Anyone using BDM to debug RTEMS on a 68332 platform?

Chris Johns cjohns at
Wed Apr 10 04:40:13 UTC 2002

Mike Panetta wrote:

> I have been trying to debug a serial problem with the MRM port, related
> to interrupt driven serial IO, but I have run into an unexpected problem
> with (I suspect) GDB with the BDM driver.  It does not seem to be able
> to report the correct values of some variables on the stack, but not all
> the time.  I have tested that the value of the variable is what I think
> it really is by doing a printk(), and it prints the correct value, but
> display, or print will not in GDB.  I can even dump the stack with x /4x
> $sp and I can see what I expect is the correct value at the correct
> location on the stack, but print still does not work.  So has anyone
> else here used GDB + the BDM patch on a 68332 platform and experienced a
> similar problem?

No. These all tend to be problems with the BDM hardware, the target 
hardware or inline code and data being in registers etc. Using c++ can 
make it even worse.


> Has anyone experienced this problem on the ColdFire? 


No. If something goes wrong on the target that is not handled cleanly 
such as a stack overrun or unhandled exception then this happens.

> Oh, and another GDB commnd that does not work properly is bt, because of
> the same reason I suspect.

Are you sure the stack is where it should be and no extra fields have 
appeared due to an exception stack frame ?


> My hunch is that the problem is related to
> inline code confusing GDB, but thats only a guess, I have no real way to
> test it.  I have tried, but could not reproduce the problem in my
> limited test case.

  Chris Johns, cjohns at

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