Nico Huber | ca41a6a | 2016-01-23 21:29:47 +0100 | [diff] [blame] | 1 | #!/usr/bin/env python2 |
Gabe Black | b6b1077 | 2013-12-08 12:48:45 -0800 | [diff] [blame] | 2 | # |
| 3 | # Copyright (C) 2013 Google Inc. |
| 4 | # |
| 5 | # Redistribution and use in source and binary forms, with or without |
| 6 | # modification, are permitted provided that the following conditions |
| 7 | # are met: |
| 8 | # 1. Redistributions of source code must retain the above copyright |
| 9 | # notice, this list of conditions and the following disclaimer. |
| 10 | # 2. Redistributions in binary form must reproduce the above copyright |
| 11 | # notice, this list of conditions and the following disclaimer in the |
| 12 | # documentation and/or other materials provided with the distribution. |
| 13 | # 3. The name of the author may not be used to endorse or promote products |
| 14 | # derived from this software without specific prior written permission. |
| 15 | # |
| 16 | # THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND |
| 17 | # ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| 18 | # IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| 19 | # ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE |
| 20 | # FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| 21 | # DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| 22 | # OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| 23 | # HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| 24 | # LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| 25 | # OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| 26 | # SUCH DAMAGE. |
| 27 | |
| 28 | """ |
| 29 | This utility computes and fills Exynos ROM checksum (for BL1 or BL2). |
| 30 | (Algorithm from U-Boot: tools/mkexynosspl.c) |
| 31 | |
| 32 | Input: IN OUT DATA_SIZE |
| 33 | |
| 34 | Output: |
| 35 | |
| 36 | IN padded out to DATA_SIZE, checksum at the end, written to OUT. |
| 37 | """ |
| 38 | |
| 39 | import struct |
| 40 | import sys |
| 41 | |
| 42 | def main(argv): |
| 43 | if len(argv) != 4: |
| 44 | exit('usage: %s IN OUT DATA_SIZE' % argv[0]) |
| 45 | |
| 46 | in_name, out_name = argv[1:3] |
| 47 | size = int(argv[3], 0) |
| 48 | checksum_format = "<I" |
| 49 | with open(in_name, "rb") as in_file, open(out_name, "wb") as out_file: |
| 50 | data = in_file.read() |
| 51 | checksum_size = struct.calcsize(checksum_format) |
| 52 | data_size = size - checksum_size |
| 53 | assert len(data) <= data_size |
| 54 | checksum = struct.pack(checksum_format, sum(map(ord, data))) |
| 55 | out_file.write(data + bytearray(data_size - len(data)) + checksum) |
| 56 | |
| 57 | |
| 58 | if __name__ == '__main__': |
| 59 | main(sys.argv) |