diff --git a/core/Makefile b/core/Makefile
index 690c9c1..ec9029b 100644
--- a/core/Makefile
+++ b/core/Makefile
@@ -1310,26 +1310,25 @@
 ifneq (true,$(TARGET_USERIMAGES_SPARSE_EXT_DISABLED))
   INTERNAL_USERIMAGES_SPARSE_EXT_FLAG := -s
 endif
-
-INTERNAL_USERIMAGES_DEPS := $(SIMG2IMG)
-INTERNAL_USERIMAGES_DEPS += $(MKEXTUSERIMG) $(MAKE_EXT4FS) $(E2FSCK) $(TUNE2FS)
-ifeq ($(TARGET_USERIMAGES_USE_F2FS),true)
-INTERNAL_USERIMAGES_DEPS += $(MKF2FSUSERIMG) $(MAKE_F2FS)
-endif
-
-ifeq ($(BOARD_AVB_ENABLE),true)
-INTERNAL_USERIMAGES_DEPS += $(AVBTOOL)
-endif
-
 ifneq (true,$(TARGET_USERIMAGES_SPARSE_SQUASHFS_DISABLED))
   INTERNAL_USERIMAGES_SPARSE_SQUASHFS_FLAG := -s
 endif
-ifneq ($(filter $(BOARD_PRODUCTIMAGE_FILE_SYSTEM_TYPE) $(BOARD_PRODUCT_SERVICESIMAGE_FILE_SYSTEM_TYPE) $(BOARD_ODMIMAGE_FILE_SYSTEM_TYPE) $(BOARD_VENDORIMAGE_FILE_SYSTEM_TYPE) $(BOARD_SYSTEMIMAGE_FILE_SYSTEM_TYPE),squashfs),)
-INTERNAL_USERIMAGES_DEPS += $(MAKE_SQUASHFS) $(MKSQUASHFSUSERIMG) $(IMG2SIMG)
+
+INTERNAL_USERIMAGES_DEPS := \
+    $(BLK_ALLOC_TO_BASE_FS) \
+    $(E2FSCK) \
+    $(MKE2FS_CONF) \
+    $(MKEXTUSERIMG) \
+    $(SIMG2IMG) \
+    $(TUNE2FS)
+
+ifeq ($(TARGET_USERIMAGES_USE_F2FS),true)
+INTERNAL_USERIMAGES_DEPS += $(MKF2FSUSERIMG)
 endif
 
-# Get a colon-separated list of search paths.
-INTERNAL_USERIMAGES_BINARY_PATHS := $(subst $(space),:,$(sort $(dir $(INTERNAL_USERIMAGES_DEPS))))
+ifneq ($(filter $(BOARD_PRODUCTIMAGE_FILE_SYSTEM_TYPE) $(BOARD_PRODUCT_SERVICESIMAGE_FILE_SYSTEM_TYPE) $(BOARD_ODMIMAGE_FILE_SYSTEM_TYPE) $(BOARD_VENDORIMAGE_FILE_SYSTEM_TYPE) $(BOARD_SYSTEMIMAGE_FILE_SYSTEM_TYPE),squashfs),)
+INTERNAL_USERIMAGES_DEPS += $(MKSQUASHFSUSERIMG)
+endif
 
 ifeq (true,$(PRODUCT_SUPPORTS_VERITY))
 INTERNAL_USERIMAGES_DEPS += $(BUILD_VERITY_METADATA) $(BUILD_VERITY_TREE) $(APPEND2SIMG) $(VERITY_SIGNER)
@@ -1338,13 +1337,16 @@
 endif
 endif
 
+ifeq ($(BOARD_AVB_ENABLE),true)
+INTERNAL_USERIMAGES_DEPS += $(AVBTOOL)
+endif
+
+# Get a colon-separated list of search paths.
+INTERNAL_USERIMAGES_BINARY_PATHS := $(subst $(space),:,$(sort $(dir $(INTERNAL_USERIMAGES_DEPS))))
+
 SELINUX_FC := $(call intermediates-dir-for,ETC,file_contexts.bin)/file_contexts.bin
 INTERNAL_USERIMAGES_DEPS += $(SELINUX_FC)
 
-INTERNAL_USERIMAGES_DEPS += $(BLK_ALLOC_TO_BASE_FS)
-
-INTERNAL_USERIMAGES_DEPS += $(MKE2FS_CONF)
-
 ifeq (true,$(PRODUCT_USE_DYNAMIC_PARTITIONS))
 
 ifeq ($(PRODUCT_SUPPORTS_VERITY),true)
@@ -3616,6 +3618,7 @@
   imgdiff \
   libconscrypt_openjdk_jni \
   lpmake \
+  lpunpack \
   make_f2fs \
   minigzip \
   mkbootfs \
@@ -4261,14 +4264,14 @@
 # $(1): output file
 # $(2): additional args
 define build-ota-package-target
-PATH=$(INTERNAL_USERIMAGES_BINARY_PATHS):$$PATH MKBOOTIMG=$(MKBOOTIMG) \
-   build/make/tools/releasetools/ota_from_target_files -v \
-   --block \
-   --extracted_input_target_files $(patsubst %.zip,%,$(BUILT_TARGET_FILES_PACKAGE)) \
-   -p $(HOST_OUT) \
-   $(if $(OEM_OTA_CONFIG), -o $(OEM_OTA_CONFIG)) \
-   $(2) \
-   $(BUILT_TARGET_FILES_PACKAGE) $(1)
+PATH=$(INTERNAL_USERIMAGES_BINARY_PATHS):$$PATH \
+    build/make/tools/releasetools/ota_from_target_files \
+    --verbose \
+    --extracted_input_target_files $(patsubst %.zip,%,$(BUILT_TARGET_FILES_PACKAGE)) \
+    --path $(HOST_OUT) \
+    $(if $(OEM_OTA_CONFIG), --oem_settings $(OEM_OTA_CONFIG)) \
+    $(2) \
+    $(BUILT_TARGET_FILES_PACKAGE) $(1)
 endef
 
 name := $(TARGET_PRODUCT)
diff --git a/core/config.mk b/core/config.mk
index 92efd34..4ce664a 100644
--- a/core/config.mk
+++ b/core/config.mk
@@ -577,16 +577,12 @@
 endif
 APICHECK := $(HOST_OUT_JAVA_LIBRARIES)/metalava$(COMMON_JAVA_PACKAGE_SUFFIX)
 FS_GET_STATS := $(HOST_OUT_EXECUTABLES)/fs_get_stats$(HOST_EXECUTABLE_SUFFIX)
-MAKE_EXT4FS := $(HOST_OUT_EXECUTABLES)/mke2fs$(HOST_EXECUTABLE_SUFFIX)
 MKEXTUSERIMG := $(HOST_OUT_EXECUTABLES)/mkuserimg_mke2fs
 MKE2FS_CONF := system/extras/ext4_utils/mke2fs.conf
 BLK_ALLOC_TO_BASE_FS := $(HOST_OUT_EXECUTABLES)/blk_alloc_to_base_fs$(HOST_EXECUTABLE_SUFFIX)
-MAKE_SQUASHFS := $(HOST_OUT_EXECUTABLES)/mksquashfs$(HOST_EXECUTABLE_SUFFIX)
 MKSQUASHFSUSERIMG := $(HOST_OUT_EXECUTABLES)/mksquashfsimage.sh
-MAKE_F2FS := $(HOST_OUT_EXECUTABLES)/make_f2fs$(HOST_EXECUTABLE_SUFFIX)
 MKF2FSUSERIMG := $(HOST_OUT_EXECUTABLES)/mkf2fsuserimg.sh
 SIMG2IMG := $(HOST_OUT_EXECUTABLES)/simg2img$(HOST_EXECUTABLE_SUFFIX)
-IMG2SIMG := $(HOST_OUT_EXECUTABLES)/img2simg$(HOST_EXECUTABLE_SUFFIX)
 E2FSCK := $(HOST_OUT_EXECUTABLES)/e2fsck$(HOST_EXECUTABLE_SUFFIX)
 MKTARBALL := build/make/tools/mktarball.sh
 TUNE2FS := $(HOST_OUT_EXECUTABLES)/tune2fs$(HOST_EXECUTABLE_SUFFIX)
diff --git a/core/main.mk b/core/main.mk
index 5cb1d34..73aa649 100644
--- a/core/main.mk
+++ b/core/main.mk
@@ -832,6 +832,9 @@
 $(call update-host-shared-libs-deps-for-suites)
 ifdef HOST_CROSS_OS
 $(call resolve-shared-libs-depes,HOST_CROSS_,,true)
+ifdef HOST_CROSS_2ND_ARCH
+$(call resolve-shared-libs-depes,HOST_CROSS_,true,true)
+endif
 endif
 
 # Pass the shared libraries dependencies to prebuilt ELF file check.
diff --git a/core/product.mk b/core/product.mk
index 838673c..9ec3257 100644
--- a/core/product.mk
+++ b/core/product.mk
@@ -541,10 +541,15 @@
 endef
 
 #
-# Strip the variables in _product_strip_var_list
+# Strip the variables in _product_var_list and a few build-system
+# internal variables, and assign the ones for the current product
+# to a shorthand that is more convenient to read from elsewhere.
 #
 define strip-product-vars
-$(foreach v,$(_product_var_list), \
+$(foreach v,\
+  $(_product_var_list) \
+    PRODUCT_ENFORCE_PACKAGES_EXIST \
+    PRODUCT_ENFORCE_PACKAGES_EXIST_WHITELIST, \
   $(eval $(v) := $(strip $(PRODUCTS.$(INTERNAL_PRODUCT).$(v)))) \
 )
 endef
diff --git a/target/product/generic.mk b/target/product/generic.mk
index 6fe4818..68130e3 100644
--- a/target/product/generic.mk
+++ b/target/product/generic.mk
@@ -25,4 +25,5 @@
 PRODUCT_DEVICE := generic
 PRODUCT_NAME := generic
 
-$(call enforce-product-packages-exist,)
+whitelist := product_manifest.xml
+$(call enforce-product-packages-exist,$(whitelist))
diff --git a/target/product/mainline_arm64.mk b/target/product/mainline_arm64.mk
index 6050924..c098c9f 100644
--- a/target/product/mainline_arm64.mk
+++ b/target/product/mainline_arm64.mk
@@ -16,7 +16,8 @@
 
 $(call inherit-product, $(SRC_TARGET_DIR)/product/core_64_bit.mk)
 $(call inherit-product, $(SRC_TARGET_DIR)/product/mainline.mk)
-$(call enforce-product-packages-exist,)
+whitelist := product_manifest.xml
+$(call enforce-product-packages-exist,$(whitelist))
 
 PRODUCT_NAME := mainline_arm64
 PRODUCT_DEVICE := mainline_arm64
diff --git a/tools/mktarball.sh b/tools/mktarball.sh
index ef0fe86..ced7e17 100755
--- a/tools/mktarball.sh
+++ b/tools/mktarball.sh
@@ -37,7 +37,7 @@
 #    echo "$f: dir: $is_dir curr: $curr_perms uid: $new_uid gid: $new_gid "\
 #         "perms: $new_perms"
     tar --no-recursion --numeric-owner --owner $new_uid \
-        --group $new_gid --mode $new_perms -p -rf ${target_tar} ${f}
+        --group $new_gid --mode $new_perms -rf ${target_tar} ${f}
 done
 
 if [ $? -eq 0 ] ; then
diff --git a/tools/releasetools/apex_utils.py b/tools/releasetools/apex_utils.py
index fb4ca76..0751125 100644
--- a/tools/releasetools/apex_utils.py
+++ b/tools/releasetools/apex_utils.py
@@ -59,9 +59,9 @@
   try:
     common.RunAndCheckOutput(cmd)
   except common.ExternalError as e:
-    raise ApexSigningError, \
+    raise ApexSigningError(
         'Failed to sign APEX payload {} with {}:\n{}'.format(
-            payload_file, payload_key_path, e), sys.exc_info()[2]
+            payload_file, payload_key_path, e))
 
   # Verify the signed payload image with specified public key.
   logger.info('Verifying %s', payload_file)
@@ -75,9 +75,9 @@
   try:
     common.RunAndCheckOutput(cmd)
   except common.ExternalError as e:
-    raise ApexSigningError, \
+    raise ApexSigningError(
         'Failed to validate payload signing for {} with {}:\n{}'.format(
-            payload_file, payload_key, e), sys.exc_info()[2]
+            payload_file, payload_key, e))
 
 
 def ParseApexPayloadInfo(payload_path):
@@ -100,9 +100,9 @@
   try:
     output = common.RunAndCheckOutput(cmd)
   except common.ExternalError as e:
-    raise ApexInfoError, \
+    raise ApexInfoError(
         'Failed to get APEX payload info for {}:\n{}'.format(
-            payload_path, e), sys.exc_info()[2]
+            payload_path, e))
 
   # Extract the Algorithm / Salt / Prop info from payload (i.e. an image signed
   # with avbtool). For example,
diff --git a/tools/releasetools/common.py b/tools/releasetools/common.py
index 7cff831..107b6f5 100644
--- a/tools/releasetools/common.py
+++ b/tools/releasetools/common.py
@@ -14,6 +14,7 @@
 
 from __future__ import print_function
 
+import base64
 import collections
 import copy
 import errno
@@ -30,7 +31,6 @@
 import re
 import shlex
 import shutil
-import string
 import subprocess
 import sys
 import tempfile
@@ -190,6 +190,8 @@
     kwargs: Any additional args to be passed to subprocess.Popen(), such as env,
         stdin, etc. stdout and stderr will default to subprocess.PIPE and
         subprocess.STDOUT respectively unless caller specifies any of them.
+        universal_newlines will default to True, as most of the users in
+        releasetools expect string output.
 
   Returns:
     A subprocess.Popen object.
@@ -197,6 +199,8 @@
   if 'stdout' not in kwargs and 'stderr' not in kwargs:
     kwargs['stdout'] = subprocess.PIPE
     kwargs['stderr'] = subprocess.STDOUT
+  if 'universal_newlines' not in kwargs:
+    kwargs['universal_newlines'] = True
   # Don't log any if caller explicitly says so.
   if verbose != False:
     logger.info("  Running: \"%s\"", " ".join(args))
@@ -314,7 +318,7 @@
 
   def read_helper(fn):
     if isinstance(input_file, zipfile.ZipFile):
-      return input_file.read(fn)
+      return input_file.read(fn).decode()
     else:
       path = os.path.join(input_file, *fn.split("/"))
       try:
@@ -526,7 +530,7 @@
   # system. Other areas assume system is always at "/system" so point /system
   # at /.
   if system_root_image:
-    assert not d.has_key("/system") and d.has_key("/")
+    assert '/system' not in d and '/' in d
     d["/system"] = d["/"]
   return d
 
@@ -953,7 +957,7 @@
     # filename listed in system.map may contain an additional leading slash
     # (i.e. "//system/framework/am.jar"). Using lstrip to get consistent
     # results.
-    arcname = string.replace(entry, which, which.upper(), 1).lstrip('/')
+    arcname = entry.replace(which, which.upper(), 1).lstrip('/')
 
     # Special handling another case, where files not under /system
     # (e.g. "/sbin/charger") are packed under ROOT/ in a target_files.zip.
@@ -1223,7 +1227,7 @@
     if basename:
       installed_files.add(basename)
 
-  for line in tf_zip.read("META/apkcerts.txt").split("\n"):
+  for line in tf_zip.read('META/apkcerts.txt').decode().split('\n'):
     line = line.strip()
     if not line:
       continue
@@ -1433,6 +1437,8 @@
 
       if not first:
         print("key file %s still missing some passwords." % (self.pwfile,))
+        if sys.version_info[0] >= 3:
+          raw_input = input  # pylint: disable=redefined-builtin
         answer = raw_input("try to edit again? [y]> ").strip()
         if answer and answer[0] not in 'yY':
           raise RuntimeError("key passwords unavailable")
@@ -2185,7 +2191,7 @@
   This gives the same result as `openssl x509 -in <filename> -outform DER`.
 
   Returns:
-    The decoded certificate string.
+    The decoded certificate bytes.
   """
   cert_buffer = []
   save = False
@@ -2196,7 +2202,7 @@
       cert_buffer.append(line)
     if "--BEGIN CERTIFICATE--" in line:
       save = True
-  cert = "".join(cert_buffer).decode('base64')
+  cert = base64.b64decode("".join(cert_buffer))
   return cert
 
 
@@ -2338,7 +2344,7 @@
 
   logger.info("putting script in %s", sh_location)
 
-  output_sink(sh_location, sh)
+  output_sink(sh_location, sh.encode())
 
 
 class DynamicPartitionUpdate(object):
diff --git a/tools/releasetools/test_common.py b/tools/releasetools/test_common.py
index 11ac9f5..914e58e 100644
--- a/tools/releasetools/test_common.py
+++ b/tools/releasetools/test_common.py
@@ -579,7 +579,7 @@
   def test_ExtractPublicKey(self):
     cert = os.path.join(self.testdata_dir, 'testkey.x509.pem')
     pubkey = os.path.join(self.testdata_dir, 'testkey.pubkey.pem')
-    with open(pubkey, 'rb') as pubkey_fp:
+    with open(pubkey) as pubkey_fp:
       self.assertEqual(pubkey_fp.read(), common.ExtractPublicKey(cert))
 
   def test_ExtractPublicKey_invalidInput(self):
@@ -590,15 +590,16 @@
   def test_ExtractAvbPublicKey(self):
     privkey = os.path.join(self.testdata_dir, 'testkey.key')
     pubkey = os.path.join(self.testdata_dir, 'testkey.pubkey.pem')
-    with open(common.ExtractAvbPublicKey(privkey)) as privkey_fp, \
-        open(common.ExtractAvbPublicKey(pubkey)) as pubkey_fp:
+    with open(common.ExtractAvbPublicKey(privkey), 'rb') as privkey_fp, \
+        open(common.ExtractAvbPublicKey(pubkey), 'rb') as pubkey_fp:
       self.assertEqual(privkey_fp.read(), pubkey_fp.read())
 
   def test_ParseCertificate(self):
     cert = os.path.join(self.testdata_dir, 'testkey.x509.pem')
 
     cmd = ['openssl', 'x509', '-in', cert, '-outform', 'DER']
-    proc = common.Run(cmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
+    proc = common.Run(cmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE,
+                      universal_newlines=False)
     expected, _ = proc.communicate()
     self.assertEqual(0, proc.returncode)
 
@@ -914,7 +915,7 @@
     target_files = common.MakeTempFile(prefix='target_files-', suffix='.zip')
     with zipfile.ZipFile(target_files, 'w') as target_files_zip:
       info_values = ''.join(
-          ['{}={}\n'.format(k, v) for k, v in sorted(info_dict.iteritems())])
+          ['{}={}\n'.format(k, v) for k, v in sorted(info_dict.items())])
       common.ZipWriteStr(target_files_zip, 'META/misc_info.txt', info_values)
 
       FSTAB_TEMPLATE = "/dev/block/system {} ext4 ro,barrier=1 defaults"
@@ -1085,7 +1086,7 @@
     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, "w+") as f:
+    with open(loc, "wb") as f:
       f.write(data)
 
   def test_full_recovery(self):
@@ -1110,7 +1111,7 @@
     validate_target_files.ValidateInstallRecoveryScript(self._tempdir,
                                                         self._info)
     # Validate 'recovery-from-boot' with bonus argument.
-    self._out_tmp_sink("etc/recovery-resource.dat", "bonus", "SYSTEM")
+    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,
@@ -1118,25 +1119,30 @@
 
 
 class MockScriptWriter(object):
-  """A class that mocks edify_generator.EdifyGenerator.
-  """
+  """A class that mocks edify_generator.EdifyGenerator."""
+
   def __init__(self, enable_comments=False):
     self.lines = []
     self.enable_comments = enable_comments
+
   def Comment(self, comment):
     if self.enable_comments:
-      self.lines.append("# {}".format(comment))
+      self.lines.append('# {}'.format(comment))
+
   def AppendExtra(self, extra):
     self.lines.append(extra)
+
   def __str__(self):
-    return "\n".join(self.lines)
+    return '\n'.join(self.lines)
 
 
 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:
@@ -1144,11 +1150,13 @@
     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
@@ -1156,12 +1164,13 @@
 
 
 class DynamicPartitionsDifferenceTest(test_utils.ReleaseToolsTestCase):
+
   @staticmethod
   def get_op_list(output_path):
     with zipfile.ZipFile(output_path) as output_zip:
-      with output_zip.open("dynamic_partitions_op_list") as op_list:
-        return [line.strip() for line in op_list.readlines()
-                if not line.startswith("#")]
+      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 = MockScriptWriter()
diff --git a/tools/releasetools/test_verity_utils.py b/tools/releasetools/test_verity_utils.py
index 1cc539f..d02bc7f 100644
--- a/tools/releasetools/test_verity_utils.py
+++ b/tools/releasetools/test_verity_utils.py
@@ -47,25 +47,22 @@
     }
 
     self.hash_algorithm = "sha256"
-    self.fixed_salt = \
-        "aee087a5be3b982978c923f566a94613496b417f2af592639bc80d141e34dfe7"
-    self.expected_root_hash = \
-        "0b7c4565e87b1026e11fbab91c0bc29e185c847a5b44d40e6e86e461e8adf80d"
+    self.fixed_salt = (
+        "aee087a5be3b982978c923f566a94613496b417f2af592639bc80d141e34dfe7")
+    self.expected_root_hash = (
+        "0b7c4565e87b1026e11fbab91c0bc29e185c847a5b44d40e6e86e461e8adf80d")
 
-  def _create_simg(self, raw_data):
+  def _CreateSimg(self, raw_data):  # pylint: disable=no-self-use
     output_file = common.MakeTempFile()
     raw_image = common.MakeTempFile()
     with open(raw_image, 'wb') as f:
       f.write(raw_data)
 
     cmd = ["img2simg", raw_image, output_file, '4096']
-    p = common.Run(cmd)
-    p.communicate()
-    self.assertEqual(0, p.returncode)
-
+    common.RunAndCheckOutput(cmd)
     return output_file
 
-  def _generate_image(self):
+  def _GenerateImage(self):
     partition_size = 1024 * 1024
     prop_dict = {
         'partition_size': str(partition_size),
@@ -79,11 +76,11 @@
     self.assertIsNotNone(verity_image_builder)
     adjusted_size = verity_image_builder.CalculateMaxImageSize()
 
-    raw_image = ""
+    raw_image = bytearray(adjusted_size)
     for i in range(adjusted_size):
-      raw_image += str(i % 10)
+      raw_image[i] = ord('0') + i % 10
 
-    output_file = self._create_simg(raw_image)
+    output_file = self._CreateSimg(raw_image)
 
     # Append the verity metadata.
     verity_image_builder.Build(output_file)
@@ -92,7 +89,7 @@
 
   @SkipIfExternalToolsUnavailable()
   def test_CreateHashtreeInfoGenerator(self):
-    image_file = sparse_img.SparseImage(self._generate_image())
+    image_file = sparse_img.SparseImage(self._GenerateImage())
 
     generator = CreateHashtreeInfoGenerator(
         'system', image_file, self.prop_dict)
@@ -103,7 +100,7 @@
 
   @SkipIfExternalToolsUnavailable()
   def test_DecomposeSparseImage(self):
-    image_file = sparse_img.SparseImage(self._generate_image())
+    image_file = sparse_img.SparseImage(self._GenerateImage())
 
     generator = VerifiedBootVersion1HashtreeInfoGenerator(
         self.partition_size, 4096, True)
@@ -114,7 +111,7 @@
 
   @SkipIfExternalToolsUnavailable()
   def test_ParseHashtreeMetadata(self):
-    image_file = sparse_img.SparseImage(self._generate_image())
+    image_file = sparse_img.SparseImage(self._GenerateImage())
     generator = VerifiedBootVersion1HashtreeInfoGenerator(
         self.partition_size, 4096, True)
     generator.DecomposeSparseImage(image_file)
@@ -131,12 +128,12 @@
   def test_ValidateHashtree_smoke(self):
     generator = VerifiedBootVersion1HashtreeInfoGenerator(
         self.partition_size, 4096, True)
-    generator.image = sparse_img.SparseImage(self._generate_image())
+    generator.image = sparse_img.SparseImage(self._GenerateImage())
 
     generator.hashtree_info = info = HashtreeInfo()
-    info.filesystem_range = RangeSet(data=[0, 991232 / 4096])
+    info.filesystem_range = RangeSet(data=[0, 991232 // 4096])
     info.hashtree_range = RangeSet(
-        data=[991232 / 4096, (991232 + 12288) / 4096])
+        data=[991232 // 4096, (991232 + 12288) // 4096])
     info.hash_algorithm = self.hash_algorithm
     info.salt = self.fixed_salt
     info.root_hash = self.expected_root_hash
@@ -147,12 +144,12 @@
   def test_ValidateHashtree_failure(self):
     generator = VerifiedBootVersion1HashtreeInfoGenerator(
         self.partition_size, 4096, True)
-    generator.image = sparse_img.SparseImage(self._generate_image())
+    generator.image = sparse_img.SparseImage(self._GenerateImage())
 
     generator.hashtree_info = info = HashtreeInfo()
-    info.filesystem_range = RangeSet(data=[0, 991232 / 4096])
+    info.filesystem_range = RangeSet(data=[0, 991232 // 4096])
     info.hashtree_range = RangeSet(
-        data=[991232 / 4096, (991232 + 12288) / 4096])
+        data=[991232 // 4096, (991232 + 12288) // 4096])
     info.hash_algorithm = self.hash_algorithm
     info.salt = self.fixed_salt
     info.root_hash = "a" + self.expected_root_hash[1:]
@@ -161,12 +158,12 @@
 
   @SkipIfExternalToolsUnavailable()
   def test_Generate(self):
-    image_file = sparse_img.SparseImage(self._generate_image())
+    image_file = sparse_img.SparseImage(self._GenerateImage())
     generator = CreateHashtreeInfoGenerator('system', 4096, self.prop_dict)
     info = generator.Generate(image_file)
 
-    self.assertEqual(RangeSet(data=[0, 991232 / 4096]), info.filesystem_range)
-    self.assertEqual(RangeSet(data=[991232 / 4096, (991232 + 12288) / 4096]),
+    self.assertEqual(RangeSet(data=[0, 991232 // 4096]), info.filesystem_range)
+    self.assertEqual(RangeSet(data=[991232 // 4096, (991232 + 12288) // 4096]),
                      info.hashtree_range)
     self.assertEqual(self.hash_algorithm, info.hash_algorithm)
     self.assertEqual(self.fixed_salt, info.salt)
diff --git a/tools/releasetools/validate_target_files.py b/tools/releasetools/validate_target_files.py
index 37d5d27..5d99c99 100755
--- a/tools/releasetools/validate_target_files.py
+++ b/tools/releasetools/validate_target_files.py
@@ -44,7 +44,7 @@
   """Constructs and returns a File object. Rounds up its size if needed."""
 
   assert os.path.exists(unpacked_name)
-  with open(unpacked_name, 'r') as f:
+  with open(unpacked_name, 'rb') as f:
     file_data = f.read()
   file_size = len(file_data)
   if round_up:
diff --git a/tools/releasetools/verity_utils.py b/tools/releasetools/verity_utils.py
index 3063800..e7f84f5 100644
--- a/tools/releasetools/verity_utils.py
+++ b/tools/releasetools/verity_utils.py
@@ -131,7 +131,8 @@
     BuildVerityImageError: On error.
   """
   try:
-    with open(target, "a") as out_file, open(file_to_append, "r") as input_file:
+    with open(target, 'ab') as out_file, \
+        open(file_to_append, 'rb') as input_file:
       for line in input_file:
         out_file.write(line)
   except IOError:
@@ -178,6 +179,8 @@
     # key_path and algorithm are only available when chain partition is used.
     key_path = prop_dict.get("avb_key_path")
     algorithm = prop_dict.get("avb_algorithm")
+
+    # Image uses hash footer.
     if prop_dict.get("avb_hash_enable") == "true":
       return VerifiedBootVersion2VerityImageBuilder(
           prop_dict["partition_name"],
@@ -188,16 +191,17 @@
           algorithm,
           prop_dict.get("avb_salt"),
           prop_dict["avb_add_hash_footer_args"])
-    else:
-      return VerifiedBootVersion2VerityImageBuilder(
-          prop_dict["partition_name"],
-          partition_size,
-          VerifiedBootVersion2VerityImageBuilder.AVB_HASHTREE_FOOTER,
-          prop_dict["avb_avbtool"],
-          key_path,
-          algorithm,
-          prop_dict.get("avb_salt"),
-          prop_dict["avb_add_hashtree_footer_args"])
+
+    # Image uses hashtree footer.
+    return VerifiedBootVersion2VerityImageBuilder(
+        prop_dict["partition_name"],
+        partition_size,
+        VerifiedBootVersion2VerityImageBuilder.AVB_HASHTREE_FOOTER,
+        prop_dict["avb_avbtool"],
+        key_path,
+        algorithm,
+        prop_dict.get("avb_salt"),
+        prop_dict["avb_add_hashtree_footer_args"])
 
   return None
 
@@ -605,19 +609,19 @@
     self.metadata_size = metadata_size
 
     self.hashtree_info.filesystem_range = RangeSet(
-        data=[0, adjusted_size / self.block_size])
+        data=[0, adjusted_size // self.block_size])
     self.hashtree_info.hashtree_range = RangeSet(
-        data=[adjusted_size / self.block_size,
-              (adjusted_size + verity_tree_size) / self.block_size])
+        data=[adjusted_size // self.block_size,
+              (adjusted_size + verity_tree_size) // self.block_size])
 
   def _ParseHashtreeMetadata(self):
     """Parses the hash_algorithm, root_hash, salt from the metadata block."""
 
     metadata_start = self.filesystem_size + self.hashtree_size
     metadata_range = RangeSet(
-        data=[metadata_start / self.block_size,
-              (metadata_start + self.metadata_size) / self.block_size])
-    meta_data = ''.join(self.image.ReadRangeSet(metadata_range))
+        data=[metadata_start // self.block_size,
+              (metadata_start + self.metadata_size) // self.block_size])
+    meta_data = b''.join(self.image.ReadRangeSet(metadata_range))
 
     # More info about the metadata structure available in:
     # system/extras/verity/build_verity_metadata.py
@@ -640,9 +644,9 @@
     assert (int(table_entries[5]) * self.block_size == self.filesystem_size and
             int(table_entries[6]) * self.block_size == self.filesystem_size)
 
-    self.hashtree_info.hash_algorithm = table_entries[7]
-    self.hashtree_info.root_hash = table_entries[8]
-    self.hashtree_info.salt = table_entries[9]
+    self.hashtree_info.hash_algorithm = table_entries[7].decode()
+    self.hashtree_info.root_hash = table_entries[8].decode()
+    self.hashtree_info.salt = table_entries[9].decode()
 
   def ValidateHashtree(self):
     """Checks that we can reconstruct the verity hash tree."""
@@ -669,8 +673,8 @@
 
     # Reads the generated hash tree and checks if it has the exact same bytes
     # as the one in the sparse image.
-    with open(generated_verity_tree, "rb") as fd:
-      return fd.read() == ''.join(self.image.ReadRangeSet(
+    with open(generated_verity_tree, 'rb') as fd:
+      return fd.read() == b''.join(self.image.ReadRangeSet(
           self.hashtree_info.hashtree_range))
 
   def Generate(self, image):
diff --git a/tools/warn.py b/tools/warn.py
index c710164..9389b7d 100755
--- a/tools/warn.py
+++ b/tools/warn.py
@@ -1,5 +1,5 @@
 #!/usr/bin/python
-# This file uses the following encoding: utf-8
+# Prefer python3 but work also with python2.
 
 """Grep warnings messages and output HTML tables or warning counts in CSV.
 
@@ -74,9 +74,11 @@
 #   escape_string, strip_escape_string, emit_warning_arrays
 #   emit_js_data():
 
+from __future__ import print_function
 import argparse
 import cgi
 import csv
+import io
 import multiprocessing
 import os
 import re
@@ -540,7 +542,7 @@
     {'category': 'java',
      'severity': Severity.LOW,
      'description':
-         'Java: Use Java\'s utility functional interfaces instead of Function\u003cA, B> for primitive types.',
+         u'Java: Use Java\'s utility functional interfaces instead of Function\u003cA, B> for primitive types.',
      'patterns': [r".*: warning: \[LambdaFunctionalInterface\] .+"]},
     {'category': 'java',
      'severity': Severity.LOW,
@@ -1270,7 +1272,7 @@
     {'category': 'java',
      'severity': Severity.MEDIUM,
      'description':
-         'Java: Prefer the short-circuiting boolean operators \u0026\u0026 and || to \u0026 and |.',
+         u'Java: Prefer the short-circuiting boolean operators \u0026\u0026 and || to \u0026 and |.',
      'patterns': [r".*: warning: \[ShortCircuitBoolean\] .+"]},
     {'category': 'java',
      'severity': Severity.MEDIUM,
@@ -1535,7 +1537,7 @@
     {'category': 'java',
      'severity': Severity.HIGH,
      'description':
-         'Java:  Implementing \'Comparable\u003cT>\' where T is not compatible with the implementing class.',
+         u'Java:  Implementing \'Comparable\u003cT>\' where T is not compatible with the implementing class.',
      'patterns': [r".*: warning: \[ComparableType\] .+"]},
     {'category': 'java',
      'severity': Severity.HIGH,
@@ -1790,7 +1792,7 @@
     {'category': 'java',
      'severity': Severity.HIGH,
      'description':
-         'Java: Path implements Iterable\u003cPath>; prefer Collection\u003cPath> for clarity',
+         u'Java: Path implements Iterable\u003cPath>; prefer Collection\u003cPath> for clarity',
      'patterns': [r".*: warning: \[IterablePathParameter\] .+"]},
     {'category': 'java',
      'severity': Severity.HIGH,
@@ -2922,17 +2924,17 @@
 
 
 def dump_html_prologue(title):
-  print '<html>\n<head>'
-  print '<title>' + title + '</title>'
-  print html_head_scripts
+  print('<html>\n<head>')
+  print('<title>' + title + '</title>')
+  print(html_head_scripts)
   emit_stats_by_project()
-  print '</head>\n<body>'
-  print html_big(title)
-  print '<p>'
+  print('</head>\n<body>')
+  print(html_big(title))
+  print('<p>')
 
 
 def dump_html_epilogue():
-  print '</body>\n</head>\n</html>'
+  print('</body>\n</head>\n</html>')
 
 
 def sort_warnings():
@@ -2943,6 +2945,7 @@
 def emit_stats_by_project():
   """Dump a google chart table of warnings per project and severity."""
   # warnings[p][s] is number of warnings in project p of severity s.
+  # pylint:disable=g-complex-comprehension
   warnings = {p: {s: 0 for s in Severity.range} for p in project_names}
   for i in warn_patterns:
     s = i['severity']
@@ -2988,11 +2991,11 @@
       total_all_severities += total_by_severity[s]
   one_row.append(total_all_projects)
   stats_rows.append(one_row)
-  print '<script>'
+  print('<script>')
   emit_const_string_array('StatsHeader', stats_header)
   emit_const_object_array('StatsRows', stats_rows)
-  print draw_table_javascript
-  print '</script>'
+  print(draw_table_javascript)
+  print('</script>')
 
 
 def dump_stats():
@@ -3008,14 +3011,14 @@
       skipped += len(i['members'])
     else:
       known += len(i['members'])
-  print 'Number of classified warnings: <b>' + str(known) + '</b><br>'
-  print 'Number of skipped warnings: <b>' + str(skipped) + '</b><br>'
-  print 'Number of unclassified warnings: <b>' + str(unknown) + '</b><br>'
+  print('Number of classified warnings: <b>' + str(known) + '</b><br>')
+  print('Number of skipped warnings: <b>' + str(skipped) + '</b><br>')
+  print('Number of unclassified warnings: <b>' + str(unknown) + '</b><br>')
   total = unknown + known + skipped
   extra_msg = ''
   if total < 1000:
     extra_msg = ' (low count may indicate incremental build)'
-  print 'Total number of warnings: <b>' + str(total) + '</b>' + extra_msg
+  print('Total number of warnings: <b>' + str(total) + '</b>' + extra_msg)
 
 
 # New base table of warnings, [severity, warn_id, project, warning_message]
@@ -3029,14 +3032,14 @@
 #     id for each warning pattern
 #     sort by project, severity, warn_id, warning_message
 def emit_buttons():
-  print ('<button class="button" onclick="expandCollapse(1);">'
-         'Expand all warnings</button>\n'
-         '<button class="button" onclick="expandCollapse(0);">'
-         'Collapse all warnings</button>\n'
-         '<button class="button" onclick="groupBySeverity();">'
-         'Group warnings by severity</button>\n'
-         '<button class="button" onclick="groupByProject();">'
-         'Group warnings by project</button><br>')
+  print('<button class="button" onclick="expandCollapse(1);">'
+        'Expand all warnings</button>\n'
+        '<button class="button" onclick="expandCollapse(0);">'
+        'Collapse all warnings</button>\n'
+        '<button class="button" onclick="groupBySeverity();">'
+        'Group warnings by severity</button>\n'
+        '<button class="button" onclick="groupByProject();">'
+        'Group warnings by project</button><br>')
 
 
 def all_patterns(category):
@@ -3051,14 +3054,14 @@
   """Show which warnings no longer occur."""
   anchor = 'fixed_warnings'
   mark = anchor + '_mark'
-  print ('\n<br><p style="background-color:lightblue"><b>'
-         '<button id="' + mark + '" '
-         'class="bt" onclick="expand(\'' + anchor + '\');">'
-         '&#x2295</button> Fixed warnings. '
-         'No more occurrences. Please consider turning these into '
-         'errors if possible, before they are reintroduced in to the build'
-         ':</b></p>')
-  print '<blockquote>'
+  print('\n<br><p style="background-color:lightblue"><b>'
+        '<button id="' + mark + '" '
+        'class="bt" onclick="expand(\'' + anchor + '\');">'
+        '&#x2295</button> Fixed warnings. '
+        'No more occurrences. Please consider turning these into '
+        'errors if possible, before they are reintroduced in to the build'
+        ':</b></p>')
+  print('<blockquote>')
   fixed_patterns = []
   for i in warn_patterns:
     if not i['members']:
@@ -3066,16 +3069,16 @@
                             all_patterns(i) + ')')
     if i['option']:
       fixed_patterns.append(' ' + i['option'])
-  fixed_patterns.sort()
-  print '<div id="' + anchor + '" style="display:none;"><table>'
+  fixed_patterns = sorted(fixed_patterns)
+  print('<div id="' + anchor + '" style="display:none;"><table>')
   cur_row_class = 0
   for text in fixed_patterns:
     cur_row_class = 1 - cur_row_class
     # remove last '\n'
     t = text[:-1] if text[-1] == '\n' else text
-    print '<tr><td class="c' + str(cur_row_class) + '">' + t + '</td></tr>'
-  print '</table></div>'
-  print '</blockquote>'
+    print('<tr><td class="c' + str(cur_row_class) + '">' + t + '</td></tr>')
+  print('</table></div>')
+  print('</blockquote>')
 
 
 def find_project_index(line):
@@ -3187,8 +3190,9 @@
 def normalize_warning_line(line):
   """Normalize file path relative to android_root in a warning line."""
   # replace fancy quotes with plain ol' quotes
-  line = line.replace('‘', "'")
-  line = line.replace('’', "'")
+  line = re.sub(u'[\u2018\u2019]', '\'', line)
+  # replace non-ASCII chars to spaces
+  line = re.sub(u'[^\x00-\x7f]', ' ', line)
   line = line.strip()
   first_column = line.find(':')
   if first_column > 0:
@@ -3246,21 +3250,22 @@
 
 
 def emit_warning_array(name):
-  print 'var warning_{} = ['.format(name)
+  print('var warning_{} = ['.format(name))
   for i in range(len(warn_patterns)):
-    print '{},'.format(warn_patterns[i][name])
-  print '];'
+    print('{},'.format(warn_patterns[i][name]))
+  print('];')
 
 
 def emit_warning_arrays():
   emit_warning_array('severity')
-  print 'var warning_description = ['
+  print('var warning_description = [')
   for i in range(len(warn_patterns)):
     if warn_patterns[i]['members']:
-      print '"{}",'.format(escape_string(warn_patterns[i]['description']))
+      print('"{}",'.format(escape_string(warn_patterns[i]['description'])))
     else:
-      print '"",'  # no such warning
-  print '];'
+      print('"",')  # no such warning
+  print('];')
+
 
 scripts_for_warning_groups = """
   function compareMessages(x1, x2) { // of the same warning type
@@ -3393,39 +3398,42 @@
 
 # Emit a JavaScript const string
 def emit_const_string(name, value):
-  print 'const ' + name + ' = "' + escape_string(value) + '";'
+  print('const ' + name + ' = "' + escape_string(value) + '";')
 
 
 # Emit a JavaScript const integer array.
 def emit_const_int_array(name, array):
-  print 'const ' + name + ' = ['
+  print('const ' + name + ' = [')
   for n in array:
-    print str(n) + ','
-  print '];'
+    print(str(n) + ',')
+  print('];')
 
 
 # Emit a JavaScript const string array.
 def emit_const_string_array(name, array):
-  print 'const ' + name + ' = ['
+  print('const ' + name + ' = [')
   for s in array:
-    print '"' + strip_escape_string(s) + '",'
-  print '];'
+    print('"' + strip_escape_string(s) + '",')
+  print('];')
 
 
 # Emit a JavaScript const string array for HTML.
 def emit_const_html_string_array(name, array):
-  print 'const ' + name + ' = ['
+  print('const ' + name + ' = [')
   for s in array:
-    print '"' + cgi.escape(strip_escape_string(s)) + '",'
-  print '];'
+    # Not using html.escape yet, to work for both python 2 and 3,
+    # until all users switch to python 3.
+    # pylint:disable=deprecated-method
+    print('"' + cgi.escape(strip_escape_string(s)) + '",')
+  print('];')
 
 
 # Emit a JavaScript const object array.
 def emit_const_object_array(name, array):
-  print 'const ' + name + ' = ['
+  print('const ' + name + ' = [')
   for x in array:
-    print str(x) + ','
-  print '];'
+    print(str(x) + ',')
+  print('];')
 
 
 def emit_js_data():
@@ -3471,18 +3479,18 @@
   dump_html_prologue('Warnings for ' + platform_version + ' - ' +
                      target_product + ' - ' + target_variant)
   dump_stats()
-  print '<br><div id="stats_table"></div><br>'
-  print '\n<script>'
+  print('<br><div id="stats_table"></div><br>')
+  print('\n<script>')
   emit_js_data()
-  print scripts_for_warning_groups
-  print '</script>'
+  print(scripts_for_warning_groups)
+  print('</script>')
   emit_buttons()
   # Warning messages are grouped by severities or project names.
-  print '<br><div id="warning_groups"></div>'
+  print('<br><div id="warning_groups"></div>')
   if args.byproject:
-    print '<script>groupByProject();</script>'
+    print('<script>groupByProject();</script>')
   else:
-    print '<script>groupBySeverity();</script>'
+    print('<script>groupBySeverity();</script>')
   dump_fixed()
   dump_html_epilogue()
 
@@ -3506,8 +3514,7 @@
       warning = kind + ': ' + description_for_csv(i)
       writer.writerow([n, '', warning])
       # print number of warnings for each project, ordered by project name.
-      projects = i['projects'].keys()
-      projects.sort()
+      projects = sorted(i['projects'].keys())
       for p in projects:
         writer.writerow([i['projects'][p], p, warning])
   writer.writerow([total, '', kind + ' warnings'])
@@ -3526,7 +3533,9 @@
 
 
 def main():
-  warning_lines = parse_input_file(open(args.buildlog, 'r'))
+  # We must use 'utf-8' codec to parse some non-ASCII code in warnings.
+  warning_lines = parse_input_file(
+      io.open(args.buildlog, mode='r', encoding='utf-8'))
   parallel_classify_warnings(warning_lines)
   # If a user pases a csv path, save the fileoutput to the path
   # If the user also passed gencsv write the output to stdout