[ECOS] RE: Interrupt vectors for FIQ

Gary Thomas gthomas@redhat.com
Sun Nov 4 15:17:00 GMT 2001

On Wed, 2001-11-14 at 08:56, Mike Checky wrote:
> I believe this is a question for 'Gary Thomas <gthomas at redhat dot
> com>'.  
> Is there any particular reason the you didn't include FIQ and SWIRQ in
> AT91EB40 interrupt processing?

No.  Just that it was not going to be tested and in general, we try and
discourage use of FIQ via the standard ISR/DSR mechanisms (since they 
tend to obviate the whole reason for using FIQ in the first place).

> I see no reason why it would not work.
> In relation to 'wu shaojie <w_shaojie at hotmail dot com>' question
> about adding FIQ processing to the AT91EB40, I think the
> 'hal_platform_ints.h' file should be changed to:
> #define CYGNUM_HAL_INTERRUPT_FIQ            0
> #define CYGNUM_HAL_INTERRUPT_SWIRQ          1
> Now for a general question:  The ARM interrupt processing is rather
> heavy weight, is there any plans to streamline this?  Not that I need
> it, I'm just curious.

How would you streamline it?  What's in there that could be [safely]
removed?  The only thing I can think of is possibly adjusting the
registers that are saved/restored to be a more minimal set.

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