diff --git a/tools/releasetools/merge/Android.bp b/tools/releasetools/merge/Android.bp
new file mode 100644
index 0000000..c07d8ee
--- /dev/null
+++ b/tools/releasetools/merge/Android.bp
@@ -0,0 +1,69 @@
+// Copyright (C) 2022 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package {
+    default_applicable_licenses: ["Android-Apache-2.0"],
+}
+
+filegroup {
+    name: "releasetools_merge_sources",
+    srcs: [
+        "merge_target_files.py",
+    ],
+}
+
+filegroup {
+    name: "releasetools_merge_tests",
+    srcs: [
+        "test_merge_target_files.py",
+    ],
+}
+
+python_binary_host {
+    name: "merge_target_files",
+    defaults: ["releasetools_binary_defaults"],
+    srcs: [":releasetools_merge_sources"],
+    libs: [
+        "releasetools_add_img_to_target_files",
+        "releasetools_build_super_image",
+        "releasetools_check_target_files_vintf",
+        "releasetools_common",
+        "releasetools_find_shareduid_violation",
+        "releasetools_img_from_target_files",
+        "releasetools_ota_from_target_files",
+    ],
+    required: [
+        "checkvintf",
+        "host_init_verifier",
+        "secilc",
+    ],
+    target: {
+        darwin: {
+            // libs dep "releasetools_ota_from_target_files" is disabled on darwin
+            enabled: false,
+        },
+    },
+}
+
+python_binary_host {
+    name: "merge_builds",
+    defaults: ["releasetools_binary_defaults"],
+    srcs: [
+        "merge_builds.py",
+    ],
+    libs: [
+        "releasetools_build_super_image",
+        "releasetools_common",
+    ],
+}
diff --git a/tools/releasetools/merge/OWNERS b/tools/releasetools/merge/OWNERS
new file mode 100644
index 0000000..9012e3a
--- /dev/null
+++ b/tools/releasetools/merge/OWNERS
@@ -0,0 +1,3 @@
+danielnorman@google.com
+jgalmes@google.com
+rseymour@google.com
diff --git a/tools/releasetools/merge/merge_builds.py b/tools/releasetools/merge/merge_builds.py
new file mode 100644
index 0000000..3ac4ec4
--- /dev/null
+++ b/tools/releasetools/merge/merge_builds.py
@@ -0,0 +1,192 @@
+#!/usr/bin/env python
+#
+# Copyright (C) 2019 The Android Open Source Project
+#
+# Licensed under the Apache License, Version 2.0 (the "License"); you may not
+# use this file except in compliance with the License. You may obtain a copy of
+# the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations under
+# the License.
+#
+"""Merges two non-dist partial builds together.
+
+Given two partial builds, a framework build and a vendor build, merge the builds
+together so that the images can be flashed using 'fastboot flashall'.
+
+To support both DAP and non-DAP vendor builds with a single framework partial
+build, the framework partial build should always be built with DAP enabled. The
+vendor partial build determines whether the merged result supports DAP.
+
+This script does not require builds to be built with 'make dist'.
+This script regenerates super_empty.img and vbmeta.img if necessary. Other
+images are assumed to not require regeneration.
+
+Usage: merge_builds.py [args]
+
+  --framework_images comma_separated_image_list
+      Comma-separated list of image names that should come from the framework
+      build.
+
+  --product_out_framework product_out_framework_path
+      Path to out/target/product/<framework build>.
+
+  --product_out_vendor product_out_vendor_path
+      Path to out/target/product/<vendor build>.
+
+  --build_vbmeta
+      If provided, vbmeta.img will be regenerated in out/target/product/<vendor
+      build>.
+
+  --framework_misc_info_keys
+      The optional path to a newline-separated config file containing keys to
+      obtain from the framework instance of misc_info.txt, used for creating
+      vbmeta.img. The remaining keys come from the vendor instance.
+"""
+from __future__ import print_function
+
+import logging
+import os
+import sys
+
+import build_super_image
+import common
+
+logger = logging.getLogger(__name__)
+
+OPTIONS = common.OPTIONS
+OPTIONS.framework_images = ("system",)
+OPTIONS.product_out_framework = None
+OPTIONS.product_out_vendor = None
+OPTIONS.build_vbmeta = False
+OPTIONS.framework_misc_info_keys = None
+
+
+def CreateImageSymlinks():
+  for image in OPTIONS.framework_images:
+    image_path = os.path.join(OPTIONS.product_out_framework, "%s.img" % image)
+    symlink_path = os.path.join(OPTIONS.product_out_vendor, "%s.img" % image)
+    if os.path.exists(symlink_path):
+      if os.path.islink(symlink_path):
+        os.remove(symlink_path)
+      else:
+        raise ValueError("Attempting to overwrite built image: %s" %
+                         symlink_path)
+    os.symlink(image_path, symlink_path)
+
+
+def BuildSuperEmpty():
+  framework_dict = common.LoadDictionaryFromFile(
+      os.path.join(OPTIONS.product_out_framework, "misc_info.txt"))
+  vendor_dict = common.LoadDictionaryFromFile(
+      os.path.join(OPTIONS.product_out_vendor, "misc_info.txt"))
+  # Regenerate super_empty.img if both partial builds enable DAP. If only the
+  # the vendor build enables DAP, the vendor build's existing super_empty.img
+  # will be reused. If only the framework build should enable DAP, super_empty
+  # should be included in the --framework_images flag to copy the existing
+  # super_empty.img from the framework build.
+  if (framework_dict.get("use_dynamic_partitions") == "true") and (
+      vendor_dict.get("use_dynamic_partitions") == "true"):
+    logger.info("Building super_empty.img.")
+    merged_dict = dict(vendor_dict)
+    merged_dict.update(
+        common.MergeDynamicPartitionInfoDicts(
+            framework_dict=framework_dict, vendor_dict=vendor_dict))
+    output_super_empty_path = os.path.join(OPTIONS.product_out_vendor,
+                                           "super_empty.img")
+    build_super_image.BuildSuperImage(merged_dict, output_super_empty_path)
+
+
+def BuildVBMeta():
+  logger.info("Building vbmeta.img.")
+
+  framework_dict = common.LoadDictionaryFromFile(
+      os.path.join(OPTIONS.product_out_framework, "misc_info.txt"))
+  vendor_dict = common.LoadDictionaryFromFile(
+      os.path.join(OPTIONS.product_out_vendor, "misc_info.txt"))
+  merged_dict = dict(vendor_dict)
+  if OPTIONS.framework_misc_info_keys:
+    for key in common.LoadListFromFile(OPTIONS.framework_misc_info_keys):
+      merged_dict[key] = framework_dict[key]
+
+  # Build vbmeta.img using partitions in product_out_vendor.
+  partitions = {}
+  for partition in common.AVB_PARTITIONS:
+    partition_path = os.path.join(OPTIONS.product_out_vendor,
+                                  "%s.img" % partition)
+    if os.path.exists(partition_path):
+      partitions[partition] = partition_path
+
+  # vbmeta_partitions includes the partitions that should be included into
+  # top-level vbmeta.img, which are the ones that are not included in any
+  # chained VBMeta image plus the chained VBMeta images themselves.
+  vbmeta_partitions = common.AVB_PARTITIONS[:]
+  for partition in common.AVB_VBMETA_PARTITIONS:
+    chained_partitions = merged_dict.get("avb_%s" % partition, "").strip()
+    if chained_partitions:
+      partitions[partition] = os.path.join(OPTIONS.product_out_vendor,
+                                           "%s.img" % partition)
+      vbmeta_partitions = [
+          item for item in vbmeta_partitions
+          if item not in chained_partitions.split()
+      ]
+      vbmeta_partitions.append(partition)
+
+  output_vbmeta_path = os.path.join(OPTIONS.product_out_vendor, "vbmeta.img")
+  OPTIONS.info_dict = merged_dict
+  common.BuildVBMeta(output_vbmeta_path, partitions, "vbmeta",
+                     vbmeta_partitions)
+
+
+def MergeBuilds():
+  CreateImageSymlinks()
+  BuildSuperEmpty()
+  if OPTIONS.build_vbmeta:
+    BuildVBMeta()
+
+
+def main():
+  common.InitLogging()
+
+  def option_handler(o, a):
+    if o == "--framework_images":
+      OPTIONS.framework_images = [i.strip() for i in a.split(",")]
+    elif o == "--product_out_framework":
+      OPTIONS.product_out_framework = a
+    elif o == "--product_out_vendor":
+      OPTIONS.product_out_vendor = a
+    elif o == "--build_vbmeta":
+      OPTIONS.build_vbmeta = True
+    elif o == "--framework_misc_info_keys":
+      OPTIONS.framework_misc_info_keys = a
+    else:
+      return False
+    return True
+
+  args = common.ParseOptions(
+      sys.argv[1:],
+      __doc__,
+      extra_long_opts=[
+          "framework_images=",
+          "product_out_framework=",
+          "product_out_vendor=",
+          "build_vbmeta",
+          "framework_misc_info_keys=",
+      ],
+      extra_option_handler=option_handler)
+
+  if (args or OPTIONS.product_out_framework is None or
+      OPTIONS.product_out_vendor is None):
+    common.Usage(__doc__)
+    sys.exit(1)
+
+  MergeBuilds()
+
+
+if __name__ == "__main__":
+  main()
diff --git a/tools/releasetools/merge/merge_target_files.py b/tools/releasetools/merge/merge_target_files.py
new file mode 100755
index 0000000..25ed60e
--- /dev/null
+++ b/tools/releasetools/merge/merge_target_files.py
@@ -0,0 +1,1541 @@
+#!/usr/bin/env python
+#
+# Copyright (C) 2022 The Android Open Source Project
+#
+# Licensed under the Apache License, Version 2.0 (the "License"); you may not
+# use this file except in compliance with the License. You may obtain a copy of
+# the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations under
+# the License.
+#
+"""This script merges two partial target files packages.
+
+One input package contains framework files, and the other contains vendor files.
+
+This script produces a complete, merged target files package:
+  - This package can be used to generate a flashable IMG package.
+    See --output-img.
+  - This package can be used to generate an OTA package. See --output-ota.
+  - The merged package is checked for compatibility between the two inputs.
+
+Usage: merge_target_files [args]
+
+  --framework-target-files framework-target-files-zip-archive
+      The input target files package containing framework bits. This is a zip
+      archive.
+
+  --framework-item-list framework-item-list-file
+      The optional path to a newline-separated config file that replaces the
+      contents of DEFAULT_FRAMEWORK_ITEM_LIST if provided.
+
+  --framework-misc-info-keys framework-misc-info-keys-file
+      The optional path to a newline-separated config file that replaces the
+      contents of DEFAULT_FRAMEWORK_MISC_INFO_KEYS if provided.
+
+  --vendor-target-files vendor-target-files-zip-archive
+      The input target files package containing vendor bits. This is a zip
+      archive.
+
+  --vendor-item-list vendor-item-list-file
+      The optional path to a newline-separated config file that replaces the
+      contents of DEFAULT_VENDOR_ITEM_LIST if provided.
+
+  --output-target-files output-target-files-package
+      If provided, the output merged target files package. Also a zip archive.
+
+  --output-dir output-directory
+      If provided, the destination directory for saving merged files. Requires
+      the --output-item-list flag.
+      Can be provided alongside --output-target-files, or by itself.
+
+  --output-item-list output-item-list-file.
+      The optional path to a newline-separated config file that specifies the
+      file patterns to copy into the --output-dir. Required if providing
+      the --output-dir flag.
+
+  --output-ota output-ota-package
+      The output ota package. This is a zip archive. Use of this flag may
+      require passing the --path common flag; see common.py.
+
+  --output-img output-img-package
+      The output img package, suitable for use with 'fastboot update'. Use of
+      this flag may require passing the --path common flag; see common.py.
+
+  --output-super-empty output-super-empty-image
+      If provided, creates a super_empty.img file from the merged target
+      files package and saves it at this path.
+
+  --rebuild_recovery
+      Copy the recovery image used by non-A/B devices, used when
+      regenerating vendor images with --rebuild-sepolicy.
+
+  --allow-duplicate-apkapex-keys
+      If provided, duplicate APK/APEX keys are ignored and the value from the
+      framework is used.
+
+  --rebuild-sepolicy
+      If provided, rebuilds odm.img or vendor.img to include merged sepolicy
+      files. If odm is present then odm is preferred.
+
+  --vendor-otatools otatools.zip
+      If provided, use this otatools.zip when recompiling the odm or vendor
+      image to include sepolicy.
+
+  --keep-tmp
+      Keep tempoary files for debugging purposes.
+
+  The following only apply when using the VSDK to perform dexopt on vendor apps:
+
+  --framework-dexpreopt-config
+      If provided, the location of framwework's dexpreopt_config.zip.
+
+  --framework-dexpreopt-tools
+      if provided, the location of framework's dexpreopt_tools.zip.
+
+  --vendor-dexpreopt-config
+      If provided, the location of vendor's dexpreopt_config.zip.
+"""
+
+import fnmatch
+import glob
+import json
+import logging
+import os
+import re
+import shutil
+import subprocess
+import sys
+import zipfile
+from xml.etree import ElementTree
+
+import add_img_to_target_files
+import apex_utils
+import build_image
+import build_super_image
+import check_target_files_vintf
+import common
+import img_from_target_files
+import find_shareduid_violation
+import ota_from_target_files
+import sparse_img
+import verity_utils
+
+from common import ExternalError
+
+logger = logging.getLogger(__name__)
+
+OPTIONS = common.OPTIONS
+# Always turn on verbose logging.
+OPTIONS.verbose = True
+OPTIONS.framework_target_files = None
+OPTIONS.framework_item_list = None
+OPTIONS.framework_misc_info_keys = None
+OPTIONS.vendor_target_files = None
+OPTIONS.vendor_item_list = None
+OPTIONS.output_target_files = None
+OPTIONS.output_dir = None
+OPTIONS.output_item_list = None
+OPTIONS.output_ota = None
+OPTIONS.output_img = None
+OPTIONS.output_super_empty = None
+OPTIONS.rebuild_recovery = False
+# TODO(b/150582573): Remove this option.
+OPTIONS.allow_duplicate_apkapex_keys = False
+OPTIONS.vendor_otatools = None
+OPTIONS.rebuild_sepolicy = False
+OPTIONS.keep_tmp = False
+OPTIONS.framework_dexpreopt_config = None
+OPTIONS.framework_dexpreopt_tools = None
+OPTIONS.vendor_dexpreopt_config = None
+
+# In an item list (framework or vendor), we may see entries that select whole
+# partitions. Such an entry might look like this 'SYSTEM/*' (e.g., for the
+# system partition). The following regex matches this and extracts the
+# partition name.
+
+PARTITION_ITEM_PATTERN = re.compile(r'^([A-Z_]+)/\*$')
+
+# In apexkeys.txt or apkcerts.txt, we will find partition tags on each entry in
+# the file. We use these partition tags to filter the entries in those files
+# from the two different target files packages to produce a merged apexkeys.txt
+# or apkcerts.txt file. A partition tag (e.g., for the product partition) looks
+# like this: 'partition="product"'. We use the group syntax grab the value of
+# the tag. We use non-greedy matching in case there are other fields on the
+# same line.
+
+PARTITION_TAG_PATTERN = re.compile(r'partition="(.*?)"')
+
+# The sorting algorithm for apexkeys.txt and apkcerts.txt does not include the
+# ".apex" or ".apk" suffix, so we use the following pattern to extract a key.
+
+MODULE_KEY_PATTERN = re.compile(r'name="(.+)\.(apex|apk)"')
+
+# DEFAULT_FRAMEWORK_ITEM_LIST is a list of items to extract from the partial
+# framework target files package as is, meaning these items will land in the
+# output target files package exactly as they appear in the input partial
+# framework target files package.
+
+DEFAULT_FRAMEWORK_ITEM_LIST = (
+    'META/apkcerts.txt',
+    'META/filesystem_config.txt',
+    'META/root_filesystem_config.txt',
+    'META/update_engine_config.txt',
+    'PRODUCT/*',
+    'ROOT/*',
+    'SYSTEM/*',
+)
+
+# DEFAULT_FRAMEWORK_MISC_INFO_KEYS is a list of keys to obtain from the
+# framework instance of META/misc_info.txt. The remaining keys should come
+# from the vendor instance.
+
+DEFAULT_FRAMEWORK_MISC_INFO_KEYS = (
+    'avb_system_hashtree_enable',
+    'avb_system_add_hashtree_footer_args',
+    'avb_system_key_path',
+    'avb_system_algorithm',
+    'avb_system_rollback_index_location',
+    'avb_product_hashtree_enable',
+    'avb_product_add_hashtree_footer_args',
+    'avb_system_ext_hashtree_enable',
+    'avb_system_ext_add_hashtree_footer_args',
+    'system_root_image',
+    'root_dir',
+    'ab_update',
+    'default_system_dev_certificate',
+    'system_size',
+    'building_system_image',
+    'building_system_ext_image',
+    'building_product_image',
+)
+
+# DEFAULT_VENDOR_ITEM_LIST is a list of items to extract from the partial
+# vendor target files package as is, meaning these items will land in the output
+# target files package exactly as they appear in the input partial vendor target
+# files package.
+
+DEFAULT_VENDOR_ITEM_LIST = (
+    'META/boot_filesystem_config.txt',
+    'META/otakeys.txt',
+    'META/releasetools.py',
+    'META/vendor_filesystem_config.txt',
+    'BOOT/*',
+    'DATA/*',
+    'ODM/*',
+    'OTA/android-info.txt',
+    'PREBUILT_IMAGES/*',
+    'RADIO/*',
+    'VENDOR/*',
+)
+
+# The merge config lists should not attempt to extract items from both
+# builds for any of the following partitions. The partitions in
+# SINGLE_BUILD_PARTITIONS should come entirely from a single build (either
+# framework or vendor, but not both).
+
+SINGLE_BUILD_PARTITIONS = (
+    'BOOT/',
+    'DATA/',
+    'ODM/',
+    'PRODUCT/',
+    'SYSTEM_EXT/',
+    'RADIO/',
+    'RECOVERY/',
+    'ROOT/',
+    'SYSTEM/',
+    'SYSTEM_OTHER/',
+    'VENDOR/',
+    'VENDOR_DLKM/',
+    'ODM_DLKM/',
+    'SYSTEM_DLKM/',
+)
+
+
+def write_sorted_data(data, path):
+  """Writes the sorted contents of either a list or dict to file.
+
+  This function sorts the contents of the list or dict and then writes the
+  resulting sorted contents to a file specified by path.
+
+  Args:
+    data: The list or dict to sort and write.
+    path: Path to the file to write the sorted values to. The file at path will
+      be overridden if it exists.
+  """
+  with open(path, 'w') as output:
+    for entry in sorted(data):
+      out_str = '{}={}\n'.format(entry, data[entry]) if isinstance(
+          data, dict) else '{}\n'.format(entry)
+      output.write(out_str)
+
+
+def extract_items(input_zip, output_dir, extract_item_list):
+  """Extracts items in extra_item_list from a zip to a dir."""
+
+  logger.info('extracting from %s', input_zip)
+
+  # Filter the extract_item_list to remove any items that do not exist in the
+  # zip file. Otherwise, the extraction step will fail.
+
+  with zipfile.ZipFile(input_zip, allowZip64=True) as input_zipfile:
+    input_namelist = input_zipfile.namelist()
+
+  filtered_extract_item_list = []
+  for pattern in extract_item_list:
+    matching_namelist = fnmatch.filter(input_namelist, pattern)
+    if not matching_namelist:
+      logger.warning('no match for %s', pattern)
+    else:
+      filtered_extract_item_list.append(pattern)
+
+  common.UnzipToDir(input_zip, output_dir, filtered_extract_item_list)
+
+
+def copy_items(from_dir, to_dir, patterns):
+  """Similar to extract_items() except uses an input dir instead of zip."""
+  file_paths = []
+  for dirpath, _, filenames in os.walk(from_dir):
+    file_paths.extend(
+        os.path.relpath(path=os.path.join(dirpath, filename), start=from_dir)
+        for filename in filenames)
+
+  filtered_file_paths = set()
+  for pattern in patterns:
+    filtered_file_paths.update(fnmatch.filter(file_paths, pattern))
+
+  for file_path in filtered_file_paths:
+    original_file_path = os.path.join(from_dir, file_path)
+    copied_file_path = os.path.join(to_dir, file_path)
+    copied_file_dir = os.path.dirname(copied_file_path)
+    if not os.path.exists(copied_file_dir):
+      os.makedirs(copied_file_dir)
+    if os.path.islink(original_file_path):
+      os.symlink(os.readlink(original_file_path), copied_file_path)
+    else:
+      shutil.copyfile(original_file_path, copied_file_path)
+
+
+def validate_config_lists():
+  """Performs validations on the merge config lists.
+
+  Returns:
+    False if a validation fails, otherwise true.
+  """
+  has_error = False
+
+  default_combined_item_set = set(DEFAULT_FRAMEWORK_ITEM_LIST)
+  default_combined_item_set.update(DEFAULT_VENDOR_ITEM_LIST)
+
+  combined_item_set = set(OPTIONS.framework_item_list)
+  combined_item_set.update(OPTIONS.vendor_item_list)
+
+  # Check that the merge config lists are not missing any item specified
+  # by the default config lists.
+  difference = default_combined_item_set.difference(combined_item_set)
+  if difference:
+    logger.error('Missing merge config items: %s', list(difference))
+    logger.error('Please ensure missing items are in either the '
+                 'framework-item-list or vendor-item-list files provided to '
+                 'this script.')
+    has_error = True
+
+  # Check that partitions only come from one input.
+  for partition in SINGLE_BUILD_PARTITIONS:
+    image_path = 'IMAGES/{}.img'.format(partition.lower().replace('/', ''))
+    in_framework = (
+        any(item.startswith(partition) for item in OPTIONS.framework_item_list)
+        or image_path in OPTIONS.framework_item_list)
+    in_vendor = (
+        any(item.startswith(partition) for item in OPTIONS.vendor_item_list) or
+        image_path in OPTIONS.vendor_item_list)
+    if in_framework and in_vendor:
+      logger.error(
+          'Cannot extract items from %s for both the framework and vendor'
+          ' builds. Please ensure only one merge config item list'
+          ' includes %s.', partition, partition)
+      has_error = True
+
+  if ('dynamic_partition_list' in OPTIONS.framework_misc_info_keys) or (
+      'super_partition_groups' in OPTIONS.framework_misc_info_keys):
+    logger.error('Dynamic partition misc info keys should come from '
+                 'the vendor instance of META/misc_info.txt.')
+    has_error = True
+
+  return not has_error
+
+
+def merge_ab_partitions_txt(framework_meta_dir, vendor_meta_dir,
+                            merged_meta_dir):
+  """Merges META/ab_partitions.txt.
+
+  The output contains the union of the partition names.
+  """
+  with open(os.path.join(framework_meta_dir, 'ab_partitions.txt')) as f:
+    framework_ab_partitions = f.read().splitlines()
+
+  with open(os.path.join(vendor_meta_dir, 'ab_partitions.txt')) as f:
+    vendor_ab_partitions = f.read().splitlines()
+
+  write_sorted_data(
+      data=set(framework_ab_partitions + vendor_ab_partitions),
+      path=os.path.join(merged_meta_dir, 'ab_partitions.txt'))
+
+
+def merge_misc_info_txt(framework_meta_dir, vendor_meta_dir, merged_meta_dir):
+  """Merges META/misc_info.txt.
+
+  The output contains a combination of key=value pairs from both inputs.
+  Most pairs are taken from the vendor input, while some are taken from
+  the framework input.
+  """
+
+  OPTIONS.framework_misc_info = common.LoadDictionaryFromFile(
+      os.path.join(framework_meta_dir, 'misc_info.txt'))
+  OPTIONS.vendor_misc_info = common.LoadDictionaryFromFile(
+      os.path.join(vendor_meta_dir, 'misc_info.txt'))
+
+  # Merged misc info is a combination of vendor misc info plus certain values
+  # from the framework misc info.
+
+  merged_dict = OPTIONS.vendor_misc_info
+  for key in OPTIONS.framework_misc_info_keys:
+    merged_dict[key] = OPTIONS.framework_misc_info[key]
+
+  # If AVB is enabled then ensure that we build vbmeta.img.
+  # Partial builds with AVB enabled may set PRODUCT_BUILD_VBMETA_IMAGE=false to
+  # skip building an incomplete vbmeta.img.
+  if merged_dict.get('avb_enable') == 'true':
+    merged_dict['avb_building_vbmeta_image'] = 'true'
+
+  return merged_dict
+
+
+def merge_dynamic_partitions_info_txt(framework_meta_dir, vendor_meta_dir,
+                                      merged_meta_dir):
+  """Merge META/dynamic_partitions_info.txt."""
+  framework_dynamic_partitions_dict = common.LoadDictionaryFromFile(
+      os.path.join(framework_meta_dir, 'dynamic_partitions_info.txt'))
+  vendor_dynamic_partitions_dict = common.LoadDictionaryFromFile(
+      os.path.join(vendor_meta_dir, 'dynamic_partitions_info.txt'))
+
+  merged_dynamic_partitions_dict = common.MergeDynamicPartitionInfoDicts(
+      framework_dict=framework_dynamic_partitions_dict,
+      vendor_dict=vendor_dynamic_partitions_dict)
+
+  write_sorted_data(
+      data=merged_dynamic_partitions_dict,
+      path=os.path.join(merged_meta_dir, 'dynamic_partitions_info.txt'))
+
+  # Merge misc info keys used for Dynamic Partitions.
+  OPTIONS.merged_misc_info.update(merged_dynamic_partitions_dict)
+  # Ensure that add_img_to_target_files rebuilds super split images for
+  # devices that retrofit dynamic partitions. This flag may have been set to
+  # false in the partial builds to prevent duplicate building of super.img.
+  OPTIONS.merged_misc_info['build_super_partition'] = 'true'
+
+
+def item_list_to_partition_set(item_list):
+  """Converts a target files item list to a partition set.
+
+  The item list contains items that might look like 'SYSTEM/*' or 'VENDOR/*' or
+  'OTA/android-info.txt'. Items that end in '/*' are assumed to match entire
+  directories where 'SYSTEM' or 'VENDOR' is a directory name that identifies the
+  contents of a partition of the same name. Other items in the list, such as the
+  'OTA' example contain metadata. This function iterates such a list, returning
+  a set that contains the partition entries.
+
+  Args:
+    item_list: A list of items in a target files package.
+
+  Returns:
+    A set of partitions extracted from the list of items.
+  """
+
+  partition_set = set()
+
+  for item in item_list:
+    match = PARTITION_ITEM_PATTERN.search(item.strip())
+    partition_tag = match.group(1).lower() if match else None
+
+    if partition_tag:
+      partition_set.add(partition_tag)
+
+  return partition_set
+
+
+def merge_package_keys_txt(framework_meta_dir, vendor_meta_dir, merged_meta_dir,
+                           file_name):
+  """Merges APK/APEX key list files."""
+
+  if file_name not in ('apkcerts.txt', 'apexkeys.txt'):
+    raise ExternalError(
+        'Unexpected file_name provided to merge_package_keys_txt: %s',
+        file_name)
+
+  def read_helper(d):
+    temp = {}
+    with open(os.path.join(d, file_name)) as f:
+      for line in f.read().splitlines():
+        line = line.strip()
+        if line:
+          name_search = MODULE_KEY_PATTERN.search(line.split()[0])
+          temp[name_search.group(1)] = line
+    return temp
+
+  framework_dict = read_helper(framework_meta_dir)
+  vendor_dict = read_helper(vendor_meta_dir)
+  merged_dict = {}
+
+  def filter_into_merged_dict(item_dict, partition_set):
+    for key, value in item_dict.items():
+      tag_search = PARTITION_TAG_PATTERN.search(value)
+
+      if tag_search is None:
+        raise ValueError('Entry missing partition tag: %s' % value)
+
+      partition_tag = tag_search.group(1)
+
+      if partition_tag in partition_set:
+        if key in merged_dict:
+          if OPTIONS.allow_duplicate_apkapex_keys:
+            # TODO(b/150582573) Always raise on duplicates.
+            logger.warning('Duplicate key %s' % key)
+            continue
+          else:
+            raise ValueError('Duplicate key %s' % key)
+
+        merged_dict[key] = value
+
+  # Prioritize framework keys first.
+  # Duplicate keys from vendor are an error, or ignored.
+  filter_into_merged_dict(framework_dict, OPTIONS.framework_partition_set)
+  filter_into_merged_dict(vendor_dict, OPTIONS.vendor_partition_set)
+
+  # The following code is similar to write_sorted_data, but different enough
+  # that we couldn't use that function. We need the output to be sorted by the
+  # basename of the apex/apk (without the ".apex" or ".apk" suffix). This
+  # allows the sort to be consistent with the framework/vendor input data and
+  # eases comparison of input data with merged data.
+  with open(os.path.join(merged_meta_dir, file_name), 'w') as output:
+    for key, value in sorted(merged_dict.items()):
+      output.write(value + '\n')
+
+
+def create_file_contexts_copies(framework_meta_dir, vendor_meta_dir,
+                                merged_meta_dir):
+  """Creates named copies of each partial build's file_contexts.bin.
+
+  Used when regenerating images from the partial build.
+  """
+
+  def copy_fc_file(source_dir, file_name):
+    for name in (file_name, 'file_contexts.bin'):
+      fc_path = os.path.join(source_dir, name)
+      if os.path.exists(fc_path):
+        shutil.copyfile(fc_path, os.path.join(merged_meta_dir, file_name))
+        return
+    raise ValueError('Missing file_contexts file from %s: %s', source_dir,
+                     file_name)
+
+  copy_fc_file(framework_meta_dir, 'framework_file_contexts.bin')
+  copy_fc_file(vendor_meta_dir, 'vendor_file_contexts.bin')
+
+  # Replace <image>_selinux_fc values with framework or vendor file_contexts.bin
+  # depending on which dictionary the key came from.
+  # Only the file basename is required because all selinux_fc properties are
+  # replaced with the full path to the file under META/ when misc_info.txt is
+  # loaded from target files for repacking. See common.py LoadInfoDict().
+  for key in OPTIONS.vendor_misc_info:
+    if key.endswith('_selinux_fc'):
+      OPTIONS.merged_misc_info[key] = 'vendor_file_contexts.bin'
+  for key in OPTIONS.framework_misc_info:
+    if key.endswith('_selinux_fc'):
+      OPTIONS.merged_misc_info[key] = 'framework_file_contexts.bin'
+
+
+def compile_split_sepolicy(target_files_dir, partition_map):
+  """Uses secilc to compile a split sepolicy file.
+
+  Depends on various */etc/selinux/* and */etc/vintf/* files within partitions.
+
+  Args:
+    target_files_dir: Extracted directory of target_files, containing partition
+      directories.
+    partition_map: A map of partition name -> relative path within
+      target_files_dir.
+
+  Returns:
+    A command list that can be executed to create the compiled sepolicy.
+  """
+
+  def get_file(partition, path):
+    if partition not in partition_map:
+      logger.warning('Cannot load SEPolicy files for missing partition %s',
+                     partition)
+      return None
+    return os.path.join(target_files_dir, partition_map[partition], path)
+
+  # Load the kernel sepolicy version from the FCM. This is normally provided
+  # directly to selinux.cpp as a build flag, but is also available in this file.
+  fcm_file = get_file('system', 'etc/vintf/compatibility_matrix.device.xml')
+  if not fcm_file or not os.path.exists(fcm_file):
+    raise ExternalError('Missing required file for loading sepolicy: %s', fcm)
+  kernel_sepolicy_version = ElementTree.parse(fcm_file).getroot().find(
+      'sepolicy/kernel-sepolicy-version').text
+
+  # Load the vendor's plat sepolicy version. This is the version used for
+  # locating sepolicy mapping files.
+  vendor_plat_version_file = get_file('vendor',
+                                      'etc/selinux/plat_sepolicy_vers.txt')
+  if not vendor_plat_version_file or not os.path.exists(
+      vendor_plat_version_file):
+    raise ExternalError('Missing required sepolicy file %s',
+                        vendor_plat_version_file)
+  with open(vendor_plat_version_file) as f:
+    vendor_plat_version = f.read().strip()
+
+  # Use the same flags and arguments as selinux.cpp OpenSplitPolicy().
+  cmd = ['secilc', '-m', '-M', 'true', '-G', '-N']
+  cmd.extend(['-c', kernel_sepolicy_version])
+  cmd.extend(['-o', os.path.join(target_files_dir, 'META/combined_sepolicy')])
+  cmd.extend(['-f', '/dev/null'])
+
+  required_policy_files = (
+      ('system', 'etc/selinux/plat_sepolicy.cil'),
+      ('system', 'etc/selinux/mapping/%s.cil' % vendor_plat_version),
+      ('vendor', 'etc/selinux/vendor_sepolicy.cil'),
+      ('vendor', 'etc/selinux/plat_pub_versioned.cil'),
+  )
+  for policy in (map(lambda partition_and_path: get_file(*partition_and_path),
+                     required_policy_files)):
+    if not policy or not os.path.exists(policy):
+      raise ExternalError('Missing required sepolicy file %s', policy)
+    cmd.append(policy)
+
+  optional_policy_files = (
+      ('system', 'etc/selinux/mapping/%s.compat.cil' % vendor_plat_version),
+      ('system_ext', 'etc/selinux/system_ext_sepolicy.cil'),
+      ('system_ext', 'etc/selinux/mapping/%s.cil' % vendor_plat_version),
+      ('product', 'etc/selinux/product_sepolicy.cil'),
+      ('product', 'etc/selinux/mapping/%s.cil' % vendor_plat_version),
+      ('odm', 'etc/selinux/odm_sepolicy.cil'),
+  )
+  for policy in (map(lambda partition_and_path: get_file(*partition_and_path),
+                     optional_policy_files)):
+    if policy and os.path.exists(policy):
+      cmd.append(policy)
+
+  return cmd
+
+
+def validate_merged_apex_info(target_files_dir, partitions):
+  """Validates the APEX files in the merged target files directory.
+
+  Checks the APEX files in all possible preinstalled APEX directories.
+  Depends on the <partition>/apex/* APEX files within partitions.
+
+  Args:
+    target_files_dir: Extracted directory of target_files, containing partition
+      directories.
+    partitions: A list of all the partitions in the output directory.
+
+  Raises:
+    RuntimeError: if apex_utils fails to parse any APEX file.
+    ExternalError: if the same APEX package is provided by multiple partitions.
+  """
+  apex_packages = set()
+
+  apex_partitions = ('system', 'system_ext', 'product', 'vendor', 'odm')
+  for partition in filter(lambda p: p in apex_partitions, partitions):
+    apex_info = apex_utils.GetApexInfoFromTargetFiles(
+        target_files_dir, partition, compressed_only=False)
+    partition_apex_packages = set([info.package_name for info in apex_info])
+    duplicates = apex_packages.intersection(partition_apex_packages)
+    if duplicates:
+      raise ExternalError(
+          'Duplicate APEX packages found in multiple partitions: %s' %
+          ' '.join(duplicates))
+    apex_packages.update(partition_apex_packages)
+
+
+def update_care_map_image_size_props(images_dir):
+  """Sets <partition>_image_size props in misc_info.
+
+  add_images_to_target_files uses these props to generate META/care_map.pb.
+  Regenerated images will have this property set during regeneration.
+
+  However, images copied directly from input partial target files packages
+  need this value calculated here.
+  """
+  for partition in common.PARTITIONS_WITH_CARE_MAP:
+    image_path = os.path.join(images_dir, '{}.img'.format(partition))
+    if os.path.exists(image_path):
+      partition_size = sparse_img.GetImagePartitionSize(image_path)
+      image_props = build_image.ImagePropFromGlobalDict(
+          OPTIONS.merged_misc_info, partition)
+      verity_image_builder = verity_utils.CreateVerityImageBuilder(image_props)
+      image_size = verity_image_builder.CalculateMaxImageSize(partition_size)
+      OPTIONS.merged_misc_info['{}_image_size'.format(partition)] = image_size
+
+
+def merge_meta_files(temp_dir, merged_dir):
+  """Merges various files in META/*."""
+
+  framework_meta_dir = os.path.join(temp_dir, 'framework_meta', 'META')
+  extract_items(
+      input_zip=OPTIONS.framework_target_files,
+      output_dir=os.path.dirname(framework_meta_dir),
+      extract_item_list=('META/*',))
+
+  vendor_meta_dir = os.path.join(temp_dir, 'vendor_meta', 'META')
+  extract_items(
+      input_zip=OPTIONS.vendor_target_files,
+      output_dir=os.path.dirname(vendor_meta_dir),
+      extract_item_list=('META/*',))
+
+  merged_meta_dir = os.path.join(merged_dir, 'META')
+
+  # Merge META/misc_info.txt into OPTIONS.merged_misc_info,
+  # but do not write it yet. The following functions may further
+  # modify this dict.
+  OPTIONS.merged_misc_info = merge_misc_info_txt(
+      framework_meta_dir=framework_meta_dir,
+      vendor_meta_dir=vendor_meta_dir,
+      merged_meta_dir=merged_meta_dir)
+
+  create_file_contexts_copies(
+      framework_meta_dir=framework_meta_dir,
+      vendor_meta_dir=vendor_meta_dir,
+      merged_meta_dir=merged_meta_dir)
+
+  if OPTIONS.merged_misc_info.get('use_dynamic_partitions') == 'true':
+    merge_dynamic_partitions_info_txt(
+        framework_meta_dir=framework_meta_dir,
+        vendor_meta_dir=vendor_meta_dir,
+        merged_meta_dir=merged_meta_dir)
+
+  if OPTIONS.merged_misc_info.get('ab_update') == 'true':
+    merge_ab_partitions_txt(
+        framework_meta_dir=framework_meta_dir,
+        vendor_meta_dir=vendor_meta_dir,
+        merged_meta_dir=merged_meta_dir)
+    update_care_map_image_size_props(images_dir=os.path.join(merged_dir, 'IMAGES'))
+
+  for file_name in ('apkcerts.txt', 'apexkeys.txt'):
+    merge_package_keys_txt(
+        framework_meta_dir=framework_meta_dir,
+        vendor_meta_dir=vendor_meta_dir,
+        merged_meta_dir=merged_meta_dir,
+        file_name=file_name)
+
+  # Write the now-finalized OPTIONS.merged_misc_info.
+  write_sorted_data(
+      data=OPTIONS.merged_misc_info,
+      path=os.path.join(merged_meta_dir, 'misc_info.txt'))
+
+
+def process_dexopt(temp_dir, output_target_files_dir):
+  """If needed, generates dexopt files for vendor apps.
+
+  Args:
+    temp_dir: Location containing an 'output' directory where target files have
+      been extracted, e.g. <temp_dir>/output/SYSTEM, <temp_dir>/output/IMAGES,
+      etc.
+    output_target_files_dir: The name of a directory that will be used to create
+      the output target files package after all the special cases are processed.
+  """
+  # Load vendor and framework META/misc_info.txt.
+  if (OPTIONS.vendor_misc_info.get('building_with_vsdk') != 'true' or
+      OPTIONS.framework_dexpreopt_tools is None or
+      OPTIONS.framework_dexpreopt_config is None or
+      OPTIONS.vendor_dexpreopt_config is None):
+    return
+
+  logger.info('applying dexpreopt')
+
+  # The directory structure to apply dexpreopt is:
+  #
+  # <temp_dir>/
+  #     framework_meta/
+  #         META/
+  #     vendor_meta/
+  #         META/
+  #     output/
+  #         SYSTEM/
+  #         VENDOR/
+  #         IMAGES/
+  #         <other items extracted from system and vendor target files>
+  #     tools/
+  #         <contents of dexpreopt_tools.zip>
+  #     system_config/
+  #         <contents of system dexpreopt_config.zip>
+  #     vendor_config/
+  #         <contents of vendor dexpreopt_config.zip>
+  #     system -> output/SYSTEM
+  #     vendor -> output/VENDOR
+  #     apex -> output/SYSTEM/apex (only for flattened APEX builds)
+  #     apex/ (extracted updatable APEX)
+  #         <apex 1>/
+  #             ...
+  #         <apex 2>/
+  #             ...
+  #         ...
+  #     out/dex2oat_result/vendor/
+  #         <app>
+  #             oat/arm64/
+  #                 package.vdex
+  #                 package.odex
+  #         <priv-app>
+  #             oat/arm64/
+  #                 package.vdex
+  #                 package.odex
+  dexpreopt_tools_files_temp_dir = os.path.join(temp_dir, 'tools')
+  dexpreopt_framework_config_files_temp_dir = os.path.join(
+      temp_dir, 'system_config')
+  dexpreopt_vendor_config_files_temp_dir = os.path.join(temp_dir,
+                                                        'vendor_config')
+
+  extract_items(
+      input_zip=OPTIONS.framework_dexpreopt_tools,
+      output_dir=dexpreopt_tools_files_temp_dir,
+      extract_item_list=('*',))
+  extract_items(
+      input_zip=OPTIONS.framework_dexpreopt_config,
+      output_dir=dexpreopt_framework_config_files_temp_dir,
+      extract_item_list=('*',))
+  extract_items(
+      input_zip=OPTIONS.vendor_dexpreopt_config,
+      output_dir=dexpreopt_vendor_config_files_temp_dir,
+      extract_item_list=('*',))
+
+  os.symlink(
+      os.path.join(output_target_files_dir, 'SYSTEM'),
+      os.path.join(temp_dir, 'system'))
+  os.symlink(
+      os.path.join(output_target_files_dir, 'VENDOR'),
+      os.path.join(temp_dir, 'vendor'))
+
+  # The directory structure for flatteded APEXes is:
+  #
+  # SYSTEM
+  #     apex
+  #         <APEX name, e.g., com.android.wifi>
+  #             apex_manifest.pb
+  #             apex_pubkey
+  #             etc/
+  #             javalib/
+  #             lib/
+  #             lib64/
+  #             priv-app/
+  #
+  # The directory structure for updatable APEXes is:
+  #
+  # SYSTEM
+  #     apex
+  #         com.android.adbd.apex
+  #         com.android.appsearch.apex
+  #         com.android.art.apex
+  #         ...
+  apex_root = os.path.join(output_target_files_dir, 'SYSTEM', 'apex')
+
+  # Check for flattended versus updatable APEX.
+  if OPTIONS.framework_misc_info.get('target_flatten_apex') == 'false':
+    # Extract APEX.
+    logging.info('extracting APEX')
+
+    apex_extract_root_dir = os.path.join(temp_dir, 'apex')
+    os.makedirs(apex_extract_root_dir)
+
+    for apex in (glob.glob(os.path.join(apex_root, '*.apex')) +
+                 glob.glob(os.path.join(apex_root, '*.capex'))):
+      logging.info('  apex: %s', apex)
+      # deapexer is in the same directory as the merge_target_files binary extracted
+      # from otatools.zip.
+      apex_json_info = subprocess.check_output(['deapexer', 'info', apex])
+      logging.info('    info: %s', apex_json_info)
+      apex_info = json.loads(apex_json_info)
+      apex_name = apex_info['name']
+      logging.info('    name: %s', apex_name)
+
+      apex_extract_dir = os.path.join(apex_extract_root_dir, apex_name)
+      os.makedirs(apex_extract_dir)
+
+      # deapexer uses debugfs_static, which is part of otatools.zip.
+      command = [
+          'deapexer',
+          '--debugfs_path',
+          'debugfs_static',
+          'extract',
+          apex,
+          apex_extract_dir,
+      ]
+      logging.info('    running %s', command)
+      subprocess.check_call(command)
+  else:
+    # Flattened APEXes don't need to be extracted since they have the necessary
+    # directory structure.
+    os.symlink(os.path.join(apex_root), os.path.join(temp_dir, 'apex'))
+
+  # Modify system config to point to the tools that have been extracted.
+  # Absolute or .. paths are not allowed  by the dexpreopt_gen tool in
+  # dexpreopt_soong.config.
+  dexpreopt_framework_soon_config = os.path.join(
+      dexpreopt_framework_config_files_temp_dir, 'dexpreopt_soong.config')
+  with open(dexpreopt_framework_soon_config, 'w') as f:
+    dexpreopt_soong_config = {
+        'Profman': 'tools/profman',
+        'Dex2oat': 'tools/dex2oatd',
+        'Aapt': 'tools/aapt2',
+        'SoongZip': 'tools/soong_zip',
+        'Zip2zip': 'tools/zip2zip',
+        'ManifestCheck': 'tools/manifest_check',
+        'ConstructContext': 'tools/construct_context',
+    }
+    json.dump(dexpreopt_soong_config, f)
+
+  # TODO(b/188179859): Make *dex location configurable to vendor or system_other.
+  use_system_other_odex = False
+
+  if use_system_other_odex:
+    dex_img = 'SYSTEM_OTHER'
+  else:
+    dex_img = 'VENDOR'
+    # Open vendor_filesystem_config to append the items generated by dexopt.
+    vendor_file_system_config = open(
+        os.path.join(temp_dir, 'output', 'META',
+                     'vendor_filesystem_config.txt'), 'a')
+
+  # Dexpreopt vendor apps.
+  dexpreopt_config_suffix = '_dexpreopt.config'
+  for config in glob.glob(
+      os.path.join(dexpreopt_vendor_config_files_temp_dir,
+                   '*' + dexpreopt_config_suffix)):
+    app = os.path.basename(config)[:-len(dexpreopt_config_suffix)]
+    logging.info('dexpreopt config: %s %s', config, app)
+
+    apk_dir = 'app'
+    apk_path = os.path.join(temp_dir, 'vendor', apk_dir, app, app + '.apk')
+    if not os.path.exists(apk_path):
+      apk_dir = 'priv-app'
+      apk_path = os.path.join(temp_dir, 'vendor', apk_dir, app, app + '.apk')
+      if not os.path.exists(apk_path):
+        logging.warning(
+            'skipping dexpreopt for %s, no apk found in vendor/app '
+            'or vendor/priv-app', app)
+        continue
+
+    # Generate dexpreopting script. Note 'out_dir' is not the output directory
+    # where the script is generated, but the OUT_DIR at build time referenced
+    # in the dexpreot config files, e.g., "out/.../core-oj.jar", so the tool knows
+    # how to adjust the path.
+    command = [
+        os.path.join(dexpreopt_tools_files_temp_dir, 'dexpreopt_gen'),
+        '-global',
+        os.path.join(dexpreopt_framework_config_files_temp_dir,
+                     'dexpreopt.config'),
+        '-global_soong',
+        os.path.join(dexpreopt_framework_config_files_temp_dir,
+                     'dexpreopt_soong.config'),
+        '-module',
+        config,
+        '-dexpreopt_script',
+        'dexpreopt_app.sh',
+        '-out_dir',
+        'out',
+        '-base_path',
+        '.',
+        '--uses_target_files',
+    ]
+
+    # Run the command from temp_dir so all tool paths are its descendants.
+    logging.info('running %s', command)
+    subprocess.check_call(command, cwd=temp_dir)
+
+    # Call the generated script.
+    command = ['sh', 'dexpreopt_app.sh', apk_path]
+    logging.info('running %s', command)
+    subprocess.check_call(command, cwd=temp_dir)
+
+    # Output files are in:
+    #
+    # <temp_dir>/out/dex2oat_result/vendor/priv-app/<app>/oat/arm64/package.vdex
+    # <temp_dir>/out/dex2oat_result/vendor/priv-app/<app>/oat/arm64/package.odex
+    # <temp_dir>/out/dex2oat_result/vendor/app/<app>/oat/arm64/package.vdex
+    # <temp_dir>/out/dex2oat_result/vendor/app/<app>/oat/arm64/package.odex
+    #
+    # Copy the files to their destination. The structure of system_other is:
+    #
+    # system_other/
+    #     system-other-odex-marker
+    #     system/
+    #         app/
+    #             <app>/oat/arm64/
+    #                 <app>.odex
+    #                 <app>.vdex
+    #             ...
+    #         priv-app/
+    #             <app>/oat/arm64/
+    #                 <app>.odex
+    #                 <app>.vdex
+    #             ...
+
+    # TODO(b/188179859): Support for other architectures.
+    arch = 'arm64'
+
+    dex_destination = os.path.join(temp_dir, 'output', dex_img, apk_dir, app,
+                                   'oat', arch)
+    os.makedirs(dex_destination)
+    dex2oat_path = os.path.join(temp_dir, 'out', 'dex2oat_result', 'vendor',
+                                apk_dir, app, 'oat', arch)
+    shutil.copy(
+        os.path.join(dex2oat_path, 'package.vdex'),
+        os.path.join(dex_destination, app + '.vdex'))
+    shutil.copy(
+        os.path.join(dex2oat_path, 'package.odex'),
+        os.path.join(dex_destination, app + '.odex'))
+
+    # Append entries to vendor_file_system_config.txt, such as:
+    #
+    # vendor/app/<app>/oat 0 2000 755 selabel=u:object_r:vendor_app_file:s0 capabilities=0x0
+    # vendor/app/<app>/oat/arm64 0 2000 755 selabel=u:object_r:vendor_app_file:s0 capabilities=0x0
+    # vendor/app/<app>/oat/arm64/<app>.odex 0 0 644 selabel=u:object_r:vendor_app_file:s0 capabilities=0x0
+    # vendor/app/<app>/oat/arm64/<app>.vdex 0 0 644 selabel=u:object_r:vendor_app_file:s0 capabilities=0x0
+    if not use_system_other_odex:
+      vendor_app_prefix = 'vendor/' + apk_dir + '/' + app + '/oat'
+      selabel = 'selabel=u:object_r:vendor_app_file:s0 capabilities=0x0'
+      vendor_file_system_config.writelines([
+          vendor_app_prefix + ' 0 2000 755 ' + selabel + '\n',
+          vendor_app_prefix + '/' + arch + ' 0 2000 755 ' + selabel + '\n',
+          vendor_app_prefix + '/' + arch + '/' + app + '.odex 0 0 644 ' +
+          selabel + '\n',
+          vendor_app_prefix + '/' + arch + '/' + app + '.vdex 0 0 644 ' +
+          selabel + '\n',
+      ])
+
+  if not use_system_other_odex:
+    vendor_file_system_config.close()
+    # Delete vendor.img so that it will be regenerated.
+    # TODO(b/188179859): Rebuilding a vendor image in GRF mode (e.g., T(framework)
+    #                    and S(vendor) may require logic similar to that in
+    #                    rebuild_image_with_sepolicy.
+    vendor_img = os.path.join(output_target_files_dir, 'IMAGES', 'vendor.img')
+    if os.path.exists(vendor_img):
+      logging.info('Deleting %s', vendor_img)
+      os.remove(vendor_img)
+
+
+def create_merged_package(temp_dir):
+  """Merges two target files packages into one target files structure.
+
+  Returns:
+    Path to merged package under temp directory.
+  """
+  # Extract "as is" items from the input framework and vendor partial target
+  # files packages directly into the output temporary directory, since these items
+  # do not need special case processing.
+
+  output_target_files_temp_dir = os.path.join(temp_dir, 'output')
+  extract_items(
+      input_zip=OPTIONS.framework_target_files,
+      output_dir=output_target_files_temp_dir,
+      extract_item_list=OPTIONS.framework_item_list)
+  extract_items(
+      input_zip=OPTIONS.vendor_target_files,
+      output_dir=output_target_files_temp_dir,
+      extract_item_list=OPTIONS.vendor_item_list)
+
+  # Perform special case processing on META/* items.
+  # After this function completes successfully, all the files we need to create
+  # the output target files package are in place.
+  merge_meta_files(temp_dir=temp_dir, merged_dir=output_target_files_temp_dir)
+
+  process_dexopt(
+      temp_dir=temp_dir, output_target_files_dir=output_target_files_temp_dir)
+
+  return output_target_files_temp_dir
+
+
+def generate_missing_images(target_files_dir):
+  """Generate any missing images from target files."""
+
+  # Regenerate IMAGES in the target directory.
+
+  add_img_args = [
+      '--verbose',
+      '--add_missing',
+  ]
+  if OPTIONS.rebuild_recovery:
+    add_img_args.append('--rebuild_recovery')
+  add_img_args.append(target_files_dir)
+
+  add_img_to_target_files.main(add_img_args)
+
+
+def rebuild_image_with_sepolicy(target_files_dir):
+  """Rebuilds odm.img or vendor.img to include merged sepolicy files.
+
+  If odm is present then odm is preferred -- otherwise vendor is used.
+  """
+  partition = 'vendor'
+  if os.path.exists(os.path.join(target_files_dir, 'ODM')) or os.path.exists(
+      os.path.join(target_files_dir, 'IMAGES/odm.img')):
+    partition = 'odm'
+  partition_img = '{}.img'.format(partition)
+  partition_map = '{}.map'.format(partition)
+
+  logger.info('Recompiling %s using the merged sepolicy files.', partition_img)
+
+  # Copy the combined SEPolicy file and framework hashes to the image that is
+  # being rebuilt.
+  def copy_selinux_file(input_path, output_filename):
+    input_filename = os.path.join(target_files_dir, input_path)
+    if not os.path.exists(input_filename):
+      input_filename = input_filename.replace('SYSTEM_EXT/', 'SYSTEM/system_ext/') \
+          .replace('PRODUCT/', 'SYSTEM/product/')
+      if not os.path.exists(input_filename):
+        logger.info('Skipping copy_selinux_file for %s', input_filename)
+        return
+    shutil.copy(
+        input_filename,
+        os.path.join(target_files_dir, partition.upper(), 'etc/selinux',
+                     output_filename))
+
+  copy_selinux_file('META/combined_sepolicy', 'precompiled_sepolicy')
+  copy_selinux_file('SYSTEM/etc/selinux/plat_sepolicy_and_mapping.sha256',
+                    'precompiled_sepolicy.plat_sepolicy_and_mapping.sha256')
+  copy_selinux_file(
+      'SYSTEM_EXT/etc/selinux/system_ext_sepolicy_and_mapping.sha256',
+      'precompiled_sepolicy.system_ext_sepolicy_and_mapping.sha256')
+  copy_selinux_file('PRODUCT/etc/selinux/product_sepolicy_and_mapping.sha256',
+                    'precompiled_sepolicy.product_sepolicy_and_mapping.sha256')
+
+  if not OPTIONS.vendor_otatools:
+    # Remove the partition from the merged target-files archive. It will be
+    # rebuilt later automatically by generate_missing_images().
+    os.remove(os.path.join(target_files_dir, 'IMAGES', partition_img))
+    return
+
+  # TODO(b/192253131): Remove the need for vendor_otatools by fixing
+  # backwards-compatibility issues when compiling images across releases.
+  if not OPTIONS.vendor_target_files:
+    raise ValueError(
+        'Expected vendor_target_files if vendor_otatools is not None.')
+  logger.info(
+      '%s recompilation will be performed using the vendor otatools.zip',
+      partition_img)
+
+  # Unzip the vendor build's otatools.zip and target-files archive.
+  vendor_otatools_dir = common.MakeTempDir(
+      prefix='merge_target_files_vendor_otatools_')
+  vendor_target_files_dir = common.MakeTempDir(
+      prefix='merge_target_files_vendor_target_files_')
+  common.UnzipToDir(OPTIONS.vendor_otatools, vendor_otatools_dir)
+  common.UnzipToDir(OPTIONS.vendor_target_files, vendor_target_files_dir)
+
+  # Copy the partition contents from the merged target-files archive to the
+  # vendor target-files archive.
+  shutil.rmtree(os.path.join(vendor_target_files_dir, partition.upper()))
+  shutil.copytree(
+      os.path.join(target_files_dir, partition.upper()),
+      os.path.join(vendor_target_files_dir, partition.upper()),
+      symlinks=True)
+
+  # Delete then rebuild the partition.
+  os.remove(os.path.join(vendor_target_files_dir, 'IMAGES', partition_img))
+  rebuild_partition_command = [
+      os.path.join(vendor_otatools_dir, 'bin', 'add_img_to_target_files'),
+      '--verbose',
+      '--add_missing',
+  ]
+  if OPTIONS.rebuild_recovery:
+    rebuild_partition_command.append('--rebuild_recovery')
+  rebuild_partition_command.append(vendor_target_files_dir)
+  logger.info('Recompiling %s: %s', partition_img,
+              ' '.join(rebuild_partition_command))
+  common.RunAndCheckOutput(rebuild_partition_command, verbose=True)
+
+  # Move the newly-created image to the merged target files dir.
+  if not os.path.exists(os.path.join(target_files_dir, 'IMAGES')):
+    os.makedirs(os.path.join(target_files_dir, 'IMAGES'))
+  shutil.move(
+      os.path.join(vendor_target_files_dir, 'IMAGES', partition_img),
+      os.path.join(target_files_dir, 'IMAGES', partition_img))
+  shutil.move(
+      os.path.join(vendor_target_files_dir, 'IMAGES', partition_map),
+      os.path.join(target_files_dir, 'IMAGES', partition_map))
+
+  def copy_recovery_file(filename):
+    for subdir in ('VENDOR', 'SYSTEM/vendor'):
+      source = os.path.join(vendor_target_files_dir, subdir, filename)
+      if os.path.exists(source):
+        dest = os.path.join(target_files_dir, subdir, filename)
+        shutil.copy(source, dest)
+        return
+    logger.info('Skipping copy_recovery_file for %s, file not found', filename)
+
+  if OPTIONS.rebuild_recovery:
+    copy_recovery_file('etc/recovery.img')
+    copy_recovery_file('bin/install-recovery.sh')
+    copy_recovery_file('recovery-from-boot.p')
+
+
+def generate_super_empty_image(target_dir, output_super_empty):
+  """Generates super_empty image from target package.
+
+  Args:
+    target_dir: Path to the target file package which contains misc_info.txt for
+      detailed information for super image.
+    output_super_empty: If provided, copies a super_empty.img file from the
+      target files package to this path.
+  """
+  # Create super_empty.img using the merged misc_info.txt.
+
+  misc_info_txt = os.path.join(target_dir, 'META', 'misc_info.txt')
+
+  use_dynamic_partitions = common.LoadDictionaryFromFile(misc_info_txt).get(
+      'use_dynamic_partitions')
+
+  if use_dynamic_partitions != 'true' and output_super_empty:
+    raise ValueError(
+        'Building super_empty.img requires use_dynamic_partitions=true.')
+  elif use_dynamic_partitions == 'true':
+    super_empty_img = os.path.join(target_dir, 'IMAGES', 'super_empty.img')
+    build_super_image_args = [
+        misc_info_txt,
+        super_empty_img,
+    ]
+    build_super_image.main(build_super_image_args)
+
+    # Copy super_empty.img to the user-provided output_super_empty location.
+    if output_super_empty:
+      shutil.copyfile(super_empty_img, output_super_empty)
+
+
+def create_target_files_archive(output_zip, source_dir, temp_dir):
+  """Creates a target_files zip archive from the input source dir.
+
+  Args:
+    output_zip: The name of the zip archive target files package.
+    source_dir: The target directory contains package to be archived.
+    temp_dir: Path to temporary directory for any intermediate files.
+  """
+  output_target_files_list = os.path.join(temp_dir, 'output.list')
+  output_target_files_meta_dir = os.path.join(source_dir, 'META')
+
+  def files_from_path(target_path, extra_args=None):
+    """Gets files under the given path and return a sorted list."""
+    find_command = ['find', target_path] + (extra_args or [])
+    find_process = common.Run(
+        find_command, stdout=subprocess.PIPE, verbose=False)
+    return common.RunAndCheckOutput(['sort'],
+                                    stdin=find_process.stdout,
+                                    verbose=False)
+
+  # META content appears first in the zip. This is done by the
+  # standard build system for optimized extraction of those files,
+  # so we do the same step for merged target_files.zips here too.
+  meta_content = files_from_path(output_target_files_meta_dir)
+  other_content = files_from_path(
+      source_dir,
+      ['-path', output_target_files_meta_dir, '-prune', '-o', '-print'])
+
+  with open(output_target_files_list, 'w') as f:
+    f.write(meta_content)
+    f.write(other_content)
+
+  command = [
+      'soong_zip',
+      '-d',
+      '-o',
+      os.path.abspath(output_zip),
+      '-C',
+      source_dir,
+      '-r',
+      output_target_files_list,
+  ]
+
+  logger.info('creating %s', output_zip)
+  common.RunAndCheckOutput(command, verbose=True)
+  logger.info('finished creating %s', output_zip)
+
+
+def merge_target_files(temp_dir):
+  """Merges two target files packages together.
+
+  This function uses framework and vendor target files packages as input,
+  performs various file extractions, special case processing, and finally
+  creates a merged zip archive as output.
+
+  Args:
+    temp_dir: The name of a directory we use when we extract items from the
+      input target files packages, and also a scratch directory that we use for
+      temporary files.
+  """
+
+  logger.info('starting: merge framework %s and vendor %s into output %s',
+              OPTIONS.framework_target_files, OPTIONS.vendor_target_files,
+              OPTIONS.output_target_files)
+
+  output_target_files_temp_dir = create_merged_package(temp_dir)
+
+  if not check_target_files_vintf.CheckVintf(output_target_files_temp_dir):
+    raise RuntimeError('Incompatible VINTF metadata')
+
+  partition_map = common.PartitionMapFromTargetFiles(
+      output_target_files_temp_dir)
+
+  # Generate and check for cross-partition violations of sharedUserId
+  # values in APKs. This requires the input target-files packages to contain
+  # *.apk files.
+  shareduid_violation_modules = os.path.join(
+      output_target_files_temp_dir, 'META', 'shareduid_violation_modules.json')
+  with open(shareduid_violation_modules, 'w') as f:
+    violation = find_shareduid_violation.FindShareduidViolation(
+        output_target_files_temp_dir, partition_map)
+
+    # Write the output to a file to enable debugging.
+    f.write(violation)
+
+    # Check for violations across the input builds' partition groups.
+    shareduid_errors = common.SharedUidPartitionViolations(
+        json.loads(violation),
+        [OPTIONS.framework_partition_set, OPTIONS.vendor_partition_set])
+    if shareduid_errors:
+      for error in shareduid_errors:
+        logger.error(error)
+      raise ValueError('sharedUserId APK error. See %s' %
+                       shareduid_violation_modules)
+
+  # host_init_verifier and secilc check only the following partitions:
+  filtered_partitions = {
+      partition: path
+      for partition, path in partition_map.items()
+      if partition in ['system', 'system_ext', 'product', 'vendor', 'odm']
+  }
+
+  # Run host_init_verifier on the combined init rc files.
+  common.RunHostInitVerifier(
+      product_out=output_target_files_temp_dir,
+      partition_map=filtered_partitions)
+
+  # Check that the split sepolicy from the multiple builds can compile.
+  split_sepolicy_cmd = compile_split_sepolicy(output_target_files_temp_dir,
+                                              filtered_partitions)
+  logger.info('Compiling split sepolicy: %s', ' '.join(split_sepolicy_cmd))
+  common.RunAndCheckOutput(split_sepolicy_cmd)
+  # Include the compiled policy in an image if requested.
+  if OPTIONS.rebuild_sepolicy:
+    rebuild_image_with_sepolicy(output_target_files_temp_dir)
+
+  # Run validation checks on the pre-installed APEX files.
+  validate_merged_apex_info(output_target_files_temp_dir, partition_map.keys())
+
+  generate_missing_images(output_target_files_temp_dir)
+
+  generate_super_empty_image(output_target_files_temp_dir,
+                             OPTIONS.output_super_empty)
+
+  # Finally, create the output target files zip archive and/or copy the
+  # output items to the output target files directory.
+
+  if OPTIONS.output_dir:
+    copy_items(output_target_files_temp_dir, OPTIONS.output_dir,
+               OPTIONS.output_item_list)
+
+  if not OPTIONS.output_target_files:
+    return
+
+  create_target_files_archive(OPTIONS.output_target_files,
+                              output_target_files_temp_dir, temp_dir)
+
+  # Create the IMG package from the merged target files package.
+  if OPTIONS.output_img:
+    img_from_target_files.main(
+        [OPTIONS.output_target_files, OPTIONS.output_img])
+
+  # Create the OTA package from the merged target files package.
+
+  if OPTIONS.output_ota:
+    ota_from_target_files.main(
+        [OPTIONS.output_target_files, OPTIONS.output_ota])
+
+
+def call_func_with_temp_dir(func, keep_tmp):
+  """Manages the creation and cleanup of the temporary directory.
+
+  This function calls the given function after first creating a temporary
+  directory. It also cleans up the temporary directory.
+
+  Args:
+    func: The function to call. Should accept one parameter, the path to the
+      temporary directory.
+    keep_tmp: Keep the temporary directory after processing is complete.
+  """
+
+  # Create a temporary directory. This will serve as the parent of directories
+  # we use when we extract items from the input target files packages, and also
+  # a scratch directory that we use for temporary files.
+
+  temp_dir = common.MakeTempDir(prefix='merge_target_files_')
+
+  try:
+    func(temp_dir)
+  finally:
+    if keep_tmp:
+      logger.info('keeping %s', temp_dir)
+    else:
+      common.Cleanup()
+
+
+def main():
+  """The main function.
+
+  Process command line arguments, then call merge_target_files to
+  perform the heavy lifting.
+  """
+
+  common.InitLogging()
+
+  def option_handler(o, a):
+    if o == '--system-target-files':
+      logger.warning(
+          '--system-target-files has been renamed to --framework-target-files')
+      OPTIONS.framework_target_files = a
+    elif o == '--framework-target-files':
+      OPTIONS.framework_target_files = a
+    elif o == '--system-item-list':
+      logger.warning(
+          '--system-item-list has been renamed to --framework-item-list')
+      OPTIONS.framework_item_list = a
+    elif o == '--framework-item-list':
+      OPTIONS.framework_item_list = a
+    elif o == '--system-misc-info-keys':
+      logger.warning('--system-misc-info-keys has been renamed to '
+                     '--framework-misc-info-keys')
+      OPTIONS.framework_misc_info_keys = a
+    elif o == '--framework-misc-info-keys':
+      OPTIONS.framework_misc_info_keys = a
+    elif o == '--other-target-files':
+      logger.warning(
+          '--other-target-files has been renamed to --vendor-target-files')
+      OPTIONS.vendor_target_files = a
+    elif o == '--vendor-target-files':
+      OPTIONS.vendor_target_files = a
+    elif o == '--other-item-list':
+      logger.warning('--other-item-list has been renamed to --vendor-item-list')
+      OPTIONS.vendor_item_list = a
+    elif o == '--vendor-item-list':
+      OPTIONS.vendor_item_list = a
+    elif o == '--output-target-files':
+      OPTIONS.output_target_files = a
+    elif o == '--output-dir':
+      OPTIONS.output_dir = a
+    elif o == '--output-item-list':
+      OPTIONS.output_item_list = a
+    elif o == '--output-ota':
+      OPTIONS.output_ota = a
+    elif o == '--output-img':
+      OPTIONS.output_img = a
+    elif o == '--output-super-empty':
+      OPTIONS.output_super_empty = a
+    elif o == '--rebuild_recovery':
+      OPTIONS.rebuild_recovery = True
+    elif o == '--allow-duplicate-apkapex-keys':
+      OPTIONS.allow_duplicate_apkapex_keys = True
+    elif o == '--vendor-otatools':
+      OPTIONS.vendor_otatools = a
+    elif o == '--rebuild-sepolicy':
+      OPTIONS.rebuild_sepolicy = True
+    elif o == '--keep-tmp':
+      OPTIONS.keep_tmp = True
+    elif o == '--framework-dexpreopt-config':
+      OPTIONS.framework_dexpreopt_config = a
+    elif o == '--framework-dexpreopt-tools':
+      OPTIONS.framework_dexpreopt_tools = a
+    elif o == '--vendor-dexpreopt-config':
+      OPTIONS.vendor_dexpreopt_config = a
+    else:
+      return False
+    return True
+
+  args = common.ParseOptions(
+      sys.argv[1:],
+      __doc__,
+      extra_long_opts=[
+          'system-target-files=',
+          'framework-target-files=',
+          'system-item-list=',
+          'framework-item-list=',
+          'system-misc-info-keys=',
+          'framework-misc-info-keys=',
+          'other-target-files=',
+          'vendor-target-files=',
+          'other-item-list=',
+          'vendor-item-list=',
+          'output-target-files=',
+          'output-dir=',
+          'output-item-list=',
+          'output-ota=',
+          'output-img=',
+          'output-super-empty=',
+          'framework-dexpreopt-config=',
+          'framework-dexpreopt-tools=',
+          'vendor-dexpreopt-config=',
+          'rebuild_recovery',
+          'allow-duplicate-apkapex-keys',
+          'vendor-otatools=',
+          'rebuild-sepolicy',
+          'keep-tmp',
+      ],
+      extra_option_handler=option_handler)
+
+  # pylint: disable=too-many-boolean-expressions
+  if (args or OPTIONS.framework_target_files is None or
+      OPTIONS.vendor_target_files is None or
+      (OPTIONS.output_target_files is None and OPTIONS.output_dir is None) or
+      (OPTIONS.output_dir is not None and OPTIONS.output_item_list is None) or
+      (OPTIONS.rebuild_recovery and not OPTIONS.rebuild_sepolicy)):
+    common.Usage(__doc__)
+    sys.exit(1)
+
+  if OPTIONS.framework_item_list:
+    OPTIONS.framework_item_list = common.LoadListFromFile(
+        OPTIONS.framework_item_list)
+  else:
+    OPTIONS.framework_item_list = DEFAULT_FRAMEWORK_ITEM_LIST
+  OPTIONS.framework_partition_set = item_list_to_partition_set(
+      OPTIONS.framework_item_list)
+
+  if OPTIONS.framework_misc_info_keys:
+    OPTIONS.framework_misc_info_keys = common.LoadListFromFile(
+        OPTIONS.framework_misc_info_keys)
+  else:
+    OPTIONS.framework_misc_info_keys = DEFAULT_FRAMEWORK_MISC_INFO_KEYS
+
+  if OPTIONS.vendor_item_list:
+    OPTIONS.vendor_item_list = common.LoadListFromFile(OPTIONS.vendor_item_list)
+  else:
+    OPTIONS.vendor_item_list = DEFAULT_VENDOR_ITEM_LIST
+  OPTIONS.vendor_partition_set = item_list_to_partition_set(
+      OPTIONS.vendor_item_list)
+
+  if OPTIONS.output_item_list:
+    OPTIONS.output_item_list = common.LoadListFromFile(OPTIONS.output_item_list)
+  else:
+    OPTIONS.output_item_list = None
+
+  if not validate_config_lists():
+    sys.exit(1)
+
+  call_func_with_temp_dir(lambda temp_dir: merge_target_files(temp_dir),
+                          OPTIONS.keep_tmp)
+
+
+if __name__ == '__main__':
+  main()
diff --git a/tools/releasetools/merge/test_merge_target_files.py b/tools/releasetools/merge/test_merge_target_files.py
new file mode 100644
index 0000000..088ebee
--- /dev/null
+++ b/tools/releasetools/merge/test_merge_target_files.py
@@ -0,0 +1,288 @@
+#
+# Copyright (C) 2017 The Android Open Source Project
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+import os.path
+import shutil
+
+import common
+import merge_target_files
+import test_utils
+from merge_target_files import (
+    validate_config_lists, DEFAULT_FRAMEWORK_ITEM_LIST,
+    DEFAULT_VENDOR_ITEM_LIST, DEFAULT_FRAMEWORK_MISC_INFO_KEYS, copy_items,
+    item_list_to_partition_set, merge_package_keys_txt, compile_split_sepolicy,
+    validate_merged_apex_info)
+
+
+class MergeTargetFilesTest(test_utils.ReleaseToolsTestCase):
+
+  def setUp(self):
+    self.testdata_dir = test_utils.get_testdata_dir()
+    self.OPTIONS = merge_target_files.OPTIONS
+    self.OPTIONS.framework_item_list = DEFAULT_FRAMEWORK_ITEM_LIST
+    self.OPTIONS.framework_misc_info_keys = DEFAULT_FRAMEWORK_MISC_INFO_KEYS
+    self.OPTIONS.vendor_item_list = DEFAULT_VENDOR_ITEM_LIST
+    self.OPTIONS.framework_partition_set = set(
+        ['product', 'system', 'system_ext'])
+    self.OPTIONS.vendor_partition_set = set(['odm', 'vendor'])
+
+  def test_copy_items_CopiesItemsMatchingPatterns(self):
+
+    def createEmptyFile(path):
+      if not os.path.exists(os.path.dirname(path)):
+        os.makedirs(os.path.dirname(path))
+      open(path, 'a').close()
+      return path
+
+    def createSymLink(source, dest):
+      os.symlink(source, dest)
+      return dest
+
+    def getRelPaths(start, filepaths):
+      return set(
+          os.path.relpath(path=filepath, start=start) for filepath in filepaths)
+
+    input_dir = common.MakeTempDir()
+    output_dir = common.MakeTempDir()
+    expected_copied_items = []
+    actual_copied_items = []
+    patterns = ['*.cpp', 'subdir/*.txt']
+
+    # Create various files that we expect to get copied because they
+    # match one of the patterns.
+    expected_copied_items.extend([
+        createEmptyFile(os.path.join(input_dir, 'a.cpp')),
+        createEmptyFile(os.path.join(input_dir, 'b.cpp')),
+        createEmptyFile(os.path.join(input_dir, 'subdir', 'c.txt')),
+        createEmptyFile(os.path.join(input_dir, 'subdir', 'd.txt')),
+        createEmptyFile(
+            os.path.join(input_dir, 'subdir', 'subsubdir', 'e.txt')),
+        createSymLink('a.cpp', os.path.join(input_dir, 'a_link.cpp')),
+    ])
+    # Create some more files that we expect to not get copied.
+    createEmptyFile(os.path.join(input_dir, 'a.h'))
+    createEmptyFile(os.path.join(input_dir, 'b.h'))
+    createEmptyFile(os.path.join(input_dir, 'subdir', 'subsubdir', 'f.gif'))
+    createSymLink('a.h', os.path.join(input_dir, 'a_link.h'))
+
+    # Copy items.
+    copy_items(input_dir, output_dir, patterns)
+
+    # Assert the actual copied items match the ones we expected.
+    for dirpath, _, filenames in os.walk(output_dir):
+      actual_copied_items.extend(
+          os.path.join(dirpath, filename) for filename in filenames)
+    self.assertEqual(
+        getRelPaths(output_dir, actual_copied_items),
+        getRelPaths(input_dir, expected_copied_items))
+    self.assertEqual(
+        os.readlink(os.path.join(output_dir, 'a_link.cpp')), 'a.cpp')
+
+  def test_validate_config_lists_ReturnsFalseIfMissingDefaultItem(self):
+    self.OPTIONS.framework_item_list = list(DEFAULT_FRAMEWORK_ITEM_LIST)
+    self.OPTIONS.framework_item_list.remove('SYSTEM/*')
+    self.assertFalse(validate_config_lists())
+
+  def test_validate_config_lists_ReturnsTrueIfDefaultItemInDifferentList(self):
+    self.OPTIONS.framework_item_list = list(DEFAULT_FRAMEWORK_ITEM_LIST)
+    self.OPTIONS.framework_item_list.remove('ROOT/*')
+    self.OPTIONS.vendor_item_list = list(DEFAULT_VENDOR_ITEM_LIST)
+    self.OPTIONS.vendor_item_list.append('ROOT/*')
+    self.assertTrue(validate_config_lists())
+
+  def test_validate_config_lists_ReturnsTrueIfExtraItem(self):
+    self.OPTIONS.framework_item_list = list(DEFAULT_FRAMEWORK_ITEM_LIST)
+    self.OPTIONS.framework_item_list.append('MY_NEW_PARTITION/*')
+    self.assertTrue(validate_config_lists())
+
+  def test_validate_config_lists_ReturnsFalseIfSharedExtractedPartition(self):
+    self.OPTIONS.vendor_item_list = list(DEFAULT_VENDOR_ITEM_LIST)
+    self.OPTIONS.vendor_item_list.append('SYSTEM/my_system_file')
+    self.assertFalse(validate_config_lists())
+
+  def test_validate_config_lists_ReturnsFalseIfSharedExtractedPartitionImage(
+      self):
+    self.OPTIONS.vendor_item_list = list(DEFAULT_VENDOR_ITEM_LIST)
+    self.OPTIONS.vendor_item_list.append('IMAGES/system.img')
+    self.assertFalse(validate_config_lists())
+
+  def test_validate_config_lists_ReturnsFalseIfBadSystemMiscInfoKeys(self):
+    for bad_key in ['dynamic_partition_list', 'super_partition_groups']:
+      self.OPTIONS.framework_misc_info_keys = list(
+          DEFAULT_FRAMEWORK_MISC_INFO_KEYS)
+      self.OPTIONS.framework_misc_info_keys.append(bad_key)
+      self.assertFalse(validate_config_lists())
+
+  def test_merge_package_keys_txt_ReturnsTrueIfNoConflicts(self):
+    output_meta_dir = common.MakeTempDir()
+
+    framework_meta_dir = common.MakeTempDir()
+    os.symlink(
+        os.path.join(self.testdata_dir, 'apexkeys_framework.txt'),
+        os.path.join(framework_meta_dir, 'apexkeys.txt'))
+
+    vendor_meta_dir = common.MakeTempDir()
+    os.symlink(
+        os.path.join(self.testdata_dir, 'apexkeys_vendor.txt'),
+        os.path.join(vendor_meta_dir, 'apexkeys.txt'))
+
+    merge_package_keys_txt(framework_meta_dir, vendor_meta_dir, output_meta_dir,
+                           'apexkeys.txt')
+
+    merged_entries = []
+    merged_path = os.path.join(self.testdata_dir, 'apexkeys_merge.txt')
+
+    with open(merged_path) as f:
+      merged_entries = f.read().split('\n')
+
+    output_entries = []
+    output_path = os.path.join(output_meta_dir, 'apexkeys.txt')
+
+    with open(output_path) as f:
+      output_entries = f.read().split('\n')
+
+    return self.assertEqual(merged_entries, output_entries)
+
+  def test_process_apex_keys_apk_certs_ReturnsFalseIfConflictsPresent(self):
+    output_meta_dir = common.MakeTempDir()
+
+    framework_meta_dir = common.MakeTempDir()
+    os.symlink(
+        os.path.join(self.testdata_dir, 'apexkeys_framework.txt'),
+        os.path.join(framework_meta_dir, 'apexkeys.txt'))
+
+    conflict_meta_dir = common.MakeTempDir()
+    os.symlink(
+        os.path.join(self.testdata_dir, 'apexkeys_framework_conflict.txt'),
+        os.path.join(conflict_meta_dir, 'apexkeys.txt'))
+
+    self.assertRaises(ValueError, merge_package_keys_txt, framework_meta_dir,
+                      conflict_meta_dir, output_meta_dir, 'apexkeys.txt')
+
+  def test_process_apex_keys_apk_certs_HandlesApkCertsSyntax(self):
+    output_meta_dir = common.MakeTempDir()
+
+    framework_meta_dir = common.MakeTempDir()
+    os.symlink(
+        os.path.join(self.testdata_dir, 'apkcerts_framework.txt'),
+        os.path.join(framework_meta_dir, 'apkcerts.txt'))
+
+    vendor_meta_dir = common.MakeTempDir()
+    os.symlink(
+        os.path.join(self.testdata_dir, 'apkcerts_vendor.txt'),
+        os.path.join(vendor_meta_dir, 'apkcerts.txt'))
+
+    merge_package_keys_txt(framework_meta_dir, vendor_meta_dir, output_meta_dir,
+                           'apkcerts.txt')
+
+    merged_entries = []
+    merged_path = os.path.join(self.testdata_dir, 'apkcerts_merge.txt')
+
+    with open(merged_path) as f:
+      merged_entries = f.read().split('\n')
+
+    output_entries = []
+    output_path = os.path.join(output_meta_dir, 'apkcerts.txt')
+
+    with open(output_path) as f:
+      output_entries = f.read().split('\n')
+
+    return self.assertEqual(merged_entries, output_entries)
+
+  def test_item_list_to_partition_set(self):
+    item_list = [
+        'META/apexkeys.txt',
+        'META/apkcerts.txt',
+        'META/filesystem_config.txt',
+        'PRODUCT/*',
+        'SYSTEM/*',
+        'SYSTEM_EXT/*',
+    ]
+    partition_set = item_list_to_partition_set(item_list)
+    self.assertEqual(set(['product', 'system', 'system_ext']), partition_set)
+
+  def test_compile_split_sepolicy(self):
+    product_out_dir = common.MakeTempDir()
+
+    def write_temp_file(path, data=''):
+      full_path = os.path.join(product_out_dir, path)
+      if not os.path.exists(os.path.dirname(full_path)):
+        os.makedirs(os.path.dirname(full_path))
+      with open(full_path, 'w') as f:
+        f.write(data)
+
+    write_temp_file(
+        'system/etc/vintf/compatibility_matrix.device.xml', """
+      <compatibility-matrix>
+        <sepolicy>
+          <kernel-sepolicy-version>30</kernel-sepolicy-version>
+        </sepolicy>
+      </compatibility-matrix>""")
+    write_temp_file('vendor/etc/selinux/plat_sepolicy_vers.txt', '30.0')
+
+    write_temp_file('system/etc/selinux/plat_sepolicy.cil')
+    write_temp_file('system/etc/selinux/mapping/30.0.cil')
+    write_temp_file('product/etc/selinux/mapping/30.0.cil')
+    write_temp_file('vendor/etc/selinux/vendor_sepolicy.cil')
+    write_temp_file('vendor/etc/selinux/plat_pub_versioned.cil')
+
+    cmd = compile_split_sepolicy(product_out_dir, {
+        'system': 'system',
+        'product': 'product',
+        'vendor': 'vendor',
+    })
+    self.assertEqual(' '.join(cmd),
+                     ('secilc -m -M true -G -N -c 30 '
+                      '-o {OTP}/META/combined_sepolicy -f /dev/null '
+                      '{OTP}/system/etc/selinux/plat_sepolicy.cil '
+                      '{OTP}/system/etc/selinux/mapping/30.0.cil '
+                      '{OTP}/vendor/etc/selinux/vendor_sepolicy.cil '
+                      '{OTP}/vendor/etc/selinux/plat_pub_versioned.cil '
+                      '{OTP}/product/etc/selinux/mapping/30.0.cil').format(
+                          OTP=product_out_dir))
+
+  def _copy_apex(self, source, output_dir, partition):
+    shutil.copy(
+        source,
+        os.path.join(output_dir, partition, 'apex', os.path.basename(source)))
+
+  @test_utils.SkipIfExternalToolsUnavailable()
+  def test_validate_merged_apex_info(self):
+    output_dir = common.MakeTempDir()
+    os.makedirs(os.path.join(output_dir, 'SYSTEM/apex'))
+    os.makedirs(os.path.join(output_dir, 'VENDOR/apex'))
+
+    self._copy_apex(
+        os.path.join(self.testdata_dir, 'has_apk.apex'), output_dir, 'SYSTEM')
+    self._copy_apex(
+        os.path.join(test_utils.get_current_dir(),
+                     'com.android.apex.compressed.v1.capex'), output_dir,
+        'VENDOR')
+    validate_merged_apex_info(output_dir, ('system', 'vendor'))
+
+  @test_utils.SkipIfExternalToolsUnavailable()
+  def test_validate_merged_apex_info_RaisesOnPackageInMultiplePartitions(self):
+    output_dir = common.MakeTempDir()
+    os.makedirs(os.path.join(output_dir, 'SYSTEM/apex'))
+    os.makedirs(os.path.join(output_dir, 'VENDOR/apex'))
+
+    same_apex_package = os.path.join(self.testdata_dir, 'has_apk.apex')
+    self._copy_apex(same_apex_package, output_dir, 'SYSTEM')
+    self._copy_apex(same_apex_package, output_dir, 'VENDOR')
+    self.assertRaisesRegexp(
+        common.ExternalError,
+        'Duplicate APEX packages found in multiple partitions: com.android.wifi',
+        validate_merged_apex_info, output_dir, ('system', 'vendor'))