Subject: Re: Garbled message from bootblocks [ Re: bootxx_ffsv1 or bootxx_ffsv2? ]
To: David Laight <david@l8s.co.uk>
From: Neil Booth <neil@daikokuya.co.uk>
List: current-users
Date: 08/12/2003 22:03:22
David Laight wrote:-

> > NetBSD/i386 ffsv1 Primary Bootstrap
> > Boot failed: Can't open /boot
> 
> You need to copy /usr/mdec/biosboot to wd0f:/boot

Done.  And I've switched to using mbr as I don't need a menu.

With these changes I now get a normal boot, apart from manually
selecting hd0a:netbsd.  Thanks!

> > NetBSD/i386 ufs Primary Bootstrap
> > >> NetBSD/i386 BIOS, Revision 3.0
> 
> I'm not sure where it went to find that!

> After the 'can't open boot' messagethe code does an 'int $0x18' bios call,
> this was originally a call to execute the rom basic inetrpreter to to
> a casette tape load (or similar), most systems go to a 'press a key to
> restart the boot sequence'.

I've got a feeling it was wd1 - presumably if booting wd0 fails the BIOS
tries wd1 instead before giving up.  Now I've got wd0 configured with
proper boot code, I'll do the same for wd1.

> None of them got changed after I modified the boot code :-)
> 
> If you setup multiple netbsd mbr partitions, you can boot with the
> root filesystem at the start of any on the partitions by using the mbr
> bootsel code.  Since there is only a single disklabel (anything else is
> far too fraught) the boot code scans the disklabel to locate the name
> of the partition that was booted.

Methinks to gain a clear understanding of all this I'd need to know
more about how NetBSD formats its disks, such as disklabel and
parition layouts, sectors reserved at the start of each partition etc.
Maybe one day.

> I've just commited a change to boot1.c that (should) make it possible
> to boot straight from the raid set (ie without the 'boot' partition).
> Use fdisk to put separate mbr partitions on the 'boot' and 'raid'
> filesystems, and you can boot either with the bootselect code.

By this do I understand that wd{0,1}f with its copy of biosboot is
unnecessary, and that copying biosboot to / on wd{0,1}a and re-issuing
the /sbin/installboot command with rwd{0,1}a will "just work"?

Thanks,

Neil.