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RE: Re: On ARM7 can one of FIQ/IRQ be used for non-eCos stuff?
- From: "Paul D. DeRocco" <pderocco at ix dot netcom dot com>
- To: <ecos-discuss at sources dot redhat dot com>
- Date: Wed, 2 Apr 2008 13:59:20 -0700
- Subject: RE: [ECOS] Re: On ARM7 can one of FIQ/IRQ be used for non-eCos stuff?
> From: Grant Edwards
>
> That's easy enough, but it'd be trickier to provide a run-time
> function to fix the places in vectors.S that are currently
> disabling FIQ.
I think the issue is that there are lots of small critical sections
scattered all over the place that mask interrupts in the CPU, and they
currently mask both IRQ and FIQ. For the ARM, HAL_*_INTERRUPTS uses 0xC0 to
manipulate both these bits. If all eCos ISRs are invoked via IRQ, and FIQ is
reserved for a special bit of driver code that merely adds functionality to
a piece of hardware (like adding a FIFO to a serial port) without invoking a
DSR, then these macros really ought to use 0x80 instead. That would be a
useful CDL option.
--
Ciao, Paul D. DeRocco
Paul mailto:pderocco@ix.netcom.com
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