[coreboot-gerrit] Change in ...coreboot[master]: util/mtkheader: Add a tool to extract bootload header from binary files.

[You-Cheng Syu (Code Review)]

You-Cheng Syu has uploaded this change for review. ( https://review.coreboot.org/c/coreboot/+/32333

Change subject: util/mtkheader: Add a tool to extract bootload header from binary files.
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util/mtkheader: Add a tool to extract bootload header from binary files.

Add a tool, extract-bl-img.py, which can extract MTK bootload header
from binary files. This could be useful for boards (e.g., Kukui) which
put the bootblock in other places (e.g., Chrome EC).

Change-Id: Ib744c80bdc2adfe27d4287365e161096e3fe08c7
Signed-off-by: You-Cheng Syu 
---
A util/mtkheader/extract-bl-img.py
1 file changed, 55 insertions(+), 0 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/33/32333/1

diff --git a/util/mtkheader/extract-bl-img.py b/util/mtkheader/extract-bl-img.py
new file mode 100755
index 0000000..21bf9eb
--- /dev/null
+++ b/util/mtkheader/extract-bl-img.py
@@ -0,0 +1,55 @@
+#!/usr/bin/env python
+# This file is part of the coreboot project.
+#
+# Copyright 2019 Google LLC
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; version 2 of the License.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+
+import argparse
+import struct
+import sys
+
+
+_DESCRIPTION = 'Extract MTK bootload header from a binary file.'
+
+
+def parse_args():
+  parser = argparse.ArgumentParser(description=_DESCRIPTION)
+  parser.add_argument('input_path', metavar='INPUT_FILE')
+  parser.add_argument('output_path', metavar='OUTPUT_FILE')
+  return parser.parse_args()
+
+
+def main():
+  args = parse_args()
+
+  with open(args.input_path, 'rb') as f:
+    data = f.read()
+
+  header = struct.pack('<8sII', 'BRLYT', 1, 2048)
+
+  start = -1
+  while True:
+    start = data.find(header, start + 1)
+    if start < 0:
+      raise RuntimeError('Cannot find MTK bootload header')
+    offset = start + len(header)
+    buf = struct.unpack('<II', data[offset:offset+8])
+    if buf[1] == 0x42424242:
+      break
+  size = buf[0]
+  offset = start - 512
+
+  with open(args.output_path, 'wb') as f:
+    f.write(data[offset:offset+size])
+
+
+if __name__ == '__main__':
+  main()