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patch.py: add secure area crc

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This commit is contained in:
Zack Buhman 2024-09-02 23:02:51 -05:00
parent c0395c9a7e
commit 838388caaf
1 changed files with 20 additions and 9 deletions
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29
patch.py
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@ -35,28 +35,39 @@ logo = [
logo_b = bytes(logo)
assert crc16_modbus(logo_b) == 0xcf56
import struct
import sys
with open(sys.argv[1], 'rb') as f:
buf = bytearray(f.read())
assert buf[0x15c] == 0x56
assert buf[0x15d] == 0xcf
#assert buf[0x15c] == 0x56
#assert buf[0x15d] == 0xcf
logo_crc = crc16_modbus(buf[0x0c0:0xc0 + 0x9c])
logo_crc = crc16_modbus(buf[0x0c0:0x15b+1])
print("logo", hex(logo_crc))
assert logo_crc == 0xcf56
header_crc = crc16_modbus(buf[0:0x15e])
print("header", hex(header_crc))
if logo_crc != 0xcf56:
for i, e in enumerate(logo):
print(i, e, hex (0xc0+i))
buf[0x0c0 + i] = e
logo_crc = crc16_modbus(buf[0x0c0:0x15b+1])
print("logo2", hex(logo_crc))
secure_area_crc = crc16_modbus(buf[0x4000:0x8000])
print("secure area", hex(secure_area_crc))
secure_area_crc_b = struct.pack('<H', secure_area_crc)
buf[0x06c] = secure_area_crc_b[0]
buf[0x06d] = secure_area_crc_b[1]
import struct
header_crc = crc16_modbus(buf[0:0x15d + 1])
print("header", hex(header_crc))
header_crc_b = struct.pack('<H', header_crc)
buf[0x15e] = header_crc_b[0]
buf[0x15f] = header_crc_b[1]
with open(sys.argv[2], 'wb') as f:
f.write(buf)
assert len(buf) <= 131072, len(buf)
i = 131072 - len(buf)
while i > 0:
f.write(bytes([0]))
i -= 1