build_image.py revision 648e40e8660135f37adad5981a48250476c2f3fd 
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(["-s"])
259    build_command.extend(["-m", prop_dict["mount_point"]])
260    if fc_config is not None:
261      build_command.extend(["-c", fc_config])
262    elif "selinux_fc" in prop_dict:
263      build_command.extend(["-c", prop_dict["selinux_fc"]])
264    if "squashfs_compressor" in prop_dict:
265      build_command.extend(["-z", prop_dict["squashfs_compressor"]])
266    if "squashfs_compressor_opt" in prop_dict:
267      build_command.extend(["-zo", prop_dict["squashfs_compressor_opt"]])
268  elif fs_type.startswith("f2fs"):
269    build_command = ["mkf2fsuserimg.sh"]
270    build_command.extend([out_file, prop_dict["partition_size"]])
271  else:
272    build_command = ["mkyaffs2image", "-f"]
273    if prop_dict.get("mkyaffs2_extra_flags", None):
274      build_command.extend(prop_dict["mkyaffs2_extra_flags"].split())
275    build_command.append(in_dir)
276    build_command.append(out_file)
277    if "selinux_fc" in prop_dict:
278      build_command.append(prop_dict["selinux_fc"])
279      build_command.append(prop_dict["mount_point"])
280
281  exit_code = RunCommand(build_command)
282  if exit_code != 0:
283    return False
284
285  # create the verified image if this is to be verified
286  if verity_supported and is_verity_partition:
287    if not MakeVerityEnabledImage(out_file, prop_dict):
288      return False
289
290  if run_fsck and prop_dict.get("skip_fsck") != "true":
291    success, unsparse_image = UnsparseImage(out_file, replace=False)
292    if not success:
293      return False
294
295    # Run e2fsck on the inflated image file
296    e2fsck_command = ["e2fsck", "-f", "-n", unsparse_image]
297    exit_code = RunCommand(e2fsck_command)
298
299    os.remove(unsparse_image)
300
301  return exit_code == 0
302
303
304def ImagePropFromGlobalDict(glob_dict, mount_point):
305  """Build an image property dictionary from the global dictionary.
306
307  Args:
308    glob_dict: the global dictionary from the build system.
309    mount_point: such as "system", "data" etc.
310  """
311  d = {}
312  if "build.prop" in glob_dict:
313    bp = glob_dict["build.prop"]
314    if "ro.build.date.utc" in bp:
315      d["timestamp"] = bp["ro.build.date.utc"]
316
317  def copy_prop(src_p, dest_p):
318    if src_p in glob_dict:
319      d[dest_p] = str(glob_dict[src_p])
320
321  common_props = (
322      "extfs_sparse_flag",
323      "mkyaffs2_extra_flags",
324      "selinux_fc",
325      "skip_fsck",
326      "verity",
327      "verity_key",
328      "verity_signer_cmd"
329      )
330  for p in common_props:
331    copy_prop(p, p)
332
333  d["mount_point"] = mount_point
334  if mount_point == "system":
335    copy_prop("fs_type", "fs_type")
336    # Copy the generic sysetem fs type first, override with specific one if available.
337    copy_prop("system_fs_type", "fs_type")
338    copy_prop("system_size", "partition_size")
339    copy_prop("system_journal_size", "journal_size")
340    copy_prop("system_verity_block_device", "verity_block_device")
341    copy_prop("system_squashfs_compressor", "squashfs_compressor")
342    copy_prop("system_squashfs_compressor_opt", "squashfs_compressor_opt")
343  elif mount_point == "data":
344    # Copy the generic fs type first, override with specific one if available.
345    copy_prop("fs_type", "fs_type")
346    copy_prop("userdata_fs_type", "fs_type")
347    copy_prop("userdata_size", "partition_size")
348  elif mount_point == "cache":
349    copy_prop("cache_fs_type", "fs_type")
350    copy_prop("cache_size", "partition_size")
351  elif mount_point == "vendor":
352    copy_prop("vendor_fs_type", "fs_type")
353    copy_prop("vendor_size", "partition_size")
354    copy_prop("vendor_journal_size", "journal_size")
355    copy_prop("vendor_verity_block_device", "verity_block_device")
356  elif mount_point == "oem":
357    copy_prop("fs_type", "fs_type")
358    copy_prop("oem_size", "partition_size")
359    copy_prop("oem_journal_size", "journal_size")
360
361  return d
362
363
364def LoadGlobalDict(filename):
365  """Load "name=value" pairs from filename"""
366  d = {}
367  f = open(filename)
368  for line in f:
369    line = line.strip()
370    if not line or line.startswith("#"):
371      continue
372    k, v = line.split("=", 1)
373    d[k] = v
374  f.close()
375  return d
376
377
378def main(argv):
379  if len(argv) != 3:
380    print __doc__
381    sys.exit(1)
382
383  in_dir = argv[0]
384  glob_dict_file = argv[1]
385  out_file = argv[2]
386
387  glob_dict = LoadGlobalDict(glob_dict_file)
388  if "mount_point" in glob_dict:
389    # The caller knows the mount point and provides a dictionay needed by BuildImage().
390    image_properties = glob_dict
391  else:
392    image_filename = os.path.basename(out_file)
393    mount_point = ""
394    if image_filename == "system.img":
395      mount_point = "system"
396    elif image_filename == "userdata.img":
397      mount_point = "data"
398    elif image_filename == "cache.img":
399      mount_point = "cache"
400    elif image_filename == "vendor.img":
401      mount_point = "vendor"
402    elif image_filename == "oem.img":
403      mount_point = "oem"
404    else:
405      print >> sys.stderr, "error: unknown image file name ", image_filename
406      exit(1)
407
408    image_properties = ImagePropFromGlobalDict(glob_dict, mount_point)
409
410  if not BuildImage(in_dir, image_properties, out_file):
411    print >> sys.stderr, "error: failed to build %s from %s" % (out_file, in_dir)
412    exit(1)
413
414
415if __name__ == '__main__':
416  main(sys.argv[1:])
417