Greg Steiert / maxim_dev

Dependents:   sensomed

tools/patch.py@0:0e018d759a2a, 2016-11-08 (annotated)

Committer:
switches
Date:
Tue Nov 08 18:27:11 2016 +0000
Revision:
0:0e018d759a2a
Initial commit

Who changed what in which revision?

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switches 0:0e018d759a2a 1 """
switches 0:0e018d759a2a 2 mbed SDK
switches 0:0e018d759a2a 3 Copyright (c) 2011-2013 ARM Limited
switches 0:0e018d759a2a 4
switches 0:0e018d759a2a 5 Licensed under the Apache License, Version 2.0 (the "License");
switches 0:0e018d759a2a 6 you may not use this file except in compliance with the License.
switches 0:0e018d759a2a 7 You may obtain a copy of the License at
switches 0:0e018d759a2a 8
switches 0:0e018d759a2a 9 http://www.apache.org/licenses/LICENSE-2.0
switches 0:0e018d759a2a 10
switches 0:0e018d759a2a 11 Unless required by applicable law or agreed to in writing, software
switches 0:0e018d759a2a 12 distributed under the License is distributed on an "AS IS" BASIS,
switches 0:0e018d759a2a 13 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
switches 0:0e018d759a2a 14 See the License for the specific language governing permissions and
switches 0:0e018d759a2a 15 limitations under the License.
switches 0:0e018d759a2a 16
switches 0:0e018d759a2a 17
switches 0:0e018d759a2a 18 http://www.nxp.com/documents/user_manual/UM10360.pdf
switches 0:0e018d759a2a 19
switches 0:0e018d759a2a 20 32.3.1.1 Criterion for Valid User Code
switches 0:0e018d759a2a 21 The reserved Cortex-M3 exception vector location 7 (offset 0x1C in the vector table)
switches 0:0e018d759a2a 22 should contain the 2's complement of the check-sum of table entries 0 through 6. This
switches 0:0e018d759a2a 23 causes the checksum of the first 8 table entries to be 0. The boot loader code checksums
switches 0:0e018d759a2a 24 the first 8 locations in sector 0 of the flash. If the result is 0, then execution control is
switches 0:0e018d759a2a 25 transferred to the user code.
switches 0:0e018d759a2a 26 """
switches 0:0e018d759a2a 27 from struct import unpack, pack
switches 0:0e018d759a2a 28
switches 0:0e018d759a2a 29
switches 0:0e018d759a2a 30 def patch(bin_path):
switches 0:0e018d759a2a 31 with open(bin_path, 'r+b') as bin:
switches 0:0e018d759a2a 32 # Read entries 0 through 6 (Little Endian 32bits words)
switches 0:0e018d759a2a 33 vector = [unpack('<I', bin.read(4))[0] for _ in range(7)]
switches 0:0e018d759a2a 34
switches 0:0e018d759a2a 35 # location 7 (offset 0x1C in the vector table) should contain the 2's
switches 0:0e018d759a2a 36 # complement of the check-sum of table entries 0 through 6
switches 0:0e018d759a2a 37 bin.seek(0x1C)
switches 0:0e018d759a2a 38 bin.write(pack('<I', (~sum(vector) + 1) & 0xFFFFFFFF))
switches 0:0e018d759a2a 39
switches 0:0e018d759a2a 40
switches 0:0e018d759a2a 41 def is_patched(bin_path):
switches 0:0e018d759a2a 42 with open(bin_path, 'rb') as bin:
switches 0:0e018d759a2a 43 # The checksum of the first 8 table entries should be 0
switches 0:0e018d759a2a 44 return (sum([unpack('<I', bin.read(4))[0] for _ in range(8)]) & 0xFFFFFFFF) == 0
switches 0:0e018d759a2a 45
switches 0:0e018d759a2a 46
switches 0:0e018d759a2a 47 if __name__ == '__main__':
switches 0:0e018d759a2a 48 bin_path = "C:/Users/emimon01/releases/emilmont/build/test/LPC1768/ARM/MBED_A1/basic.bin"
switches 0:0e018d759a2a 49 patch(bin_path)
switches 0:0e018d759a2a 50 assert is_patched(bin_path), "The file is not patched"