Re: single-stepping remote target fails

[Ramana Radhakrishnan <ramana dot radhakrishnan at codito dot com>]

On Thu, 2005-06-23 at 11:40 -0400, Chad Phillips wrote:
>  >On Thu, Jun 23, 2005 at 11:18:28AM -0400, Chad Phillips wrote:
>  >> Problem 1.
>  >> Single stepping in C source only steps by single machine instruction.
>  >> I had expected that GDB might try to set breakpoints on the next
>  >> instruction and then continue, but I see no such requests from GDB.
>  >> How does GDB cause single steps through C (any high level language)
>  >> source?
>  >It does hardware single steps until the source line of the $pc changes.
> 
> Interesting.  It makes no requests to set breakpoints.  If I explicitly 
> set breakpoints, they work.   But when I issue the step command, I get 
> no breakpoint commands at my proxy application from GDB.  Any Ideas?

Can your stub single step by itself without the debugger ? Guess you can
do with the JTAG on. Does your remote stub support the single stepping
packet ? 

In any case do a set debug remote 1 just before you single step and
paste the output log over here. That could help answering.  

cheers
Ramana	



> 
>  >> Problem 2.
>  >> When I issue the step command (or si, n, ni) to the target, GDB does
>  >> a _lot_ of memory reads.  It reads from the start of main up to the
>  >> current PC (in main).  What is it doing, and how can I make it stop?
> 
>  >Preumably it is doing prologue analysis.  You need to work out (A) why
>  >it triggered the prolgoue analyzer and (B) whether you should be using
>  >unwind information instead of prologue analysis.
> 
> Thanks.  That make sense.
> 
> -Chad