build_image.py revision f21cb5a2198b843fe1c8e9577cc2ad61e0f5cfb4
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 31import simg_map 32 33FIXED_SALT = "aee087a5be3b982978c923f566a94613496b417f2af592639bc80d141e34dfe7" 34 35def RunCommand(cmd): 36 """ Echo and run the given command 37 38 Args: 39 cmd: the command represented as a list of strings. 40 Returns: 41 The exit code. 42 """ 43 print "Running: ", " ".join(cmd) 44 p = subprocess.Popen(cmd) 45 p.communicate() 46 return p.returncode 47 48def GetVerityTreeSize(partition_size): 49 cmd = "build_verity_tree -s %d" 50 cmd %= partition_size 51 status, output = commands.getstatusoutput(cmd) 52 if status: 53 print output 54 return False, 0 55 return True, int(output) 56 57def GetVerityMetadataSize(partition_size): 58 cmd = "system/extras/verity/build_verity_metadata.py -s %d" 59 cmd %= partition_size 60 status, output = commands.getstatusoutput(cmd) 61 if status: 62 print output 63 return False, 0 64 return True, int(output) 65 66def AdjustPartitionSizeForVerity(partition_size): 67 """Modifies the provided partition size to account for the verity metadata. 68 69 This information is used to size the created image appropriately. 70 Args: 71 partition_size: the size of the partition to be verified. 72 Returns: 73 The size of the partition adjusted for verity metadata. 74 """ 75 success, verity_tree_size = GetVerityTreeSize(partition_size) 76 if not success: 77 return 0; 78 success, verity_metadata_size = GetVerityMetadataSize(partition_size) 79 if not success: 80 return 0 81 return partition_size - verity_tree_size - verity_metadata_size 82 83def BuildVerityTree(sparse_image_path, verity_image_path, prop_dict): 84 cmd = ("build_verity_tree -A %s %s %s" % (FIXED_SALT, sparse_image_path, verity_image_path)) 85 print cmd 86 status, output = commands.getstatusoutput(cmd) 87 if status: 88 print "Could not build verity tree! Error: %s" % output 89 return False 90 root, salt = output.split() 91 prop_dict["verity_root_hash"] = root 92 prop_dict["verity_salt"] = salt 93 return True 94 95def BuildVerityMetadata(image_size, verity_metadata_path, root_hash, salt, 96 block_device, signer_path, key): 97 cmd = ("system/extras/verity/build_verity_metadata.py %s %s %s %s %s %s %s" % 98 (image_size, 99 verity_metadata_path, 100 root_hash, 101 salt, 102 block_device, 103 signer_path, 104 key)) 105 print cmd 106 status, output = commands.getstatusoutput(cmd) 107 if status: 108 print "Could not build verity metadata! Error: %s" % output 109 return False 110 return True 111 112def Append2Simg(sparse_image_path, unsparse_image_path, error_message): 113 """Appends the unsparse image to the given sparse image. 114 115 Args: 116 sparse_image_path: the path to the (sparse) image 117 unsparse_image_path: the path to the (unsparse) image 118 Returns: 119 True on success, False on failure. 120 """ 121 cmd = "append2simg %s %s" 122 cmd %= (sparse_image_path, unsparse_image_path) 123 print cmd 124 status, output = commands.getstatusoutput(cmd) 125 if status: 126 print "%s: %s" % (error_message, output) 127 return False 128 return True 129 130def BuildVerifiedImage(data_image_path, verity_image_path, verity_metadata_path): 131 if not Append2Simg(data_image_path, verity_metadata_path, "Could not append verity metadata!"): 132 return False 133 if not Append2Simg(data_image_path, verity_image_path, "Could not append verity tree!"): 134 return False 135 return True 136 137def UnsparseImage(sparse_image_path, replace=True): 138 img_dir = os.path.dirname(sparse_image_path) 139 unsparse_image_path = "unsparse_" + os.path.basename(sparse_image_path) 140 unsparse_image_path = os.path.join(img_dir, unsparse_image_path) 141 if os.path.exists(unsparse_image_path): 142 if replace: 143 os.unlink(unsparse_image_path) 144 else: 145 return True, unsparse_image_path 146 inflate_command = ["simg2img", sparse_image_path, unsparse_image_path] 147 exit_code = RunCommand(inflate_command) 148 if exit_code != 0: 149 os.remove(unsparse_image_path) 150 return False, None 151 return True, unsparse_image_path 152 153def MappedUnsparseImage(sparse_image_path, unsparse_image_path, 154 map_path, mapped_unsparse_image_path): 155 if simg_map.ComputeMap(sparse_image_path, unsparse_image_path, 156 map_path, mapped_unsparse_image_path): 157 return False 158 return True 159 160def MakeVerityEnabledImage(out_file, prop_dict): 161 """Creates an image that is verifiable using dm-verity. 162 163 Args: 164 out_file: the location to write the verifiable image at 165 prop_dict: a dictionary of properties required for image creation and verification 166 Returns: 167 True on success, False otherwise. 168 """ 169 # get properties 170 image_size = prop_dict["partition_size"] 171 block_dev = prop_dict["verity_block_device"] 172 signer_key = prop_dict["verity_key"] 173 signer_path = prop_dict["verity_signer_cmd"] 174 175 # make a tempdir 176 tempdir_name = tempfile.mkdtemp(suffix="_verity_images") 177 178 # get partial image paths 179 verity_image_path = os.path.join(tempdir_name, "verity.img") 180 verity_metadata_path = os.path.join(tempdir_name, "verity_metadata.img") 181 182 # build the verity tree and get the root hash and salt 183 if not BuildVerityTree(out_file, verity_image_path, prop_dict): 184 shutil.rmtree(tempdir_name, ignore_errors=True) 185 return False 186 187 # build the metadata blocks 188 root_hash = prop_dict["verity_root_hash"] 189 salt = prop_dict["verity_salt"] 190 if not BuildVerityMetadata(image_size, 191 verity_metadata_path, 192 root_hash, 193 salt, 194 block_dev, 195 signer_path, 196 signer_key): 197 shutil.rmtree(tempdir_name, ignore_errors=True) 198 return False 199 200 # build the full verified image 201 if not BuildVerifiedImage(out_file, 202 verity_image_path, 203 verity_metadata_path): 204 shutil.rmtree(tempdir_name, ignore_errors=True) 205 return False 206 207 shutil.rmtree(tempdir_name, ignore_errors=True) 208 return True 209 210def BuildImage(in_dir, prop_dict, out_file, 211 fs_config=None, 212 fc_config=None, 213 block_list=None): 214 """Build an image to out_file from in_dir with property prop_dict. 215 216 Args: 217 in_dir: path of input directory. 218 prop_dict: property dictionary. 219 out_file: path of the output image file. 220 fs_config: path to the fs_config file (typically 221 META/filesystem_config.txt). If None then the configuration in 222 the local client will be used. 223 fc_config: path to the SELinux file_contexts file. If None then 224 the value from prop_dict['selinux_fc'] will be used. 225 226 Returns: 227 True iff the image is built successfully. 228 """ 229 build_command = [] 230 fs_type = prop_dict.get("fs_type", "") 231 run_fsck = False 232 233 is_verity_partition = "verity_block_device" in prop_dict 234 verity_supported = prop_dict.get("verity") == "true" 235 # adjust the partition size to make room for the hashes if this is to be verified 236 if verity_supported and is_verity_partition: 237 partition_size = int(prop_dict.get("partition_size")) 238 adjusted_size = AdjustPartitionSizeForVerity(partition_size) 239 if not adjusted_size: 240 return False 241 prop_dict["partition_size"] = str(adjusted_size) 242 prop_dict["original_partition_size"] = str(partition_size) 243 244 if fs_type.startswith("ext"): 245 build_command = ["mkuserimg.sh"] 246 if "extfs_sparse_flag" in prop_dict: 247 build_command.append(prop_dict["extfs_sparse_flag"]) 248 run_fsck = True 249 build_command.extend([in_dir, out_file, fs_type, 250 prop_dict["mount_point"]]) 251 build_command.append(prop_dict["partition_size"]) 252 if "timestamp" in prop_dict: 253 build_command.extend(["-T", str(prop_dict["timestamp"])]) 254 if fs_config is not None: 255 build_command.extend(["-C", fs_config]) 256 if block_list is not None: 257 build_command.extend(["-B", block_list]) 258 if fc_config is not None: 259 build_command.append(fc_config) 260 elif "selinux_fc" in prop_dict: 261 build_command.append(prop_dict["selinux_fc"]) 262 elif fs_type.startswith("f2fs"): 263 build_command = ["mkf2fsuserimg.sh"] 264 build_command.extend([out_file, prop_dict["partition_size"]]) 265 else: 266 build_command = ["mkyaffs2image", "-f"] 267 if prop_dict.get("mkyaffs2_extra_flags", None): 268 build_command.extend(prop_dict["mkyaffs2_extra_flags"].split()) 269 build_command.append(in_dir) 270 build_command.append(out_file) 271 if "selinux_fc" in prop_dict: 272 build_command.append(prop_dict["selinux_fc"]) 273 build_command.append(prop_dict["mount_point"]) 274 275 exit_code = RunCommand(build_command) 276 if exit_code != 0: 277 return False 278 279 # create the verified image if this is to be verified 280 if verity_supported and is_verity_partition: 281 if not MakeVerityEnabledImage(out_file, prop_dict): 282 return False 283 284 if run_fsck and prop_dict.get("skip_fsck") != "true": 285 success, unsparse_image = UnsparseImage(out_file, replace=False) 286 if not success: 287 return False 288 289 # Run e2fsck on the inflated image file 290 e2fsck_command = ["e2fsck", "-f", "-n", unsparse_image] 291 exit_code = RunCommand(e2fsck_command) 292 293 os.remove(unsparse_image) 294 295 return exit_code == 0 296 297 298def ImagePropFromGlobalDict(glob_dict, mount_point): 299 """Build an image property dictionary from the global dictionary. 300 301 Args: 302 glob_dict: the global dictionary from the build system. 303 mount_point: such as "system", "data" etc. 304 """ 305 d = {} 306 if "build.prop" in glob_dict: 307 bp = glob_dict["build.prop"] 308 if "ro.build.date.utc" in bp: 309 d["timestamp"] = bp["ro.build.date.utc"] 310 311 def copy_prop(src_p, dest_p): 312 if src_p in glob_dict: 313 d[dest_p] = str(glob_dict[src_p]) 314 315 common_props = ( 316 "extfs_sparse_flag", 317 "mkyaffs2_extra_flags", 318 "selinux_fc", 319 "skip_fsck", 320 "verity", 321 "verity_key", 322 "verity_signer_cmd" 323 ) 324 for p in common_props: 325 copy_prop(p, p) 326 327 d["mount_point"] = mount_point 328 if mount_point == "system": 329 copy_prop("fs_type", "fs_type") 330 copy_prop("system_size", "partition_size") 331 copy_prop("system_verity_block_device", "verity_block_device") 332 elif mount_point == "data": 333 # Copy the generic fs type first, override with specific one if available. 334 copy_prop("fs_type", "fs_type") 335 copy_prop("userdata_fs_type", "fs_type") 336 copy_prop("userdata_size", "partition_size") 337 elif mount_point == "cache": 338 copy_prop("cache_fs_type", "fs_type") 339 copy_prop("cache_size", "partition_size") 340 elif mount_point == "vendor": 341 copy_prop("vendor_fs_type", "fs_type") 342 copy_prop("vendor_size", "partition_size") 343 copy_prop("vendor_verity_block_device", "verity_block_device") 344 elif mount_point == "oem": 345 copy_prop("fs_type", "fs_type") 346 copy_prop("oem_size", "partition_size") 347 348 return d 349 350 351def LoadGlobalDict(filename): 352 """Load "name=value" pairs from filename""" 353 d = {} 354 f = open(filename) 355 for line in f: 356 line = line.strip() 357 if not line or line.startswith("#"): 358 continue 359 k, v = line.split("=", 1) 360 d[k] = v 361 f.close() 362 return d 363 364 365def main(argv): 366 if len(argv) != 3: 367 print __doc__ 368 sys.exit(1) 369 370 in_dir = argv[0] 371 glob_dict_file = argv[1] 372 out_file = argv[2] 373 374 glob_dict = LoadGlobalDict(glob_dict_file) 375 image_filename = os.path.basename(out_file) 376 mount_point = "" 377 if image_filename == "system.img": 378 mount_point = "system" 379 elif image_filename == "userdata.img": 380 mount_point = "data" 381 elif image_filename == "cache.img": 382 mount_point = "cache" 383 elif image_filename == "vendor.img": 384 mount_point = "vendor" 385 elif image_filename == "oem.img": 386 mount_point = "oem" 387 else: 388 print >> sys.stderr, "error: unknown image file name ", image_filename 389 exit(1) 390 391 image_properties = ImagePropFromGlobalDict(glob_dict, mount_point) 392 if not BuildImage(in_dir, image_properties, out_file): 393 print >> sys.stderr, "error: failed to build %s from %s" % (out_file, in_dir) 394 exit(1) 395 396 397if __name__ == '__main__': 398 main(sys.argv[1:]) 399