Subject: Re: boot blocks
To: Chuck McManis <>
From: John Hayward <>
List: port-vax
Date: 10/03/2000 08:09:50
Dear vax people,

Sorry wasted bandwidth.

I had a couple of problems - I had unpacked the i386 ALPHA2 sets on my vax
(-{ (big problem) and in switching between net booting and attempting to
boot off the disk entered netbsd for the boot file when the boot flag was
on to prompt for the boot file.  I have since unpacked the vax sets, a
kernel which has the dma offset removed and turned off the boot flag and I
can boot ALPHA2 on my M3100.  It seems faster than running of the network
(maybe because I could hear the disks doing stuff).

At any rate I'm a happy camper.

I'm going to file a send-pr on the dma offset problem.

I'd still like to know if any one has docs on how the DMA should work on
the 3100 - I'm concerned that the tkxx drive hanging off the scsiA chain
might have dma problems with disks doing dma on the scsiB chain.  I need
to clean my tkxx drives to see if I can get them to work but this is a
lower priority item for me.

On Mon, 2 Oct 2000, Chuck McManis wrote:

> Date: Mon, 02 Oct 2000 13:37:49 -0700
> From: Chuck McManis <>
> To: John Hayward <>,
> Subject: Re: boot blocks
> Depends.
> If you want to label a disk with boot blocks that are compatible with the 
> system the is currently running on the machine, then typing
>          disklabel -B sd0
> would do the trick.
> If you're trying to use the Alpha2 snapshot of 1.5 then nothing will help 
> you except to get a new kernel because, as reported here earlier, the SCSI 
> support on the M3100 is broken.
Did you see my post on how I resolved this problem for at least the

> If you're trying to "upgrade" your boot blocks (that is to say you're 
> running 1.4 and you need to upgrade to the 1.5 boot blocks but you're still 
> using 1.4 during the install) then you need something like
>          disklabel -B sd0 -b /mnt/usr/mdec/sdboot
> --Chuck
> At 02:42 PM 10/2/00 -0500, John Hayward wrote:
> >Dear Vax People,
> >    How does one write a bootstrap for an scsi disk on 3100?  I see in
> >/usr/mdec sdboot but no bootsd.  Both man pages for disklabel and
> >installboot seem to imply there may be both boot blocks and a bootstrap
> >program.  I do see a boot program but not one labeled sdboot.
> >    Should I have a sdboot program?  Should I explicitly refer to the
> >boot program for the secondary boot?  Should I be able to boot with just
> >the boot blocks?
> >    TIA for pointers suggestions.
> >johnh...