NetBSD on ARM6 and newer based machines (NetBSD/acorn32)

Ben Harris | 5 Aug 2006 18:20

Re: timecounters was Re:Fixes for acorn32 build after GCC4 upgrade

On Thu, 3 Aug 2006, Mike Pumford wrote:

> Ben Harris wrote:
> 
> > That will only work so long as timer 1 isn't being used to provide a
> > properly randomised statclock, which it really should be made to do.  It
> > would be better to build something based on timer 0, using the
> > interrupt-pending bit and the hardclock handler to emulate the high-order
> > bits of the timecounter.
> > 
> Okay, I've now done this (apart from the interrupt pending bit part) modelled
> on the i8254 timer from i386. I don't think the i8254 code actually utilises
> the interrupt pending flag either.

In case you hadn't noticed, I've committed that.  I suspect there may be 
circumstances where not checking the interrupt-pending flag will cause it 
to give the wrong answer, but they're likely to be very rare.

--

-- 
Ben Harris                                                   <bjh21 <at> NetBSD.org>
Portmaster, NetBSD/acorn26           <URL:http://www.NetBSD.org/Ports/acorn26/>

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Mike Pumford | 5 Aug 2006 20:52

Re: timecounters was Re:Fixes for acorn32 build after GCC4 upgrade

Ben Harris wrote:

> In case you hadn't noticed, I've committed that.  I suspect there may be 
> circumstances where not checking the interrupt-pending flag will cause it 
> to give the wrong answer, but they're likely to be very rare.
> 
I did notice thanks for doing that. I thought there was probably a good 
reason for taking the int-pending flag into consideration which is why I 
  left some TODO comments in there as a reminder to myself to revisit it 
later.

Mike