Solved [Re: delete first partition XP and reformat as ufs -> kernel not found]

[Dan Strick]

On Sun, 30 Nov 2003, Dorin H <bj93542 at yahoo.com> wrote:
>>
> Hi there,
>  Hoping that this will help somebody else:
>  Deleting the XP boot partition that came first on
> disk (the FreeBSD was the last) and changing its type
> to FreeBSD FS render my laptop unbootable.
>  I got the prompt when trying to boot FreeBSD:
>
> >> FreeBSD/i386 BOOT
> Default: 0:ad(0,a)/kernel
> boot:
>
>   The problem was that the new XP partition, not yet
> labeled,  was still marked as bootable, as well as the
> real bootable FreeBSD partition.  Flipping that flag
> off repair the problem!
>
>  QUESTION:
>
>  Where I can find an explanation of the syntax for
> previous prompt (boot2 prompt according to handbook) ?
>   All my attempts to redirect the boot to search in
> the correct partition failed.
>   Thanks a lot,
> /Dorin.
>>

The second stage FreeBSD boostrap program, "boot2", assumes that the the
slice being booted is the FreeBSD slice with the active partition flag
set or (if no FreeBSD slice has the active partition flag) the first
FreeBSD slice.  If you have two FreeBSD slices on a single disk and your
MBR (master bootstrap record) program does not rewrite the MBR with the
active flag set for the selected slice before it runs boot2, either
because you have disabled that feature with the boot0cfg command or
because you are not using the FreeBSD boot0 MBR program, then boot2
could very easily try to boot the wrong slice.

If I understand your email, you must have run afoul of the fragile
assumptions made by boot2.  What program were you using for the master
bootstrap?  Do you know which slice had the active partition flag?

Dan Strick
strick at covad.net