From: Girish Venkatachalam (girishvenkatachalamgmail.com)
Date: Sat Nov 01 2008 - 21:10:12 CDT

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On 10:35:43 Nov 01, Michael wrote:
> I have been trying to install 4.4 on a previous 4.3 partition, but keep
> getting this message after formatting and new installation:
> installboot: broken MBR
> And then when booting from the hd, all I get is: ERR M
>

This means that installboot failed(I think).

> I have tried a new installation 3 times and then tried "upgrading" after the 3rd try, with same error.
>
> I use Air-Boot for boot manager and have used it for years.
> Here is the openbsd and "a" partition within my 40 gig hd:
> hd: 78125000 sectors
> A6 starts 12546765 size 13350015 for 25896780
> "a" partition starts 12546765 and ends 13366080
>

Is it beyond the addressable limit of your BIOS? I wonder. Is it set to
LBA mode or linear mode?

Just guessing.

> Josh Grosse had me try the following commands:
> Step 1) Boot 4.4 installation media, select the shell at the
> Install/Upgrade/Shell prompt.
>
> Step 2) Mount your "a" partition as /mnt:
>
> # mount /dev/wd0a /mnt
>
> Step 3) Ensure the second stage boot loader is stored in /mnt/boot:
>
> # cp -p /usr/mdec/boot /mnt/boot
>
> Step 4) Rerun installboot, installing a new biosboot that points to /mnt/boot:
>
> # /usr/mdec/installboot -v /mnt/boot /usr/mdec/biosboot wd0
>

I never give the full patch for the first stage bootloader.

I usually give

# cd /mnt

# /usr/mdec/installboot -v boot /mnt/biosboot wd0

It should not be /usr/mdec/biosboot. Definitely not.

If you mount your /dev/wd0a partition on /mnt, then the above command
will work. Otherwise you have to choose the mount point of your root
partition.

Does installboot -v report any errors? If that goes thro' then I think
you are mostly safe though I have never heard of Air-Boot boot manager
ever. ;)

> I got the same results (installboot: broken MBR and then ERR M when booting openbsd).
> I then thought that since 4.3 installed just fine why not try his command with the 4.3 cd, so I did.
> The commands worked perfectly and now I am able to boot into 4.4.
>
> Why would it work with the 4.3 cd and not 4.4 cd? It's the same partition with new install.

I dunno. My guess is as good as mine. I am sure Nick will reply to this
but I will do my bit. ;)

Can you reformat your disk and start from the beginning?

And ensure that you install OpenBSD on the right cylinder boundaries?

Are you very particular that you have to use a 'boot manager' and
multiboot?

I was thinking that multiboot was a big pain in the neck and only for
those who have not yet decided which OS is best for their needs...

Best of luck and I do hope you solve your problem soon.

-Girish

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