RE: how to compare two hex files

ashokraj — Wed, 03 Oct 2018 13:26:26 GMT

Thanks for the response. Reason for this question: There are two versions of the software. we wil have to upload only version 2 in the control box but not so sure which version of software is in the control box so I would like to compare and decide.

RE: how to compare two hex files

AmbystomaLabs — Tue, 02 Oct 2018 21:22:41 GMT

There are many hex editing utilities out there that will let you compare two hex files and even edit them.

One such utility is HxD: https://mh-nexus.de/en/hxd/

The better question is, is it fruitful to compare two hex files. Unless you know precisely which bits you want to twiddle the answer is no. Even two copies of the same compiler won't produce the same output unless precisely everything is the same. Same versions of all libraries and supporting files, same settings, even the pathways can affect the output.

So unless you are particularly talented at reading assembly you won't find much there. Hex files are just a bunch of opcodes, memory addresses and numbers. You can decompile the hex, but most of the readable structure won't be there. You will end up with a vaguely C looking thing that will be very different looking than what you started with.

Here is a fun link I found on the web, discusses the same as above but gives a real life example: https://reverseengineering.stackexchange.com/questions/11650/how-can-i-decompile-an-arm-cortex-m0-hex-file-to-c