Subject: Re:
To: None <Richard.Earnshaw@arm.com>
From: Ben Harris <bjh21@netbsd.org>
List: port-arm26
Date: 02/25/2001 16:31:44
On Sun, 25 Feb 2001, Richard Earnshaw wrote:

> > 
> > The above file needs to be common between the arm platforms
> > so that gdb support for kcore and kernel debugging can work.
> > It would be nice if all registers could be contained in the
> > pcb as that greatly simplifies gdb support.
> 
> Can we also ensure that there is enough space in this structure to save 
> the VFP context.

I don't see that as being a problem.

> Assuming a process can either be enabled for VFP code or FPA code, but not 
> both, I guess we could overlay the information on the FPE status, and use 
> a control byte to tell us which is in use.  [Do we want to make such an 
> assumption?]

I'd prefer not to.  While the idea of a CPU with both VFP and FPA is
strange, and that of a program using both of them is stranger, they are
theoretically orthogonal and I think we should treat them as such.  The
pcb is pageable, so space in it isn't all that precious.

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