Add a simple script to extract payload-based OTAs

Based on:
* system/update_engine/scripts/simulate_ota.py
* system/update_engine/scripts/update_payload/applier.py

Change-Id: I08085f7826e682f15602e8b628c16d054193e0bb

extract_ota.py

@@ -0,0 +1,96 @@
+#!/usr/bin/env python3
+#
+# Copyright (C) 2020 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.
+#
+
+"""Script to extract payload.bin from an OTA update."""
+
+import argparse
+import os
+import tempfile
+import zipfile
+
+import update_payload
+from update_payload import applier
+
+def extract_ota(payload_path, list_partitions, output_dir, partitions):
+  """Extract OTA payload"""
+  payload = update_payload.Payload(payload_path)
+  payload.Init()
+
+  new_parts = {}
+  new_part_info = {}
+  install_operations = []
+  for part in payload.manifest.partitions:
+    name = part.partition_name
+    if list_partitions:
+      print(name)
+    if partitions and name not in partitions:
+      continue
+    new_image = os.path.join(output_dir, name + ".img")
+    new_parts[name] = new_image
+    new_part_info[name] = part.new_partition_info
+    install_operations.append((name, part.operations))
+
+  if not list_partitions:
+    for name, operations in install_operations:
+      applier.PayloadApplier(payload)._ApplyToPartition(
+            operations, name, '%s_install_operations' % name, new_parts[name],
+            new_part_info[name])
+
+def main():
+  parser = argparse.ArgumentParser(
+      description="Extract payload.bin from OTA package")
+  parser.add_argument(
+      "payload",
+      help="payload.bin for the OTA package, or a zip of OTA package itself",
+      nargs=1
+  )
+  parser.add_argument(
+      "-l",
+      dest="list_partitions",
+      help="List partitions, without extracting",
+      action='store_true')
+  parser.add_argument(
+      "-o",
+      dest="output_dir",
+      help="Output directory to put all images, current directory by default"
+  )
+  parser.add_argument(
+      "-p",
+      dest="partitions",
+      help="List of partitions to extract, all by default",
+      nargs="*"
+  )
+  args = parser.parse_args()
+
+  # pylint: disable=no-member
+  with tempfile.TemporaryDirectory() as tempdir:
+    payload_path = args.payload[0]
+    if zipfile.is_zipfile(payload_path):
+      with zipfile.ZipFile(payload_path, "r") as zfp:
+        payload_entry_name = 'payload.bin'
+        zfp.extract(payload_entry_name, tempdir)
+        payload_path = os.path.join(tempdir, payload_entry_name)
+    if args.output_dir is None:
+      args.output_dir = "."
+    if not os.path.exists(args.output_dir):
+      os.makedirs(args.output_dir, exist_ok=True)
+    assert os.path.isdir(args.output_dir)
+    extract_ota(payload_path, args.list_partitions, args.output_dir, args.partitions)
+
+
+if __name__ == '__main__':
+  main()

update_payload

@@ -0,0 +1 @@
+../../system/update_engine/scripts/update_payload