Subject: Re: NetBSD without MMU?
To: Ignatios Souvatzis <ignatios@theory.cs.uni-bonn.de>
From: Stefan Grefen <grefen@hprc.tandem.com>
List: tech-kern
Date: 10/29/1998 22:54:38
In message <19981029111246.E6028@cs.uni-bonn.de>  Ignatios Souvatzis wrote:
> On Thu, Oct 29, 1998 at 09:50:43AM +0100, Stefan Grefen wrote:
> > 
> > It think it depends which functionality he wants to port.
> > The process stuff will be the worst (at least on non-segmented CPU's),
> > and fork() will be a royal pain (at expensive like hell). 
> 
> Yeah. But OTOH, if your compiler always produces PC-relative code for the
> shared code segment, and data accesses relative to either the stack or an
> static data area pointer register, its easy.
> 
> OS/9 level 1 on m6809 worked that way.
> OS/9 on 68000, too, I think.

Yes it did (on my Atari :-))).
But it was 'pseudo'-segmented as there was this 64k limit (all data
was relative to a a register with max. 16bit offset.


Stefan

> 
> Regards,
> 	-is

--
Stefan Grefen                                Tandem Computers Europe Inc.
grefen@hprc.tandem.com                       High Performance Research Center
 --- Hacking's just another word for nothing left to kludge. ---