Subject: Re: reinstalling bootblocks / boot selector
To: David Laight <david@l8s.co.uk>
From: Rasputin <rasputin@idoru.mine.nu>
List: netbsd-help
Date: 07/16/2002 09:34:18
* David Laight <david@l8s.co.uk> [020715 11:56]:
> On Mon, Jul 15, 2002 at 11:03:21AM +0100, Rasputin wrote:
> > 
> > I've been toying with using mbrlabel to make my (unused)
> > win98 partitions readable.
> 
> Not sure what you mean by that....
> If you want netbsd to be able to use the space just edit the
> netbsd disklabel (with disklabel).

That's what mbrlabel(8) does, effectively.

> > STr last time I did this I got an unbootable drive, and someone
> > mentioned I should reinstall the boot blocks after running fdisk?
> > 
> > If I wanted to do this, I'd run
> > 
> > /usr/mdec/installboot /usr/mdec/biosboot.sym /dev/rwd0a
> > 
> > correct?
> 
> fdisk doesn't go anywhere near anywhere that /usr/mdec/installboot 
> will write to.

Maybe I'm remembering that wrong  - would you have to reinstall them
after updating the disklabel?

> > Now, since this is writing to the root filesystem (I think),
> > how would I go about rewriting the boot selector
> > (which looks like it's in the MBR someowhere).
> 
> fdisk -c and/or fdisk -B

Right, does that install a bog-standard mbr, or the boot selector?

> > mbr(8) seems to confirm this, but doesn't explain how to reinstall it.
> 
> i386 has more layers of bootstrap than I've cooked hot dinners :-)

[ snip: boot explanation ]

> Clear as mud yet?

:) 

Thanks, that should get me started.

(OT: can our boot selector boot win98 off a second disk, or is there
some limitation in windoze (surely not!) that prevents it booting off
a non primary-master?)

-- 
Rasputin :: Jack of All Trades - Master of Nuns