arm debuging and exception handler.

Pavel Pisa ppisa4lists at
Mon Feb 20 23:47:23 UTC 2006

On Monday 20 February 2006 10:41, you wrote:
> Hi Pavel,
> I remeber you asked me information on arm debugging, well i'm trying to
> work in this direction too, and I'd like to know what have you done so
> far?
> It looks like the arm exception handlers for under, data abort and
> prefetch abort are a bit flaky.
> I'm working to rewrite them using eCos excption handler as template.
> next step will be to integrate Till's gdb stub
> (
> I was thinking to use eCos gdb-stub as template also.
> Philippe

Hello Philippe,

I have working well solution for ARM RTEMS target debugging now.
It is port of Linux KGDB patches.
The GPL license disallows their inclusion into final
firmware builds, but they are good for development
and for opensource projects.

I can send sources. You have to adapt connection to the serial
code and FIQ source to port them to other than MX1 ARM chip.

I have found some problems with UNDEF stack setup and other ARM
exception related code. You can find fixes for these
in my public RTEMS patches and build helpers repository;a=summary

The next two patches could help


The second one has to be ported to your SoC chip, it is for MX1 only.
I have send these to Jay Monkman two months ago, but they have not been
reviewed and I have not received final resolution for RTEMS CVS yet.

I have even almost original or may be little Linux inspired generic
exception handling code capable to save and restore all ARM registers
reasonable for debugger connection.

I have similar code stack to do ARM debugging for system-less
arrangement as well. I have already mentioned some of my progress
on the list in December.

By the way, there is new open source JTAG solution for ARM debugging
available now

I want to test it in near future.

All these debugging options are full system stop type ones,
some thread aware, thread group stop only solution would
be interresting as well.

I am sending copy to the list, because some other developers
could be interrested into these informations as well.
I hope you do not mind that.

Best wishes


More information about the users mailing list