topic Re: Codewarrior 5.9.0 stop debugger on exception 0x700 instead of continuing execution to exception handler in Classic/Legacy CodeWarrior

Codewarrior 5.9.0 stop debugger on exception 0x700 instead of continuing execution to exception handler

stefanoesposito — Thu, 27 Mar 2014 16:47:56 GMT

I'm working on a fault injection campaign and I'm interested in processing the 0x700 (invalid opcode) exception through my ISR, but Codewarrior is just showing a dialog and stops the debug session. My system features an MPC7448 processor and I'm using a CodeWarrior USB TAP. How can I stop this from happening and have the exception handler properly executed?

Re: Codewarrior 5.9.0 stop debugger on exception 0x700 instead of continuing execution to exception handler

yipingwang — Thu, 10 Apr 2014 11:41:26 GMT

For MPC7448 target, the CodeWarrior Debugger places a Hardware breakpoint at the exception address(0x00000700 or 0xFFF00700, depending on MSR[IP]) When the chip hit a breakpoint address, it will treat the Program exception as part of breaking handling process, it is import that a valid non-fetching instruction located at this Exception vector points, and it resides in valid memory. Also, the target code must not alter the MSR[IP] while it is running if you expect to hit a breakpoint. Please check your debug environment to meet this debug environment.

In addition, please put "writereg SP 0x0000000F" in CodeWarrior initialization file to interpret EABI stack frames. These stack frames include pointers, and if the debugger reads invalid stack frames then it will not work.

Re: Codewarrior 5.9.0 stop debugger on exception 0x700 instead of continuing execution to exception handler

stefanoesposito — Thu, 10 Apr 2014 12:02:30 GMT

Thanks for the answer. Could you just clarify what you mean by "non-fetching instruction", please? Thank you.

Re: Codewarrior 5.9.0 stop debugger on exception 0x700 instead of continuing execution to exception handler

stefanoesposito — Thu, 10 Apr 2014 14:32:15 GMT

I've just checked my board initialization file, and besides writereg SP 0x0000000F, I've also found the instruction writemem.l 0x700 0x48000000, is this what you meant by non-fetching instruction?

Re: Codewarrior 5.9.0 stop debugger on exception 0x700 instead of continuing execution to exception handler

yipingwang — Tue, 06 May 2014 10:35:20 GMT

Yes, the infinite loop at program exception prevents taking the exception again.