build_image.py revision 405e71dcd3e96457766c3ac3f2aa3d4bd9f95e32 
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 sparse_img
32import tempfile
33
34OPTIONS = common.OPTIONS
35
36FIXED_SALT = "aee087a5be3b982978c923f566a94613496b417f2af592639bc80d141e34dfe7"
37BLOCK_SIZE = 4096
38
39def RunCommand(cmd):
40  """Echo and run the given command.
41
42  Args:
43    cmd: the command represented as a list of strings.
44  Returns:
45    A tuple of the output and the exit code.
46  """
47  print "Running: ", " ".join(cmd)
48  p = subprocess.Popen(cmd, stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
49  output, _ = p.communicate()
50  print "%s" % (output.rstrip(),)
51  return (output, p.returncode)
52
53def GetVerityFECSize(partition_size):
54  cmd = "fec -s %d" % partition_size
55  status, output = commands.getstatusoutput(cmd)
56  if status:
57    print output
58    return False, 0
59  return True, int(output)
60
61def GetVerityTreeSize(partition_size):
62  cmd = "build_verity_tree -s %d"
63  cmd %= partition_size
64  status, output = commands.getstatusoutput(cmd)
65  if status:
66    print output
67    return False, 0
68  return True, int(output)
69
70def GetVerityMetadataSize(partition_size):
71  cmd = "system/extras/verity/build_verity_metadata.py -s %d"
72  cmd %= partition_size
73
74  status, output = commands.getstatusoutput(cmd)
75  if status:
76    print output
77    return False, 0
78  return True, int(output)
79
80def GetVeritySize(partition_size, fec_supported):
81  success, verity_tree_size = GetVerityTreeSize(partition_size)
82  if not success:
83    return 0
84  success, verity_metadata_size = GetVerityMetadataSize(partition_size)
85  if not success:
86    return 0
87  verity_size = verity_tree_size + verity_metadata_size
88  if fec_supported:
89    success, fec_size = GetVerityFECSize(partition_size + verity_size)
90    if not success:
91      return 0
92    return verity_size + fec_size
93  return verity_size
94
95def GetSimgSize(image_file):
96  simg = sparse_img.SparseImage(image_file, build_map=False)
97  return simg.blocksize * simg.total_blocks
98
99def ZeroPadSimg(image_file, pad_size):
100  blocks = pad_size // BLOCK_SIZE
101  print("Padding %d blocks (%d bytes)" % (blocks, pad_size))
102  simg = sparse_img.SparseImage(image_file, mode="r+b", build_map=False)
103  simg.AppendFillChunk(0, blocks)
104
105def AdjustPartitionSizeForVerity(partition_size, fec_supported):
106  """Modifies the provided partition size to account for the verity metadata.
107
108  This information is used to size the created image appropriately.
109  Args:
110    partition_size: the size of the partition to be verified.
111  Returns:
112    The size of the partition adjusted for verity metadata.
113  """
114  key = "%d %d" % (partition_size, fec_supported)
115  if key in AdjustPartitionSizeForVerity.results:
116    return AdjustPartitionSizeForVerity.results[key]
117
118  hi = partition_size
119  if hi % BLOCK_SIZE != 0:
120    hi = (hi // BLOCK_SIZE) * BLOCK_SIZE
121
122  # verity tree and fec sizes depend on the partition size, which
123  # means this estimate is always going to be unnecessarily small
124  lo = partition_size - GetVeritySize(hi, fec_supported)
125  result = lo
126
127  # do a binary search for the optimal size
128  while lo < hi:
129    i = ((lo + hi) // (2 * BLOCK_SIZE)) * BLOCK_SIZE
130    size = i + GetVeritySize(i, fec_supported)
131    if size <= partition_size:
132      if result < i:
133        result = i
134      lo = i + BLOCK_SIZE
135    else:
136      hi = i
137
138  AdjustPartitionSizeForVerity.results[key] = result
139  return result
140
141AdjustPartitionSizeForVerity.results = {}
142
143def BuildVerityFEC(sparse_image_path, verity_path, verity_fec_path):
144  cmd = "fec -e %s %s %s" % (sparse_image_path, verity_path, verity_fec_path)
145  print cmd
146  status, output = commands.getstatusoutput(cmd)
147  if status:
148    print "Could not build FEC data! Error: %s" % output
149    return False
150  return True
151
152def BuildVerityTree(sparse_image_path, verity_image_path, prop_dict):
153  cmd = "build_verity_tree -A %s %s %s" % (
154      FIXED_SALT, sparse_image_path, verity_image_path)
155  print cmd
156  status, output = commands.getstatusoutput(cmd)
157  if status:
158    print "Could not build verity tree! Error: %s" % output
159    return False
160  root, salt = output.split()
161  prop_dict["verity_root_hash"] = root
162  prop_dict["verity_salt"] = salt
163  return True
164
165def BuildVerityMetadata(image_size, verity_metadata_path, root_hash, salt,
166                        block_device, signer_path, key):
167  cmd_template = (
168      "system/extras/verity/build_verity_metadata.py %s %s %s %s %s %s %s")
169  cmd = cmd_template % (image_size, verity_metadata_path, root_hash, salt,
170                        block_device, signer_path, key)
171  print cmd
172  status, output = commands.getstatusoutput(cmd)
173  if status:
174    print "Could not build verity metadata! Error: %s" % output
175    return False
176  return True
177
178def Append2Simg(sparse_image_path, unsparse_image_path, error_message):
179  """Appends the unsparse image to the given sparse image.
180
181  Args:
182    sparse_image_path: the path to the (sparse) image
183    unsparse_image_path: the path to the (unsparse) image
184  Returns:
185    True on success, False on failure.
186  """
187  cmd = "append2simg %s %s"
188  cmd %= (sparse_image_path, unsparse_image_path)
189  print cmd
190  status, output = commands.getstatusoutput(cmd)
191  if status:
192    print "%s: %s" % (error_message, output)
193    return False
194  return True
195
196def Append(target, file_to_append, error_message):
197  cmd = 'cat %s >> %s' % (file_to_append, target)
198  print cmd
199  status, output = commands.getstatusoutput(cmd)
200  if status:
201    print "%s: %s" % (error_message, output)
202    return False
203  return True
204
205def BuildVerifiedImage(data_image_path, verity_image_path,
206                       verity_metadata_path, verity_fec_path,
207                       fec_supported):
208  if not Append(verity_image_path, verity_metadata_path,
209                "Could not append verity metadata!"):
210    return False
211
212  if fec_supported:
213    # build FEC for the entire partition, including metadata
214    if not BuildVerityFEC(data_image_path, verity_image_path,
215                          verity_fec_path):
216      return False
217
218    if not Append(verity_image_path, verity_fec_path, "Could not append FEC!"):
219      return False
220
221  if not Append2Simg(data_image_path, verity_image_path,
222                     "Could not append verity data!"):
223    return False
224  return True
225
226def UnsparseImage(sparse_image_path, replace=True):
227  img_dir = os.path.dirname(sparse_image_path)
228  unsparse_image_path = "unsparse_" + os.path.basename(sparse_image_path)
229  unsparse_image_path = os.path.join(img_dir, unsparse_image_path)
230  if os.path.exists(unsparse_image_path):
231    if replace:
232      os.unlink(unsparse_image_path)
233    else:
234      return True, unsparse_image_path
235  inflate_command = ["simg2img", sparse_image_path, unsparse_image_path]
236  (_, exit_code) = RunCommand(inflate_command)
237  if exit_code != 0:
238    os.remove(unsparse_image_path)
239    return False, None
240  return True, unsparse_image_path
241
242def MakeVerityEnabledImage(out_file, fec_supported, prop_dict):
243  """Creates an image that is verifiable using dm-verity.
244
245  Args:
246    out_file: the location to write the verifiable image at
247    prop_dict: a dictionary of properties required for image creation and
248               verification
249  Returns:
250    True on success, False otherwise.
251  """
252  # get properties
253  image_size = prop_dict["partition_size"]
254  block_dev = prop_dict["verity_block_device"]
255  signer_key = prop_dict["verity_key"] + ".pk8"
256  if OPTIONS.verity_signer_path is not None:
257    signer_path = OPTIONS.verity_signer_path + ' '
258    signer_path += ' '.join(OPTIONS.verity_signer_args)
259  else:
260    signer_path = prop_dict["verity_signer_cmd"]
261
262  # make a tempdir
263  tempdir_name = tempfile.mkdtemp(suffix="_verity_images")
264
265  # get partial image paths
266  verity_image_path = os.path.join(tempdir_name, "verity.img")
267  verity_metadata_path = os.path.join(tempdir_name, "verity_metadata.img")
268  verity_fec_path = os.path.join(tempdir_name, "verity_fec.img")
269
270  # build the verity tree and get the root hash and salt
271  if not BuildVerityTree(out_file, verity_image_path, prop_dict):
272    shutil.rmtree(tempdir_name, ignore_errors=True)
273    return False
274
275  # build the metadata blocks
276  root_hash = prop_dict["verity_root_hash"]
277  salt = prop_dict["verity_salt"]
278  if not BuildVerityMetadata(image_size, verity_metadata_path, root_hash, salt,
279                             block_dev, signer_path, signer_key):
280    shutil.rmtree(tempdir_name, ignore_errors=True)
281    return False
282
283  # build the full verified image
284  if not BuildVerifiedImage(out_file,
285                            verity_image_path,
286                            verity_metadata_path,
287                            verity_fec_path,
288                            fec_supported):
289    shutil.rmtree(tempdir_name, ignore_errors=True)
290    return False
291
292  shutil.rmtree(tempdir_name, ignore_errors=True)
293  return True
294
295def BuildImage(in_dir, prop_dict, out_file, target_out=None):
296  """Build an image to out_file from in_dir with property prop_dict.
297
298  Args:
299    in_dir: path of input directory.
300    prop_dict: property dictionary.
301    out_file: path of the output image file.
302    target_out: path of the product out directory to read device specific FS config files.
303
304  Returns:
305    True iff the image is built successfully.
306  """
307  # system_root_image=true: build a system.img that combines the contents of
308  # /system and the ramdisk, and can be mounted at the root of the file system.
309  origin_in = in_dir
310  fs_config = prop_dict.get("fs_config")
311  if (prop_dict.get("system_root_image") == "true"
312      and prop_dict["mount_point"] == "system"):
313    in_dir = tempfile.mkdtemp()
314    # Change the mount point to "/"
315    prop_dict["mount_point"] = "/"
316    if fs_config:
317      # We need to merge the fs_config files of system and ramdisk.
318      fd, merged_fs_config = tempfile.mkstemp(prefix="root_fs_config",
319                                              suffix=".txt")
320      os.close(fd)
321      with open(merged_fs_config, "w") as fw:
322        if "ramdisk_fs_config" in prop_dict:
323          with open(prop_dict["ramdisk_fs_config"]) as fr:
324            fw.writelines(fr.readlines())
325        with open(fs_config) as fr:
326          fw.writelines(fr.readlines())
327      fs_config = merged_fs_config
328
329  build_command = []
330  fs_type = prop_dict.get("fs_type", "")
331  run_fsck = False
332
333  fs_spans_partition = True
334  if fs_type.startswith("squash"):
335    fs_spans_partition = False
336
337  is_verity_partition = "verity_block_device" in prop_dict
338  verity_supported = prop_dict.get("verity") == "true"
339  verity_fec_supported = prop_dict.get("verity_fec") == "true"
340
341  # Adjust the partition size to make room for the hashes if this is to be
342  # verified.
343  if verity_supported and is_verity_partition:
344    partition_size = int(prop_dict.get("partition_size"))
345    adjusted_size = AdjustPartitionSizeForVerity(partition_size,
346                                                 verity_fec_supported)
347    if not adjusted_size:
348      return False
349    prop_dict["partition_size"] = str(adjusted_size)
350    prop_dict["original_partition_size"] = str(partition_size)
351
352  if fs_type.startswith("ext"):
353    build_command = ["mkuserimg.sh"]
354    if "extfs_sparse_flag" in prop_dict:
355      build_command.append(prop_dict["extfs_sparse_flag"])
356      run_fsck = True
357    build_command.extend([in_dir, out_file, fs_type,
358                          prop_dict["mount_point"]])
359    build_command.append(prop_dict["partition_size"])
360    if "journal_size" in prop_dict:
361      build_command.extend(["-j", prop_dict["journal_size"]])
362    if "timestamp" in prop_dict:
363      build_command.extend(["-T", str(prop_dict["timestamp"])])
364    if fs_config:
365      build_command.extend(["-C", fs_config])
366    if target_out:
367      build_command.extend(["-D", target_out])
368    if "block_list" in prop_dict:
369      build_command.extend(["-B", prop_dict["block_list"]])
370    build_command.extend(["-L", prop_dict["mount_point"]])
371    if "selinux_fc" in prop_dict:
372      build_command.append(prop_dict["selinux_fc"])
373  elif fs_type.startswith("squash"):
374    build_command = ["mksquashfsimage.sh"]
375    build_command.extend([in_dir, out_file])
376    if "squashfs_sparse_flag" in prop_dict:
377      build_command.extend([prop_dict["squashfs_sparse_flag"]])
378    build_command.extend(["-m", prop_dict["mount_point"]])
379    if target_out:
380      build_command.extend(["-d", target_out])
381    if "selinux_fc" in prop_dict:
382      build_command.extend(["-c", prop_dict["selinux_fc"]])
383    if "squashfs_compressor" in prop_dict:
384      build_command.extend(["-z", prop_dict["squashfs_compressor"]])
385    if "squashfs_compressor_opt" in prop_dict:
386      build_command.extend(["-zo", prop_dict["squashfs_compressor_opt"]])
387  elif fs_type.startswith("f2fs"):
388    build_command = ["mkf2fsuserimg.sh"]
389    build_command.extend([out_file, prop_dict["partition_size"]])
390  else:
391    build_command = ["mkyaffs2image", "-f"]
392    if prop_dict.get("mkyaffs2_extra_flags", None):
393      build_command.extend(prop_dict["mkyaffs2_extra_flags"].split())
394    build_command.append(in_dir)
395    build_command.append(out_file)
396    if "selinux_fc" in prop_dict:
397      build_command.append(prop_dict["selinux_fc"])
398      build_command.append(prop_dict["mount_point"])
399
400  if in_dir != origin_in:
401    # Construct a staging directory of the root file system.
402    ramdisk_dir = prop_dict.get("ramdisk_dir")
403    if ramdisk_dir:
404      shutil.rmtree(in_dir)
405      shutil.copytree(ramdisk_dir, in_dir, symlinks=True)
406    staging_system = os.path.join(in_dir, "system")
407    shutil.rmtree(staging_system, ignore_errors=True)
408    shutil.copytree(origin_in, staging_system, symlinks=True)
409
410  reserved_blocks = prop_dict.get("has_ext4_reserved_blocks") == "true"
411  ext4fs_output = None
412
413  try:
414    if reserved_blocks and fs_type.startswith("ext4"):
415      (ext4fs_output, exit_code) = RunCommand(build_command)
416    else:
417      (_, exit_code) = RunCommand(build_command)
418  finally:
419    if in_dir != origin_in:
420      # Clean up temporary directories and files.
421      shutil.rmtree(in_dir, ignore_errors=True)
422      if fs_config:
423        os.remove(fs_config)
424  if exit_code != 0:
425    return False
426
427  # Bug: 21522719, 22023465
428  # There are some reserved blocks on ext4 FS (lesser of 4096 blocks and 2%).
429  # We need to deduct those blocks from the available space, since they are
430  # not writable even with root privilege. It only affects devices using
431  # file-based OTA and a kernel version of 3.10 or greater (currently just
432  # sprout).
433  if reserved_blocks and fs_type.startswith("ext4"):
434    assert ext4fs_output is not None
435    ext4fs_stats = re.compile(
436        r'Created filesystem with .* (?P<used_blocks>[0-9]+)/'
437        r'(?P<total_blocks>[0-9]+) blocks')
438    m = ext4fs_stats.match(ext4fs_output.strip().split('\n')[-1])
439    used_blocks = int(m.groupdict().get('used_blocks'))
440    total_blocks = int(m.groupdict().get('total_blocks'))
441    reserved_blocks = min(4096, int(total_blocks * 0.02))
442    adjusted_blocks = total_blocks - reserved_blocks
443    if used_blocks > adjusted_blocks:
444      mount_point = prop_dict.get("mount_point")
445      print("Error: Not enough room on %s (total: %d blocks, used: %d blocks, "
446            "reserved: %d blocks, available: %d blocks)" % (
447                mount_point, total_blocks, used_blocks, reserved_blocks,
448                adjusted_blocks))
449      return False
450
451  if not fs_spans_partition:
452    mount_point = prop_dict.get("mount_point")
453    partition_size = int(prop_dict.get("partition_size"))
454    image_size = GetSimgSize(out_file)
455    if image_size > partition_size:
456      print("Error: %s image size of %d is larger than partition size of "
457            "%d" % (mount_point, image_size, partition_size))
458      return False
459    if verity_supported and is_verity_partition:
460      ZeroPadSimg(out_file, partition_size - image_size)
461
462  # create the verified image if this is to be verified
463  if verity_supported and is_verity_partition:
464    if not MakeVerityEnabledImage(out_file, verity_fec_supported, prop_dict):
465      return False
466
467  if run_fsck and prop_dict.get("skip_fsck") != "true":
468    success, unsparse_image = UnsparseImage(out_file, replace=False)
469    if not success:
470      return False
471
472    # Run e2fsck on the inflated image file
473    e2fsck_command = ["e2fsck", "-f", "-n", unsparse_image]
474    (_, exit_code) = RunCommand(e2fsck_command)
475
476    os.remove(unsparse_image)
477
478  return exit_code == 0
479
480
481def ImagePropFromGlobalDict(glob_dict, mount_point):
482  """Build an image property dictionary from the global dictionary.
483
484  Args:
485    glob_dict: the global dictionary from the build system.
486    mount_point: such as "system", "data" etc.
487  """
488  d = {}
489
490  if "build.prop" in glob_dict:
491    bp = glob_dict["build.prop"]
492    if "ro.build.date.utc" in bp:
493      d["timestamp"] = bp["ro.build.date.utc"]
494
495  def copy_prop(src_p, dest_p):
496    if src_p in glob_dict:
497      d[dest_p] = str(glob_dict[src_p])
498
499  common_props = (
500      "extfs_sparse_flag",
501      "squashfs_sparse_flag",
502      "mkyaffs2_extra_flags",
503      "selinux_fc",
504      "skip_fsck",
505      "verity",
506      "verity_key",
507      "verity_signer_cmd",
508      "verity_fec"
509      )
510  for p in common_props:
511    copy_prop(p, p)
512
513  d["mount_point"] = mount_point
514  if mount_point == "system":
515    copy_prop("fs_type", "fs_type")
516    # Copy the generic sysetem fs type first, override with specific one if
517    # available.
518    copy_prop("system_fs_type", "fs_type")
519    copy_prop("system_size", "partition_size")
520    copy_prop("system_journal_size", "journal_size")
521    copy_prop("system_verity_block_device", "verity_block_device")
522    copy_prop("system_root_image", "system_root_image")
523    copy_prop("ramdisk_dir", "ramdisk_dir")
524    copy_prop("ramdisk_fs_config", "ramdisk_fs_config")
525    copy_prop("has_ext4_reserved_blocks", "has_ext4_reserved_blocks")
526    copy_prop("system_squashfs_compressor", "squashfs_compressor")
527    copy_prop("system_squashfs_compressor_opt", "squashfs_compressor_opt")
528  elif mount_point == "data":
529    # Copy the generic fs type first, override with specific one if available.
530    copy_prop("fs_type", "fs_type")
531    copy_prop("userdata_fs_type", "fs_type")
532    copy_prop("userdata_size", "partition_size")
533  elif mount_point == "cache":
534    copy_prop("cache_fs_type", "fs_type")
535    copy_prop("cache_size", "partition_size")
536  elif mount_point == "vendor":
537    copy_prop("vendor_fs_type", "fs_type")
538    copy_prop("vendor_size", "partition_size")
539    copy_prop("vendor_journal_size", "journal_size")
540    copy_prop("vendor_verity_block_device", "verity_block_device")
541    copy_prop("has_ext4_reserved_blocks", "has_ext4_reserved_blocks")
542    copy_prop("vendor_squashfs_compressor", "squashfs_compressor")
543    copy_prop("vendor_squashfs_compressor_opt", "squashfs_compressor_opt")
544  elif mount_point == "oem":
545    copy_prop("fs_type", "fs_type")
546    copy_prop("oem_size", "partition_size")
547    copy_prop("oem_journal_size", "journal_size")
548    copy_prop("has_ext4_reserved_blocks", "has_ext4_reserved_blocks")
549
550  return d
551
552
553def LoadGlobalDict(filename):
554  """Load "name=value" pairs from filename"""
555  d = {}
556  f = open(filename)
557  for line in f:
558    line = line.strip()
559    if not line or line.startswith("#"):
560      continue
561    k, v = line.split("=", 1)
562    d[k] = v
563  f.close()
564  return d
565
566
567def main(argv):
568  if len(argv) != 4:
569    print __doc__
570    sys.exit(1)
571
572  in_dir = argv[0]
573  glob_dict_file = argv[1]
574  out_file = argv[2]
575  target_out = argv[3]
576
577  glob_dict = LoadGlobalDict(glob_dict_file)
578  if "mount_point" in glob_dict:
579    # The caller knows the mount point and provides a dictionay needed by
580    # BuildImage().
581    image_properties = glob_dict
582  else:
583    image_filename = os.path.basename(out_file)
584    mount_point = ""
585    if image_filename == "system.img":
586      mount_point = "system"
587    elif image_filename == "userdata.img":
588      mount_point = "data"
589    elif image_filename == "cache.img":
590      mount_point = "cache"
591    elif image_filename == "vendor.img":
592      mount_point = "vendor"
593    elif image_filename == "oem.img":
594      mount_point = "oem"
595    else:
596      print >> sys.stderr, "error: unknown image file name ", image_filename
597      exit(1)
598
599    image_properties = ImagePropFromGlobalDict(glob_dict, mount_point)
600
601  if not BuildImage(in_dir, image_properties, out_file, target_out):
602    print >> sys.stderr, "error: failed to build %s from %s" % (out_file,
603                                                                in_dir)
604    exit(1)
605
606
607if __name__ == '__main__':
608  main(sys.argv[1:])
609