1502494cba
BUG=chromium:1023662
TEST=1. Create a tiny file `in.txt` as input
2. Run `fixed_cksum.py in.txt out.txt 20` with py2 and py3 version,
the output is the same
3. Run `variable_cksum.py in.txt out.txt` with py2 and py3 version,
the output is the same
Signed-off-by: Yilin Yang <kerker@google.com>
Change-Id: I9428269dfb826a3a95fffef9ea3f7c1a7107ef84
Reviewed-on: https://review.coreboot.org/c/coreboot/+/45460
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Hung-Te Lin <hungte@chromium.org>
Reviewed-by: Yu-Ping Wu <yupingso@google.com>
36 lines
882 B
Python
Executable file
36 lines
882 B
Python
Executable file
#!/usr/bin/env python3
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#
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# SPDX-License-Identifier: BSD-3-Clause
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"""
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This utility computes and fills Exynos ROM checksum (for BL1 or BL2).
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(Algorithm from U-Boot: tools/mkexynosspl.c)
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Input: IN OUT DATA_SIZE
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Output:
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IN padded out to DATA_SIZE, checksum at the end, written to OUT.
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"""
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import struct
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import sys
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def main(argv):
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if len(argv) != 4:
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exit('usage: %s IN OUT DATA_SIZE' % argv[0])
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in_name, out_name = argv[1:3]
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size = int(argv[3], 0)
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checksum_format = "<I"
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with open(in_name, "rb") as in_file, open(out_name, "wb") as out_file:
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data = in_file.read()
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checksum_size = struct.calcsize(checksum_format)
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data_size = size - checksum_size
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assert len(data) <= data_size
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checksum = struct.pack(checksum_format, sum(data))
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out_file.write(data + bytearray(data_size - len(data)) + checksum)
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if __name__ == '__main__':
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main(sys.argv)
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