Context Switch Problem

[Samuel Bitton]

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.

Regards
Sam

 -----Original Message-----
From: 	Joel Sherrill [mailto:joel.sherrill at oarcorp.com] 
Sent:	12 May 2006 16:21
To:	Chris Johns
Cc:	Samuel Bitton; rtems-users at rtems.com
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:
>
>  http://www.rtems.org/wiki/index.php/DebuggingHints
>
> 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. :)

--joel

> Regards
> Chris