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Date: Thu, 13 Nov 2008 18:57:41 +0100
From: Gilles Chanteperdrix <gilles.chanteperdrix@xenomai.org>
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Subject: Re: [Xenomai-help] Mode switch when using RT heap on ARM
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To: Wolfgang Grandegger <wg@domain.hid>
Cc: xenomai-help <xenomai@xenomai.org>

Wolfgang Grandegger wrote:
> Hello,
> 
> I realized that accessing memory allocated with rt_heap_alloc() causes
> mode switches on ARM i.mx31. The attached patch provides a demo program
> to demonstrate the problem, which actually does *not* show up on my
> PowerPC TQM5200 board.

Ok. I ran your test on an ARMv5 using an old version of Xenomai, and I
only get a fault on first write to the heap, being either cached or non
cached.

I will now run the tests on AT91RM9200 with a more recent version of
xenomai to confirm that we get the same effect, but if we do, this means
that we are facing an armv6 specific issue and that for a workaround, we
need to understand armv6 memory management.

-- 
                                                 Gilles.