Re: Remote breakpoint problem

[Daniel Jacobowitz <drow at mvista dot com>]

On Fri, Feb 14, 2003 at 05:28:43PM +0100, Jan Hoogerbrugge wrote:
> >From: Mark Salter <msalter@redhat.com>
> >To: ac131313@redhat.com
> >>>>>> Andrew Cagney writes:
> >
> >>> Hi,
> >>>
> >>> I am porting gdb to a new target processor were remote debugging is 
> >used. I have a problem with breakpoints. When I place a breakpoint on foo 
> >followed by a continue I see the following communication between gdb and 
> >the stub on the other side:
> >>>
> >>> - the instruction at foo is saved
> >>> - foo is replaced by a breakpoint instruction
> >>> - gdb sends a continue command
> >>> - the stub reports the breakpoint hit (signal = 5, pc = foo)
> >>> - gdb replaces the code at foo with the saved instruction
> >>> - gdb sends a step instruction command
> >>> - tbe stub reports again a breakpoint hit at foo (signal = 5, pc = foo)
> >
> >> Shouldn't this stop beyond foo?
> >
> >I wonder if the stub is flushing the icache after gdb puts the
> >saved instruction back...
> 
> Caches are properly syncronisched. The respone of the remote target and its 
> stub is correct as far as I can see. It is gdb that issues a continue 
> command to the stub after hitting the breakpoint and single stepping the 
> instruction on which teh breakpoint was placed.

If you single-step over the instruction at foo, and the stub reports a
stop at foo, something is wrong.  You're stopped at the _following_
instruction.


-- 
Daniel Jacobowitz
MontaVista Software                         Debian GNU/Linux Developer