On Wed, Feb 27, 2002 at 03:45:29PM -0500, Thomas Mueller wrote:
> I think FreeBSD and OpenBSD are similar to NetBSD in the way they access the
> hard disk with disklabel rather than primary and logical partitions.  So it
> can be tricky to access a secondary non-BSD hard disk which would naturally
> not have a BSD disklabel.  I don't think one would want to write a BSD
> disklabel on a non-BSD disk, it would likely interfere with something.

ISTR that the freeBSD disklabel describes slices relative to the
partition - so cannot acces all of the disk.

Indeed - you also have to have one of the primary partitions marked
as a netbsd one in order for the disklabel to be found.

There is some odd code to generate wd0[efgh] from the main partitions
if a disklabel cannot be found - but I don't know whether it is
actually useful!
> 
> Possibly a Linux subpartition could be booted from a NetBSD boot prompt with
> something like boot wd0i:vmlinuz,

Only if your linux kernel is in an ffs filesystem, and if the linux kernel
doesn't expect any argument or environment from the loader, and is
loaded to the correct address.

The reverse also won't work.  The NetBSD kernel is passed some paramters
by the boot code.

The NetBSD bootselect code should be able to boot linux though.

> though I am not planning to experiment in
> that regard, and I don't know if Linux could recognize a BSD disklabel if the
> BSD slice didn't have an entry in the MBR.

If the BSD partition doesn't have an entry in the MBR, then it doesn't exist!
I also doubt that linux would know what to do about it anyway.


	David

-- 
David Laight: david@l8s.co.uk