build_image.py revision f99b53143d3a25bf157ac32a8fe80378ab57d7a8 
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 re
26import subprocess
27import sys
28import commands
29import common
30import shutil
31import tempfile
32
33OPTIONS = common.OPTIONS
34
35FIXED_SALT = "aee087a5be3b982978c923f566a94613496b417f2af592639bc80d141e34dfe7"
36BLOCK_SIZE = 4096
37
38def RunCommand(cmd):
39  """Echo and run the given command.
40
41  Args:
42    cmd: the command represented as a list of strings.
43  Returns:
44    A tuple of the output and the exit code.
45  """
46  print "Running: ", " ".join(cmd)
47  p = subprocess.Popen(cmd, stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
48  output, _ = p.communicate()
49  print "%s" % (output.rstrip(),)
50  return (output, p.returncode)
51
52def GetVerityFECSize(partition_size):
53  cmd = "fec -s %d" % partition_size
54  status, output = commands.getstatusoutput(cmd)
55  if status:
56    print output
57    return False, 0
58  return True, int(output)
59
60def GetVerityTreeSize(partition_size):
61  cmd = "build_verity_tree -s %d"
62  cmd %= partition_size
63  status, output = commands.getstatusoutput(cmd)
64  if status:
65    print output
66    return False, 0
67  return True, int(output)
68
69def GetVerityMetadataSize(partition_size):
70  cmd = "system/extras/verity/build_verity_metadata.py -s %d"
71  cmd %= partition_size
72
73  status, output = commands.getstatusoutput(cmd)
74  if status:
75    print output
76    return False, 0
77  return True, int(output)
78
79def GetVeritySize(partition_size, fec_supported):
80  success, verity_tree_size = GetVerityTreeSize(partition_size)
81  if not success:
82    return 0
83  success, verity_metadata_size = GetVerityMetadataSize(partition_size)
84  if not success:
85    return 0
86  verity_size = verity_tree_size + verity_metadata_size
87  if fec_supported:
88    success, fec_size = GetVerityFECSize(partition_size + verity_size)
89    if not success:
90      return 0
91    return verity_size + fec_size
92  return verity_size
93
94def AdjustPartitionSizeForVerity(partition_size, fec_supported):
95  """Modifies the provided partition size to account for the verity metadata.
96
97  This information is used to size the created image appropriately.
98  Args:
99    partition_size: the size of the partition to be verified.
100  Returns:
101    The size of the partition adjusted for verity metadata.
102  """
103  key = "%d %d" % (partition_size, fec_supported)
104  if key in AdjustPartitionSizeForVerity.results:
105    return AdjustPartitionSizeForVerity.results[key]
106
107  hi = partition_size
108  if hi % BLOCK_SIZE != 0:
109    hi = (hi // BLOCK_SIZE) * BLOCK_SIZE
110
111  # verity tree and fec sizes depend on the partition size, which
112  # means this estimate is always going to be unnecessarily small
113  lo = partition_size - GetVeritySize(hi, fec_supported)
114  result = lo
115
116  # do a binary search for the optimal size
117  while lo < hi:
118    i = ((lo + hi) // (2 * BLOCK_SIZE)) * BLOCK_SIZE
119    size = i + GetVeritySize(i, fec_supported)
120    if size <= partition_size:
121      if result < i:
122        result = i
123      lo = i + BLOCK_SIZE
124    else:
125      hi = i
126
127  AdjustPartitionSizeForVerity.results[key] = result
128  return result
129
130AdjustPartitionSizeForVerity.results = {}
131
132def BuildVerityFEC(sparse_image_path, verity_fec_path, prop_dict):
133  cmd = "fec -e %s %s" % (sparse_image_path, verity_fec_path)
134  print cmd
135  status, output = commands.getstatusoutput(cmd)
136  if status:
137    print "Could not build FEC data! Error: %s" % output
138    return False
139  return True
140
141def BuildVerityTree(sparse_image_path, verity_image_path, prop_dict):
142  cmd = "build_verity_tree -A %s %s %s" % (
143      FIXED_SALT, sparse_image_path, verity_image_path)
144  print cmd
145  status, output = commands.getstatusoutput(cmd)
146  if status:
147    print "Could not build verity tree! Error: %s" % output
148    return False
149  root, salt = output.split()
150  prop_dict["verity_root_hash"] = root
151  prop_dict["verity_salt"] = salt
152  return True
153
154def BuildVerityMetadata(image_size, verity_metadata_path, root_hash, salt,
155                        block_device, signer_path, key):
156  cmd_template = (
157      "system/extras/verity/build_verity_metadata.py %s %s %s %s %s %s %s")
158  cmd = cmd_template % (image_size, verity_metadata_path, root_hash, salt,
159                        block_device, signer_path, key)
160  print cmd
161  status, output = commands.getstatusoutput(cmd)
162  if status:
163    print "Could not build verity metadata! Error: %s" % output
164    return False
165  return True
166
167def Append2Simg(sparse_image_path, unsparse_image_path, error_message):
168  """Appends the unsparse image to the given sparse image.
169
170  Args:
171    sparse_image_path: the path to the (sparse) image
172    unsparse_image_path: the path to the (unsparse) image
173  Returns:
174    True on success, False on failure.
175  """
176  cmd = "append2simg %s %s"
177  cmd %= (sparse_image_path, unsparse_image_path)
178  print cmd
179  status, output = commands.getstatusoutput(cmd)
180  if status:
181    print "%s: %s" % (error_message, output)
182    return False
183  return True
184
185def BuildVerifiedImage(data_image_path, verity_image_path,
186                       verity_metadata_path):
187  if not Append2Simg(data_image_path, verity_image_path,
188                     "Could not append verity tree!"):
189    return False
190  if not Append2Simg(data_image_path, verity_metadata_path,
191                     "Could not append verity metadata!"):
192    return False
193  return True
194
195def UnsparseImage(sparse_image_path, replace=True):
196  img_dir = os.path.dirname(sparse_image_path)
197  unsparse_image_path = "unsparse_" + os.path.basename(sparse_image_path)
198  unsparse_image_path = os.path.join(img_dir, unsparse_image_path)
199  if os.path.exists(unsparse_image_path):
200    if replace:
201      os.unlink(unsparse_image_path)
202    else:
203      return True, unsparse_image_path
204  inflate_command = ["simg2img", sparse_image_path, unsparse_image_path]
205  (_, exit_code) = RunCommand(inflate_command)
206  if exit_code != 0:
207    os.remove(unsparse_image_path)
208    return False, None
209  return True, unsparse_image_path
210
211def MakeVerityEnabledImage(out_file, fec_supported, prop_dict):
212  """Creates an image that is verifiable using dm-verity.
213
214  Args:
215    out_file: the location to write the verifiable image at
216    prop_dict: a dictionary of properties required for image creation and
217               verification
218  Returns:
219    True on success, False otherwise.
220  """
221  # get properties
222  image_size = prop_dict["partition_size"]
223  block_dev = prop_dict["verity_block_device"]
224  signer_key = prop_dict["verity_key"] + ".pk8"
225  if OPTIONS.verity_signer_path is not None:
226    signer_path = OPTIONS.verity_signer_path + ' '
227    signer_path += ' '.join(OPTIONS.verity_signer_args)
228  else:
229    signer_path = prop_dict["verity_signer_cmd"]
230
231  # make a tempdir
232  tempdir_name = tempfile.mkdtemp(suffix="_verity_images")
233
234  # get partial image paths
235  verity_image_path = os.path.join(tempdir_name, "verity.img")
236  verity_metadata_path = os.path.join(tempdir_name, "verity_metadata.img")
237  verity_fec_path = os.path.join(tempdir_name, "verity_fec.img")
238
239  # build the verity tree and get the root hash and salt
240  if not BuildVerityTree(out_file, verity_image_path, prop_dict):
241    shutil.rmtree(tempdir_name, ignore_errors=True)
242    return False
243
244  # build the metadata blocks
245  root_hash = prop_dict["verity_root_hash"]
246  salt = prop_dict["verity_salt"]
247  if not BuildVerityMetadata(image_size, verity_metadata_path, root_hash, salt,
248                             block_dev, signer_path, signer_key):
249    shutil.rmtree(tempdir_name, ignore_errors=True)
250    return False
251
252  # build the full verified image
253  if not BuildVerifiedImage(out_file,
254                            verity_image_path,
255                            verity_metadata_path):
256    shutil.rmtree(tempdir_name, ignore_errors=True)
257    return False
258
259  if fec_supported:
260    # build FEC for the entire partition, including metadata
261    if not BuildVerityFEC(out_file, verity_fec_path, prop_dict):
262      shutil.rmtree(tempdir_name, ignore_errors=True)
263      return False
264
265    if not Append2Simg(out_file, verity_fec_path, "Could not append FEC!"):
266      shutil.rmtree(tempdir_name, ignore_errors=True)
267      return False
268
269  shutil.rmtree(tempdir_name, ignore_errors=True)
270  return True
271
272def BuildImage(in_dir, prop_dict, out_file, target_out=None):
273  """Build an image to out_file from in_dir with property prop_dict.
274
275  Args:
276    in_dir: path of input directory.
277    prop_dict: property dictionary.
278    out_file: path of the output image file.
279    target_out: path of the product out directory to read device specific FS config files.
280
281  Returns:
282    True iff the image is built successfully.
283  """
284  # system_root_image=true: build a system.img that combines the contents of
285  # /system and the ramdisk, and can be mounted at the root of the file system.
286  origin_in = in_dir
287  fs_config = prop_dict.get("fs_config")
288  if (prop_dict.get("system_root_image") == "true"
289      and prop_dict["mount_point"] == "system"):
290    in_dir = tempfile.mkdtemp()
291    # Change the mount point to "/"
292    prop_dict["mount_point"] = "/"
293    if fs_config:
294      # We need to merge the fs_config files of system and ramdisk.
295      fd, merged_fs_config = tempfile.mkstemp(prefix="root_fs_config",
296                                              suffix=".txt")
297      os.close(fd)
298      with open(merged_fs_config, "w") as fw:
299        if "ramdisk_fs_config" in prop_dict:
300          with open(prop_dict["ramdisk_fs_config"]) as fr:
301            fw.writelines(fr.readlines())
302        with open(fs_config) as fr:
303          fw.writelines(fr.readlines())
304      fs_config = merged_fs_config
305
306  build_command = []
307  fs_type = prop_dict.get("fs_type", "")
308  run_fsck = False
309
310  fs_spans_partition = True
311  if fs_type.startswith("squash"):
312    fs_spans_partition = False
313
314  is_verity_partition = "verity_block_device" in prop_dict
315  verity_supported = prop_dict.get("verity") == "true"
316  verity_fec_supported = prop_dict.get("verity_fec") == "true"
317
318  # Adjust the partition size to make room for the hashes if this is to be
319  # verified.
320  if verity_supported and is_verity_partition and fs_spans_partition:
321    partition_size = int(prop_dict.get("partition_size"))
322    adjusted_size = AdjustPartitionSizeForVerity(partition_size,
323                                                 verity_fec_supported)
324    if not adjusted_size:
325      return False
326    prop_dict["partition_size"] = str(adjusted_size)
327    prop_dict["original_partition_size"] = str(partition_size)
328
329  if fs_type.startswith("ext"):
330    build_command = ["mkuserimg.sh"]
331    if "extfs_sparse_flag" in prop_dict:
332      build_command.append(prop_dict["extfs_sparse_flag"])
333      run_fsck = True
334    build_command.extend([in_dir, out_file, fs_type,
335                          prop_dict["mount_point"]])
336    build_command.append(prop_dict["partition_size"])
337    if "journal_size" in prop_dict:
338      build_command.extend(["-j", prop_dict["journal_size"]])
339    if "timestamp" in prop_dict:
340      build_command.extend(["-T", str(prop_dict["timestamp"])])
341    if fs_config:
342      build_command.extend(["-C", fs_config])
343    if target_out:
344      build_command.extend(["-D", target_out])
345    if "block_list" in prop_dict:
346      build_command.extend(["-B", prop_dict["block_list"]])
347    build_command.extend(["-L", prop_dict["mount_point"]])
348    if "selinux_fc" in prop_dict:
349      build_command.append(prop_dict["selinux_fc"])
350  elif fs_type.startswith("squash"):
351    build_command = ["mksquashfsimage.sh"]
352    build_command.extend([in_dir, out_file])
353    build_command.extend(["-s"])
354    build_command.extend(["-m", prop_dict["mount_point"]])
355    if target_out:
356      build_command.extend(["-d", target_out])
357    if "selinux_fc" in prop_dict:
358      build_command.extend(["-c", prop_dict["selinux_fc"]])
359    if "squashfs_compressor" in prop_dict:
360      build_command.extend(["-z", prop_dict["squashfs_compressor"]])
361    if "squashfs_compressor_opt" in prop_dict:
362      build_command.extend(["-zo", prop_dict["squashfs_compressor_opt"]])
363  elif fs_type.startswith("f2fs"):
364    build_command = ["mkf2fsuserimg.sh"]
365    build_command.extend([out_file, prop_dict["partition_size"]])
366  else:
367    build_command = ["mkyaffs2image", "-f"]
368    if prop_dict.get("mkyaffs2_extra_flags", None):
369      build_command.extend(prop_dict["mkyaffs2_extra_flags"].split())
370    build_command.append(in_dir)
371    build_command.append(out_file)
372    if "selinux_fc" in prop_dict:
373      build_command.append(prop_dict["selinux_fc"])
374      build_command.append(prop_dict["mount_point"])
375
376  if in_dir != origin_in:
377    # Construct a staging directory of the root file system.
378    ramdisk_dir = prop_dict.get("ramdisk_dir")
379    if ramdisk_dir:
380      shutil.rmtree(in_dir)
381      shutil.copytree(ramdisk_dir, in_dir, symlinks=True)
382    staging_system = os.path.join(in_dir, "system")
383    shutil.rmtree(staging_system, ignore_errors=True)
384    shutil.copytree(origin_in, staging_system, symlinks=True)
385
386  reserved_blocks = prop_dict.get("has_ext4_reserved_blocks") == "true"
387  ext4fs_output = None
388
389  try:
390    if reserved_blocks and fs_type.startswith("ext4"):
391      (ext4fs_output, exit_code) = RunCommand(build_command)
392    else:
393      (_, exit_code) = RunCommand(build_command)
394  finally:
395    if in_dir != origin_in:
396      # Clean up temporary directories and files.
397      shutil.rmtree(in_dir, ignore_errors=True)
398      if fs_config:
399        os.remove(fs_config)
400  if exit_code != 0:
401    return False
402
403  # Bug: 21522719, 22023465
404  # There are some reserved blocks on ext4 FS (lesser of 4096 blocks and 2%).
405  # We need to deduct those blocks from the available space, since they are
406  # not writable even with root privilege. It only affects devices using
407  # file-based OTA and a kernel version of 3.10 or greater (currently just
408  # sprout).
409  if reserved_blocks and fs_type.startswith("ext4"):
410    assert ext4fs_output is not None
411    ext4fs_stats = re.compile(
412        r'Created filesystem with .* (?P<used_blocks>[0-9]+)/'
413        r'(?P<total_blocks>[0-9]+) blocks')
414    m = ext4fs_stats.match(ext4fs_output.strip().split('\n')[-1])
415    used_blocks = int(m.groupdict().get('used_blocks'))
416    total_blocks = int(m.groupdict().get('total_blocks'))
417    reserved_blocks = min(4096, int(total_blocks * 0.02))
418    adjusted_blocks = total_blocks - reserved_blocks
419    if used_blocks > adjusted_blocks:
420      mount_point = prop_dict.get("mount_point")
421      print("Error: Not enough room on %s (total: %d blocks, used: %d blocks, "
422            "reserved: %d blocks, available: %d blocks)" % (
423                mount_point, total_blocks, used_blocks, reserved_blocks,
424                adjusted_blocks))
425      return False
426
427  if not fs_spans_partition:
428    mount_point = prop_dict.get("mount_point")
429    partition_size = int(prop_dict.get("partition_size"))
430    image_size = os.stat(out_file).st_size
431    if image_size > partition_size:
432      print("Error: %s image size of %d is larger than partition size of "
433            "%d" % (mount_point, image_size, partition_size))
434      return False
435    if verity_supported and is_verity_partition:
436      if 2 * image_size - AdjustPartitionSizeForVerity(image_size, verity_fec_supported) > partition_size:
437        print "Error: No more room on %s to fit verity data" % mount_point
438        return False
439    prop_dict["original_partition_size"] = prop_dict["partition_size"]
440    prop_dict["partition_size"] = str(image_size)
441
442  # create the verified image if this is to be verified
443  if verity_supported and is_verity_partition:
444    if not MakeVerityEnabledImage(out_file, verity_fec_supported, prop_dict):
445      return False
446
447  if run_fsck and prop_dict.get("skip_fsck") != "true":
448    success, unsparse_image = UnsparseImage(out_file, replace=False)
449    if not success:
450      return False
451
452    # Run e2fsck on the inflated image file
453    e2fsck_command = ["e2fsck", "-f", "-n", unsparse_image]
454    (_, exit_code) = RunCommand(e2fsck_command)
455
456    os.remove(unsparse_image)
457
458  return exit_code == 0
459
460
461def ImagePropFromGlobalDict(glob_dict, mount_point):
462  """Build an image property dictionary from the global dictionary.
463
464  Args:
465    glob_dict: the global dictionary from the build system.
466    mount_point: such as "system", "data" etc.
467  """
468  d = {}
469
470  if "build.prop" in glob_dict:
471    bp = glob_dict["build.prop"]
472    if "ro.build.date.utc" in bp:
473      d["timestamp"] = bp["ro.build.date.utc"]
474
475  def copy_prop(src_p, dest_p):
476    if src_p in glob_dict:
477      d[dest_p] = str(glob_dict[src_p])
478
479  common_props = (
480      "extfs_sparse_flag",
481      "mkyaffs2_extra_flags",
482      "selinux_fc",
483      "skip_fsck",
484      "verity",
485      "verity_key",
486      "verity_signer_cmd",
487      "verity_fec"
488      )
489  for p in common_props:
490    copy_prop(p, p)
491
492  d["mount_point"] = mount_point
493  if mount_point == "system":
494    copy_prop("fs_type", "fs_type")
495    # Copy the generic sysetem fs type first, override with specific one if
496    # available.
497    copy_prop("system_fs_type", "fs_type")
498    copy_prop("system_size", "partition_size")
499    copy_prop("system_journal_size", "journal_size")
500    copy_prop("system_verity_block_device", "verity_block_device")
501    copy_prop("system_root_image", "system_root_image")
502    copy_prop("ramdisk_dir", "ramdisk_dir")
503    copy_prop("ramdisk_fs_config", "ramdisk_fs_config")
504    copy_prop("has_ext4_reserved_blocks", "has_ext4_reserved_blocks")
505    copy_prop("system_squashfs_compressor", "squashfs_compressor")
506    copy_prop("system_squashfs_compressor_opt", "squashfs_compressor_opt")
507  elif mount_point == "data":
508    # Copy the generic fs type first, override with specific one if available.
509    copy_prop("fs_type", "fs_type")
510    copy_prop("userdata_fs_type", "fs_type")
511    copy_prop("userdata_size", "partition_size")
512  elif mount_point == "cache":
513    copy_prop("cache_fs_type", "fs_type")
514    copy_prop("cache_size", "partition_size")
515  elif mount_point == "vendor":
516    copy_prop("vendor_fs_type", "fs_type")
517    copy_prop("vendor_size", "partition_size")
518    copy_prop("vendor_journal_size", "journal_size")
519    copy_prop("vendor_verity_block_device", "verity_block_device")
520    copy_prop("has_ext4_reserved_blocks", "has_ext4_reserved_blocks")
521  elif mount_point == "oem":
522    copy_prop("fs_type", "fs_type")
523    copy_prop("oem_size", "partition_size")
524    copy_prop("oem_journal_size", "journal_size")
525    copy_prop("has_ext4_reserved_blocks", "has_ext4_reserved_blocks")
526
527  return d
528
529
530def LoadGlobalDict(filename):
531  """Load "name=value" pairs from filename"""
532  d = {}
533  f = open(filename)
534  for line in f:
535    line = line.strip()
536    if not line or line.startswith("#"):
537      continue
538    k, v = line.split("=", 1)
539    d[k] = v
540  f.close()
541  return d
542
543
544def main(argv):
545  if len(argv) != 4:
546    print __doc__
547    sys.exit(1)
548
549  in_dir = argv[0]
550  glob_dict_file = argv[1]
551  out_file = argv[2]
552  target_out = argv[3]
553
554  glob_dict = LoadGlobalDict(glob_dict_file)
555  if "mount_point" in glob_dict:
556    # The caller knows the mount point and provides a dictionay needed by
557    # BuildImage().
558    image_properties = glob_dict
559  else:
560    image_filename = os.path.basename(out_file)
561    mount_point = ""
562    if image_filename == "system.img":
563      mount_point = "system"
564    elif image_filename == "userdata.img":
565      mount_point = "data"
566    elif image_filename == "cache.img":
567      mount_point = "cache"
568    elif image_filename == "vendor.img":
569      mount_point = "vendor"
570    elif image_filename == "oem.img":
571      mount_point = "oem"
572    else:
573      print >> sys.stderr, "error: unknown image file name ", image_filename
574      exit(1)
575
576    image_properties = ImagePropFromGlobalDict(glob_dict, mount_point)
577
578  if not BuildImage(in_dir, image_properties, out_file, target_out):
579    print >> sys.stderr, "error: failed to build %s from %s" % (out_file,
580                                                                in_dir)
581    exit(1)
582
583
584if __name__ == '__main__':
585  main(sys.argv[1:])
586