Fix warning in OpenOCD about LPC vector checksum

Warn : Verification will fail since checksum in image (0x1a00ab8d) to be written to flash is different from calculated vector checksum (0x53fc729a).
Warn : To remove this warning modify build tools on developer PC to inject correct LPC vector checksum.

The solution to the problem is quite easy, just modify your favorite build tool to run this script before you flash your file, and it will add the missing checksum so the warning disappears:

The code was translated from the C version you can get from this blogpost:

Cortex-M3 Exception Vector Checksum

It works too, but it is a C program. I didn’t want to compile it nor push pre-compiled binaries to my repository. I wanted a plug and play solution that would ‘just work’ after pulling my repository on a different machine, so I rewrote it in Python.

Thanks for reading.