[Xenomai] OMAP L138

Peter Howard pjh at northern-ridge.com.au
Tue Apr 8 04:37:52 CEST 2014

On Mon, 2014-04-07 at 11:53 +0200, Gilles Chanteperdrix wrote:
> On 04/07/2014 07:34 AM, Peter Howard wrote:
> > 
> > On Wed, 2014-04-02 at 09:24 +0200, Gilles Chanteperdrix wrote:
> >> On 04/02/2014 04:59 AM, Peter Howard wrote:
> >>> Hi,
> >>>
> >>> I'm interested in running xenomai on a TI-OMAP L138 board.  I found the
> >>> following thread in the archives:
> >>>
> >>> http://www.xenomai.org/pipermail/xenomai/2010-January/018898.html
> >>>
> >>> where someone was working on porting ipipe and xenomai to that board.
> >>> However, the thread ended with problems still unresolved, and the patch
> >>> in the thread (just the changes for ipipe) isn't in the ipipe
> >>> repository.
> >>>
> >>> Does anyone know if this work was completed or just faded into the
> >>> ether?
> >>
> >> We never merged a patch for this processor. And a lot of things changed
> >> since that time. If you are interested in porting the I-pipe patch to
> >> this processor, see:
> >>
> >> http://www.xenomai.org/index.php/I-pipe-core:ArmPorting
> >>
> > 
> > Contrary to what I said last week, I'm working on a patch off the head
> > of the ipipe repo.  I have built a kernel with an ipipe port and with
> > xenomai patched in.  However the latency results are bad right now:
> Well, in that case enable the I-pipe tracer, and run latency with the -f
> option to know why.

I turned the tracing on and . . . start getting kernel panics from a
NULL pointer dereference.  If I have tracing on from boot it dies
shortly after getting to the login prompt.  If I disable it at boot, I
start getting ext-3 errors as soon as I enable it (losing the ability to
read the filesystem at all), then get the panic a few seconds later.  I
get an I-pipe tracer log along with the panic, but aren't really sure
how to interpret it in this context.   In all cases the failure appears
to be in the context of __ipipe_trace():

Unable to handle kernel NULL pointer dereference at virtual address 00000004    
pgd = c73e8000, hw pgd = c73e8000                                               
[00000004] *pgd=c72a3831, *pte=00000000, *ppte=00000000                         
Internal error: Oops: 817 [#1] PREEMPT ARM                                      
Modules linked in:                                                              
CPU: 0 PID: 2307 Comm: run-parts Not tainted 3.10.0-ipipe-00165-g9a2c8c8-dirty 5
task: c70ef800 ti: c737a000 task.ti: c737a000                                   
PC is at get_page_from_freelist+0x164/0x750                                     
LR is at __ipipe_trace+0xa8/0x5b8                                           

I'm going to keep digging to see if I can work out what the actual
failure is, but any suggestions would be appreciated.  (I can provide
full dump and following trace log if it would be useful)

Peter Howard <pjh at northern-ridge.com.au>

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