[ECOS] Re: On ARM7 can one of FIQ/IRQ be used for non-eCos stuff?

Paul D. DeRocco pderocco@ix.netcom.com
Wed Apr 2 20:59:00 GMT 2008

> 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

Before posting, please read the FAQ: http://ecos.sourceware.org/fom/ecos
and search the list archive: http://ecos.sourceware.org/ml/ecos-discuss

More information about the Ecos-discuss mailing list