Subject: Re: Alignment problems on Acorn{26,32}
To: Steve Woodford <scw@NetBSD.org>
From: Richard Earnshaw <rearnsha@arm.com>
List: port-arm
Date: 11/03/2003 23:56:23
> On Monday 03 November 2003 11:00 pm, Richard Earnshaw wrote:
> 
> > STRH cannot be used on any Acorn machine since a store that misses
> > the cache goes straight to the memory system.
> >
> > LDRH can be used only if it can be guaranteed that the page is marked
> > cacheable (not true for user-space since a shared page may be NCB).
> >
> > In either case, these instructions can only be used if it is a
> > SA-only kernel.
> 
> I think in this case, adding an override option which prevents alignment 
> fault being enabled is the best way forward.
> 
> Affected ports can define it in std.<machine>, or some other suitable 
> place.

Is it possible to do this only for kernels?  Ie, user-space is restricted 
to strict-alignment, but the kernel (which is normally processor-specific 
anyway) can do whichever is appropriate.

R.