48 lines
1.3 KiB
Python
48 lines
1.3 KiB
Python
#!/usr/bin/env python3
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import sys
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import struct
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def align(num, alignment):
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if num % alignment != 0:
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num += (alignment - num % alignment)
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return num
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def process_file(input, output):
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with open(input, 'rb') as fin:
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content = bytearray(fin.read())
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align_value = 512
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padded_length = align(len(content), align_value)
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# pad file to actual length
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content += b'\x00' * (padded_length - len(content))
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struct_format = '<L8sLL'
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(instruction, magic, checksum, length) = struct.unpack_from(struct_format, content)
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if magic != b'eGON.BT0':
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print("Magic is invalid:", magic)
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return 2
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checksum = 0x5F0A6C39
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length = align(length, align_value)
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struct.pack_into(struct_format, content, 0, instruction, magic, checksum, length)
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checksum = 0
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for i in range(0, length, 4):
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(n, ) = struct.unpack_from('<L', content, i)
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checksum += n
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checksum %= 4294967296
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struct.pack_into(struct_format, content, 0, instruction, magic, checksum, length)
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with open(output, 'wb') as fout:
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fout.write(content)
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return 0
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if __name__ == "__main__":
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if len(sys.argv) != 3:
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print("Usage: mksunxi.py input.bin output.bin")
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exit(1)
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exit(process_file(sys.argv[1], sys.argv[2])) |