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- """
- mbed SDK
- Copyright (c) 2011-2013 ARM Limited
-
- Licensed under the Apache License, Version 2.0 (the "License");
- you may not use this file except in compliance with the License.
- You may obtain a copy of the License at
-
- http://www.apache.org/licenses/LICENSE-2.0
-
- Unless required by applicable law or agreed to in writing, software
- distributed under the License is distributed on an "AS IS" BASIS,
- WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- See the License for the specific language governing permissions and
- limitations under the License.
-
-
- http://www.nxp.com/documents/user_manual/UM10360.pdf
-
- 32.3.1.1 Criterion for Valid User Code
- The reserved Cortex-M3 exception vector location 7 (offset 0x1C in the vector table)
- should contain the 2's complement of the check-sum of table entries 0 through 6. This
- causes the checksum of the first 8 table entries to be 0. The boot loader code checksums
- the first 8 locations in sector 0 of the flash. If the result is 0, then execution control is
- transferred to the user code.
- """
- from struct import unpack, pack
-
-
- def patch(bin_path):
- with open(bin_path, 'r+b') as bin:
- # Read entries 0 through 6 (Little Endian 32bits words)
- vector = [unpack('<I', bin.read(4))[0] for _ in range(7)]
-
- # location 7 (offset 0x1C in the vector table) should contain the 2's
- # complement of the check-sum of table entries 0 through 6
- bin.seek(0x1C)
- bin.write(pack('<I', (~sum(vector) + 1) & 0xFFFFFFFF))
-
-
- def is_patched(bin_path):
- with open(bin_path, 'rb') as bin:
- # The checksum of the first 8 table entries should be 0
- return (sum([unpack('<I', bin.read(4))[0] for _ in range(8)]) & 0xFFFFFFFF) == 0
-
-
- if __name__ == '__main__':
- bin_path = "C:/Users/emimon01/releases/emilmont/build/test/LPC1768/ARM/MBED_A1/basic.bin"
- patch(bin_path)
- assert is_patched(bin_path), "The file is not patched"
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