Debugging firmware from a microcontroller

[andrewlynes]

Hello community!

I am a humble CodeWarrior novice and have a question which I hope that the community may be able to help answer.

I have an automotive component which uses an s12x microcontroller. I wonder if it is possible to extract the firmware by jtag and then run the binary in a simulation in Code Warrior to analyse in a controlled environment (e.g. provoke my own inputs/outputs) and also debug. Is this something that can be done with Code Warrior?

Thanks in advance.

Andy Lynes

[Lundin · Accepted solution]

The S12 family uses something called BDM, which is similar to JTAG. If the S12 sits on a shipped automotive PCB, it will most certainly have MCU security enabled, blocking all attempts to read the binary. This is done through internal hardware in the MCU and the intention is to block copy cats from stealing the program. The only way you can access a secured chip is to erase it completely then download a new program.

So you need to have the original source code.

[andrewlynes]

Bump! Just wondering if anybody had a chance to ponder this question over the weekend?

Thanks