image_path 150 151def MakeVerityEnabledImage(out_file, prop_dict): 152 """Creates an image that is verifiable using dm-verity. 153 154 Args: 155 out_file: the location to write the verifiable image at 156 prop_dict: a dictionary of properties required for image creation and verification 157 Returns: 158 True on success, False otherwise. 159 """ 160 # get properties 161 image_size = prop_dict["partition_size"] 162 block_dev = prop_dict["verity_block_device"] 163 signer_key = prop_dict["verity_key"] + ".pk8" 164 signer_path = prop_dict["verity_signer_cmd"] 165 166 # make a tempdir 167 tempdir_name = tempfile.mkdtemp(suffix="_verity_images") 168 169 # get partial image paths 170 verity_image_path = os.path.join(tempdir_name, "verity.img") 171 verity_metadata_path = os.path.join(tempdir_name, "verity_metadata.img") 172 173 # build the verity tree and get the root hash and salt 174 if not BuildVerityTree(out_file, verity_image_path, prop_dict): 175 shutil.rmtree(tempdir_name, ignore_errors=True) 176 return False 177 178 # build the metadata blocks 179 root_hash = prop_dict["verity_root_hash"] 180 salt = prop_dict["verity_salt"] 181 if not BuildVerityMetadata(image_size, 182 verity_metadata_path, 183 root_hash, 184 salt, 185 block_dev, 186 signer_path, 187 signer_key): 188 shutil.rmtree(tempdir_name, ignore_errors=True) 189 return False 190 191 # build the full verified image 192 if not BuildVerifiedImage(out_file, 193 verity_image_path, 194 verity_metadata_path): 195 shutil.rmtree(tempdir_name, ignore_errors=True) 196 return False 197 198 shutil.rmtree(tempdir_name, ignore_errors=True) 199 return True 200 201def BuildImage(in_dir, prop_dict, out_file, 202 fs_config=None, 203 fc_config=None, 204 block_list=None): 205 """Build an image to out_file from in_dir with property prop_dict. 206 207 Args: 208 in_dir: path of input directory. 209 prop_dict: property dictionary. 210 out_file: path of the output image file. 211 fs_config: path to the fs_config file (typically 212 META/filesystem_config.txt). If None then the configuration in 213 the local client will be used. 214 fc_config: path to the SELinux file_contexts file. If None then 215 the value from prop_dict['selinux_fc'] will be used. 216 217 Returns: 218 True iff the image is built successfully. 219 """ 220 build_command = [] 221 fs_type = prop_dict.get("fs_type", "") 222 run_fsck = False 223 224 is_verity_partition = "verity_block_device" in prop_dict 225 verity_supported = prop_dict.get("verity") == "true" 226 # adjust the partition size to make room for the hashes if this is to be verified 227 if verity_supported and is_verity_partition: 228 partition_size = int(prop_dict.get("partition_size")) 229 adjusted_size = AdjustPartitionSizeForVerity(partition_size) 230 if not adjusted_size: 231 return False 232 prop_dict["partition_size"] = str(adjusted_size) 233 prop_dict["original_partition_size"] = str(partition_size) 234 235 if fs_type.startswith("ext"): 236 build_command = ["mkuserimg.sh"] 237 if "extfs_sparse_flag" in prop_dict: 238 build_command.append(prop_dict["extfs_sparse_flag"]) 239 run_fsck = True 240 build_command.extend([in_dir, out_file, fs_type, 241 prop_dict["mount_point"]]) 242 build_command.append(prop_dict["partition_size"]) 243 if "journal_size" in prop_dict: 244 build_command.extend(["-j", prop_dict["journal_size"]]) 245 if "timestamp" in prop_dict: 246 build_command.extend(["-T", str(prop_dict["timestamp"])]) 247 if fs_config is not None: 248 build_command.extend(["-C", fs_config]) 249 if block_list is not None: 250 build_command.extend(["-B", block_list]) 251 if fc_config is not None: 252 build_command.append(fc_config) 253 elif "selinux_fc" in prop_dict: 254 build_command.append(prop_dict["selinux_fc"]) 255 elif fs_type.startswith("squash"): 256 build_command = ["mksquashfsimage.sh"] 257 build_command.extend([in_dir, out_file]) 258 build_command.extend(["-m", prop_dict["mount_point"]]) 259 if fc_config is not None: 260 build_command.extend(["-c", fc_config]) 261 elif "selinux_fc" in prop_dict: 262 build_command.extend(["-c", prop_dict["selinux_fc"]]) 263 elif fs_type.startswith("f2fs"): 264 build_command = ["mkf2fsuserimg.sh"] 265 build_command.extend([out_file, prop_dict["partition_size"]]) 266 else: 267 build_command = ["mkyaffs2image", "-f"] 268 if prop_dict.get("mkyaffs2_extra_flags", None): 269 build_command.extend(prop_dict["mkyaffs2_extra_flags"].split()) 270 build_command.append(in_dir) 271 build_command.append(out_file) 272 if "selinux_fc" in prop_dict: 273 build_command.append(prop_dict["selinux_fc"]) 274 build_command.append(prop_dict["mount_point"]) 275 276 exit_code = RunCommand(build_command) 277 if exit_code != 0: 278 return False 279 280 # create the verified image if this is to be verified 281 if verity_supported and is_verity_partition: 282 if not MakeVerityEnabledImage(out_file, prop_dict): 283 return False 284 285 if run_fsck and prop_dict.get("skip_fsck") != "true": 286 success, unsparse_image = UnsparseImage(out_file, replace=False) 287 if not success: 288 return False 289 290 # Run e2fsck on the inflated image file 291 e2fsck_command = ["e2fsck", "-f", "-n", unsparse_image] 292 exit_code = RunCommand(e2fsck_command) 293 294 os.remove(unsparse_image) 295 296 return exit_code == 0 297 298 299def ImagePropFromGlobalDict(glob_dict, mount_point): 300 """Build an image property dictionary from the global dictionary. 301 302 Args: 303 glob_dict: the global dictionary from the build system. 304 mount_point: such as "system", "data" etc. 305 """ 306 d = {} 307 if "build.prop" in glob_dict: 308 bp = glob_dict["build.prop"] 309 if "ro.build.date.utc" in bp: 310 d["timestamp"] = bp["ro.build.date.utc"] 311 312 def copy_prop(src_p, dest_p): 313 if src_p in glob_dict: 314 d[dest_p] = str(glob_dict[src_p]) 315 316 common_props = ( 317 "extfs_sparse_flag", 318 "mkyaffs2_extra_flags", 319 "selinux_fc", 320 "skip_fsck", 321 "verity", 322 "verity_key", 323 "verity_signer_cmd" 324 ) 325 for p in common_props: 326 copy_prop(p, p) 327 328 d["mount_point"] = mount_point 329 if mount_point == "system": 330 copy_prop("fs_type", "fs_type") 331 # Copy the generic sysetem fs type first, override with specific one if available. 332 copy_prop("system_fs_type", "fs_type") 333 copy_prop("system_size", "partition_size") 334 copy_prop("system_journal_size", "journal_size") 335 copy_prop("system_verity_block_device", "verity_block_device") 336 elif mount_point == "data": 337 # Copy the generic fs type first, override with specific one if available. 338 copy_prop("fs_type", "fs_type") 339 copy_prop("userdata_fs_type", "fs_type") 340 copy_prop("userdata_size", "partition_size") 341 elif mount_point == "cache": 342 copy_prop("cache_fs_type", "fs_type") 343 copy_prop("cache_size", "partition_size") 344 elif mount_point == "vendor": 345 copy_prop("vendor_fs_type", "fs_type") 346 copy_prop("vendor_size", "partition_size") 347 copy_prop("vendor_journal_size", "journal_size") 348 copy_prop("vendor_verity_block_device", "verity_block_device") 349 elif mount_point == "oem": 350 copy_prop("fs_type", "fs_type") 351 copy_prop("oem_size", "partition_size") 352 copy_prop("oem_journal_size", "journal_size") 353 354 return d 355 356 357def LoadGlobalDict(filename): 358 """Load "name=value" pairs from filename""" 359 d = {} 360 f = open(filename) 361 for line in f: 362 line = line.strip() 363 if not line or line.startswith("#"): 364 continue 365 k, v = line.split("=", 1) 366 d[k] = v 367 f.close() 368 return d 369 370 371def main(argv): 372 if len(argv) != 3: 373 print __doc__ 374 sys.exit(1) 375 376 in_dir = argv[0] 377 glob_dict_file = argv[1] 378 out_file = argv[2] 379 380 glob_dict = LoadGlobalDict(glob_dict_file) 381 if "mount_point" in glob_dict: 382 # The caller knows the mount point and provides a dictionay needed by BuildImage(). 383 image_properties = glob_dict 384 else: 385 image_filename = os.path.basename(out_file) 386 mount_point = "" 387 if image_filename == "system.img": 388 mount_point = "system" 389 elif image_filename == "userdata.img": 390 mount_point = "data" 391 elif image_filename == "cache.img": 392 mount_point = "cache" 393 elif image_filename == "vendor.img": 394 mount_point = "vendor" 395 elif image_filename == "oem.img": 396 mount_point = "oem" 397 else: 398 print >> sys.stderr, "error: unknown image file name ", image_filename 399 exit(1) 400 401 image_properties = ImagePropFromGlobalDict(glob_dict, mount_point) 402 403 if not BuildImage(in_dir, image_properties, out_file): 404 print >> sys.stderr, "error: failed to build %s from %s" % (out_file, in_dir) 405 exit(1) 406 407 408if __name__ == '__main__': 409 main(sys.argv[1:]) 410