Write the packaged USB gadget app in binary mode.

tools/usb_gadget/package.py

 #!/usr/bin/python
 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """Utility to package and upload the USB gadget framework.
 """
 
 import argparse
 import hashlib
@@ skipping 64 matching lines @@
       '--upload', type=str, metavar='HOST[:PORT]',
       help='upload package to target system')
   parser.add_argument(
       'files', metavar='FILE', type=str, nargs='*',
       help='source files')
 
   args = parser.parse_args()
 
   content, md5 = MakeZip(directory=args.dir, files=args.files)
   if args.zip_file:
-    with open(args.zip_file, 'w') as zip_file:
+    with open(args.zip_file, 'wb') as zip_file:
       zip_file.write(content)
   if args.hash_file:
-    with open(args.hash_file, 'w') as hash_file:
+    with open(args.hash_file, 'wb') as hash_file:
       hash_file.write(md5)
   if args.upload:
     UploadZip(content, md5, args.upload)
 
 
 if __name__ == '__main__':
   main()