OpenOCD tips and tricks?

[Chris Johns]

On 18/08/2015 4:27 am, Ric Claus wrote:
> 
> On Aug 17, 2015, at 4:42 AM, Chris Johns <chrisj at rtems.org> wrote:
> 
>>>
>>>  Unfortunately, now I’ve run into openocd’s software breakpoints being ignored.  Hardware breakpoints, however, do work.  Curiously, gdb’s breakpoints do kind of work, and these seem to translate to software openocd breakpoints.  I say “kind of” because gdb’s step, next and continue commands after having stopped at a breakpoint don’t work.  The PC just remains fixed at the breakpoint address.  I’ve been digging through the mailing lists, looking at the gdbserver transactions and openocd’s diagnostics trying to find a clue, but so far have not come up with anything. Do you have any ideas?
>>
>> As I said in the other thread, I need to find time to dig into OpenOCD
>> and see if the L2 cache is the issue. Paul Fertser over at the OpenOCD
>> project knows there is an issue and it has been sitting with me for a
>> while now.
> 
> You and Jiri appear to be correct, as I read the code.  It looks like a fix should be almost simple, but I’m not through the details yet.  I don’t know to what extent I can help, but I’ll go ahead and volunteer anyway.  If you could provide guidance, I’d much appreciate it.  On the other hand, if you’d rather take care of it, that’s fine, too, just let me know.
> 

I am more than happy for you to take a look. We can take this off line
from here as it is not RTEMS related and maybe include Paul.

I know the L2 cache is a core cell from ARM but I am not sure how this
is handled in OpenOCD. The layering around the cortexa.c code means you
have to look into a few different bits.

Chris