Re: Debian GNU/HURD for Alpha?

[Ad Buijsen <ad@basket.iae.nl>]

On 17 Jul, Ron Farrer wrote:
> 
> Hello all;
> 
> I've been reading through the list archives (all the way from the
> beginning). I am a die hard Alpha user (currently Debian GNU/Linux) 
> and I am interested in seeing Debian GNU/HURD on Alpha. 
> 
> There seem to be different opinions on how one should start porting
> things over. Having read through a LOT of mail and docs I've outlined
> this: 
> 
> 1. Port a microkernel to Alpha; Some say to use a previous Mach that
> was ported to Alpha, some say to go ahead and try to port GNU Mach,
> others say to find another microkernel (i.e. not a Mach-based one). 
> 
The problem with using the existing Alpha Mach (provided the sources are
available at all) is that it will probably be quite old: EV4 only.
Porting it to something more modern will involve tweaking PALcode at
least.  Maybe, however, Mach's PALcode is closely related to DU's, so
that could be used (like Linux does) or relatively easily adapted.  
Likewise, the porting of GNU Mach may or may not require the
development of its own Privileged Architecture Library.  This is a
difficult task and you may need tools from Digital, I mean Compaq.

(For those who are wondering what I am on about: EV4 was the first
generation of Alphas; the present one is EV6.  As the hardware, even
within the same generation, tends to vary vastly, there is a layer of
software which hides these differences from the OS; this layer is the
PAL.  It has maximal privilege and thus maximal opportunity for wrecking
the system.)

There seems to be some interest in getting the Hurd ported to the L4
microkernel, especially on Alpha.  See:

  http://www.cse.unsw.edu.au/~disy/L4/

Note that L4 doesn't resemble Mach much, so some amount of redesigning
might be in order.  Still, it is very micro...

> 2. Create/port some type of boot loader.
>
Methods for booting L4 from SRM are described; they may even be of some
use for Mach.
 
> 3. Port the C library and friends.
> 
> After these three things have been done it should be fairly easy to get
> the rest to work. There is interest from others to port, but none seem
> to have gone further then an inquiry. 
> 
> Did I get all the above correct? 
> 

I think so.  The non-progress seems to me to be mainly caused by the
fact that the Alpha is a little-used architecture.  It's just too bloody
expensive............... 



Cordially, 
   Ad Buijsen