Subject: Re: building libkvm
To: Ben Harris <bjh21@netbsd.org>
From: Chris Gilbert <chris@paradox.demon.co.uk>
List: port-arm
Date: 07/17/2001 13:59:34
On Thursday 12 July 2001  1:05 pm, Ben Harris wrote:
> On Thu, 12 Jul 2001, Chris Gilbert wrote:
> > I've been trying to get libkvm building on my cats box (with the newly
> > layed out includes dir structure)  and have been having to do a few
> > dubious things to get it to build.  The main one being some dummy include
> > files that are just empty but stop the build complaining they don't
> > exist.  I also had to make a machine/pch.h that points at arm32/pcb.h.
>
> Does something in userland actually care about the shape of struct pcb
> then?  If so, we either need to stop it doing so or standardise its shape
> across arm26 and arm32.

Yes, libkvm does in libkvm/kvm_proc.c in the function kvm_getproc2.  It uses 
kread to read a struct user (of which a member is struct pcb)  I note though 
that it doesn't actually access the pcb structure, just the pstats part of 
user.

Potentially we could share pcb.h, although I'm not sure I like that idea or 
not, I don't think that userland should actually see the pcb information, so 
I'd rather see a different mechanism to get the information.  But I don't 
know what mechanism to use instead.

> > Looking at libkvm I'm not sure that it can be shared across arm26 and
> > arm32, it's very much tied into the kernel.
>
> If all else fails, it can switch between implementations at run-time.

we could do, but I'd rather not use that unless we really have to.

Cheers
Chris