| #!/usr/bin/env python3 |
| # |
| # SPDX-License-Identifier: BSD-3-Clause |
| |
| """ |
| This utility computes and fills Exynos ROM checksum (for BL1 or BL2). |
| (Algorithm from U-Boot: tools/mkexynosspl.c) |
| |
| Input: IN OUT DATA_SIZE |
| |
| Output: |
| |
| IN padded out to DATA_SIZE, checksum at the end, written to OUT. |
| """ |
| |
| import struct |
| import sys |
| |
| def main(argv): |
| if len(argv) != 4: |
| exit('usage: %s IN OUT DATA_SIZE' % argv[0]) |
| |
| in_name, out_name = argv[1:3] |
| size = int(argv[3], 0) |
| checksum_format = "<I" |
| with open(in_name, "rb") as in_file, open(out_name, "wb") as out_file: |
| data = in_file.read() |
| checksum_size = struct.calcsize(checksum_format) |
| data_size = size - checksum_size |
| assert len(data) <= data_size |
| checksum = struct.pack(checksum_format, sum(data)) |
| out_file.write(data + bytearray(data_size - len(data)) + checksum) |
| |
| |
| if __name__ == '__main__': |
| main(sys.argv) |
