Re: [Openocd-development] 'flash write_image' and 'verify_image' commands fail if there are no more hardware breakpoints available

[Ø. H. <oyv...@zy...>]

On Thu, Jul 31, 2008 at 11:13 AM, Dario Vecchio <dar...@ti...> wrote:
> Hi all,
>
> I found that after manually setting hardware breakpoints 'flash write_image'
> and 'verify_image' commands fail if there are no more hardware breakpoints
> available.
>
> I think they should be removed before command execution and then restored.

I guess the problem is that that would be another code path to test... The
code is working as intended otherwise.

This would have to be done *everywhere* in the code and at that point I'd
rather place this responsibility with the debugger, which can enable/disable
breakpoints before/after stepping/running.

You could define a few step/breakpoint commands in tcl that has this
functionality. The existing functions would then be the low level implementation
of hardware/software breakpoints.

This isn't a problem when debugging with GDB, is it?

> ---------------------------------------------------------
>
> Another question, about 'working_area'.
>
> By default scripts (at least str9comstick.cfg) point at the beginning of
> SRAM.
> For this reason it is not very clear what 'working_area' is (unless you read
> the documentation...) and one can believe (me, for example...) it is the
> beginning of internal SRAM.
> If you load an application into the RAM at the same address (normally at the
> beginning of SRAM) using 'load-image' there is no check of this conflict and
> the load_image algorithm will overwrite itself while running.
>
> Similar problem can happen if you are stepping an application (loaded in
> flash) and you want to load an image (data for debugging purpose) into the
> RAM at a known free address and then resume the application.
> The beginning of the RAM will be overwritten by the algorithm code so some
> variable of your running application is now dirty (registers too?).
> In this case you can use the 'backup' option of 'working_area' command but
> it is not in the default script (should it be?) nor a warning is given to
> the user.
>
> The problem is evident only with 'dcc_downloads' enabled.

How do you propose to deal with this from a users point of view?

-- 
Øyvind Harboe
http://www.zylin.com/zy1000.html
ARM7 ARM9 XScale Cortex
JTAG debugger and flash programmer