diff --git a/tools/releasetools/Android.bp b/tools/releasetools/Android.bp
index ee266b7..ad014af 100644
--- a/tools/releasetools/Android.bp
+++ b/tools/releasetools/Android.bp
@@ -483,8 +483,13 @@
     defaults: ["releasetools_binary_defaults"],
     srcs: [
         "make_recovery_patch.py",
+        "non_ab_ota.py",
+        "edify_generator.py",
+        "check_target_files_vintf.py",
     ],
     libs: [
+        "ota_utils_lib",
+        "ota_metadata_proto",
         "releasetools_common",
     ],
 }
diff --git a/tools/releasetools/check_target_files_vintf.py b/tools/releasetools/check_target_files_vintf.py
index 33624f5..e7d3a18 100755
--- a/tools/releasetools/check_target_files_vintf.py
+++ b/tools/releasetools/check_target_files_vintf.py
@@ -31,7 +31,6 @@
 import zipfile
 
 import common
-from apex_manifest import ParseApexManifest
 
 logger = logging.getLogger(__name__)
 
diff --git a/tools/releasetools/common.py b/tools/releasetools/common.py
index 893eced..d97611c 100644
--- a/tools/releasetools/common.py
+++ b/tools/releasetools/common.py
@@ -15,7 +15,6 @@
 from __future__ import print_function
 
 import base64
-import collections
 import copy
 import datetime
 import errno
@@ -23,7 +22,6 @@
 import getopt
 import getpass
 import gzip
-import imp
 import json
 import logging
 import logging.config
@@ -36,17 +34,13 @@
 import stat
 import sys
 import tempfile
-import threading
-import time
 import zipfile
 from dataclasses import dataclass
-from genericpath import isdir
 from hashlib import sha1, sha256
 
 import images
-import rangelib
 import sparse_img
-from blockimgdiff import BlockImageDiff
+
 
 logger = logging.getLogger(__name__)
 
@@ -155,35 +149,6 @@
         self.partition, self.rollback_index_location, self.pubkey_path)
 
 
-class ErrorCode(object):
-  """Define error_codes for failures that happen during the actual
-  update package installation.
-
-  Error codes 0-999 are reserved for failures before the package
-  installation (i.e. low battery, package verification failure).
-  Detailed code in 'bootable/recovery/error_code.h' """
-
-  SYSTEM_VERIFICATION_FAILURE = 1000
-  SYSTEM_UPDATE_FAILURE = 1001
-  SYSTEM_UNEXPECTED_CONTENTS = 1002
-  SYSTEM_NONZERO_CONTENTS = 1003
-  SYSTEM_RECOVER_FAILURE = 1004
-  VENDOR_VERIFICATION_FAILURE = 2000
-  VENDOR_UPDATE_FAILURE = 2001
-  VENDOR_UNEXPECTED_CONTENTS = 2002
-  VENDOR_NONZERO_CONTENTS = 2003
-  VENDOR_RECOVER_FAILURE = 2004
-  OEM_PROP_MISMATCH = 3000
-  FINGERPRINT_MISMATCH = 3001
-  THUMBPRINT_MISMATCH = 3002
-  OLDER_BUILD = 3003
-  DEVICE_MISMATCH = 3004
-  BAD_PATCH_FILE = 3005
-  INSUFFICIENT_CACHE_SPACE = 3006
-  TUNE_PARTITION_FAILURE = 3007
-  APPLY_PATCH_FAILURE = 3008
-
-
 class ExternalError(RuntimeError):
   pass
 
@@ -3134,107 +3099,6 @@
   zipfile.ZIP64_LIMIT = saved_zip64_limit
 
 
-class DeviceSpecificParams(object):
-  module = None
-
-  def __init__(self, **kwargs):
-    """Keyword arguments to the constructor become attributes of this
-    object, which is passed to all functions in the device-specific
-    module."""
-    for k, v in kwargs.items():
-      setattr(self, k, v)
-    self.extras = OPTIONS.extras
-
-    if self.module is None:
-      path = OPTIONS.device_specific
-      if not path:
-        return
-      try:
-        if os.path.isdir(path):
-          info = imp.find_module("releasetools", [path])
-        else:
-          d, f = os.path.split(path)
-          b, x = os.path.splitext(f)
-          if x == ".py":
-            f = b
-          info = imp.find_module(f, [d])
-        logger.info("loaded device-specific extensions from %s", path)
-        self.module = imp.load_module("device_specific", *info)
-      except ImportError:
-        logger.info("unable to load device-specific module; assuming none")
-
-  def _DoCall(self, function_name, *args, **kwargs):
-    """Call the named function in the device-specific module, passing
-    the given args and kwargs.  The first argument to the call will be
-    the DeviceSpecific object itself.  If there is no module, or the
-    module does not define the function, return the value of the
-    'default' kwarg (which itself defaults to None)."""
-    if self.module is None or not hasattr(self.module, function_name):
-      return kwargs.get("default")
-    return getattr(self.module, function_name)(*((self,) + args), **kwargs)
-
-  def FullOTA_Assertions(self):
-    """Called after emitting the block of assertions at the top of a
-    full OTA package.  Implementations can add whatever additional
-    assertions they like."""
-    return self._DoCall("FullOTA_Assertions")
-
-  def FullOTA_InstallBegin(self):
-    """Called at the start of full OTA installation."""
-    return self._DoCall("FullOTA_InstallBegin")
-
-  def FullOTA_GetBlockDifferences(self):
-    """Called during full OTA installation and verification.
-    Implementation should return a list of BlockDifference objects describing
-    the update on each additional partitions.
-    """
-    return self._DoCall("FullOTA_GetBlockDifferences")
-
-  def FullOTA_InstallEnd(self):
-    """Called at the end of full OTA installation; typically this is
-    used to install the image for the device's baseband processor."""
-    return self._DoCall("FullOTA_InstallEnd")
-
-  def IncrementalOTA_Assertions(self):
-    """Called after emitting the block of assertions at the top of an
-    incremental OTA package.  Implementations can add whatever
-    additional assertions they like."""
-    return self._DoCall("IncrementalOTA_Assertions")
-
-  def IncrementalOTA_VerifyBegin(self):
-    """Called at the start of the verification phase of incremental
-    OTA installation; additional checks can be placed here to abort
-    the script before any changes are made."""
-    return self._DoCall("IncrementalOTA_VerifyBegin")
-
-  def IncrementalOTA_VerifyEnd(self):
-    """Called at the end of the verification phase of incremental OTA
-    installation; additional checks can be placed here to abort the
-    script before any changes are made."""
-    return self._DoCall("IncrementalOTA_VerifyEnd")
-
-  def IncrementalOTA_InstallBegin(self):
-    """Called at the start of incremental OTA installation (after
-    verification is complete)."""
-    return self._DoCall("IncrementalOTA_InstallBegin")
-
-  def IncrementalOTA_GetBlockDifferences(self):
-    """Called during incremental OTA installation and verification.
-    Implementation should return a list of BlockDifference objects describing
-    the update on each additional partitions.
-    """
-    return self._DoCall("IncrementalOTA_GetBlockDifferences")
-
-  def IncrementalOTA_InstallEnd(self):
-    """Called at the end of incremental OTA installation; typically
-    this is used to install the image for the device's baseband
-    processor."""
-    return self._DoCall("IncrementalOTA_InstallEnd")
-
-  def VerifyOTA_Assertions(self):
-    return self._DoCall("VerifyOTA_Assertions")
-
-
 class File(object):
   def __init__(self, name, data, compress_size=None):
     self.name = name
@@ -3264,454 +3128,11 @@
     ZipWriteStr(z, self.name, self.data, compress_type=compression)
 
 
-DIFF_PROGRAM_BY_EXT = {
-    ".gz": "imgdiff",
-    ".zip": ["imgdiff", "-z"],
-    ".jar": ["imgdiff", "-z"],
-    ".apk": ["imgdiff", "-z"],
-    ".img": "imgdiff",
-}
-
-
-class Difference(object):
-  def __init__(self, tf, sf, diff_program=None):
-    self.tf = tf
-    self.sf = sf
-    self.patch = None
-    self.diff_program = diff_program
-
-  def ComputePatch(self):
-    """Compute the patch (as a string of data) needed to turn sf into
-    tf.  Returns the same tuple as GetPatch()."""
-
-    tf = self.tf
-    sf = self.sf
-
-    if self.diff_program:
-      diff_program = self.diff_program
-    else:
-      ext = os.path.splitext(tf.name)[1]
-      diff_program = DIFF_PROGRAM_BY_EXT.get(ext, "bsdiff")
-
-    ttemp = tf.WriteToTemp()
-    stemp = sf.WriteToTemp()
-
-    ext = os.path.splitext(tf.name)[1]
-
-    try:
-      ptemp = tempfile.NamedTemporaryFile()
-      if isinstance(diff_program, list):
-        cmd = copy.copy(diff_program)
-      else:
-        cmd = [diff_program]
-      cmd.append(stemp.name)
-      cmd.append(ttemp.name)
-      cmd.append(ptemp.name)
-      p = Run(cmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
-      err = []
-
-      def run():
-        _, e = p.communicate()
-        if e:
-          err.append(e)
-      th = threading.Thread(target=run)
-      th.start()
-      th.join(timeout=300)   # 5 mins
-      if th.is_alive():
-        logger.warning("diff command timed out")
-        p.terminate()
-        th.join(5)
-        if th.is_alive():
-          p.kill()
-          th.join()
-
-      if p.returncode != 0:
-        logger.warning("Failure running %s:\n%s\n", cmd, "".join(err))
-        self.patch = None
-        return None, None, None
-      diff = ptemp.read()
-    finally:
-      ptemp.close()
-      stemp.close()
-      ttemp.close()
-
-    self.patch = diff
-    return self.tf, self.sf, self.patch
-
-  def GetPatch(self):
-    """Returns a tuple of (target_file, source_file, patch_data).
-
-    patch_data may be None if ComputePatch hasn't been called, or if
-    computing the patch failed.
-    """
-    return self.tf, self.sf, self.patch
-
-
-def ComputeDifferences(diffs):
-  """Call ComputePatch on all the Difference objects in 'diffs'."""
-  logger.info("%d diffs to compute", len(diffs))
-
-  # Do the largest files first, to try and reduce the long-pole effect.
-  by_size = [(i.tf.size, i) for i in diffs]
-  by_size.sort(reverse=True)
-  by_size = [i[1] for i in by_size]
-
-  lock = threading.Lock()
-  diff_iter = iter(by_size)   # accessed under lock
-
-  def worker():
-    try:
-      lock.acquire()
-      for d in diff_iter:
-        lock.release()
-        start = time.time()
-        d.ComputePatch()
-        dur = time.time() - start
-        lock.acquire()
-
-        tf, sf, patch = d.GetPatch()
-        if sf.name == tf.name:
-          name = tf.name
-        else:
-          name = "%s (%s)" % (tf.name, sf.name)
-        if patch is None:
-          logger.error("patching failed! %40s", name)
-        else:
-          logger.info(
-              "%8.2f sec %8d / %8d bytes (%6.2f%%) %s", dur, len(patch),
-              tf.size, 100.0 * len(patch) / tf.size, name)
-      lock.release()
-    except Exception:
-      logger.exception("Failed to compute diff from worker")
-      raise
-
-  # start worker threads; wait for them all to finish.
-  threads = [threading.Thread(target=worker)
-             for i in range(OPTIONS.worker_threads)]
-  for th in threads:
-    th.start()
-  while threads:
-    threads.pop().join()
-
-
-class BlockDifference(object):
-  def __init__(self, partition, tgt, src=None, check_first_block=False,
-               version=None, disable_imgdiff=False):
-    self.tgt = tgt
-    self.src = src
-    self.partition = partition
-    self.check_first_block = check_first_block
-    self.disable_imgdiff = disable_imgdiff
-
-    if version is None:
-      version = max(
-          int(i) for i in
-          OPTIONS.info_dict.get("blockimgdiff_versions", "1").split(","))
-    assert version >= 3
-    self.version = version
-
-    b = BlockImageDiff(tgt, src, threads=OPTIONS.worker_threads,
-                       version=self.version,
-                       disable_imgdiff=self.disable_imgdiff)
-    self.path = os.path.join(MakeTempDir(), partition)
-    b.Compute(self.path)
-    self._required_cache = b.max_stashed_size
-    self.touched_src_ranges = b.touched_src_ranges
-    self.touched_src_sha1 = b.touched_src_sha1
-
-    # On devices with dynamic partitions, for new partitions,
-    # src is None but OPTIONS.source_info_dict is not.
-    if OPTIONS.source_info_dict is None:
-      is_dynamic_build = OPTIONS.info_dict.get(
-          "use_dynamic_partitions") == "true"
-      is_dynamic_source = False
-    else:
-      is_dynamic_build = OPTIONS.source_info_dict.get(
-          "use_dynamic_partitions") == "true"
-      is_dynamic_source = partition in shlex.split(
-          OPTIONS.source_info_dict.get("dynamic_partition_list", "").strip())
-
-    is_dynamic_target = partition in shlex.split(
-        OPTIONS.info_dict.get("dynamic_partition_list", "").strip())
-
-    # For dynamic partitions builds, check partition list in both source
-    # and target build because new partitions may be added, and existing
-    # partitions may be removed.
-    is_dynamic = is_dynamic_build and (is_dynamic_source or is_dynamic_target)
-
-    if is_dynamic:
-      self.device = 'map_partition("%s")' % partition
-    else:
-      if OPTIONS.source_info_dict is None:
-        _, device_expr = GetTypeAndDeviceExpr("/" + partition,
-                                              OPTIONS.info_dict)
-      else:
-        _, device_expr = GetTypeAndDeviceExpr("/" + partition,
-                                              OPTIONS.source_info_dict)
-      self.device = device_expr
-
-  @property
-  def required_cache(self):
-    return self._required_cache
-
-  def WriteScript(self, script, output_zip, progress=None,
-                  write_verify_script=False):
-    if not self.src:
-      # write the output unconditionally
-      script.Print("Patching %s image unconditionally..." % (self.partition,))
-    else:
-      script.Print("Patching %s image after verification." % (self.partition,))
-
-    if progress:
-      script.ShowProgress(progress, 0)
-    self._WriteUpdate(script, output_zip)
-
-    if write_verify_script:
-      self.WritePostInstallVerifyScript(script)
-
-  def WriteStrictVerifyScript(self, script):
-    """Verify all the blocks in the care_map, including clobbered blocks.
-
-    This differs from the WriteVerifyScript() function: a) it prints different
-    error messages; b) it doesn't allow half-way updated images to pass the
-    verification."""
-
-    partition = self.partition
-    script.Print("Verifying %s..." % (partition,))
-    ranges = self.tgt.care_map
-    ranges_str = ranges.to_string_raw()
-    script.AppendExtra(
-        'range_sha1(%s, "%s") == "%s" && ui_print("    Verified.") || '
-        'ui_print("%s has unexpected contents.");' % (
-            self.device, ranges_str,
-            self.tgt.TotalSha1(include_clobbered_blocks=True),
-            self.partition))
-    script.AppendExtra("")
-
-  def WriteVerifyScript(self, script, touched_blocks_only=False):
-    partition = self.partition
-
-    # full OTA
-    if not self.src:
-      script.Print("Image %s will be patched unconditionally." % (partition,))
-
-    # incremental OTA
-    else:
-      if touched_blocks_only:
-        ranges = self.touched_src_ranges
-        expected_sha1 = self.touched_src_sha1
-      else:
-        ranges = self.src.care_map.subtract(self.src.clobbered_blocks)
-        expected_sha1 = self.src.TotalSha1()
-
-      # No blocks to be checked, skipping.
-      if not ranges:
-        return
-
-      ranges_str = ranges.to_string_raw()
-      script.AppendExtra(
-          'if (range_sha1(%s, "%s") == "%s" || block_image_verify(%s, '
-          'package_extract_file("%s.transfer.list"), "%s.new.dat", '
-          '"%s.patch.dat")) then' % (
-              self.device, ranges_str, expected_sha1,
-              self.device, partition, partition, partition))
-      script.Print('Verified %s image...' % (partition,))
-      script.AppendExtra('else')
-
-      if self.version >= 4:
-
-        # Bug: 21124327
-        # When generating incrementals for the system and vendor partitions in
-        # version 4 or newer, explicitly check the first block (which contains
-        # the superblock) of the partition to see if it's what we expect. If
-        # this check fails, give an explicit log message about the partition
-        # having been remounted R/W (the most likely explanation).
-        if self.check_first_block:
-          script.AppendExtra('check_first_block(%s);' % (self.device,))
-
-        # If version >= 4, try block recovery before abort update
-        if partition == "system":
-          code = ErrorCode.SYSTEM_RECOVER_FAILURE
-        else:
-          code = ErrorCode.VENDOR_RECOVER_FAILURE
-        script.AppendExtra((
-            'ifelse (block_image_recover({device}, "{ranges}") && '
-            'block_image_verify({device}, '
-            'package_extract_file("{partition}.transfer.list"), '
-            '"{partition}.new.dat", "{partition}.patch.dat"), '
-            'ui_print("{partition} recovered successfully."), '
-            'abort("E{code}: {partition} partition fails to recover"));\n'
-            'endif;').format(device=self.device, ranges=ranges_str,
-                             partition=partition, code=code))
-
-      # Abort the OTA update. Note that the incremental OTA cannot be applied
-      # even if it may match the checksum of the target partition.
-      # a) If version < 3, operations like move and erase will make changes
-      #    unconditionally and damage the partition.
-      # b) If version >= 3, it won't even reach here.
-      else:
-        if partition == "system":
-          code = ErrorCode.SYSTEM_VERIFICATION_FAILURE
-        else:
-          code = ErrorCode.VENDOR_VERIFICATION_FAILURE
-        script.AppendExtra((
-            'abort("E%d: %s partition has unexpected contents");\n'
-            'endif;') % (code, partition))
-
-  def WritePostInstallVerifyScript(self, script):
-    partition = self.partition
-    script.Print('Verifying the updated %s image...' % (partition,))
-    # Unlike pre-install verification, clobbered_blocks should not be ignored.
-    ranges = self.tgt.care_map
-    ranges_str = ranges.to_string_raw()
-    script.AppendExtra(
-        'if range_sha1(%s, "%s") == "%s" then' % (
-            self.device, ranges_str,
-            self.tgt.TotalSha1(include_clobbered_blocks=True)))
-
-    # Bug: 20881595
-    # Verify that extended blocks are really zeroed out.
-    if self.tgt.extended:
-      ranges_str = self.tgt.extended.to_string_raw()
-      script.AppendExtra(
-          'if range_sha1(%s, "%s") == "%s" then' % (
-              self.device, ranges_str,
-              self._HashZeroBlocks(self.tgt.extended.size())))
-      script.Print('Verified the updated %s image.' % (partition,))
-      if partition == "system":
-        code = ErrorCode.SYSTEM_NONZERO_CONTENTS
-      else:
-        code = ErrorCode.VENDOR_NONZERO_CONTENTS
-      script.AppendExtra(
-          'else\n'
-          '  abort("E%d: %s partition has unexpected non-zero contents after '
-          'OTA update");\n'
-          'endif;' % (code, partition))
-    else:
-      script.Print('Verified the updated %s image.' % (partition,))
-
-    if partition == "system":
-      code = ErrorCode.SYSTEM_UNEXPECTED_CONTENTS
-    else:
-      code = ErrorCode.VENDOR_UNEXPECTED_CONTENTS
-
-    script.AppendExtra(
-        'else\n'
-        '  abort("E%d: %s partition has unexpected contents after OTA '
-        'update");\n'
-        'endif;' % (code, partition))
-
-  def _WriteUpdate(self, script, output_zip):
-    ZipWrite(output_zip,
-             '{}.transfer.list'.format(self.path),
-             '{}.transfer.list'.format(self.partition))
-
-    # For full OTA, compress the new.dat with brotli with quality 6 to reduce
-    # its size. Quailty 9 almost triples the compression time but doesn't
-    # further reduce the size too much. For a typical 1.8G system.new.dat
-    #                       zip  | brotli(quality 6)  | brotli(quality 9)
-    #   compressed_size:    942M | 869M (~8% reduced) | 854M
-    #   compression_time:   75s  | 265s               | 719s
-    #   decompression_time: 15s  | 25s                | 25s
-
-    if not self.src:
-      brotli_cmd = ['brotli', '--quality=6',
-                    '--output={}.new.dat.br'.format(self.path),
-                    '{}.new.dat'.format(self.path)]
-      print("Compressing {}.new.dat with brotli".format(self.partition))
-      RunAndCheckOutput(brotli_cmd)
-
-      new_data_name = '{}.new.dat.br'.format(self.partition)
-      ZipWrite(output_zip,
-               '{}.new.dat.br'.format(self.path),
-               new_data_name,
-               compress_type=zipfile.ZIP_STORED)
-    else:
-      new_data_name = '{}.new.dat'.format(self.partition)
-      ZipWrite(output_zip, '{}.new.dat'.format(self.path), new_data_name)
-
-    ZipWrite(output_zip,
-             '{}.patch.dat'.format(self.path),
-             '{}.patch.dat'.format(self.partition),
-             compress_type=zipfile.ZIP_STORED)
-
-    if self.partition == "system":
-      code = ErrorCode.SYSTEM_UPDATE_FAILURE
-    else:
-      code = ErrorCode.VENDOR_UPDATE_FAILURE
-
-    call = ('block_image_update({device}, '
-            'package_extract_file("{partition}.transfer.list"), '
-            '"{new_data_name}", "{partition}.patch.dat") ||\n'
-            '  abort("E{code}: Failed to update {partition} image.");'.format(
-                device=self.device, partition=self.partition,
-                new_data_name=new_data_name, code=code))
-    script.AppendExtra(script.WordWrap(call))
-
-  def _HashBlocks(self, source, ranges):  # pylint: disable=no-self-use
-    data = source.ReadRangeSet(ranges)
-    ctx = sha1()
-
-    for p in data:
-      ctx.update(p)
-
-    return ctx.hexdigest()
-
-  def _HashZeroBlocks(self, num_blocks):  # pylint: disable=no-self-use
-    """Return the hash value for all zero blocks."""
-    zero_block = '\x00' * 4096
-    ctx = sha1()
-    for _ in range(num_blocks):
-      ctx.update(zero_block)
-
-    return ctx.hexdigest()
-
-
 # Expose these two classes to support vendor-specific scripts
 DataImage = images.DataImage
 EmptyImage = images.EmptyImage
 
 
-# map recovery.fstab's fs_types to mount/format "partition types"
-PARTITION_TYPES = {
-    "ext4": "EMMC",
-    "emmc": "EMMC",
-    "f2fs": "EMMC",
-    "squashfs": "EMMC",
-    "erofs": "EMMC"
-}
-
-
-def GetTypeAndDevice(mount_point, info, check_no_slot=True):
-  """
-  Use GetTypeAndDeviceExpr whenever possible. This function is kept for
-  backwards compatibility. It aborts if the fstab entry has slotselect option
-  (unless check_no_slot is explicitly set to False).
-  """
-  fstab = info["fstab"]
-  if fstab:
-    if check_no_slot:
-      assert not fstab[mount_point].slotselect, \
-          "Use GetTypeAndDeviceExpr instead"
-    return (PARTITION_TYPES[fstab[mount_point].fs_type],
-            fstab[mount_point].device)
-  raise KeyError
-
-
-def GetTypeAndDeviceExpr(mount_point, info):
-  """
-  Return the filesystem of the partition, and an edify expression that evaluates
-  to the device at runtime.
-  """
-  fstab = info["fstab"]
-  if fstab:
-    p = fstab[mount_point]
-    device_expr = '"%s"' % fstab[mount_point].device
-    if p.slotselect:
-      device_expr = 'add_slot_suffix(%s)' % device_expr
-    return (PARTITION_TYPES[fstab[mount_point].fs_type], device_expr)
-  raise KeyError
-
 
 def GetEntryForDevice(fstab, device):
   """
@@ -3787,349 +3208,6 @@
   return output
 
 
-def MakeRecoveryPatch(input_dir, output_sink, recovery_img, boot_img,
-                      info_dict=None):
-  """Generates the recovery-from-boot patch and writes the script to output.
-
-  Most of the space in the boot and recovery images is just the kernel, which is
-  identical for the two, so the resulting patch should be efficient. Add it to
-  the output zip, along with a shell script that is run from init.rc on first
-  boot to actually do the patching and install the new recovery image.
-
-  Args:
-    input_dir: The top-level input directory of the target-files.zip.
-    output_sink: The callback function that writes the result.
-    recovery_img: File object for the recovery image.
-    boot_img: File objects for the boot image.
-    info_dict: A dict returned by common.LoadInfoDict() on the input
-        target_files. Will use OPTIONS.info_dict if None has been given.
-  """
-  if info_dict is None:
-    info_dict = OPTIONS.info_dict
-
-  full_recovery_image = info_dict.get("full_recovery_image") == "true"
-  board_uses_vendorimage = info_dict.get("board_uses_vendorimage") == "true"
-
-  if board_uses_vendorimage:
-    # In this case, the output sink is rooted at VENDOR
-    recovery_img_path = "etc/recovery.img"
-    recovery_resource_dat_path = "VENDOR/etc/recovery-resource.dat"
-    sh_dir = "bin"
-  else:
-    # In this case the output sink is rooted at SYSTEM
-    recovery_img_path = "vendor/etc/recovery.img"
-    recovery_resource_dat_path = "SYSTEM/vendor/etc/recovery-resource.dat"
-    sh_dir = "vendor/bin"
-
-  if full_recovery_image:
-    output_sink(recovery_img_path, recovery_img.data)
-
-  else:
-    system_root_image = info_dict.get("system_root_image") == "true"
-    include_recovery_dtbo = info_dict.get("include_recovery_dtbo") == "true"
-    include_recovery_acpio = info_dict.get("include_recovery_acpio") == "true"
-    path = os.path.join(input_dir, recovery_resource_dat_path)
-    # With system-root-image, boot and recovery images will have mismatching
-    # entries (only recovery has the ramdisk entry) (Bug: 72731506). Use bsdiff
-    # to handle such a case.
-    if system_root_image or include_recovery_dtbo or include_recovery_acpio:
-      diff_program = ["bsdiff"]
-      bonus_args = ""
-      assert not os.path.exists(path)
-    else:
-      diff_program = ["imgdiff"]
-      if os.path.exists(path):
-        diff_program.append("-b")
-        diff_program.append(path)
-        bonus_args = "--bonus /vendor/etc/recovery-resource.dat"
-      else:
-        bonus_args = ""
-
-    d = Difference(recovery_img, boot_img, diff_program=diff_program)
-    _, _, patch = d.ComputePatch()
-    output_sink("recovery-from-boot.p", patch)
-
-  try:
-    # The following GetTypeAndDevice()s need to use the path in the target
-    # info_dict instead of source_info_dict.
-    boot_type, boot_device = GetTypeAndDevice("/boot", info_dict,
-                                              check_no_slot=False)
-    recovery_type, recovery_device = GetTypeAndDevice("/recovery", info_dict,
-                                                      check_no_slot=False)
-  except KeyError:
-    return
-
-  if full_recovery_image:
-
-    # Note that we use /vendor to refer to the recovery resources. This will
-    # work for a separate vendor partition mounted at /vendor or a
-    # /system/vendor subdirectory on the system partition, for which init will
-    # create a symlink from /vendor to /system/vendor.
-
-    sh = """#!/vendor/bin/sh
-if ! applypatch --check %(type)s:%(device)s:%(size)d:%(sha1)s; then
-  applypatch \\
-          --flash /vendor/etc/recovery.img \\
-          --target %(type)s:%(device)s:%(size)d:%(sha1)s && \\
-      log -t recovery "Installing new recovery image: succeeded" || \\
-      log -t recovery "Installing new recovery image: failed"
-else
-  log -t recovery "Recovery image already installed"
-fi
-""" % {'type': recovery_type,
-       'device': recovery_device,
-       'sha1': recovery_img.sha1,
-       'size': recovery_img.size}
-  else:
-    sh = """#!/vendor/bin/sh
-if ! applypatch --check %(recovery_type)s:%(recovery_device)s:%(recovery_size)d:%(recovery_sha1)s; then
-  applypatch %(bonus_args)s \\
-          --patch /vendor/recovery-from-boot.p \\
-          --source %(boot_type)s:%(boot_device)s:%(boot_size)d:%(boot_sha1)s \\
-          --target %(recovery_type)s:%(recovery_device)s:%(recovery_size)d:%(recovery_sha1)s && \\
-      log -t recovery "Installing new recovery image: succeeded" || \\
-      log -t recovery "Installing new recovery image: failed"
-else
-  log -t recovery "Recovery image already installed"
-fi
-""" % {'boot_size': boot_img.size,
-       'boot_sha1': boot_img.sha1,
-       'recovery_size': recovery_img.size,
-       'recovery_sha1': recovery_img.sha1,
-       'boot_type': boot_type,
-       'boot_device': boot_device + '$(getprop ro.boot.slot_suffix)',
-       'recovery_type': recovery_type,
-       'recovery_device': recovery_device + '$(getprop ro.boot.slot_suffix)',
-       'bonus_args': bonus_args}
-
-  # The install script location moved from /system/etc to /system/bin in the L
-  # release. In the R release it is in VENDOR/bin or SYSTEM/vendor/bin.
-  sh_location = os.path.join(sh_dir, "install-recovery.sh")
-
-  logger.info("putting script in %s", sh_location)
-
-  output_sink(sh_location, sh.encode())
-
-
-class DynamicPartitionUpdate(object):
-  def __init__(self, src_group=None, tgt_group=None, progress=None,
-               block_difference=None):
-    self.src_group = src_group
-    self.tgt_group = tgt_group
-    self.progress = progress
-    self.block_difference = block_difference
-
-  @property
-  def src_size(self):
-    if not self.block_difference:
-      return 0
-    return DynamicPartitionUpdate._GetSparseImageSize(self.block_difference.src)
-
-  @property
-  def tgt_size(self):
-    if not self.block_difference:
-      return 0
-    return DynamicPartitionUpdate._GetSparseImageSize(self.block_difference.tgt)
-
-  @staticmethod
-  def _GetSparseImageSize(img):
-    if not img:
-      return 0
-    return img.blocksize * img.total_blocks
-
-
-class DynamicGroupUpdate(object):
-  def __init__(self, src_size=None, tgt_size=None):
-    # None: group does not exist. 0: no size limits.
-    self.src_size = src_size
-    self.tgt_size = tgt_size
-
-
-class DynamicPartitionsDifference(object):
-  def __init__(self, info_dict, block_diffs, progress_dict=None,
-               source_info_dict=None):
-    if progress_dict is None:
-      progress_dict = {}
-
-    self._remove_all_before_apply = False
-    if source_info_dict is None:
-      self._remove_all_before_apply = True
-      source_info_dict = {}
-
-    block_diff_dict = collections.OrderedDict(
-        [(e.partition, e) for e in block_diffs])
-
-    assert len(block_diff_dict) == len(block_diffs), \
-        "Duplicated BlockDifference object for {}".format(
-            [partition for partition, count in
-             collections.Counter(e.partition for e in block_diffs).items()
-             if count > 1])
-
-    self._partition_updates = collections.OrderedDict()
-
-    for p, block_diff in block_diff_dict.items():
-      self._partition_updates[p] = DynamicPartitionUpdate()
-      self._partition_updates[p].block_difference = block_diff
-
-    for p, progress in progress_dict.items():
-      if p in self._partition_updates:
-        self._partition_updates[p].progress = progress
-
-    tgt_groups = shlex.split(info_dict.get(
-        "super_partition_groups", "").strip())
-    src_groups = shlex.split(source_info_dict.get(
-        "super_partition_groups", "").strip())
-
-    for g in tgt_groups:
-      for p in shlex.split(info_dict.get(
-              "super_%s_partition_list" % g, "").strip()):
-        assert p in self._partition_updates, \
-            "{} is in target super_{}_partition_list but no BlockDifference " \
-            "object is provided.".format(p, g)
-        self._partition_updates[p].tgt_group = g
-
-    for g in src_groups:
-      for p in shlex.split(source_info_dict.get(
-              "super_%s_partition_list" % g, "").strip()):
-        assert p in self._partition_updates, \
-            "{} is in source super_{}_partition_list but no BlockDifference " \
-            "object is provided.".format(p, g)
-        self._partition_updates[p].src_group = g
-
-    target_dynamic_partitions = set(shlex.split(info_dict.get(
-        "dynamic_partition_list", "").strip()))
-    block_diffs_with_target = set(p for p, u in self._partition_updates.items()
-                                  if u.tgt_size)
-    assert block_diffs_with_target == target_dynamic_partitions, \
-        "Target Dynamic partitions: {}, BlockDifference with target: {}".format(
-            list(target_dynamic_partitions), list(block_diffs_with_target))
-
-    source_dynamic_partitions = set(shlex.split(source_info_dict.get(
-        "dynamic_partition_list", "").strip()))
-    block_diffs_with_source = set(p for p, u in self._partition_updates.items()
-                                  if u.src_size)
-    assert block_diffs_with_source == source_dynamic_partitions, \
-        "Source Dynamic partitions: {}, BlockDifference with source: {}".format(
-            list(source_dynamic_partitions), list(block_diffs_with_source))
-
-    if self._partition_updates:
-      logger.info("Updating dynamic partitions %s",
-                  self._partition_updates.keys())
-
-    self._group_updates = collections.OrderedDict()
-
-    for g in tgt_groups:
-      self._group_updates[g] = DynamicGroupUpdate()
-      self._group_updates[g].tgt_size = int(info_dict.get(
-          "super_%s_group_size" % g, "0").strip())
-
-    for g in src_groups:
-      if g not in self._group_updates:
-        self._group_updates[g] = DynamicGroupUpdate()
-      self._group_updates[g].src_size = int(source_info_dict.get(
-          "super_%s_group_size" % g, "0").strip())
-
-    self._Compute()
-
-  def WriteScript(self, script, output_zip, write_verify_script=False):
-    script.Comment('--- Start patching dynamic partitions ---')
-    for p, u in self._partition_updates.items():
-      if u.src_size and u.tgt_size and u.src_size > u.tgt_size:
-        script.Comment('Patch partition %s' % p)
-        u.block_difference.WriteScript(script, output_zip, progress=u.progress,
-                                       write_verify_script=False)
-
-    op_list_path = MakeTempFile()
-    with open(op_list_path, 'w') as f:
-      for line in self._op_list:
-        f.write('{}\n'.format(line))
-
-    ZipWrite(output_zip, op_list_path, "dynamic_partitions_op_list")
-
-    script.Comment('Update dynamic partition metadata')
-    script.AppendExtra('assert(update_dynamic_partitions('
-                       'package_extract_file("dynamic_partitions_op_list")));')
-
-    if write_verify_script:
-      for p, u in self._partition_updates.items():
-        if u.src_size and u.tgt_size and u.src_size > u.tgt_size:
-          u.block_difference.WritePostInstallVerifyScript(script)
-          script.AppendExtra('unmap_partition("%s");' % p)  # ignore errors
-
-    for p, u in self._partition_updates.items():
-      if u.tgt_size and u.src_size <= u.tgt_size:
-        script.Comment('Patch partition %s' % p)
-        u.block_difference.WriteScript(script, output_zip, progress=u.progress,
-                                       write_verify_script=write_verify_script)
-        if write_verify_script:
-          script.AppendExtra('unmap_partition("%s");' % p)  # ignore errors
-
-    script.Comment('--- End patching dynamic partitions ---')
-
-  def _Compute(self):
-    self._op_list = list()
-
-    def append(line):
-      self._op_list.append(line)
-
-    def comment(line):
-      self._op_list.append("# %s" % line)
-
-    if self._remove_all_before_apply:
-      comment('Remove all existing dynamic partitions and groups before '
-              'applying full OTA')
-      append('remove_all_groups')
-
-    for p, u in self._partition_updates.items():
-      if u.src_group and not u.tgt_group:
-        append('remove %s' % p)
-
-    for p, u in self._partition_updates.items():
-      if u.src_group and u.tgt_group and u.src_group != u.tgt_group:
-        comment('Move partition %s from %s to default' % (p, u.src_group))
-        append('move %s default' % p)
-
-    for p, u in self._partition_updates.items():
-      if u.src_size and u.tgt_size and u.src_size > u.tgt_size:
-        comment('Shrink partition %s from %d to %d' %
-                (p, u.src_size, u.tgt_size))
-        append('resize %s %s' % (p, u.tgt_size))
-
-    for g, u in self._group_updates.items():
-      if u.src_size is not None and u.tgt_size is None:
-        append('remove_group %s' % g)
-      if (u.src_size is not None and u.tgt_size is not None and
-              u.src_size > u.tgt_size):
-        comment('Shrink group %s from %d to %d' % (g, u.src_size, u.tgt_size))
-        append('resize_group %s %d' % (g, u.tgt_size))
-
-    for g, u in self._group_updates.items():
-      if u.src_size is None and u.tgt_size is not None:
-        comment('Add group %s with maximum size %d' % (g, u.tgt_size))
-        append('add_group %s %d' % (g, u.tgt_size))
-      if (u.src_size is not None and u.tgt_size is not None and
-              u.src_size < u.tgt_size):
-        comment('Grow group %s from %d to %d' % (g, u.src_size, u.tgt_size))
-        append('resize_group %s %d' % (g, u.tgt_size))
-
-    for p, u in self._partition_updates.items():
-      if u.tgt_group and not u.src_group:
-        comment('Add partition %s to group %s' % (p, u.tgt_group))
-        append('add %s %s' % (p, u.tgt_group))
-
-    for p, u in self._partition_updates.items():
-      if u.tgt_size and u.src_size < u.tgt_size:
-        comment('Grow partition %s from %d to %d' %
-                (p, u.src_size, u.tgt_size))
-        append('resize %s %d' % (p, u.tgt_size))
-
-    for p, u in self._partition_updates.items():
-      if u.src_group and u.tgt_group and u.src_group != u.tgt_group:
-        comment('Move partition %s from default to %s' %
-                (p, u.tgt_group))
-        append('move %s %s' % (p, u.tgt_group))
-
-
 def GetBootImageBuildProp(boot_img, ramdisk_format=RamdiskFormat.LZ4):
   """
   Get build.prop from ramdisk within the boot image
diff --git a/tools/releasetools/edify_generator.py b/tools/releasetools/edify_generator.py
index 033c02e..664d5cd 100644
--- a/tools/releasetools/edify_generator.py
+++ b/tools/releasetools/edify_generator.py
@@ -16,6 +16,36 @@
 
 import common
 
+
+class ErrorCode(object):
+  """Define error_codes for failures that happen during the actual
+  update package installation.
+
+  Error codes 0-999 are reserved for failures before the package
+  installation (i.e. low battery, package verification failure).
+  Detailed code in 'bootable/recovery/error_code.h' """
+
+  SYSTEM_VERIFICATION_FAILURE = 1000
+  SYSTEM_UPDATE_FAILURE = 1001
+  SYSTEM_UNEXPECTED_CONTENTS = 1002
+  SYSTEM_NONZERO_CONTENTS = 1003
+  SYSTEM_RECOVER_FAILURE = 1004
+  VENDOR_VERIFICATION_FAILURE = 2000
+  VENDOR_UPDATE_FAILURE = 2001
+  VENDOR_UNEXPECTED_CONTENTS = 2002
+  VENDOR_NONZERO_CONTENTS = 2003
+  VENDOR_RECOVER_FAILURE = 2004
+  OEM_PROP_MISMATCH = 3000
+  FINGERPRINT_MISMATCH = 3001
+  THUMBPRINT_MISMATCH = 3002
+  OLDER_BUILD = 3003
+  DEVICE_MISMATCH = 3004
+  BAD_PATCH_FILE = 3005
+  INSUFFICIENT_CACHE_SPACE = 3006
+  TUNE_PARTITION_FAILURE = 3007
+  APPLY_PATCH_FAILURE = 3008
+
+
 class EdifyGenerator(object):
   """Class to generate scripts in the 'edify' recovery script language
   used from donut onwards."""
@@ -88,7 +118,7 @@
         'abort("E{code}: This package expects the value \\"{values}\\" for '
         '\\"{name}\\"; this has value \\"" + '
         '{get_prop_command} + "\\".");').format(
-            code=common.ErrorCode.OEM_PROP_MISMATCH,
+            code=ErrorCode.OEM_PROP_MISMATCH,
             get_prop_command=get_prop_command, name=name,
             values='\\" or \\"'.join(values))
     self.script.append(cmd)
@@ -101,7 +131,7 @@
                              for i in fp]) +
            ' ||\n    abort("E%d: Package expects build fingerprint of %s; '
            'this device has " + getprop("ro.build.fingerprint") + ".");') % (
-               common.ErrorCode.FINGERPRINT_MISMATCH, " or ".join(fp))
+               ErrorCode.FINGERPRINT_MISMATCH, " or ".join(fp))
     self.script.append(cmd)
 
   def AssertSomeThumbprint(self, *fp):
@@ -112,7 +142,7 @@
                              for i in fp]) +
            ' ||\n    abort("E%d: Package expects build thumbprint of %s; this '
            'device has " + getprop("ro.build.thumbprint") + ".");') % (
-               common.ErrorCode.THUMBPRINT_MISMATCH, " or ".join(fp))
+               ErrorCode.THUMBPRINT_MISMATCH, " or ".join(fp))
     self.script.append(cmd)
 
   def AssertFingerprintOrThumbprint(self, fp, tp):
@@ -133,14 +163,14 @@
         ('(!less_than_int(%s, getprop("ro.build.date.utc"))) || '
          'abort("E%d: Can\'t install this package (%s) over newer '
          'build (" + getprop("ro.build.date") + ").");') % (
-             timestamp, common.ErrorCode.OLDER_BUILD, timestamp_text))
+             timestamp, ErrorCode.OLDER_BUILD, timestamp_text))
 
   def AssertDevice(self, device):
     """Assert that the device identifier is the given string."""
     cmd = ('getprop("ro.product.device") == "%s" || '
            'abort("E%d: This package is for \\"%s\\" devices; '
            'this is a \\"" + getprop("ro.product.device") + "\\".");') % (
-               device, common.ErrorCode.DEVICE_MISMATCH, device)
+               device, ErrorCode.DEVICE_MISMATCH, device)
     self.script.append(cmd)
 
   def AssertSomeBootloader(self, *bootloaders):
@@ -207,7 +237,7 @@
         'unexpected contents."));').format(
             target=target_expr,
             source=source_expr,
-            code=common.ErrorCode.BAD_PATCH_FILE)))
+            code=ErrorCode.BAD_PATCH_FILE)))
 
   def CacheFreeSpaceCheck(self, amount):
     """Check that there's at least 'amount' space that can be made
@@ -216,7 +246,7 @@
     self.script.append(('apply_patch_space(%d) || abort("E%d: Not enough free '
                         'space on /cache to apply patches.");') % (
                             amount,
-                            common.ErrorCode.INSUFFICIENT_CACHE_SPACE))
+                            ErrorCode.INSUFFICIENT_CACHE_SPACE))
 
   def Mount(self, mount_point, mount_options_by_format=""):
     """Mount the partition with the given mount_point.
@@ -264,7 +294,7 @@
         'tune2fs(' + "".join(['"%s", ' % (i,) for i in options]) +
         '%s) || abort("E%d: Failed to tune partition %s");' % (
             self._GetSlotSuffixDeviceForEntry(p),
-            common.ErrorCode.TUNE_PARTITION_FAILURE, partition))
+            ErrorCode.TUNE_PARTITION_FAILURE, partition))
 
   def FormatPartition(self, partition):
     """Format the given partition, specified by its mount point (eg,
@@ -354,7 +384,7 @@
             target=target_expr,
             source=source_expr,
             patch=patch_expr,
-            code=common.ErrorCode.APPLY_PATCH_FAILURE)))
+            code=ErrorCode.APPLY_PATCH_FAILURE)))
 
   def _GetSlotSuffixDeviceForEntry(self, entry=None):
     """
diff --git a/tools/releasetools/make_recovery_patch.py b/tools/releasetools/make_recovery_patch.py
index 1497d69..397bf23 100644
--- a/tools/releasetools/make_recovery_patch.py
+++ b/tools/releasetools/make_recovery_patch.py
@@ -21,6 +21,7 @@
 import sys
 
 import common
+from non_ab_ota import MakeRecoveryPatch
 
 if sys.hexversion < 0x02070000:
   print("Python 2.7 or newer is required.", file=sys.stderr)
@@ -60,7 +61,7 @@
                            *fn.split("/")), "wb") as f:
       f.write(data)
 
-  common.MakeRecoveryPatch(input_dir, output_sink, recovery_img, boot_img)
+  MakeRecoveryPatch(input_dir, output_sink, recovery_img, boot_img)
 
 
 if __name__ == '__main__':
diff --git a/tools/releasetools/non_ab_ota.py b/tools/releasetools/non_ab_ota.py
index 667891c..5839d17 100644
--- a/tools/releasetools/non_ab_ota.py
+++ b/tools/releasetools/non_ab_ota.py
@@ -13,17 +13,25 @@
 # limitations under the License.
 
 import collections
+import copy
+import imp
 import logging
 import os
+import time
+import threading
+import tempfile
 import zipfile
+import subprocess
+import shlex
 
 import common
 import edify_generator
-import verity_utils
+from edify_generator import ErrorCode
 from check_target_files_vintf import CheckVintfIfTrebleEnabled, HasPartition
-from common import OPTIONS
+from common import OPTIONS, Run, MakeTempDir, RunAndCheckOutput, ZipWrite, MakeTempFile
 from ota_utils import UNZIP_PATTERN, FinalizeMetadata, GetPackageMetadata, PropertyFiles
-import subprocess
+from blockimgdiff import BlockImageDiff
+from hashlib import sha1
 
 logger = logging.getLogger(__name__)
 
@@ -51,7 +59,7 @@
     check_first_block = partition_source_info.fs_type == "ext4"
     # Disable imgdiff because it relies on zlib to produce stable output
     # across different versions, which is often not the case.
-    return common.BlockDifference(name, partition_tgt, partition_src,
+    return BlockDifference(name, partition_tgt, partition_src,
                                   check_first_block,
                                   version=blockimgdiff_version,
                                   disable_imgdiff=True)
@@ -76,7 +84,7 @@
       tgt = common.GetUserImage(partition, OPTIONS.input_tmp, target_zip,
                                 info_dict=target_info,
                                 reset_file_map=True)
-      block_diff_dict[partition] = common.BlockDifference(partition, tgt,
+      block_diff_dict[partition] = BlockDifference(partition, tgt,
                                                           src=None)
     # Incremental OTA update.
     else:
@@ -95,7 +103,7 @@
     function_name = "FullOTA_GetBlockDifferences"
 
   if device_specific_diffs:
-    assert all(isinstance(diff, common.BlockDifference)
+    assert all(isinstance(diff, BlockDifference)
                for diff in device_specific_diffs), \
         "{} is not returning a list of BlockDifference objects".format(
             function_name)
@@ -131,7 +139,7 @@
   output_zip = zipfile.ZipFile(
       staging_file, "w", compression=zipfile.ZIP_DEFLATED)
 
-  device_specific = common.DeviceSpecificParams(
+  device_specific = DeviceSpecificParams(
       input_zip=input_zip,
       input_version=target_api_version,
       output_zip=output_zip,
@@ -217,7 +225,7 @@
   if target_info.get('use_dynamic_partitions') == "true":
     # Use empty source_info_dict to indicate that all partitions / groups must
     # be re-added.
-    dynamic_partitions_diff = common.DynamicPartitionsDifference(
+    dynamic_partitions_diff = DynamicPartitionsDifference(
         info_dict=OPTIONS.info_dict,
         block_diffs=block_diff_dict.values(),
         progress_dict=progress_dict)
@@ -309,7 +317,7 @@
   output_zip = zipfile.ZipFile(
       staging_file, "w", compression=zipfile.ZIP_DEFLATED)
 
-  device_specific = common.DeviceSpecificParams(
+  device_specific = DeviceSpecificParams(
       source_zip=source_zip,
       source_version=source_api_version,
       source_tmp=OPTIONS.source_tmp,
@@ -404,9 +412,9 @@
   required_cache_sizes = [diff.required_cache for diff in
                           block_diff_dict.values()]
   if updating_boot:
-    boot_type, boot_device_expr = common.GetTypeAndDeviceExpr("/boot",
+    boot_type, boot_device_expr = GetTypeAndDeviceExpr("/boot",
                                                               source_info)
-    d = common.Difference(target_boot, source_boot, "bsdiff")
+    d = Difference(target_boot, source_boot, "bsdiff")
     _, _, d = d.ComputePatch()
     if d is None:
       include_full_boot = True
@@ -461,7 +469,7 @@
     if OPTIONS.target_info_dict.get("use_dynamic_partitions") != "true":
       raise RuntimeError(
           "can't generate incremental that disables dynamic partitions")
-    dynamic_partitions_diff = common.DynamicPartitionsDifference(
+    dynamic_partitions_diff = DynamicPartitionsDifference(
         info_dict=OPTIONS.target_info_dict,
         source_info_dict=OPTIONS.source_info_dict,
         block_diffs=block_diff_dict.values(),
@@ -687,3 +695,891 @@
 
   namelist = target_files_zip.namelist()
   return patch in namelist or img in namelist
+
+
+class DeviceSpecificParams(object):
+  module = None
+
+  def __init__(self, **kwargs):
+    """Keyword arguments to the constructor become attributes of this
+    object, which is passed to all functions in the device-specific
+    module."""
+    for k, v in kwargs.items():
+      setattr(self, k, v)
+    self.extras = OPTIONS.extras
+
+    if self.module is None:
+      path = OPTIONS.device_specific
+      if not path:
+        return
+      try:
+        if os.path.isdir(path):
+          info = imp.find_module("releasetools", [path])
+        else:
+          d, f = os.path.split(path)
+          b, x = os.path.splitext(f)
+          if x == ".py":
+            f = b
+          info = imp.find_module(f, [d])
+        logger.info("loaded device-specific extensions from %s", path)
+        self.module = imp.load_module("device_specific", *info)
+      except ImportError:
+        logger.info("unable to load device-specific module; assuming none")
+
+  def _DoCall(self, function_name, *args, **kwargs):
+    """Call the named function in the device-specific module, passing
+    the given args and kwargs.  The first argument to the call will be
+    the DeviceSpecific object itself.  If there is no module, or the
+    module does not define the function, return the value of the
+    'default' kwarg (which itself defaults to None)."""
+    if self.module is None or not hasattr(self.module, function_name):
+      return kwargs.get("default")
+    return getattr(self.module, function_name)(*((self,) + args), **kwargs)
+
+  def FullOTA_Assertions(self):
+    """Called after emitting the block of assertions at the top of a
+    full OTA package.  Implementations can add whatever additional
+    assertions they like."""
+    return self._DoCall("FullOTA_Assertions")
+
+  def FullOTA_InstallBegin(self):
+    """Called at the start of full OTA installation."""
+    return self._DoCall("FullOTA_InstallBegin")
+
+  def FullOTA_GetBlockDifferences(self):
+    """Called during full OTA installation and verification.
+    Implementation should return a list of BlockDifference objects describing
+    the update on each additional partitions.
+    """
+    return self._DoCall("FullOTA_GetBlockDifferences")
+
+  def FullOTA_InstallEnd(self):
+    """Called at the end of full OTA installation; typically this is
+    used to install the image for the device's baseband processor."""
+    return self._DoCall("FullOTA_InstallEnd")
+
+  def IncrementalOTA_Assertions(self):
+    """Called after emitting the block of assertions at the top of an
+    incremental OTA package.  Implementations can add whatever
+    additional assertions they like."""
+    return self._DoCall("IncrementalOTA_Assertions")
+
+  def IncrementalOTA_VerifyBegin(self):
+    """Called at the start of the verification phase of incremental
+    OTA installation; additional checks can be placed here to abort
+    the script before any changes are made."""
+    return self._DoCall("IncrementalOTA_VerifyBegin")
+
+  def IncrementalOTA_VerifyEnd(self):
+    """Called at the end of the verification phase of incremental OTA
+    installation; additional checks can be placed here to abort the
+    script before any changes are made."""
+    return self._DoCall("IncrementalOTA_VerifyEnd")
+
+  def IncrementalOTA_InstallBegin(self):
+    """Called at the start of incremental OTA installation (after
+    verification is complete)."""
+    return self._DoCall("IncrementalOTA_InstallBegin")
+
+  def IncrementalOTA_GetBlockDifferences(self):
+    """Called during incremental OTA installation and verification.
+    Implementation should return a list of BlockDifference objects describing
+    the update on each additional partitions.
+    """
+    return self._DoCall("IncrementalOTA_GetBlockDifferences")
+
+  def IncrementalOTA_InstallEnd(self):
+    """Called at the end of incremental OTA installation; typically
+    this is used to install the image for the device's baseband
+    processor."""
+    return self._DoCall("IncrementalOTA_InstallEnd")
+
+  def VerifyOTA_Assertions(self):
+    return self._DoCall("VerifyOTA_Assertions")
+
+
+DIFF_PROGRAM_BY_EXT = {
+    ".gz": "imgdiff",
+    ".zip": ["imgdiff", "-z"],
+    ".jar": ["imgdiff", "-z"],
+    ".apk": ["imgdiff", "-z"],
+    ".img": "imgdiff",
+}
+
+
+class Difference(object):
+  def __init__(self, tf, sf, diff_program=None):
+    self.tf = tf
+    self.sf = sf
+    self.patch = None
+    self.diff_program = diff_program
+
+  def ComputePatch(self):
+    """Compute the patch (as a string of data) needed to turn sf into
+    tf.  Returns the same tuple as GetPatch()."""
+
+    tf = self.tf
+    sf = self.sf
+
+    if self.diff_program:
+      diff_program = self.diff_program
+    else:
+      ext = os.path.splitext(tf.name)[1]
+      diff_program = DIFF_PROGRAM_BY_EXT.get(ext, "bsdiff")
+
+    ttemp = tf.WriteToTemp()
+    stemp = sf.WriteToTemp()
+
+    ext = os.path.splitext(tf.name)[1]
+
+    try:
+      ptemp = tempfile.NamedTemporaryFile()
+      if isinstance(diff_program, list):
+        cmd = copy.copy(diff_program)
+      else:
+        cmd = [diff_program]
+      cmd.append(stemp.name)
+      cmd.append(ttemp.name)
+      cmd.append(ptemp.name)
+      p = Run(cmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
+      err = []
+
+      def run():
+        _, e = p.communicate()
+        if e:
+          err.append(e)
+      th = threading.Thread(target=run)
+      th.start()
+      th.join(timeout=300)   # 5 mins
+      if th.is_alive():
+        logger.warning("diff command timed out")
+        p.terminate()
+        th.join(5)
+        if th.is_alive():
+          p.kill()
+          th.join()
+
+      if p.returncode != 0:
+        logger.warning("Failure running %s:\n%s\n", cmd, "".join(err))
+        self.patch = None
+        return None, None, None
+      diff = ptemp.read()
+    finally:
+      ptemp.close()
+      stemp.close()
+      ttemp.close()
+
+    self.patch = diff
+    return self.tf, self.sf, self.patch
+
+  def GetPatch(self):
+    """Returns a tuple of (target_file, source_file, patch_data).
+
+    patch_data may be None if ComputePatch hasn't been called, or if
+    computing the patch failed.
+    """
+    return self.tf, self.sf, self.patch
+
+
+def ComputeDifferences(diffs):
+  """Call ComputePatch on all the Difference objects in 'diffs'."""
+  logger.info("%d diffs to compute", len(diffs))
+
+  # Do the largest files first, to try and reduce the long-pole effect.
+  by_size = [(i.tf.size, i) for i in diffs]
+  by_size.sort(reverse=True)
+  by_size = [i[1] for i in by_size]
+
+  lock = threading.Lock()
+  diff_iter = iter(by_size)   # accessed under lock
+
+  def worker():
+    try:
+      lock.acquire()
+      for d in diff_iter:
+        lock.release()
+        start = time.time()
+        d.ComputePatch()
+        dur = time.time() - start
+        lock.acquire()
+
+        tf, sf, patch = d.GetPatch()
+        if sf.name == tf.name:
+          name = tf.name
+        else:
+          name = "%s (%s)" % (tf.name, sf.name)
+        if patch is None:
+          logger.error("patching failed! %40s", name)
+        else:
+          logger.info(
+              "%8.2f sec %8d / %8d bytes (%6.2f%%) %s", dur, len(patch),
+              tf.size, 100.0 * len(patch) / tf.size, name)
+      lock.release()
+    except Exception:
+      logger.exception("Failed to compute diff from worker")
+      raise
+
+  # start worker threads; wait for them all to finish.
+  threads = [threading.Thread(target=worker)
+             for i in range(OPTIONS.worker_threads)]
+  for th in threads:
+    th.start()
+  while threads:
+    threads.pop().join()
+
+
+class BlockDifference(object):
+  def __init__(self, partition, tgt, src=None, check_first_block=False,
+               version=None, disable_imgdiff=False):
+    self.tgt = tgt
+    self.src = src
+    self.partition = partition
+    self.check_first_block = check_first_block
+    self.disable_imgdiff = disable_imgdiff
+
+    if version is None:
+      version = max(
+          int(i) for i in
+          OPTIONS.info_dict.get("blockimgdiff_versions", "1").split(","))
+    assert version >= 3
+    self.version = version
+
+    b = BlockImageDiff(tgt, src, threads=OPTIONS.worker_threads,
+                       version=self.version,
+                       disable_imgdiff=self.disable_imgdiff)
+    self.path = os.path.join(MakeTempDir(), partition)
+    b.Compute(self.path)
+    self._required_cache = b.max_stashed_size
+    self.touched_src_ranges = b.touched_src_ranges
+    self.touched_src_sha1 = b.touched_src_sha1
+
+    # On devices with dynamic partitions, for new partitions,
+    # src is None but OPTIONS.source_info_dict is not.
+    if OPTIONS.source_info_dict is None:
+      is_dynamic_build = OPTIONS.info_dict.get(
+          "use_dynamic_partitions") == "true"
+      is_dynamic_source = False
+    else:
+      is_dynamic_build = OPTIONS.source_info_dict.get(
+          "use_dynamic_partitions") == "true"
+      is_dynamic_source = partition in shlex.split(
+          OPTIONS.source_info_dict.get("dynamic_partition_list", "").strip())
+
+    is_dynamic_target = partition in shlex.split(
+        OPTIONS.info_dict.get("dynamic_partition_list", "").strip())
+
+    # For dynamic partitions builds, check partition list in both source
+    # and target build because new partitions may be added, and existing
+    # partitions may be removed.
+    is_dynamic = is_dynamic_build and (is_dynamic_source or is_dynamic_target)
+
+    if is_dynamic:
+      self.device = 'map_partition("%s")' % partition
+    else:
+      if OPTIONS.source_info_dict is None:
+        _, device_expr = GetTypeAndDeviceExpr("/" + partition,
+                                              OPTIONS.info_dict)
+      else:
+        _, device_expr = GetTypeAndDeviceExpr("/" + partition,
+                                              OPTIONS.source_info_dict)
+      self.device = device_expr
+
+  @property
+  def required_cache(self):
+    return self._required_cache
+
+  def WriteScript(self, script, output_zip, progress=None,
+                  write_verify_script=False):
+    if not self.src:
+      # write the output unconditionally
+      script.Print("Patching %s image unconditionally..." % (self.partition,))
+    else:
+      script.Print("Patching %s image after verification." % (self.partition,))
+
+    if progress:
+      script.ShowProgress(progress, 0)
+    self._WriteUpdate(script, output_zip)
+
+    if write_verify_script:
+      self.WritePostInstallVerifyScript(script)
+
+  def WriteStrictVerifyScript(self, script):
+    """Verify all the blocks in the care_map, including clobbered blocks.
+
+    This differs from the WriteVerifyScript() function: a) it prints different
+    error messages; b) it doesn't allow half-way updated images to pass the
+    verification."""
+
+    partition = self.partition
+    script.Print("Verifying %s..." % (partition,))
+    ranges = self.tgt.care_map
+    ranges_str = ranges.to_string_raw()
+    script.AppendExtra(
+        'range_sha1(%s, "%s") == "%s" && ui_print("    Verified.") || '
+        'ui_print("%s has unexpected contents.");' % (
+            self.device, ranges_str,
+            self.tgt.TotalSha1(include_clobbered_blocks=True),
+            self.partition))
+    script.AppendExtra("")
+
+  def WriteVerifyScript(self, script, touched_blocks_only=False):
+    partition = self.partition
+
+    # full OTA
+    if not self.src:
+      script.Print("Image %s will be patched unconditionally." % (partition,))
+
+    # incremental OTA
+    else:
+      if touched_blocks_only:
+        ranges = self.touched_src_ranges
+        expected_sha1 = self.touched_src_sha1
+      else:
+        ranges = self.src.care_map.subtract(self.src.clobbered_blocks)
+        expected_sha1 = self.src.TotalSha1()
+
+      # No blocks to be checked, skipping.
+      if not ranges:
+        return
+
+      ranges_str = ranges.to_string_raw()
+      script.AppendExtra(
+          'if (range_sha1(%s, "%s") == "%s" || block_image_verify(%s, '
+          'package_extract_file("%s.transfer.list"), "%s.new.dat", '
+          '"%s.patch.dat")) then' % (
+              self.device, ranges_str, expected_sha1,
+              self.device, partition, partition, partition))
+      script.Print('Verified %s image...' % (partition,))
+      script.AppendExtra('else')
+
+      if self.version >= 4:
+
+        # Bug: 21124327
+        # When generating incrementals for the system and vendor partitions in
+        # version 4 or newer, explicitly check the first block (which contains
+        # the superblock) of the partition to see if it's what we expect. If
+        # this check fails, give an explicit log message about the partition
+        # having been remounted R/W (the most likely explanation).
+        if self.check_first_block:
+          script.AppendExtra('check_first_block(%s);' % (self.device,))
+
+        # If version >= 4, try block recovery before abort update
+        if partition == "system":
+          code = ErrorCode.SYSTEM_RECOVER_FAILURE
+        else:
+          code = ErrorCode.VENDOR_RECOVER_FAILURE
+        script.AppendExtra((
+            'ifelse (block_image_recover({device}, "{ranges}") && '
+            'block_image_verify({device}, '
+            'package_extract_file("{partition}.transfer.list"), '
+            '"{partition}.new.dat", "{partition}.patch.dat"), '
+            'ui_print("{partition} recovered successfully."), '
+            'abort("E{code}: {partition} partition fails to recover"));\n'
+            'endif;').format(device=self.device, ranges=ranges_str,
+                             partition=partition, code=code))
+
+      # Abort the OTA update. Note that the incremental OTA cannot be applied
+      # even if it may match the checksum of the target partition.
+      # a) If version < 3, operations like move and erase will make changes
+      #    unconditionally and damage the partition.
+      # b) If version >= 3, it won't even reach here.
+      else:
+        if partition == "system":
+          code = ErrorCode.SYSTEM_VERIFICATION_FAILURE
+        else:
+          code = ErrorCode.VENDOR_VERIFICATION_FAILURE
+        script.AppendExtra((
+            'abort("E%d: %s partition has unexpected contents");\n'
+            'endif;') % (code, partition))
+
+  def WritePostInstallVerifyScript(self, script):
+    partition = self.partition
+    script.Print('Verifying the updated %s image...' % (partition,))
+    # Unlike pre-install verification, clobbered_blocks should not be ignored.
+    ranges = self.tgt.care_map
+    ranges_str = ranges.to_string_raw()
+    script.AppendExtra(
+        'if range_sha1(%s, "%s") == "%s" then' % (
+            self.device, ranges_str,
+            self.tgt.TotalSha1(include_clobbered_blocks=True)))
+
+    # Bug: 20881595
+    # Verify that extended blocks are really zeroed out.
+    if self.tgt.extended:
+      ranges_str = self.tgt.extended.to_string_raw()
+      script.AppendExtra(
+          'if range_sha1(%s, "%s") == "%s" then' % (
+              self.device, ranges_str,
+              self._HashZeroBlocks(self.tgt.extended.size())))
+      script.Print('Verified the updated %s image.' % (partition,))
+      if partition == "system":
+        code = ErrorCode.SYSTEM_NONZERO_CONTENTS
+      else:
+        code = ErrorCode.VENDOR_NONZERO_CONTENTS
+      script.AppendExtra(
+          'else\n'
+          '  abort("E%d: %s partition has unexpected non-zero contents after '
+          'OTA update");\n'
+          'endif;' % (code, partition))
+    else:
+      script.Print('Verified the updated %s image.' % (partition,))
+
+    if partition == "system":
+      code = ErrorCode.SYSTEM_UNEXPECTED_CONTENTS
+    else:
+      code = ErrorCode.VENDOR_UNEXPECTED_CONTENTS
+
+    script.AppendExtra(
+        'else\n'
+        '  abort("E%d: %s partition has unexpected contents after OTA '
+        'update");\n'
+        'endif;' % (code, partition))
+
+  def _WriteUpdate(self, script, output_zip):
+    ZipWrite(output_zip,
+             '{}.transfer.list'.format(self.path),
+             '{}.transfer.list'.format(self.partition))
+
+    # For full OTA, compress the new.dat with brotli with quality 6 to reduce
+    # its size. Quailty 9 almost triples the compression time but doesn't
+    # further reduce the size too much. For a typical 1.8G system.new.dat
+    #                       zip  | brotli(quality 6)  | brotli(quality 9)
+    #   compressed_size:    942M | 869M (~8% reduced) | 854M
+    #   compression_time:   75s  | 265s               | 719s
+    #   decompression_time: 15s  | 25s                | 25s
+
+    if not self.src:
+      brotli_cmd = ['brotli', '--quality=6',
+                    '--output={}.new.dat.br'.format(self.path),
+                    '{}.new.dat'.format(self.path)]
+      print("Compressing {}.new.dat with brotli".format(self.partition))
+      RunAndCheckOutput(brotli_cmd)
+
+      new_data_name = '{}.new.dat.br'.format(self.partition)
+      ZipWrite(output_zip,
+               '{}.new.dat.br'.format(self.path),
+               new_data_name,
+               compress_type=zipfile.ZIP_STORED)
+    else:
+      new_data_name = '{}.new.dat'.format(self.partition)
+      ZipWrite(output_zip, '{}.new.dat'.format(self.path), new_data_name)
+
+    ZipWrite(output_zip,
+             '{}.patch.dat'.format(self.path),
+             '{}.patch.dat'.format(self.partition),
+             compress_type=zipfile.ZIP_STORED)
+
+    if self.partition == "system":
+      code = ErrorCode.SYSTEM_UPDATE_FAILURE
+    else:
+      code = ErrorCode.VENDOR_UPDATE_FAILURE
+
+    call = ('block_image_update({device}, '
+            'package_extract_file("{partition}.transfer.list"), '
+            '"{new_data_name}", "{partition}.patch.dat") ||\n'
+            '  abort("E{code}: Failed to update {partition} image.");'.format(
+                device=self.device, partition=self.partition,
+                new_data_name=new_data_name, code=code))
+    script.AppendExtra(script.WordWrap(call))
+
+  def _HashBlocks(self, source, ranges):  # pylint: disable=no-self-use
+    data = source.ReadRangeSet(ranges)
+    ctx = sha1()
+
+    for p in data:
+      ctx.update(p)
+
+    return ctx.hexdigest()
+
+  def _HashZeroBlocks(self, num_blocks):  # pylint: disable=no-self-use
+    """Return the hash value for all zero blocks."""
+    zero_block = '\x00' * 4096
+    ctx = sha1()
+    for _ in range(num_blocks):
+      ctx.update(zero_block)
+
+    return ctx.hexdigest()
+
+
+def MakeRecoveryPatch(input_dir, output_sink, recovery_img, boot_img,
+                      info_dict=None):
+  """Generates the recovery-from-boot patch and writes the script to output.
+
+  Most of the space in the boot and recovery images is just the kernel, which is
+  identical for the two, so the resulting patch should be efficient. Add it to
+  the output zip, along with a shell script that is run from init.rc on first
+  boot to actually do the patching and install the new recovery image.
+
+  Args:
+    input_dir: The top-level input directory of the target-files.zip.
+    output_sink: The callback function that writes the result.
+    recovery_img: File object for the recovery image.
+    boot_img: File objects for the boot image.
+    info_dict: A dict returned by common.LoadInfoDict() on the input
+        target_files. Will use OPTIONS.info_dict if None has been given.
+  """
+  if info_dict is None:
+    info_dict = OPTIONS.info_dict
+
+  full_recovery_image = info_dict.get("full_recovery_image") == "true"
+  board_uses_vendorimage = info_dict.get("board_uses_vendorimage") == "true"
+
+  if board_uses_vendorimage:
+    # In this case, the output sink is rooted at VENDOR
+    recovery_img_path = "etc/recovery.img"
+    recovery_resource_dat_path = "VENDOR/etc/recovery-resource.dat"
+    sh_dir = "bin"
+  else:
+    # In this case the output sink is rooted at SYSTEM
+    recovery_img_path = "vendor/etc/recovery.img"
+    recovery_resource_dat_path = "SYSTEM/vendor/etc/recovery-resource.dat"
+    sh_dir = "vendor/bin"
+
+  if full_recovery_image:
+    output_sink(recovery_img_path, recovery_img.data)
+
+  else:
+    system_root_image = info_dict.get("system_root_image") == "true"
+    include_recovery_dtbo = info_dict.get("include_recovery_dtbo") == "true"
+    include_recovery_acpio = info_dict.get("include_recovery_acpio") == "true"
+    path = os.path.join(input_dir, recovery_resource_dat_path)
+    # With system-root-image, boot and recovery images will have mismatching
+    # entries (only recovery has the ramdisk entry) (Bug: 72731506). Use bsdiff
+    # to handle such a case.
+    if system_root_image or include_recovery_dtbo or include_recovery_acpio:
+      diff_program = ["bsdiff"]
+      bonus_args = ""
+      assert not os.path.exists(path)
+    else:
+      diff_program = ["imgdiff"]
+      if os.path.exists(path):
+        diff_program.append("-b")
+        diff_program.append(path)
+        bonus_args = "--bonus /vendor/etc/recovery-resource.dat"
+      else:
+        bonus_args = ""
+
+    d = Difference(recovery_img, boot_img, diff_program=diff_program)
+    _, _, patch = d.ComputePatch()
+    output_sink("recovery-from-boot.p", patch)
+
+  try:
+    # The following GetTypeAndDevice()s need to use the path in the target
+    # info_dict instead of source_info_dict.
+    boot_type, boot_device = GetTypeAndDevice("/boot", info_dict,
+                                              check_no_slot=False)
+    recovery_type, recovery_device = GetTypeAndDevice("/recovery", info_dict,
+                                                      check_no_slot=False)
+  except KeyError:
+    return
+
+  if full_recovery_image:
+
+    # Note that we use /vendor to refer to the recovery resources. This will
+    # work for a separate vendor partition mounted at /vendor or a
+    # /system/vendor subdirectory on the system partition, for which init will
+    # create a symlink from /vendor to /system/vendor.
+
+    sh = """#!/vendor/bin/sh
+if ! applypatch --check %(type)s:%(device)s:%(size)d:%(sha1)s; then
+  applypatch \\
+          --flash /vendor/etc/recovery.img \\
+          --target %(type)s:%(device)s:%(size)d:%(sha1)s && \\
+      log -t recovery "Installing new recovery image: succeeded" || \\
+      log -t recovery "Installing new recovery image: failed"
+else
+  log -t recovery "Recovery image already installed"
+fi
+""" % {'type': recovery_type,
+       'device': recovery_device,
+       'sha1': recovery_img.sha1,
+       'size': recovery_img.size}
+  else:
+    sh = """#!/vendor/bin/sh
+if ! applypatch --check %(recovery_type)s:%(recovery_device)s:%(recovery_size)d:%(recovery_sha1)s; then
+  applypatch %(bonus_args)s \\
+          --patch /vendor/recovery-from-boot.p \\
+          --source %(boot_type)s:%(boot_device)s:%(boot_size)d:%(boot_sha1)s \\
+          --target %(recovery_type)s:%(recovery_device)s:%(recovery_size)d:%(recovery_sha1)s && \\
+      log -t recovery "Installing new recovery image: succeeded" || \\
+      log -t recovery "Installing new recovery image: failed"
+else
+  log -t recovery "Recovery image already installed"
+fi
+""" % {'boot_size': boot_img.size,
+       'boot_sha1': boot_img.sha1,
+       'recovery_size': recovery_img.size,
+       'recovery_sha1': recovery_img.sha1,
+       'boot_type': boot_type,
+       'boot_device': boot_device + '$(getprop ro.boot.slot_suffix)',
+       'recovery_type': recovery_type,
+       'recovery_device': recovery_device + '$(getprop ro.boot.slot_suffix)',
+       'bonus_args': bonus_args}
+
+  # The install script location moved from /system/etc to /system/bin in the L
+  # release. In the R release it is in VENDOR/bin or SYSTEM/vendor/bin.
+  sh_location = os.path.join(sh_dir, "install-recovery.sh")
+
+  logger.info("putting script in %s", sh_location)
+
+  output_sink(sh_location, sh.encode())
+
+
+class DynamicPartitionUpdate(object):
+  def __init__(self, src_group=None, tgt_group=None, progress=None,
+               block_difference=None):
+    self.src_group = src_group
+    self.tgt_group = tgt_group
+    self.progress = progress
+    self.block_difference = block_difference
+
+  @property
+  def src_size(self):
+    if not self.block_difference:
+      return 0
+    return DynamicPartitionUpdate._GetSparseImageSize(self.block_difference.src)
+
+  @property
+  def tgt_size(self):
+    if not self.block_difference:
+      return 0
+    return DynamicPartitionUpdate._GetSparseImageSize(self.block_difference.tgt)
+
+  @staticmethod
+  def _GetSparseImageSize(img):
+    if not img:
+      return 0
+    return img.blocksize * img.total_blocks
+
+
+class DynamicGroupUpdate(object):
+  def __init__(self, src_size=None, tgt_size=None):
+    # None: group does not exist. 0: no size limits.
+    self.src_size = src_size
+    self.tgt_size = tgt_size
+
+
+class DynamicPartitionsDifference(object):
+  def __init__(self, info_dict, block_diffs, progress_dict=None,
+               source_info_dict=None):
+    if progress_dict is None:
+      progress_dict = {}
+
+    self._remove_all_before_apply = False
+    if source_info_dict is None:
+      self._remove_all_before_apply = True
+      source_info_dict = {}
+
+    block_diff_dict = collections.OrderedDict(
+        [(e.partition, e) for e in block_diffs])
+
+    assert len(block_diff_dict) == len(block_diffs), \
+        "Duplicated BlockDifference object for {}".format(
+            [partition for partition, count in
+             collections.Counter(e.partition for e in block_diffs).items()
+             if count > 1])
+
+    self._partition_updates = collections.OrderedDict()
+
+    for p, block_diff in block_diff_dict.items():
+      self._partition_updates[p] = DynamicPartitionUpdate()
+      self._partition_updates[p].block_difference = block_diff
+
+    for p, progress in progress_dict.items():
+      if p in self._partition_updates:
+        self._partition_updates[p].progress = progress
+
+    tgt_groups = shlex.split(info_dict.get(
+        "super_partition_groups", "").strip())
+    src_groups = shlex.split(source_info_dict.get(
+        "super_partition_groups", "").strip())
+
+    for g in tgt_groups:
+      for p in shlex.split(info_dict.get(
+              "super_%s_partition_list" % g, "").strip()):
+        assert p in self._partition_updates, \
+            "{} is in target super_{}_partition_list but no BlockDifference " \
+            "object is provided.".format(p, g)
+        self._partition_updates[p].tgt_group = g
+
+    for g in src_groups:
+      for p in shlex.split(source_info_dict.get(
+              "super_%s_partition_list" % g, "").strip()):
+        assert p in self._partition_updates, \
+            "{} is in source super_{}_partition_list but no BlockDifference " \
+            "object is provided.".format(p, g)
+        self._partition_updates[p].src_group = g
+
+    target_dynamic_partitions = set(shlex.split(info_dict.get(
+        "dynamic_partition_list", "").strip()))
+    block_diffs_with_target = set(p for p, u in self._partition_updates.items()
+                                  if u.tgt_size)
+    assert block_diffs_with_target == target_dynamic_partitions, \
+        "Target Dynamic partitions: {}, BlockDifference with target: {}".format(
+            list(target_dynamic_partitions), list(block_diffs_with_target))
+
+    source_dynamic_partitions = set(shlex.split(source_info_dict.get(
+        "dynamic_partition_list", "").strip()))
+    block_diffs_with_source = set(p for p, u in self._partition_updates.items()
+                                  if u.src_size)
+    assert block_diffs_with_source == source_dynamic_partitions, \
+        "Source Dynamic partitions: {}, BlockDifference with source: {}".format(
+            list(source_dynamic_partitions), list(block_diffs_with_source))
+
+    if self._partition_updates:
+      logger.info("Updating dynamic partitions %s",
+                  self._partition_updates.keys())
+
+    self._group_updates = collections.OrderedDict()
+
+    for g in tgt_groups:
+      self._group_updates[g] = DynamicGroupUpdate()
+      self._group_updates[g].tgt_size = int(info_dict.get(
+          "super_%s_group_size" % g, "0").strip())
+
+    for g in src_groups:
+      if g not in self._group_updates:
+        self._group_updates[g] = DynamicGroupUpdate()
+      self._group_updates[g].src_size = int(source_info_dict.get(
+          "super_%s_group_size" % g, "0").strip())
+
+    self._Compute()
+
+  def WriteScript(self, script, output_zip, write_verify_script=False):
+    script.Comment('--- Start patching dynamic partitions ---')
+    for p, u in self._partition_updates.items():
+      if u.src_size and u.tgt_size and u.src_size > u.tgt_size:
+        script.Comment('Patch partition %s' % p)
+        u.block_difference.WriteScript(script, output_zip, progress=u.progress,
+                                       write_verify_script=False)
+
+    op_list_path = MakeTempFile()
+    with open(op_list_path, 'w') as f:
+      for line in self._op_list:
+        f.write('{}\n'.format(line))
+
+    ZipWrite(output_zip, op_list_path, "dynamic_partitions_op_list")
+
+    script.Comment('Update dynamic partition metadata')
+    script.AppendExtra('assert(update_dynamic_partitions('
+                       'package_extract_file("dynamic_partitions_op_list")));')
+
+    if write_verify_script:
+      for p, u in self._partition_updates.items():
+        if u.src_size and u.tgt_size and u.src_size > u.tgt_size:
+          u.block_difference.WritePostInstallVerifyScript(script)
+          script.AppendExtra('unmap_partition("%s");' % p)  # ignore errors
+
+    for p, u in self._partition_updates.items():
+      if u.tgt_size and u.src_size <= u.tgt_size:
+        script.Comment('Patch partition %s' % p)
+        u.block_difference.WriteScript(script, output_zip, progress=u.progress,
+                                       write_verify_script=write_verify_script)
+        if write_verify_script:
+          script.AppendExtra('unmap_partition("%s");' % p)  # ignore errors
+
+    script.Comment('--- End patching dynamic partitions ---')
+
+  def _Compute(self):
+    self._op_list = list()
+
+    def append(line):
+      self._op_list.append(line)
+
+    def comment(line):
+      self._op_list.append("# %s" % line)
+
+    if self._remove_all_before_apply:
+      comment('Remove all existing dynamic partitions and groups before '
+              'applying full OTA')
+      append('remove_all_groups')
+
+    for p, u in self._partition_updates.items():
+      if u.src_group and not u.tgt_group:
+        append('remove %s' % p)
+
+    for p, u in self._partition_updates.items():
+      if u.src_group and u.tgt_group and u.src_group != u.tgt_group:
+        comment('Move partition %s from %s to default' % (p, u.src_group))
+        append('move %s default' % p)
+
+    for p, u in self._partition_updates.items():
+      if u.src_size and u.tgt_size and u.src_size > u.tgt_size:
+        comment('Shrink partition %s from %d to %d' %
+                (p, u.src_size, u.tgt_size))
+        append('resize %s %s' % (p, u.tgt_size))
+
+    for g, u in self._group_updates.items():
+      if u.src_size is not None and u.tgt_size is None:
+        append('remove_group %s' % g)
+      if (u.src_size is not None and u.tgt_size is not None and
+              u.src_size > u.tgt_size):
+        comment('Shrink group %s from %d to %d' % (g, u.src_size, u.tgt_size))
+        append('resize_group %s %d' % (g, u.tgt_size))
+
+    for g, u in self._group_updates.items():
+      if u.src_size is None and u.tgt_size is not None:
+        comment('Add group %s with maximum size %d' % (g, u.tgt_size))
+        append('add_group %s %d' % (g, u.tgt_size))
+      if (u.src_size is not None and u.tgt_size is not None and
+              u.src_size < u.tgt_size):
+        comment('Grow group %s from %d to %d' % (g, u.src_size, u.tgt_size))
+        append('resize_group %s %d' % (g, u.tgt_size))
+
+    for p, u in self._partition_updates.items():
+      if u.tgt_group and not u.src_group:
+        comment('Add partition %s to group %s' % (p, u.tgt_group))
+        append('add %s %s' % (p, u.tgt_group))
+
+    for p, u in self._partition_updates.items():
+      if u.tgt_size and u.src_size < u.tgt_size:
+        comment('Grow partition %s from %d to %d' %
+                (p, u.src_size, u.tgt_size))
+        append('resize %s %d' % (p, u.tgt_size))
+
+    for p, u in self._partition_updates.items():
+      if u.src_group and u.tgt_group and u.src_group != u.tgt_group:
+        comment('Move partition %s from default to %s' %
+                (p, u.tgt_group))
+        append('move %s %s' % (p, u.tgt_group))
+
+
+# map recovery.fstab's fs_types to mount/format "partition types"
+PARTITION_TYPES = {
+    "ext4": "EMMC",
+    "emmc": "EMMC",
+    "f2fs": "EMMC",
+    "squashfs": "EMMC",
+    "erofs": "EMMC"
+}
+
+
+def GetTypeAndDevice(mount_point, info, check_no_slot=True):
+  """
+  Use GetTypeAndDeviceExpr whenever possible. This function is kept for
+  backwards compatibility. It aborts if the fstab entry has slotselect option
+  (unless check_no_slot is explicitly set to False).
+  """
+  fstab = info["fstab"]
+  if fstab:
+    if check_no_slot:
+      assert not fstab[mount_point].slotselect, \
+          "Use GetTypeAndDeviceExpr instead"
+    return (PARTITION_TYPES[fstab[mount_point].fs_type],
+            fstab[mount_point].device)
+  raise KeyError
+
+
+def GetTypeAndDeviceExpr(mount_point, info):
+  """
+  Return the filesystem of the partition, and an edify expression that evaluates
+  to the device at runtime.
+  """
+  fstab = info["fstab"]
+  if fstab:
+    p = fstab[mount_point]
+    device_expr = '"%s"' % fstab[mount_point].device
+    if p.slotselect:
+      device_expr = 'add_slot_suffix(%s)' % device_expr
+    return (PARTITION_TYPES[fstab[mount_point].fs_type], device_expr)
+  raise KeyError
diff --git a/tools/releasetools/test_common.py b/tools/releasetools/test_common.py
index 14f0e88..8052821 100644
--- a/tools/releasetools/test_common.py
+++ b/tools/releasetools/test_common.py
@@ -26,7 +26,6 @@
 import common
 import test_utils
 import validate_target_files
-from images import EmptyImage, DataImage
 from rangelib import RangeSet
 
 
@@ -1671,292 +1670,6 @@
                       test_file.name, 'generic_kernel')
 
 
-class InstallRecoveryScriptFormatTest(test_utils.ReleaseToolsTestCase):
-  """Checks the format of install-recovery.sh.
-
-  Its format should match between common.py and validate_target_files.py.
-  """
-
-  def setUp(self):
-    self._tempdir = common.MakeTempDir()
-    # Create a fake dict that contains the fstab info for boot&recovery.
-    self._info = {"fstab": {}}
-    fake_fstab = [
-        "/dev/soc.0/by-name/boot /boot emmc defaults defaults",
-        "/dev/soc.0/by-name/recovery /recovery emmc defaults defaults"]
-    self._info["fstab"] = common.LoadRecoveryFSTab("\n".join, 2, fake_fstab)
-    # Construct the gzipped recovery.img and boot.img
-    self.recovery_data = bytearray([
-        0x1f, 0x8b, 0x08, 0x00, 0x81, 0x11, 0x02, 0x5a, 0x00, 0x03, 0x2b, 0x4a,
-        0x4d, 0xce, 0x2f, 0x4b, 0x2d, 0xaa, 0x04, 0x00, 0xc9, 0x93, 0x43, 0xf3,
-        0x08, 0x00, 0x00, 0x00
-    ])
-    # echo -n "boot" | gzip -f | hd
-    self.boot_data = bytearray([
-        0x1f, 0x8b, 0x08, 0x00, 0x8c, 0x12, 0x02, 0x5a, 0x00, 0x03, 0x4b, 0xca,
-        0xcf, 0x2f, 0x01, 0x00, 0xc4, 0xae, 0xed, 0x46, 0x04, 0x00, 0x00, 0x00
-    ])
-
-  def _out_tmp_sink(self, name, data, prefix="SYSTEM"):
-    loc = os.path.join(self._tempdir, prefix, name)
-    if not os.path.exists(os.path.dirname(loc)):
-      os.makedirs(os.path.dirname(loc))
-    with open(loc, "wb") as f:
-      f.write(data)
-
-  def test_full_recovery(self):
-    recovery_image = common.File("recovery.img", self.recovery_data)
-    boot_image = common.File("boot.img", self.boot_data)
-    self._info["full_recovery_image"] = "true"
-
-    common.MakeRecoveryPatch(self._tempdir, self._out_tmp_sink,
-                             recovery_image, boot_image, self._info)
-    validate_target_files.ValidateInstallRecoveryScript(self._tempdir,
-                                                        self._info)
-
-  @test_utils.SkipIfExternalToolsUnavailable()
-  def test_recovery_from_boot(self):
-    recovery_image = common.File("recovery.img", self.recovery_data)
-    self._out_tmp_sink("recovery.img", recovery_image.data, "IMAGES")
-    boot_image = common.File("boot.img", self.boot_data)
-    self._out_tmp_sink("boot.img", boot_image.data, "IMAGES")
-
-    common.MakeRecoveryPatch(self._tempdir, self._out_tmp_sink,
-                             recovery_image, boot_image, self._info)
-    validate_target_files.ValidateInstallRecoveryScript(self._tempdir,
-                                                        self._info)
-    # Validate 'recovery-from-boot' with bonus argument.
-    self._out_tmp_sink("etc/recovery-resource.dat", b"bonus", "SYSTEM")
-    common.MakeRecoveryPatch(self._tempdir, self._out_tmp_sink,
-                             recovery_image, boot_image, self._info)
-    validate_target_files.ValidateInstallRecoveryScript(self._tempdir,
-                                                        self._info)
-
-
-class MockBlockDifference(object):
-
-  def __init__(self, partition, tgt, src=None):
-    self.partition = partition
-    self.tgt = tgt
-    self.src = src
-
-  def WriteScript(self, script, _, progress=None,
-                  write_verify_script=False):
-    if progress:
-      script.AppendExtra("progress({})".format(progress))
-    script.AppendExtra("patch({});".format(self.partition))
-    if write_verify_script:
-      self.WritePostInstallVerifyScript(script)
-
-  def WritePostInstallVerifyScript(self, script):
-    script.AppendExtra("verify({});".format(self.partition))
-
-
-class FakeSparseImage(object):
-
-  def __init__(self, size):
-    self.blocksize = 4096
-    self.total_blocks = size // 4096
-    assert size % 4096 == 0, "{} is not a multiple of 4096".format(size)
-
-
-class DynamicPartitionsDifferenceTest(test_utils.ReleaseToolsTestCase):
-
-  @staticmethod
-  def get_op_list(output_path):
-    with zipfile.ZipFile(output_path, allowZip64=True) as output_zip:
-      with output_zip.open('dynamic_partitions_op_list') as op_list:
-        return [line.decode().strip() for line in op_list.readlines()
-                if not line.startswith(b'#')]
-
-  def setUp(self):
-    self.script = test_utils.MockScriptWriter()
-    self.output_path = common.MakeTempFile(suffix='.zip')
-
-  def test_full(self):
-    target_info = common.LoadDictionaryFromLines("""
-dynamic_partition_list=system vendor
-super_partition_groups=group_foo
-super_group_foo_group_size={group_size}
-super_group_foo_partition_list=system vendor
-""".format(group_size=4 * GiB).split("\n"))
-    block_diffs = [MockBlockDifference("system", FakeSparseImage(3 * GiB)),
-                   MockBlockDifference("vendor", FakeSparseImage(1 * GiB))]
-
-    dp_diff = common.DynamicPartitionsDifference(target_info, block_diffs)
-    with zipfile.ZipFile(self.output_path, 'w', allowZip64=True) as output_zip:
-      dp_diff.WriteScript(self.script, output_zip, write_verify_script=True)
-
-    self.assertEqual(str(self.script).strip(), """
-assert(update_dynamic_partitions(package_extract_file("dynamic_partitions_op_list")));
-patch(system);
-verify(system);
-unmap_partition("system");
-patch(vendor);
-verify(vendor);
-unmap_partition("vendor");
-""".strip())
-
-    lines = self.get_op_list(self.output_path)
-
-    remove_all_groups = lines.index("remove_all_groups")
-    add_group = lines.index("add_group group_foo 4294967296")
-    add_vendor = lines.index("add vendor group_foo")
-    add_system = lines.index("add system group_foo")
-    resize_vendor = lines.index("resize vendor 1073741824")
-    resize_system = lines.index("resize system 3221225472")
-
-    self.assertLess(remove_all_groups, add_group,
-                    "Should add groups after removing all groups")
-    self.assertLess(add_group, min(add_vendor, add_system),
-                    "Should add partitions after adding group")
-    self.assertLess(add_system, resize_system,
-                    "Should resize system after adding it")
-    self.assertLess(add_vendor, resize_vendor,
-                    "Should resize vendor after adding it")
-
-  def test_inc_groups(self):
-    source_info = common.LoadDictionaryFromLines("""
-super_partition_groups=group_foo group_bar group_baz
-super_group_foo_group_size={group_foo_size}
-super_group_bar_group_size={group_bar_size}
-""".format(group_foo_size=4 * GiB, group_bar_size=3 * GiB).split("\n"))
-    target_info = common.LoadDictionaryFromLines("""
-super_partition_groups=group_foo group_baz group_qux
-super_group_foo_group_size={group_foo_size}
-super_group_baz_group_size={group_baz_size}
-super_group_qux_group_size={group_qux_size}
-""".format(group_foo_size=3 * GiB, group_baz_size=4 * GiB,
-           group_qux_size=1 * GiB).split("\n"))
-
-    dp_diff = common.DynamicPartitionsDifference(target_info,
-                                                 block_diffs=[],
-                                                 source_info_dict=source_info)
-    with zipfile.ZipFile(self.output_path, 'w', allowZip64=True) as output_zip:
-      dp_diff.WriteScript(self.script, output_zip, write_verify_script=True)
-
-    lines = self.get_op_list(self.output_path)
-
-    removed = lines.index("remove_group group_bar")
-    shrunk = lines.index("resize_group group_foo 3221225472")
-    grown = lines.index("resize_group group_baz 4294967296")
-    added = lines.index("add_group group_qux 1073741824")
-
-    self.assertLess(max(removed, shrunk),
-                    min(grown, added),
-                    "ops that remove / shrink partitions must precede ops that "
-                    "grow / add partitions")
-
-  def test_incremental(self):
-    source_info = common.LoadDictionaryFromLines("""
-dynamic_partition_list=system vendor product system_ext
-super_partition_groups=group_foo
-super_group_foo_group_size={group_foo_size}
-super_group_foo_partition_list=system vendor product system_ext
-""".format(group_foo_size=4 * GiB).split("\n"))
-    target_info = common.LoadDictionaryFromLines("""
-dynamic_partition_list=system vendor product odm
-super_partition_groups=group_foo group_bar
-super_group_foo_group_size={group_foo_size}
-super_group_foo_partition_list=system vendor odm
-super_group_bar_group_size={group_bar_size}
-super_group_bar_partition_list=product
-""".format(group_foo_size=3 * GiB, group_bar_size=1 * GiB).split("\n"))
-
-    block_diffs = [MockBlockDifference("system", FakeSparseImage(1536 * MiB),
-                                       src=FakeSparseImage(1024 * MiB)),
-                   MockBlockDifference("vendor", FakeSparseImage(512 * MiB),
-                                       src=FakeSparseImage(1024 * MiB)),
-                   MockBlockDifference("product", FakeSparseImage(1024 * MiB),
-                                       src=FakeSparseImage(1024 * MiB)),
-                   MockBlockDifference("system_ext", None,
-                                       src=FakeSparseImage(1024 * MiB)),
-                   MockBlockDifference("odm", FakeSparseImage(1024 * MiB),
-                                       src=None)]
-
-    dp_diff = common.DynamicPartitionsDifference(target_info, block_diffs,
-                                                 source_info_dict=source_info)
-    with zipfile.ZipFile(self.output_path, 'w', allowZip64=True) as output_zip:
-      dp_diff.WriteScript(self.script, output_zip, write_verify_script=True)
-
-    metadata_idx = self.script.lines.index(
-        'assert(update_dynamic_partitions(package_extract_file('
-        '"dynamic_partitions_op_list")));')
-    self.assertLess(self.script.lines.index('patch(vendor);'), metadata_idx)
-    self.assertLess(metadata_idx, self.script.lines.index('verify(vendor);'))
-    for p in ("product", "system", "odm"):
-      patch_idx = self.script.lines.index("patch({});".format(p))
-      verify_idx = self.script.lines.index("verify({});".format(p))
-      self.assertLess(metadata_idx, patch_idx,
-                      "Should patch {} after updating metadata".format(p))
-      self.assertLess(patch_idx, verify_idx,
-                      "Should verify {} after patching".format(p))
-
-    self.assertNotIn("patch(system_ext);", self.script.lines)
-
-    lines = self.get_op_list(self.output_path)
-
-    remove = lines.index("remove system_ext")
-    move_product_out = lines.index("move product default")
-    shrink = lines.index("resize vendor 536870912")
-    shrink_group = lines.index("resize_group group_foo 3221225472")
-    add_group_bar = lines.index("add_group group_bar 1073741824")
-    add_odm = lines.index("add odm group_foo")
-    grow_existing = lines.index("resize system 1610612736")
-    grow_added = lines.index("resize odm 1073741824")
-    move_product_in = lines.index("move product group_bar")
-
-    max_idx_move_partition_out_foo = max(remove, move_product_out, shrink)
-    min_idx_move_partition_in_foo = min(add_odm, grow_existing, grow_added)
-
-    self.assertLess(max_idx_move_partition_out_foo, shrink_group,
-                    "Must shrink group after partitions inside group are shrunk"
-                    " / removed")
-
-    self.assertLess(add_group_bar, move_product_in,
-                    "Must add partitions to group after group is added")
-
-    self.assertLess(max_idx_move_partition_out_foo,
-                    min_idx_move_partition_in_foo,
-                    "Must shrink partitions / remove partitions from group"
-                    "before adding / moving partitions into group")
-
-  def test_remove_partition(self):
-    source_info = common.LoadDictionaryFromLines("""
-blockimgdiff_versions=3,4
-use_dynamic_partitions=true
-dynamic_partition_list=foo
-super_partition_groups=group_foo
-super_group_foo_group_size={group_foo_size}
-super_group_foo_partition_list=foo
-""".format(group_foo_size=4 * GiB).split("\n"))
-    target_info = common.LoadDictionaryFromLines("""
-blockimgdiff_versions=3,4
-use_dynamic_partitions=true
-super_partition_groups=group_foo
-super_group_foo_group_size={group_foo_size}
-""".format(group_foo_size=4 * GiB).split("\n"))
-
-    common.OPTIONS.info_dict = target_info
-    common.OPTIONS.target_info_dict = target_info
-    common.OPTIONS.source_info_dict = source_info
-    common.OPTIONS.cache_size = 4 * 4096
-
-    block_diffs = [common.BlockDifference("foo", EmptyImage(),
-                                          src=DataImage("source", pad=True))]
-
-    dp_diff = common.DynamicPartitionsDifference(target_info, block_diffs,
-                                                 source_info_dict=source_info)
-    with zipfile.ZipFile(self.output_path, 'w', allowZip64=True) as output_zip:
-      dp_diff.WriteScript(self.script, output_zip, write_verify_script=True)
-
-    self.assertNotIn("block_image_update", str(self.script),
-                     "Removed partition should not be patched.")
-
-    lines = self.get_op_list(self.output_path)
-    self.assertEqual(lines, ["remove foo"])
-
-
 class PartitionBuildPropsTest(test_utils.ReleaseToolsTestCase):
   def setUp(self):
     self.odm_build_prop = [
diff --git a/tools/releasetools/test_non_ab_ota.py b/tools/releasetools/test_non_ab_ota.py
index 5207e2f..7a5ccd3 100644
--- a/tools/releasetools/test_non_ab_ota.py
+++ b/tools/releasetools/test_non_ab_ota.py
@@ -15,19 +15,24 @@
 #
 
 import copy
+import os
 import zipfile
 
 import common
 import test_utils
+import validate_target_files
 
-from non_ab_ota import NonAbOtaPropertyFiles, WriteFingerprintAssertion
+from images import EmptyImage, DataImage
+from non_ab_ota import NonAbOtaPropertyFiles, WriteFingerprintAssertion, BlockDifference, DynamicPartitionsDifference, MakeRecoveryPatch
 from test_utils import PropertyFilesTestCase
 
 
 class NonAbOtaPropertyFilesTest(PropertyFilesTestCase):
   """Additional validity checks specialized for NonAbOtaPropertyFiles."""
+
   def setUp(self):
-     common.OPTIONS.no_signing = False
+    common.OPTIONS.no_signing = False
+
   def test_init(self):
     property_files = NonAbOtaPropertyFiles()
     self.assertEqual('ota-property-files', property_files.name)
@@ -55,7 +60,8 @@
     with zipfile.ZipFile(zip_file) as zip_fp:
       raw_metadata = property_files.GetPropertyFilesString(
           zip_fp, reserve_space=False)
-      property_files_string = property_files.Finalize(zip_fp, len(raw_metadata))
+      property_files_string = property_files.Finalize(
+          zip_fp, len(raw_metadata))
     tokens = self._parse_property_files_string(property_files_string)
 
     self.assertEqual(2, len(tokens))
@@ -77,6 +83,7 @@
 
       property_files.Verify(zip_fp, raw_metadata)
 
+
 class NonAbOTATest(test_utils.ReleaseToolsTestCase):
   TEST_TARGET_INFO_DICT = {
       'build.prop': common.PartitionBuildProps.FromDictionary(
@@ -98,7 +105,7 @@
       ),
       'vendor.build.prop': common.PartitionBuildProps.FromDictionary(
           'vendor', {
-               'ro.vendor.build.fingerprint': 'vendor-build-fingerprint'}
+              'ro.vendor.build.fingerprint': 'vendor-build-fingerprint'}
       ),
       'property1': 'value1',
       'property2': 4096,
@@ -118,6 +125,7 @@
           'ro.product.device': 'device3',
       },
   ]
+
   def test_WriteFingerprintAssertion_without_oem_props(self):
     target_info = common.BuildInfo(self.TEST_TARGET_INFO_DICT, None)
     source_info_dict = copy.deepcopy(self.TEST_TARGET_INFO_DICT)
@@ -170,3 +178,296 @@
         [('AssertSomeThumbprint', 'build-thumbprint',
           'source-build-thumbprint')],
         script_writer.lines)
+
+
+KiB = 1024
+MiB = 1024 * KiB
+GiB = 1024 * MiB
+
+
+class MockBlockDifference(object):
+
+  def __init__(self, partition, tgt, src=None):
+    self.partition = partition
+    self.tgt = tgt
+    self.src = src
+
+  def WriteScript(self, script, _, progress=None,
+                  write_verify_script=False):
+    if progress:
+      script.AppendExtra("progress({})".format(progress))
+    script.AppendExtra("patch({});".format(self.partition))
+    if write_verify_script:
+      self.WritePostInstallVerifyScript(script)
+
+  def WritePostInstallVerifyScript(self, script):
+    script.AppendExtra("verify({});".format(self.partition))
+
+
+class FakeSparseImage(object):
+
+  def __init__(self, size):
+    self.blocksize = 4096
+    self.total_blocks = size // 4096
+    assert size % 4096 == 0, "{} is not a multiple of 4096".format(size)
+
+
+class DynamicPartitionsDifferenceTest(test_utils.ReleaseToolsTestCase):
+
+  @staticmethod
+  def get_op_list(output_path):
+    with zipfile.ZipFile(output_path, allowZip64=True) as output_zip:
+      with output_zip.open('dynamic_partitions_op_list') as op_list:
+        return [line.decode().strip() for line in op_list.readlines()
+                if not line.startswith(b'#')]
+
+  def setUp(self):
+    self.script = test_utils.MockScriptWriter()
+    self.output_path = common.MakeTempFile(suffix='.zip')
+
+  def test_full(self):
+    target_info = common.LoadDictionaryFromLines("""
+dynamic_partition_list=system vendor
+super_partition_groups=group_foo
+super_group_foo_group_size={group_size}
+super_group_foo_partition_list=system vendor
+""".format(group_size=4 * GiB).split("\n"))
+    block_diffs = [MockBlockDifference("system", FakeSparseImage(3 * GiB)),
+                   MockBlockDifference("vendor", FakeSparseImage(1 * GiB))]
+
+    dp_diff = DynamicPartitionsDifference(target_info, block_diffs)
+    with zipfile.ZipFile(self.output_path, 'w', allowZip64=True) as output_zip:
+      dp_diff.WriteScript(self.script, output_zip, write_verify_script=True)
+
+    self.assertEqual(str(self.script).strip(), """
+assert(update_dynamic_partitions(package_extract_file("dynamic_partitions_op_list")));
+patch(system);
+verify(system);
+unmap_partition("system");
+patch(vendor);
+verify(vendor);
+unmap_partition("vendor");
+""".strip())
+
+    lines = self.get_op_list(self.output_path)
+
+    remove_all_groups = lines.index("remove_all_groups")
+    add_group = lines.index("add_group group_foo 4294967296")
+    add_vendor = lines.index("add vendor group_foo")
+    add_system = lines.index("add system group_foo")
+    resize_vendor = lines.index("resize vendor 1073741824")
+    resize_system = lines.index("resize system 3221225472")
+
+    self.assertLess(remove_all_groups, add_group,
+                    "Should add groups after removing all groups")
+    self.assertLess(add_group, min(add_vendor, add_system),
+                    "Should add partitions after adding group")
+    self.assertLess(add_system, resize_system,
+                    "Should resize system after adding it")
+    self.assertLess(add_vendor, resize_vendor,
+                    "Should resize vendor after adding it")
+
+  def test_inc_groups(self):
+    source_info = common.LoadDictionaryFromLines("""
+super_partition_groups=group_foo group_bar group_baz
+super_group_foo_group_size={group_foo_size}
+super_group_bar_group_size={group_bar_size}
+""".format(group_foo_size=4 * GiB, group_bar_size=3 * GiB).split("\n"))
+    target_info = common.LoadDictionaryFromLines("""
+super_partition_groups=group_foo group_baz group_qux
+super_group_foo_group_size={group_foo_size}
+super_group_baz_group_size={group_baz_size}
+super_group_qux_group_size={group_qux_size}
+""".format(group_foo_size=3 * GiB, group_baz_size=4 * GiB,
+           group_qux_size=1 * GiB).split("\n"))
+
+    dp_diff = DynamicPartitionsDifference(target_info,
+                                                 block_diffs=[],
+                                                 source_info_dict=source_info)
+    with zipfile.ZipFile(self.output_path, 'w', allowZip64=True) as output_zip:
+      dp_diff.WriteScript(self.script, output_zip, write_verify_script=True)
+
+    lines = self.get_op_list(self.output_path)
+
+    removed = lines.index("remove_group group_bar")
+    shrunk = lines.index("resize_group group_foo 3221225472")
+    grown = lines.index("resize_group group_baz 4294967296")
+    added = lines.index("add_group group_qux 1073741824")
+
+    self.assertLess(max(removed, shrunk),
+                    min(grown, added),
+                    "ops that remove / shrink partitions must precede ops that "
+                    "grow / add partitions")
+
+  def test_incremental(self):
+    source_info = common.LoadDictionaryFromLines("""
+dynamic_partition_list=system vendor product system_ext
+super_partition_groups=group_foo
+super_group_foo_group_size={group_foo_size}
+super_group_foo_partition_list=system vendor product system_ext
+""".format(group_foo_size=4 * GiB).split("\n"))
+    target_info = common.LoadDictionaryFromLines("""
+dynamic_partition_list=system vendor product odm
+super_partition_groups=group_foo group_bar
+super_group_foo_group_size={group_foo_size}
+super_group_foo_partition_list=system vendor odm
+super_group_bar_group_size={group_bar_size}
+super_group_bar_partition_list=product
+""".format(group_foo_size=3 * GiB, group_bar_size=1 * GiB).split("\n"))
+
+    block_diffs = [MockBlockDifference("system", FakeSparseImage(1536 * MiB),
+                                       src=FakeSparseImage(1024 * MiB)),
+                   MockBlockDifference("vendor", FakeSparseImage(512 * MiB),
+                                       src=FakeSparseImage(1024 * MiB)),
+                   MockBlockDifference("product", FakeSparseImage(1024 * MiB),
+                                       src=FakeSparseImage(1024 * MiB)),
+                   MockBlockDifference("system_ext", None,
+                                       src=FakeSparseImage(1024 * MiB)),
+                   MockBlockDifference("odm", FakeSparseImage(1024 * MiB),
+                                       src=None)]
+
+    dp_diff = DynamicPartitionsDifference(target_info, block_diffs,
+                                                 source_info_dict=source_info)
+    with zipfile.ZipFile(self.output_path, 'w', allowZip64=True) as output_zip:
+      dp_diff.WriteScript(self.script, output_zip, write_verify_script=True)
+
+    metadata_idx = self.script.lines.index(
+        'assert(update_dynamic_partitions(package_extract_file('
+        '"dynamic_partitions_op_list")));')
+    self.assertLess(self.script.lines.index('patch(vendor);'), metadata_idx)
+    self.assertLess(metadata_idx, self.script.lines.index('verify(vendor);'))
+    for p in ("product", "system", "odm"):
+      patch_idx = self.script.lines.index("patch({});".format(p))
+      verify_idx = self.script.lines.index("verify({});".format(p))
+      self.assertLess(metadata_idx, patch_idx,
+                      "Should patch {} after updating metadata".format(p))
+      self.assertLess(patch_idx, verify_idx,
+                      "Should verify {} after patching".format(p))
+
+    self.assertNotIn("patch(system_ext);", self.script.lines)
+
+    lines = self.get_op_list(self.output_path)
+
+    remove = lines.index("remove system_ext")
+    move_product_out = lines.index("move product default")
+    shrink = lines.index("resize vendor 536870912")
+    shrink_group = lines.index("resize_group group_foo 3221225472")
+    add_group_bar = lines.index("add_group group_bar 1073741824")
+    add_odm = lines.index("add odm group_foo")
+    grow_existing = lines.index("resize system 1610612736")
+    grow_added = lines.index("resize odm 1073741824")
+    move_product_in = lines.index("move product group_bar")
+
+    max_idx_move_partition_out_foo = max(remove, move_product_out, shrink)
+    min_idx_move_partition_in_foo = min(add_odm, grow_existing, grow_added)
+
+    self.assertLess(max_idx_move_partition_out_foo, shrink_group,
+                    "Must shrink group after partitions inside group are shrunk"
+                    " / removed")
+
+    self.assertLess(add_group_bar, move_product_in,
+                    "Must add partitions to group after group is added")
+
+    self.assertLess(max_idx_move_partition_out_foo,
+                    min_idx_move_partition_in_foo,
+                    "Must shrink partitions / remove partitions from group"
+                    "before adding / moving partitions into group")
+
+  def test_remove_partition(self):
+    source_info = common.LoadDictionaryFromLines("""
+blockimgdiff_versions=3,4
+use_dynamic_partitions=true
+dynamic_partition_list=foo
+super_partition_groups=group_foo
+super_group_foo_group_size={group_foo_size}
+super_group_foo_partition_list=foo
+""".format(group_foo_size=4 * GiB).split("\n"))
+    target_info = common.LoadDictionaryFromLines("""
+blockimgdiff_versions=3,4
+use_dynamic_partitions=true
+super_partition_groups=group_foo
+super_group_foo_group_size={group_foo_size}
+""".format(group_foo_size=4 * GiB).split("\n"))
+
+    common.OPTIONS.info_dict = target_info
+    common.OPTIONS.target_info_dict = target_info
+    common.OPTIONS.source_info_dict = source_info
+    common.OPTIONS.cache_size = 4 * 4096
+
+    block_diffs = [BlockDifference("foo", EmptyImage(),
+                                   src=DataImage("source", pad=True))]
+
+    dp_diff = DynamicPartitionsDifference(target_info, block_diffs,
+                                          source_info_dict=source_info)
+    with zipfile.ZipFile(self.output_path, 'w', allowZip64=True) as output_zip:
+      dp_diff.WriteScript(self.script, output_zip, write_verify_script=True)
+
+    self.assertNotIn("block_image_update", str(self.script),
+                     "Removed partition should not be patched.")
+
+    lines = self.get_op_list(self.output_path)
+    self.assertEqual(lines, ["remove foo"])
+
+
+
+class InstallRecoveryScriptFormatTest(test_utils.ReleaseToolsTestCase):
+  """Checks the format of install-recovery.sh.
+
+  Its format should match between common.py and validate_target_files.py.
+  """
+
+  def setUp(self):
+    self._tempdir = common.MakeTempDir()
+    # Create a fake dict that contains the fstab info for boot&recovery.
+    self._info = {"fstab": {}}
+    fake_fstab = [
+        "/dev/soc.0/by-name/boot /boot emmc defaults defaults",
+        "/dev/soc.0/by-name/recovery /recovery emmc defaults defaults"]
+    self._info["fstab"] = common.LoadRecoveryFSTab("\n".join, 2, fake_fstab)
+    # Construct the gzipped recovery.img and boot.img
+    self.recovery_data = bytearray([
+        0x1f, 0x8b, 0x08, 0x00, 0x81, 0x11, 0x02, 0x5a, 0x00, 0x03, 0x2b, 0x4a,
+        0x4d, 0xce, 0x2f, 0x4b, 0x2d, 0xaa, 0x04, 0x00, 0xc9, 0x93, 0x43, 0xf3,
+        0x08, 0x00, 0x00, 0x00
+    ])
+    # echo -n "boot" | gzip -f | hd
+    self.boot_data = bytearray([
+        0x1f, 0x8b, 0x08, 0x00, 0x8c, 0x12, 0x02, 0x5a, 0x00, 0x03, 0x4b, 0xca,
+        0xcf, 0x2f, 0x01, 0x00, 0xc4, 0xae, 0xed, 0x46, 0x04, 0x00, 0x00, 0x00
+    ])
+
+  def _out_tmp_sink(self, name, data, prefix="SYSTEM"):
+    loc = os.path.join(self._tempdir, prefix, name)
+    if not os.path.exists(os.path.dirname(loc)):
+      os.makedirs(os.path.dirname(loc))
+    with open(loc, "wb") as f:
+      f.write(data)
+
+  def test_full_recovery(self):
+    recovery_image = common.File("recovery.img", self.recovery_data)
+    boot_image = common.File("boot.img", self.boot_data)
+    self._info["full_recovery_image"] = "true"
+
+    MakeRecoveryPatch(self._tempdir, self._out_tmp_sink,
+                             recovery_image, boot_image, self._info)
+    validate_target_files.ValidateInstallRecoveryScript(self._tempdir,
+                                                        self._info)
+
+  @test_utils.SkipIfExternalToolsUnavailable()
+  def test_recovery_from_boot(self):
+    recovery_image = common.File("recovery.img", self.recovery_data)
+    self._out_tmp_sink("recovery.img", recovery_image.data, "IMAGES")
+    boot_image = common.File("boot.img", self.boot_data)
+    self._out_tmp_sink("boot.img", boot_image.data, "IMAGES")
+
+    MakeRecoveryPatch(self._tempdir, self._out_tmp_sink,
+                             recovery_image, boot_image, self._info)
+    validate_target_files.ValidateInstallRecoveryScript(self._tempdir,
+                                                        self._info)
+    # Validate 'recovery-from-boot' with bonus argument.
+    self._out_tmp_sink("etc/recovery-resource.dat", b"bonus", "SYSTEM")
+    MakeRecoveryPatch(self._tempdir, self._out_tmp_sink,
+                             recovery_image, boot_image, self._info)
+    validate_target_files.ValidateInstallRecoveryScript(self._tempdir,
+                                                        self._info)
+