diff --git a/scripts/update_payload/update_metadata_pb2.py b/scripts/update_payload/update_metadata_pb2.py
new file mode 100644
index 0000000..92a7506
--- /dev/null
+++ b/scripts/update_payload/update_metadata_pb2.py
@@ -0,0 +1,390 @@
+# Generated by the protocol buffer compiler.  DO NOT EDIT!
+
+from google.protobuf import descriptor
+from google.protobuf import message
+from google.protobuf import reflection
+from google.protobuf import descriptor_pb2
+# @@protoc_insertion_point(imports)
+
+
+DESCRIPTOR = descriptor.FileDescriptor(
+  name='update_metadata.proto',
+  package='chromeos_update_engine',
+  serialized_pb='\n\x15update_metadata.proto\x12\x16\x63hromeos_update_engine\"1\n\x06\x45xtent\x12\x13\n\x0bstart_block\x18\x01 \x01(\x04\x12\x12\n\nnum_blocks\x18\x02 \x01(\x04\"z\n\nSignatures\x12@\n\nsignatures\x18\x01 \x03(\x0b\x32,.chromeos_update_engine.Signatures.Signature\x1a*\n\tSignature\x12\x0f\n\x07version\x18\x01 \x01(\r\x12\x0c\n\x04\x64\x61ta\x18\x02 \x01(\x0c\"+\n\rPartitionInfo\x12\x0c\n\x04size\x18\x01 \x01(\x04\x12\x0c\n\x04hash\x18\x02 \x01(\x0c\"\x99\x07\n\x14\x44\x65ltaArchiveManifest\x12Y\n\x12install_operations\x18\x01 \x03(\x0b\x32=.chromeos_update_engine.DeltaArchiveManifest.InstallOperation\x12`\n\x19kernel_install_operations\x18\x02 \x03(\x0b\x32=.chromeos_update_engine.DeltaArchiveManifest.InstallOperation\x12\x18\n\nblock_size\x18\x03 \x01(\r:\x04\x34\x30\x39\x36\x12\x19\n\x11signatures_offset\x18\x04 \x01(\x04\x12\x17\n\x0fsignatures_size\x18\x05 \x01(\x04\x12>\n\x0fold_kernel_info\x18\x06 \x01(\x0b\x32%.chromeos_update_engine.PartitionInfo\x12>\n\x0fnew_kernel_info\x18\x07 \x01(\x0b\x32%.chromeos_update_engine.PartitionInfo\x12>\n\x0fold_rootfs_info\x18\x08 \x01(\x0b\x32%.chromeos_update_engine.PartitionInfo\x12>\n\x0fnew_rootfs_info\x18\t \x01(\x0b\x32%.chromeos_update_engine.PartitionInfo\x1a\xf5\x02\n\x10InstallOperation\x12P\n\x04type\x18\x01 \x02(\x0e\x32\x42.chromeos_update_engine.DeltaArchiveManifest.InstallOperation.Type\x12\x13\n\x0b\x64\x61ta_offset\x18\x02 \x01(\r\x12\x13\n\x0b\x64\x61ta_length\x18\x03 \x01(\r\x12\x33\n\x0bsrc_extents\x18\x04 \x03(\x0b\x32\x1e.chromeos_update_engine.Extent\x12\x12\n\nsrc_length\x18\x05 \x01(\x04\x12\x33\n\x0b\x64st_extents\x18\x06 \x03(\x0b\x32\x1e.chromeos_update_engine.Extent\x12\x12\n\ndst_length\x18\x07 \x01(\x04\x12\x18\n\x10\x64\x61ta_sha256_hash\x18\x08 \x01(\x0c\"9\n\x04Type\x12\x0b\n\x07REPLACE\x10\x00\x12\x0e\n\nREPLACE_BZ\x10\x01\x12\x08\n\x04MOVE\x10\x02\x12\n\n\x06\x42SDIFF\x10\x03')
+
+
+
+_DELTAARCHIVEMANIFEST_INSTALLOPERATION_TYPE = descriptor.EnumDescriptor(
+  name='Type',
+  full_name='chromeos_update_engine.DeltaArchiveManifest.InstallOperation.Type',
+  filename=None,
+  file=DESCRIPTOR,
+  values=[
+    descriptor.EnumValueDescriptor(
+      name='REPLACE', index=0, number=0,
+      options=None,
+      type=None),
+    descriptor.EnumValueDescriptor(
+      name='REPLACE_BZ', index=1, number=1,
+      options=None,
+      type=None),
+    descriptor.EnumValueDescriptor(
+      name='MOVE', index=2, number=2,
+      options=None,
+      type=None),
+    descriptor.EnumValueDescriptor(
+      name='BSDIFF', index=3, number=3,
+      options=None,
+      type=None),
+  ],
+  containing_type=None,
+  options=None,
+  serialized_start=1134,
+  serialized_end=1191,
+)
+
+
+_EXTENT = descriptor.Descriptor(
+  name='Extent',
+  full_name='chromeos_update_engine.Extent',
+  filename=None,
+  file=DESCRIPTOR,
+  containing_type=None,
+  fields=[
+    descriptor.FieldDescriptor(
+      name='start_block', full_name='chromeos_update_engine.Extent.start_block', index=0,
+      number=1, type=4, cpp_type=4, label=1,
+      has_default_value=False, default_value=0,
+      message_type=None, enum_type=None, containing_type=None,
+      is_extension=False, extension_scope=None,
+      options=None),
+    descriptor.FieldDescriptor(
+      name='num_blocks', full_name='chromeos_update_engine.Extent.num_blocks', index=1,
+      number=2, type=4, cpp_type=4, label=1,
+      has_default_value=False, default_value=0,
+      message_type=None, enum_type=None, containing_type=None,
+      is_extension=False, extension_scope=None,
+      options=None),
+  ],
+  extensions=[
+  ],
+  nested_types=[],
+  enum_types=[
+  ],
+  options=None,
+  is_extendable=False,
+  extension_ranges=[],
+  serialized_start=49,
+  serialized_end=98,
+)
+
+
+_SIGNATURES_SIGNATURE = descriptor.Descriptor(
+  name='Signature',
+  full_name='chromeos_update_engine.Signatures.Signature',
+  filename=None,
+  file=DESCRIPTOR,
+  containing_type=None,
+  fields=[
+    descriptor.FieldDescriptor(
+      name='version', full_name='chromeos_update_engine.Signatures.Signature.version', index=0,
+      number=1, type=13, cpp_type=3, label=1,
+      has_default_value=False, default_value=0,
+      message_type=None, enum_type=None, containing_type=None,
+      is_extension=False, extension_scope=None,
+      options=None),
+    descriptor.FieldDescriptor(
+      name='data', full_name='chromeos_update_engine.Signatures.Signature.data', index=1,
+      number=2, type=12, cpp_type=9, label=1,
+      has_default_value=False, default_value="",
+      message_type=None, enum_type=None, containing_type=None,
+      is_extension=False, extension_scope=None,
+      options=None),
+  ],
+  extensions=[
+  ],
+  nested_types=[],
+  enum_types=[
+  ],
+  options=None,
+  is_extendable=False,
+  extension_ranges=[],
+  serialized_start=180,
+  serialized_end=222,
+)
+
+_SIGNATURES = descriptor.Descriptor(
+  name='Signatures',
+  full_name='chromeos_update_engine.Signatures',
+  filename=None,
+  file=DESCRIPTOR,
+  containing_type=None,
+  fields=[
+    descriptor.FieldDescriptor(
+      name='signatures', full_name='chromeos_update_engine.Signatures.signatures', index=0,
+      number=1, 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,
+      options=None),
+  ],
+  extensions=[
+  ],
+  nested_types=[_SIGNATURES_SIGNATURE, ],
+  enum_types=[
+  ],
+  options=None,
+  is_extendable=False,
+  extension_ranges=[],
+  serialized_start=100,
+  serialized_end=222,
+)
+
+
+_PARTITIONINFO = descriptor.Descriptor(
+  name='PartitionInfo',
+  full_name='chromeos_update_engine.PartitionInfo',
+  filename=None,
+  file=DESCRIPTOR,
+  containing_type=None,
+  fields=[
+    descriptor.FieldDescriptor(
+      name='size', full_name='chromeos_update_engine.PartitionInfo.size', index=0,
+      number=1, type=4, cpp_type=4, label=1,
+      has_default_value=False, default_value=0,
+      message_type=None, enum_type=None, containing_type=None,
+      is_extension=False, extension_scope=None,
+      options=None),
+    descriptor.FieldDescriptor(
+      name='hash', full_name='chromeos_update_engine.PartitionInfo.hash', index=1,
+      number=2, type=12, cpp_type=9, label=1,
+      has_default_value=False, default_value="",
+      message_type=None, enum_type=None, containing_type=None,
+      is_extension=False, extension_scope=None,
+      options=None),
+  ],
+  extensions=[
+  ],
+  nested_types=[],
+  enum_types=[
+  ],
+  options=None,
+  is_extendable=False,
+  extension_ranges=[],
+  serialized_start=224,
+  serialized_end=267,
+)
+
+
+_DELTAARCHIVEMANIFEST_INSTALLOPERATION = descriptor.Descriptor(
+  name='InstallOperation',
+  full_name='chromeos_update_engine.DeltaArchiveManifest.InstallOperation',
+  filename=None,
+  file=DESCRIPTOR,
+  containing_type=None,
+  fields=[
+    descriptor.FieldDescriptor(
+      name='type', full_name='chromeos_update_engine.DeltaArchiveManifest.InstallOperation.type', index=0,
+      number=1, type=14, cpp_type=8, label=2,
+      has_default_value=False, default_value=0,
+      message_type=None, enum_type=None, containing_type=None,
+      is_extension=False, extension_scope=None,
+      options=None),
+    descriptor.FieldDescriptor(
+      name='data_offset', full_name='chromeos_update_engine.DeltaArchiveManifest.InstallOperation.data_offset', index=1,
+      number=2, type=13, cpp_type=3, label=1,
+      has_default_value=False, default_value=0,
+      message_type=None, enum_type=None, containing_type=None,
+      is_extension=False, extension_scope=None,
+      options=None),
+    descriptor.FieldDescriptor(
+      name='data_length', full_name='chromeos_update_engine.DeltaArchiveManifest.InstallOperation.data_length', index=2,
+      number=3, type=13, cpp_type=3, label=1,
+      has_default_value=False, default_value=0,
+      message_type=None, enum_type=None, containing_type=None,
+      is_extension=False, extension_scope=None,
+      options=None),
+    descriptor.FieldDescriptor(
+      name='src_extents', full_name='chromeos_update_engine.DeltaArchiveManifest.InstallOperation.src_extents', 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,
+      options=None),
+    descriptor.FieldDescriptor(
+      name='src_length', full_name='chromeos_update_engine.DeltaArchiveManifest.InstallOperation.src_length', index=4,
+      number=5, type=4, cpp_type=4, label=1,
+      has_default_value=False, default_value=0,
+      message_type=None, enum_type=None, containing_type=None,
+      is_extension=False, extension_scope=None,
+      options=None),
+    descriptor.FieldDescriptor(
+      name='dst_extents', full_name='chromeos_update_engine.DeltaArchiveManifest.InstallOperation.dst_extents', index=5,
+      number=6, 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,
+      options=None),
+    descriptor.FieldDescriptor(
+      name='dst_length', full_name='chromeos_update_engine.DeltaArchiveManifest.InstallOperation.dst_length', index=6,
+      number=7, type=4, cpp_type=4, label=1,
+      has_default_value=False, default_value=0,
+      message_type=None, enum_type=None, containing_type=None,
+      is_extension=False, extension_scope=None,
+      options=None),
+    descriptor.FieldDescriptor(
+      name='data_sha256_hash', full_name='chromeos_update_engine.DeltaArchiveManifest.InstallOperation.data_sha256_hash', index=7,
+      number=8, type=12, cpp_type=9, label=1,
+      has_default_value=False, default_value="",
+      message_type=None, enum_type=None, containing_type=None,
+      is_extension=False, extension_scope=None,
+      options=None),
+  ],
+  extensions=[
+  ],
+  nested_types=[],
+  enum_types=[
+    _DELTAARCHIVEMANIFEST_INSTALLOPERATION_TYPE,
+  ],
+  options=None,
+  is_extendable=False,
+  extension_ranges=[],
+  serialized_start=818,
+  serialized_end=1191,
+)
+
+_DELTAARCHIVEMANIFEST = descriptor.Descriptor(
+  name='DeltaArchiveManifest',
+  full_name='chromeos_update_engine.DeltaArchiveManifest',
+  filename=None,
+  file=DESCRIPTOR,
+  containing_type=None,
+  fields=[
+    descriptor.FieldDescriptor(
+      name='install_operations', full_name='chromeos_update_engine.DeltaArchiveManifest.install_operations', index=0,
+      number=1, 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,
+      options=None),
+    descriptor.FieldDescriptor(
+      name='kernel_install_operations', full_name='chromeos_update_engine.DeltaArchiveManifest.kernel_install_operations', index=1,
+      number=2, 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,
+      options=None),
+    descriptor.FieldDescriptor(
+      name='block_size', full_name='chromeos_update_engine.DeltaArchiveManifest.block_size', index=2,
+      number=3, type=13, cpp_type=3, label=1,
+      has_default_value=True, default_value=4096,
+      message_type=None, enum_type=None, containing_type=None,
+      is_extension=False, extension_scope=None,
+      options=None),
+    descriptor.FieldDescriptor(
+      name='signatures_offset', full_name='chromeos_update_engine.DeltaArchiveManifest.signatures_offset', index=3,
+      number=4, type=4, cpp_type=4, label=1,
+      has_default_value=False, default_value=0,
+      message_type=None, enum_type=None, containing_type=None,
+      is_extension=False, extension_scope=None,
+      options=None),
+    descriptor.FieldDescriptor(
+      name='signatures_size', full_name='chromeos_update_engine.DeltaArchiveManifest.signatures_size', index=4,
+      number=5, type=4, cpp_type=4, label=1,
+      has_default_value=False, default_value=0,
+      message_type=None, enum_type=None, containing_type=None,
+      is_extension=False, extension_scope=None,
+      options=None),
+    descriptor.FieldDescriptor(
+      name='old_kernel_info', full_name='chromeos_update_engine.DeltaArchiveManifest.old_kernel_info', 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,
+      options=None),
+    descriptor.FieldDescriptor(
+      name='new_kernel_info', full_name='chromeos_update_engine.DeltaArchiveManifest.new_kernel_info', index=6,
+      number=7, 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,
+      options=None),
+    descriptor.FieldDescriptor(
+      name='old_rootfs_info', full_name='chromeos_update_engine.DeltaArchiveManifest.old_rootfs_info', index=7,
+      number=8, 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,
+      options=None),
+    descriptor.FieldDescriptor(
+      name='new_rootfs_info', full_name='chromeos_update_engine.DeltaArchiveManifest.new_rootfs_info', index=8,
+      number=9, 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,
+      options=None),
+  ],
+  extensions=[
+  ],
+  nested_types=[_DELTAARCHIVEMANIFEST_INSTALLOPERATION, ],
+  enum_types=[
+  ],
+  options=None,
+  is_extendable=False,
+  extension_ranges=[],
+  serialized_start=270,
+  serialized_end=1191,
+)
+
+
+_SIGNATURES_SIGNATURE.containing_type = _SIGNATURES;
+_SIGNATURES.fields_by_name['signatures'].message_type = _SIGNATURES_SIGNATURE
+_DELTAARCHIVEMANIFEST_INSTALLOPERATION.fields_by_name['type'].enum_type = _DELTAARCHIVEMANIFEST_INSTALLOPERATION_TYPE
+_DELTAARCHIVEMANIFEST_INSTALLOPERATION.fields_by_name['src_extents'].message_type = _EXTENT
+_DELTAARCHIVEMANIFEST_INSTALLOPERATION.fields_by_name['dst_extents'].message_type = _EXTENT
+_DELTAARCHIVEMANIFEST_INSTALLOPERATION.containing_type = _DELTAARCHIVEMANIFEST;
+_DELTAARCHIVEMANIFEST_INSTALLOPERATION_TYPE.containing_type = _DELTAARCHIVEMANIFEST_INSTALLOPERATION;
+_DELTAARCHIVEMANIFEST.fields_by_name['install_operations'].message_type = _DELTAARCHIVEMANIFEST_INSTALLOPERATION
+_DELTAARCHIVEMANIFEST.fields_by_name['kernel_install_operations'].message_type = _DELTAARCHIVEMANIFEST_INSTALLOPERATION
+_DELTAARCHIVEMANIFEST.fields_by_name['old_kernel_info'].message_type = _PARTITIONINFO
+_DELTAARCHIVEMANIFEST.fields_by_name['new_kernel_info'].message_type = _PARTITIONINFO
+_DELTAARCHIVEMANIFEST.fields_by_name['old_rootfs_info'].message_type = _PARTITIONINFO
+_DELTAARCHIVEMANIFEST.fields_by_name['new_rootfs_info'].message_type = _PARTITIONINFO
+
+class Extent(message.Message):
+  __metaclass__ = reflection.GeneratedProtocolMessageType
+  DESCRIPTOR = _EXTENT
+  
+  # @@protoc_insertion_point(class_scope:chromeos_update_engine.Extent)
+
+class Signatures(message.Message):
+  __metaclass__ = reflection.GeneratedProtocolMessageType
+  
+  class Signature(message.Message):
+    __metaclass__ = reflection.GeneratedProtocolMessageType
+    DESCRIPTOR = _SIGNATURES_SIGNATURE
+    
+    # @@protoc_insertion_point(class_scope:chromeos_update_engine.Signatures.Signature)
+  DESCRIPTOR = _SIGNATURES
+  
+  # @@protoc_insertion_point(class_scope:chromeos_update_engine.Signatures)
+
+class PartitionInfo(message.Message):
+  __metaclass__ = reflection.GeneratedProtocolMessageType
+  DESCRIPTOR = _PARTITIONINFO
+  
+  # @@protoc_insertion_point(class_scope:chromeos_update_engine.PartitionInfo)
+
+class DeltaArchiveManifest(message.Message):
+  __metaclass__ = reflection.GeneratedProtocolMessageType
+  
+  class InstallOperation(message.Message):
+    __metaclass__ = reflection.GeneratedProtocolMessageType
+    DESCRIPTOR = _DELTAARCHIVEMANIFEST_INSTALLOPERATION
+    
+    # @@protoc_insertion_point(class_scope:chromeos_update_engine.DeltaArchiveManifest.InstallOperation)
+  DESCRIPTOR = _DELTAARCHIVEMANIFEST
+  
+  # @@protoc_insertion_point(class_scope:chromeos_update_engine.DeltaArchiveManifest)
+
+# @@protoc_insertion_point(module_scope)