Subject: Re: callgraph ARM7
To: Reinoud Zandijk <reinoud@netbsd.org>
From: Ben Harris <bjh21@netbsd.org>
List: port-arm
Date: 09/26/2001 14:12:43
On Wed, 26 Sep 2001, Reinoud Zandijk wrote:

> I'll also try to investigate the statclock stuff... what about FIQ for
> statclock?

Not a good idea, since there isn't a timer that will trigger FIQs (unless
the BBC I/O board allows you to wire up the 6522 IRQ line to PFIQ, but I
don't think it does).  In any case, we don't yet have a proper FIQ sharing
mechanism, though I'll have to implement one once I get round to floppy
support on arm26.

The right thing to do (on IOMD systems, at least)  is to use IOMD timer 1
as the statclock, like arm26 does.  See cpu_initclocks() and
ioc_irq_statclock() in sys/arch/arm26/iobus/ioc.c for an example.  There's
a similar scheme in sys/arch/sparc/sparc/clock.c.

-- 
Ben Harris                                                   <bjh21@netbsd.org>
Portmaster, NetBSD/arm26               <URL:http://www.netbsd.org/Ports/arm26/>