1 files changed, 87 insertions, 0 deletions
diff --git a/scripts/cow_converter.py b/scripts/cow_converter.py
new file mode 100644
index 00000000..14e016cb
--- /dev/null
+++ b/scripts/cow_converter.py
@@ -0,0 +1,87 @@
+#!/usr/bin/env python3
+#
+# Copyright (C) 2021 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.
+#
+
+"""Command-line tool for converting OTA payloads to VABC style COW images."""
+
+import os
+import sys
+import tempfile
+import zipfile
+import subprocess
+
+
+def IsSparseImage(filepath):
+  """Determine if an image is a sparse image
+  Args:
+    filepath: str, a path to an .img file
+
+  Returns:
+    return true iff the filepath is a sparse image.
+
+  """
+  with open(filepath, 'rb') as fp:
+    # Magic for android sparse image format
+    # https://source.android.com/devices/bootloader/images
+    return fp.read(4) == b'\x3A\xFF\x26\xED'
+
+
+def ConvertCOW(ota_path, target_file_path, tmp_dir, output_dir):
+  """Convert ota payload to COW IMAGE
+  Args:
+    ota_path: str, path to ota.zip
+    target_file_path: str, path to target_file.zip,
+      must be the target build for OTA.
+    tmp_dir: A temp dir as scratch space
+    output_dir: A directory where all converted COW images will be written.
+  """
+  with zipfile.ZipFile(ota_path) as ota_zip:
+    payload_path = ota_zip.extract("payload.bin", output_dir)
+  with zipfile.ZipFile(target_file_path) as zfp:
+    for fileinfo in zfp.infolist():
+      img_name = os.path.basename(fileinfo.filename)
+      if not fileinfo.filename.endswith(".img"):
+        continue
+      if fileinfo.filename.startswith("IMAGES/") or \
+              fileinfo.filename.startswith("RADIO/"):
+        img_path = zfp.extract(fileinfo, tmp_dir)
+        target_img_path = os.path.join(output_dir, img_name)
+        if IsSparseImage(img_path):
+          subprocess.check_call(["simg2img", img_path, target_img_path])
+        else:
+          os.rename(img_path, target_img_path)
+        print("Extracted", fileinfo.filename, "size:", fileinfo.file_size)
+
+  subprocess.call(["cow_converter", payload_path,
+                   output_dir])
+
+
+def main():
+  if len(sys.argv) != 4:
+    print(
+        "Usage:", sys.argv[0], "<your_ota.zip> <target_file.zip> <output dir>")
+    return 1
+  ota_path = sys.argv[1]
+  target_file_path = sys.argv[2]
+  output_dir = sys.argv[3]
+  os.makedirs(output_dir, exist_ok=True)
+  with tempfile.TemporaryDirectory() as tmp_dir:
+    ConvertCOW(ota_path, target_file_path, tmp_dir, output_dir)
+  return 0
+
+
+if __name__ == '__main__':
+  sys.exit(main())