Aleksandar Ristovski(deleted)
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Aleksandar Ristovski(deleted)
11/17/2008 9:55 AM
post16665
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Cédric Schaffter wrote:
> Hi!
>
> I recently wrote an interrupt handler and it works fine. But I would like to know if I have/need to save the FPU
context when an interrupt occurs?
>
> Or is it automatically performed by the kernel? Is there some documentation about that?
I believe that it is being saved for you, but you can pose
this question in OSTech forum, you will get a better answer
faster.
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Thomas Haupt
11/17/2008 9:57 AM
post16667
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Hi Cédric,
the kernel does not save/restore the FPU context around interrupt
handling, because this would cause a lot of overhead that's usually
not required.
Saving the FPU context would only be necessary if the FPU was used
within an interrupt handler, which is hardly ever the case.
If you should really feel an urgent need to do floating pint in
an ISR, you'll have to do the save/restore yourself. I even think
there's some documentation regarding this topic.
- Thomas
> -----Ursprüngliche Nachricht-----
> Von: Cédric Schaffter [mailto:community-noreply@qnx.com]
> Gesendet: 17 November 2008 15:53
> An: general-community
> Betreff: save FPU context
>
>
> Hi!
>
> I recently wrote an interrupt handler and it works fine. But
> I would like to know if I have/need to save the FPU context
> when an interrupt occurs?
>
> Or is it automatically performed by the kernel? Is there some
> documentation about that?
>
> Best regards,
> Cédric
>
> _______________________________________________
> General
> http://community.qnx.com/sf/go/post16664
>
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