diff --git a/tools/releasetools/ota_metadata.proto b/tools/releasetools/ota_metadata.proto
index ff6114d..20d3091 100644
--- a/tools/releasetools/ota_metadata.proto
+++ b/tools/releasetools/ota_metadata.proto
@@ -14,6 +14,11 @@
  * limitations under the License.
  */
 
+// If you change this file,
+// Please update ota_metadata_pb2.py by executing
+// protoc ota_metadata.proto --python_out $ANDROID_BUILD_TOP/build/tools/releasetools
+
+
 syntax = "proto3";
 
 package build.tools.releasetools;
diff --git a/tools/releasetools/ota_metadata_pb2.py b/tools/releasetools/ota_metadata_pb2.py
new file mode 100644
index 0000000..ff2b2c5
--- /dev/null
+++ b/tools/releasetools/ota_metadata_pb2.py
@@ -0,0 +1,343 @@
+# -*- coding: utf-8 -*-
+# Generated by the protocol buffer compiler.  DO NOT EDIT!
+# source: ota_metadata.proto
+
+from google.protobuf import descriptor as _descriptor
+from google.protobuf import message as _message
+from google.protobuf import reflection as _reflection
+from google.protobuf import symbol_database as _symbol_database
+# @@protoc_insertion_point(imports)
+
+_sym_db = _symbol_database.Default()
+
+
+
+
+DESCRIPTOR = _descriptor.FileDescriptor(
+  name='ota_metadata.proto',
+  package='build.tools.releasetools',
+  syntax='proto3',
+  serialized_options=b'H\003',
+  serialized_pb=b'\n\x12ota_metadata.proto\x12\x18\x62uild.tools.releasetools\"X\n\x0ePartitionState\x12\x16\n\x0epartition_name\x18\x01 \x01(\t\x12\x0e\n\x06\x64\x65vice\x18\x02 \x03(\t\x12\r\n\x05\x62uild\x18\x03 \x03(\t\x12\x0f\n\x07version\x18\x04 \x01(\t\"\xce\x01\n\x0b\x44\x65viceState\x12\x0e\n\x06\x64\x65vice\x18\x01 \x03(\t\x12\r\n\x05\x62uild\x18\x02 \x03(\t\x12\x19\n\x11\x62uild_incremental\x18\x03 \x01(\t\x12\x11\n\ttimestamp\x18\x04 \x01(\x03\x12\x11\n\tsdk_level\x18\x05 \x01(\t\x12\x1c\n\x14security_patch_level\x18\x06 \x01(\t\x12\x41\n\x0fpartition_state\x18\x07 \x03(\x0b\x32(.build.tools.releasetools.PartitionState\"\xe1\x03\n\x0bOtaMetadata\x12;\n\x04type\x18\x01 \x01(\x0e\x32-.build.tools.releasetools.OtaMetadata.OtaType\x12\x0c\n\x04wipe\x18\x02 \x01(\x08\x12\x11\n\tdowngrade\x18\x03 \x01(\x08\x12P\n\x0eproperty_files\x18\x04 \x03(\x0b\x32\x38.build.tools.releasetools.OtaMetadata.PropertyFilesEntry\x12;\n\x0cprecondition\x18\x05 \x01(\x0b\x32%.build.tools.releasetools.DeviceState\x12<\n\rpostcondition\x18\x06 \x01(\x0b\x32%.build.tools.releasetools.DeviceState\x12#\n\x1bretrofit_dynamic_partitions\x18\x07 \x01(\x08\x12\x16\n\x0erequired_cache\x18\x08 \x01(\x03\x1a\x34\n\x12PropertyFilesEntry\x12\x0b\n\x03key\x18\x01 \x01(\t\x12\r\n\x05value\x18\x02 \x01(\t:\x02\x38\x01\"4\n\x07OtaType\x12\x0b\n\x07UNKNOWN\x10\x00\x12\x06\n\x02\x41\x42\x10\x01\x12\t\n\x05\x42LOCK\x10\x02\x12\t\n\x05\x42RICK\x10\x03\x42\x02H\x03\x62\x06proto3'
+)
+
+
+
+_OTAMETADATA_OTATYPE = _descriptor.EnumDescriptor(
+  name='OtaType',
+  full_name='build.tools.releasetools.OtaMetadata.OtaType',
+  filename=None,
+  file=DESCRIPTOR,
+  values=[
+    _descriptor.EnumValueDescriptor(
+      name='UNKNOWN', index=0, number=0,
+      serialized_options=None,
+      type=None),
+    _descriptor.EnumValueDescriptor(
+      name='AB', index=1, number=1,
+      serialized_options=None,
+      type=None),
+    _descriptor.EnumValueDescriptor(
+      name='BLOCK', index=2, number=2,
+      serialized_options=None,
+      type=None),
+    _descriptor.EnumValueDescriptor(
+      name='BRICK', index=3, number=3,
+      serialized_options=None,
+      type=None),
+  ],
+  containing_type=None,
+  serialized_options=None,
+  serialized_start=777,
+  serialized_end=829,
+)
+_sym_db.RegisterEnumDescriptor(_OTAMETADATA_OTATYPE)
+
+
+_PARTITIONSTATE = _descriptor.Descriptor(
+  name='PartitionState',
+  full_name='build.tools.releasetools.PartitionState',
+  filename=None,
+  file=DESCRIPTOR,
+  containing_type=None,
+  fields=[
+    _descriptor.FieldDescriptor(
+      name='partition_name', full_name='build.tools.releasetools.PartitionState.partition_name', index=0,
+      number=1, type=9, cpp_type=9, label=1,
+      has_default_value=False, default_value=b"".decode('utf-8'),
+      message_type=None, enum_type=None, containing_type=None,
+      is_extension=False, extension_scope=None,
+      serialized_options=None, file=DESCRIPTOR),
+    _descriptor.FieldDescriptor(
+      name='device', full_name='build.tools.releasetools.PartitionState.device', index=1,
+      number=2, type=9, cpp_type=9, label=3,
+      has_default_value=False, default_value=[],
+      message_type=None, enum_type=None, containing_type=None,
+      is_extension=False, extension_scope=None,
+      serialized_options=None, file=DESCRIPTOR),
+    _descriptor.FieldDescriptor(
+      name='build', full_name='build.tools.releasetools.PartitionState.build', index=2,
+      number=3, type=9, cpp_type=9, label=3,
+      has_default_value=False, default_value=[],
+      message_type=None, enum_type=None, containing_type=None,
+      is_extension=False, extension_scope=None,
+      serialized_options=None, file=DESCRIPTOR),
+    _descriptor.FieldDescriptor(
+      name='version', full_name='build.tools.releasetools.PartitionState.version', index=3,
+      number=4, type=9, cpp_type=9, label=1,
+      has_default_value=False, default_value=b"".decode('utf-8'),
+      message_type=None, enum_type=None, containing_type=None,
+      is_extension=False, extension_scope=None,
+      serialized_options=None, file=DESCRIPTOR),
+  ],
+  extensions=[
+  ],
+  nested_types=[],
+  enum_types=[
+  ],
+  serialized_options=None,
+  is_extendable=False,
+  syntax='proto3',
+  extension_ranges=[],
+  oneofs=[
+  ],
+  serialized_start=48,
+  serialized_end=136,
+)
+
+
+_DEVICESTATE = _descriptor.Descriptor(
+  name='DeviceState',
+  full_name='build.tools.releasetools.DeviceState',
+  filename=None,
+  file=DESCRIPTOR,
+  containing_type=None,
+  fields=[
+    _descriptor.FieldDescriptor(
+      name='device', full_name='build.tools.releasetools.DeviceState.device', index=0,
+      number=1, type=9, cpp_type=9, label=3,
+      has_default_value=False, default_value=[],
+      message_type=None, enum_type=None, containing_type=None,
+      is_extension=False, extension_scope=None,
+      serialized_options=None, file=DESCRIPTOR),
+    _descriptor.FieldDescriptor(
+      name='build', full_name='build.tools.releasetools.DeviceState.build', index=1,
+      number=2, type=9, cpp_type=9, label=3,
+      has_default_value=False, default_value=[],
+      message_type=None, enum_type=None, containing_type=None,
+      is_extension=False, extension_scope=None,
+      serialized_options=None, file=DESCRIPTOR),
+    _descriptor.FieldDescriptor(
+      name='build_incremental', full_name='build.tools.releasetools.DeviceState.build_incremental', index=2,
+      number=3, type=9, cpp_type=9, label=1,
+      has_default_value=False, default_value=b"".decode('utf-8'),
+      message_type=None, enum_type=None, containing_type=None,
+      is_extension=False, extension_scope=None,
+      serialized_options=None, file=DESCRIPTOR),
+    _descriptor.FieldDescriptor(
+      name='timestamp', full_name='build.tools.releasetools.DeviceState.timestamp', index=3,
+      number=4, type=3, cpp_type=2, label=1,
+      has_default_value=False, default_value=0,
+      message_type=None, enum_type=None, containing_type=None,
+      is_extension=False, extension_scope=None,
+      serialized_options=None, file=DESCRIPTOR),
+    _descriptor.FieldDescriptor(
+      name='sdk_level', full_name='build.tools.releasetools.DeviceState.sdk_level', index=4,
+      number=5, type=9, cpp_type=9, label=1,
+      has_default_value=False, default_value=b"".decode('utf-8'),
+      message_type=None, enum_type=None, containing_type=None,
+      is_extension=False, extension_scope=None,
+      serialized_options=None, file=DESCRIPTOR),
+    _descriptor.FieldDescriptor(
+      name='security_patch_level', full_name='build.tools.releasetools.DeviceState.security_patch_level', index=5,
+      number=6, type=9, cpp_type=9, label=1,
+      has_default_value=False, default_value=b"".decode('utf-8'),
+      message_type=None, enum_type=None, containing_type=None,
+      is_extension=False, extension_scope=None,
+      serialized_options=None, file=DESCRIPTOR),
+    _descriptor.FieldDescriptor(
+      name='partition_state', full_name='build.tools.releasetools.DeviceState.partition_state', index=6,
+      number=7, type=11, cpp_type=10, label=3,
+      has_default_value=False, default_value=[],
+      message_type=None, enum_type=None, containing_type=None,
+      is_extension=False, extension_scope=None,
+      serialized_options=None, file=DESCRIPTOR),
+  ],
+  extensions=[
+  ],
+  nested_types=[],
+  enum_types=[
+  ],
+  serialized_options=None,
+  is_extendable=False,
+  syntax='proto3',
+  extension_ranges=[],
+  oneofs=[
+  ],
+  serialized_start=139,
+  serialized_end=345,
+)
+
+
+_OTAMETADATA_PROPERTYFILESENTRY = _descriptor.Descriptor(
+  name='PropertyFilesEntry',
+  full_name='build.tools.releasetools.OtaMetadata.PropertyFilesEntry',
+  filename=None,
+  file=DESCRIPTOR,
+  containing_type=None,
+  fields=[
+    _descriptor.FieldDescriptor(
+      name='key', full_name='build.tools.releasetools.OtaMetadata.PropertyFilesEntry.key', index=0,
+      number=1, type=9, cpp_type=9, label=1,
+      has_default_value=False, default_value=b"".decode('utf-8'),
+      message_type=None, enum_type=None, containing_type=None,
+      is_extension=False, extension_scope=None,
+      serialized_options=None, file=DESCRIPTOR),
+    _descriptor.FieldDescriptor(
+      name='value', full_name='build.tools.releasetools.OtaMetadata.PropertyFilesEntry.value', index=1,
+      number=2, type=9, cpp_type=9, label=1,
+      has_default_value=False, default_value=b"".decode('utf-8'),
+      message_type=None, enum_type=None, containing_type=None,
+      is_extension=False, extension_scope=None,
+      serialized_options=None, file=DESCRIPTOR),
+  ],
+  extensions=[
+  ],
+  nested_types=[],
+  enum_types=[
+  ],
+  serialized_options=b'8\001',
+  is_extendable=False,
+  syntax='proto3',
+  extension_ranges=[],
+  oneofs=[
+  ],
+  serialized_start=723,
+  serialized_end=775,
+)
+
+_OTAMETADATA = _descriptor.Descriptor(
+  name='OtaMetadata',
+  full_name='build.tools.releasetools.OtaMetadata',
+  filename=None,
+  file=DESCRIPTOR,
+  containing_type=None,
+  fields=[
+    _descriptor.FieldDescriptor(
+      name='type', full_name='build.tools.releasetools.OtaMetadata.type', index=0,
+      number=1, type=14, cpp_type=8, label=1,
+      has_default_value=False, default_value=0,
+      message_type=None, enum_type=None, containing_type=None,
+      is_extension=False, extension_scope=None,
+      serialized_options=None, file=DESCRIPTOR),
+    _descriptor.FieldDescriptor(
+      name='wipe', full_name='build.tools.releasetools.OtaMetadata.wipe', index=1,
+      number=2, type=8, cpp_type=7, label=1,
+      has_default_value=False, default_value=False,
+      message_type=None, enum_type=None, containing_type=None,
+      is_extension=False, extension_scope=None,
+      serialized_options=None, file=DESCRIPTOR),
+    _descriptor.FieldDescriptor(
+      name='downgrade', full_name='build.tools.releasetools.OtaMetadata.downgrade', index=2,
+      number=3, type=8, cpp_type=7, label=1,
+      has_default_value=False, default_value=False,
+      message_type=None, enum_type=None, containing_type=None,
+      is_extension=False, extension_scope=None,
+      serialized_options=None, file=DESCRIPTOR),
+    _descriptor.FieldDescriptor(
+      name='property_files', full_name='build.tools.releasetools.OtaMetadata.property_files', index=3,
+      number=4, type=11, cpp_type=10, label=3,
+      has_default_value=False, default_value=[],
+      message_type=None, enum_type=None, containing_type=None,
+      is_extension=False, extension_scope=None,
+      serialized_options=None, file=DESCRIPTOR),
+    _descriptor.FieldDescriptor(
+      name='precondition', full_name='build.tools.releasetools.OtaMetadata.precondition', index=4,
+      number=5, type=11, cpp_type=10, label=1,
+      has_default_value=False, default_value=None,
+      message_type=None, enum_type=None, containing_type=None,
+      is_extension=False, extension_scope=None,
+      serialized_options=None, file=DESCRIPTOR),
+    _descriptor.FieldDescriptor(
+      name='postcondition', full_name='build.tools.releasetools.OtaMetadata.postcondition', index=5,
+      number=6, type=11, cpp_type=10, label=1,
+      has_default_value=False, default_value=None,
+      message_type=None, enum_type=None, containing_type=None,
+      is_extension=False, extension_scope=None,
+      serialized_options=None, file=DESCRIPTOR),
+    _descriptor.FieldDescriptor(
+      name='retrofit_dynamic_partitions', full_name='build.tools.releasetools.OtaMetadata.retrofit_dynamic_partitions', index=6,
+      number=7, type=8, cpp_type=7, label=1,
+      has_default_value=False, default_value=False,
+      message_type=None, enum_type=None, containing_type=None,
+      is_extension=False, extension_scope=None,
+      serialized_options=None, file=DESCRIPTOR),
+    _descriptor.FieldDescriptor(
+      name='required_cache', full_name='build.tools.releasetools.OtaMetadata.required_cache', index=7,
+      number=8, type=3, cpp_type=2, label=1,
+      has_default_value=False, default_value=0,
+      message_type=None, enum_type=None, containing_type=None,
+      is_extension=False, extension_scope=None,
+      serialized_options=None, file=DESCRIPTOR),
+  ],
+  extensions=[
+  ],
+  nested_types=[_OTAMETADATA_PROPERTYFILESENTRY, ],
+  enum_types=[
+    _OTAMETADATA_OTATYPE,
+  ],
+  serialized_options=None,
+  is_extendable=False,
+  syntax='proto3',
+  extension_ranges=[],
+  oneofs=[
+  ],
+  serialized_start=348,
+  serialized_end=829,
+)
+
+_DEVICESTATE.fields_by_name['partition_state'].message_type = _PARTITIONSTATE
+_OTAMETADATA_PROPERTYFILESENTRY.containing_type = _OTAMETADATA
+_OTAMETADATA.fields_by_name['type'].enum_type = _OTAMETADATA_OTATYPE
+_OTAMETADATA.fields_by_name['property_files'].message_type = _OTAMETADATA_PROPERTYFILESENTRY
+_OTAMETADATA.fields_by_name['precondition'].message_type = _DEVICESTATE
+_OTAMETADATA.fields_by_name['postcondition'].message_type = _DEVICESTATE
+_OTAMETADATA_OTATYPE.containing_type = _OTAMETADATA
+DESCRIPTOR.message_types_by_name['PartitionState'] = _PARTITIONSTATE
+DESCRIPTOR.message_types_by_name['DeviceState'] = _DEVICESTATE
+DESCRIPTOR.message_types_by_name['OtaMetadata'] = _OTAMETADATA
+_sym_db.RegisterFileDescriptor(DESCRIPTOR)
+
+PartitionState = _reflection.GeneratedProtocolMessageType('PartitionState', (_message.Message,), {
+  'DESCRIPTOR' : _PARTITIONSTATE,
+  '__module__' : 'ota_metadata_pb2'
+  # @@protoc_insertion_point(class_scope:build.tools.releasetools.PartitionState)
+  })
+_sym_db.RegisterMessage(PartitionState)
+
+DeviceState = _reflection.GeneratedProtocolMessageType('DeviceState', (_message.Message,), {
+  'DESCRIPTOR' : _DEVICESTATE,
+  '__module__' : 'ota_metadata_pb2'
+  # @@protoc_insertion_point(class_scope:build.tools.releasetools.DeviceState)
+  })
+_sym_db.RegisterMessage(DeviceState)
+
+OtaMetadata = _reflection.GeneratedProtocolMessageType('OtaMetadata', (_message.Message,), {
+
+  'PropertyFilesEntry' : _reflection.GeneratedProtocolMessageType('PropertyFilesEntry', (_message.Message,), {
+    'DESCRIPTOR' : _OTAMETADATA_PROPERTYFILESENTRY,
+    '__module__' : 'ota_metadata_pb2'
+    # @@protoc_insertion_point(class_scope:build.tools.releasetools.OtaMetadata.PropertyFilesEntry)
+    })
+  ,
+  'DESCRIPTOR' : _OTAMETADATA,
+  '__module__' : 'ota_metadata_pb2'
+  # @@protoc_insertion_point(class_scope:build.tools.releasetools.OtaMetadata)
+  })
+_sym_db.RegisterMessage(OtaMetadata)
+_sym_db.RegisterMessage(OtaMetadata.PropertyFilesEntry)
+
+
+DESCRIPTOR._options = None
+_OTAMETADATA_PROPERTYFILESENTRY._options = None
+# @@protoc_insertion_point(module_scope)