Context Switch Problem

Samuel Bitton S.Bitton at
Fri May 12 14:34:50 UTC 2006

I don't believe that's the problem though as the software actually breaks during context switch, i.e. I don't come out of the _Context_Switch, and as far as I can tell the enabling of the interrupts is not done by _Context_Switch but by _ISR_Enable which happens just after.


 -----Original Message-----
From: 	Joel Sherrill [mailto:joel.sherrill at] 
Sent:	12 May 2006 16:21
To:	Chris Johns
Cc:	Samuel Bitton; rtems-users at
Subject:	Re: Context Switch Problem

Chris Johns wrote:

> Samuel Bitton wrote:
>> Hi
>> I'm currently working on a new RTEMS BSP for a custom made board 
>> based around the i386ex processor.
>> The software currently breaks towards the end of RTEMS 
>> initialisation, at the point where it is doing the first context 
>> switch (_Context_Switch called at the end of 
>> _Thread_Start_multitasking).
>> My application only has one small init task which toggles a line 
>> indefinitely.
>> Any idea what could be going wrong.
>> I'm using RTEMS 4.6.4.
> Have you look over this page:
> It has some reasons a BSP can fail.
And the most likely reason is included there -- an interrupt is pending 
and you are taking
an exception.  The first context switch enables CPU interrupts and any 
device not in a
quiescent state will slap you here. :)


> Regards
> Chris

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