Subject: miniroot w/ultrix 4.2a
To: Isaac Kohen <>
From: Jonathan Stone <jonathan@DSG.Stanford.EDU>
List: port-pmax
Date: 02/24/1997 18:56:40
On  Tue, 10 Dec 1996 03:13:53 -0500 (EST),
Isaac Kohen <> writes:

>Hi there. I have a DECStation 5000/120 at home. I have been
>trying to use the ultrix disk label to write a miniroot 
>but it always gives me usage errors. I tried writing 
>in different syntax but same error always appears.

This won't work.  You need to use the NetBSD disklabel program
cross-compiled to run under Ultrix. 

The ultrix disk label doesn't recognize NetBSD-style bootblocks and
almost certainly won't write them. Also, Ultrix disklabels aren't kept
in the same place as NetBSD disklabels, they have less information
than NetBSD disklabels,  and the Ultrix disklable program won't
recognize NetBSD-style disktab entries.

In short, you want to write a NetBSD disklabel with NetBSD bootblocks.
The simplest way to do that is to use the NetBSD disklabel program
that's been ported to Ultrix.  You can  put the NetBSD bootblocks
in the Ultrix /usr/mdec; the Ultrix utilities will safely ignore them.

>I am
>running Ultrix 4.2a on a 120 with 32mb ram. I was trying
>to write to a 200mb DEC SCSI drive. I also heard it is possible
>to boot NetBSD off my linux box but I dont at all know how.
>If you have
>any ideas on how to boot the dec, please help. 

Yes, it's possible to boot diskless over the network from any system
that supports either (1) MOP with ECOFF files (e.g., another Ultrix
system), or (2) bootp and tftp.  In either case you need an
ECOFF-format kernel, since that's all the DECstation prom understands.

A summary is: find the ethernet address of your machine from the PROM
using cnfg (or CNFG 3?).  Configure a bootp server with the ethernet
address and the IP address you want to use.   Configure a TFTP server
with an ECOFF-format kernel where the DECstation can TFTP it.

(I think on some versions of Linux, this may mean naming the ECOFF
file with a symlink that's the IP address of the diskless machine,
encoded in hex as eight ASCII bytes).  

You also need to make sure that bootpd and tftpd are correctly
running: e.g., by commenting them into /etc/inetd.conf on the server
machine, and restarting inetd on the server.  see man bootpd, man
tftpd for details.   

If memory serves, someone got a 3100 up recently using a Linux
machine as a diskless boot host; see the port-pmax archives for
details, but note that the  bootpath syntax for the TurboChannel
machines is completely different.

>Thank you.

Hope that helps