util/unpack_ftb.py: a script to convert FTB file into bin file

ST firmwares are released in FTB format, which can't be written to flash
directly.  This python script can convert a file in FTB format into
bin file.  Currently, we only support FTB files of whiskers touchpad
firmware.

BRANCH=none
BUG=none
TEST=manual
Signed-off-by: Wei-Han Chen <stimim@chromium.org>

Change-Id: I179de12663580881347a31f11b5b10659e00b879
Reviewed-on: https://chromium-review.googlesource.com/918603
Commit-Ready: Wei-Han Chen <stimim@chromium.org>
Tested-by: Wei-Han Chen <stimim@chromium.org>
Reviewed-by: Nicolas Boichat <drinkcat@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/982319
Reviewed-by: Furquan Shaikh <furquan@chromium.org>
Commit-Queue: Furquan Shaikh <furquan@chromium.org>
Tested-by: Furquan Shaikh <furquan@chromium.org>
Trybot-Ready: Furquan Shaikh <furquan@chromium.org>

1 files changed, 105 insertions, 0 deletions

diff --git a/util/unpack_ftb.py b/util/unpack_ftb.py
new file mode 100755
index 0000000000..49f4d0ab5b
--- /dev/null
+++ b/util/unpack_ftb.py
@@ -0,0 +1,105 @@
+#!/usr/bin/env python
+# Copyright 2018 The Chromium OS Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+from __future__ import print_function
+import argparse
+import ctypes
+import os
+
+
+class Header(ctypes.Structure):
+  _pack_ = 1
+  _fields_ = [
+      ('signature', ctypes.c_uint32),
+      ('ftb_ver', ctypes.c_uint32),
+      ('chip_id', ctypes.c_uint32),
+      ('svn_ver', ctypes.c_uint32),
+      ('fw_ver', ctypes.c_uint32),
+      ('config_id', ctypes.c_uint32),
+      ('config_ver', ctypes.c_uint32),
+      ('reserved', ctypes.c_uint8 * 8),
+      ('release_info', ctypes.c_ulonglong),
+      ('sec_size', ctypes.c_uint32 * 4),
+      ('crc', ctypes.c_uint32),
+  ]
+
+FW_HEADER_SIZE = 64
+FW_HEADER_SIGNATURE = 0xAA55AA55
+FW_FTB_VER = 0x00000001
+FW_CHIP_ID = 0x3936
+FW_BYTES_ALIGN = 4
+FW_BIN_VER_OFFSET = 16
+FW_BIN_CONFIG_ID_OFFSET = 20
+
+# Starting address in flash for each section
+FLASH_SEC_ADDR = [
+    0x0000 * 4,  # CODE
+    0x7C00 * 4,  # CONFIG
+    0x7000 * 4,  # CX
+    None  # This section shouldn't exist
+]
+
+OUTPUT_FILE_SIZE = 128 * 1024  # 128KB
+
+
+def main():
+  parser = argparse.ArgumentParser()
+  parser.add_argument('--input', '-i', required=True)
+  parser.add_argument('--output', '-o', required=True)
+  args = parser.parse_args()
+
+  with open(args.input) as f:
+    bs = f.read()
+
+  size = len(bs)
+  if size < FW_HEADER_SIZE + FW_BYTES_ALIGN:
+    raise Exception('FW size too small')
+
+  print('FTB file size:', size)
+
+  header = Header()
+  assert ctypes.sizeof(header) == FW_HEADER_SIZE
+
+  ctypes.memmove(ctypes.addressof(header), bs, ctypes.sizeof(header))
+  if (header.signature != FW_HEADER_SIGNATURE or
+      header.ftb_ver != FW_FTB_VER or
+      header.chip_id != FW_CHIP_ID):
+    raise Exception('Invalid header')
+
+  for key, _ in header._fields_:
+    v = getattr(header, key)
+    if isinstance(v, ctypes.Array):
+      print(key, map(hex, v))
+    else:
+      print(key, hex(v))
+
+  dimension = sum(header.sec_size)
+
+  assert dimension + FW_HEADER_SIZE + FW_BYTES_ALIGN == size
+  data = bs[FW_HEADER_SIZE:FW_HEADER_SIZE + dimension]
+
+  with open(args.output, 'wb') as f:
+    # ensure the file size
+    f.seek(OUTPUT_FILE_SIZE - 1, os.SEEK_SET)
+    f.write('\x00')
+
+    offset = 0
+    # write each sections
+    for i, addr in enumerate(FLASH_SEC_ADDR):
+      size = header.sec_size[i]
+      assert addr is not None or size == 0
+
+      if size == 0:
+        continue
+
+      f.seek(addr, os.SEEK_SET)
+      f.write(data[offset : offset + size])
+      offset += size
+
+    f.flush()
+
+
+if __name__ == '__main__':
+  main()