Subject: Re: NetBSD + LINUX
To: None <netbsd-users@netbsd.org>
From: David Laight <David.Laight@btinternet.com>
List: netbsd-users
Date: 01/09/2002 22:14:09
> > I made some progress but I still can't bring LINUX up.
> > I reinstalled LINUX in the drive hdbX (thats the LINUX device
> > name). When I do 'fdisk -B /dev/rwd1'  and reboot, LINUX is 
> 
> You have NetBSD on wd0 and linux on wd1, rigth ? So you don't need
> to put the NetBSD boot loader on wd1. If you had installed lilo in the
> MBR you trashed it.

lilo can't possibly fit into the mbr, not ever, not never, not in a month
of sundays....
It won't even fit in the extra space that (is probably) lurking in the pbr.
My guess is that, like the second part of the interactive BSD loader it
is loaded from filestore using a canned list of sector numbers.

All the mbr code will do is to load the pbr code (1 sector) of the active
partition then jump to it.
> 
> > listed as F1, NetBSD F4. When I press F1, the thing times out and
> > reboots.

It isn't quite clear from the documentation (or fdisk).  But F1-F4 load
the pbr of partition 1-4 - provided the text comment isn't null and the
partition isn't allocated.  So adding a comment enables the load.

Pressing F6 will read the mbr (sector 0) of disk 1 (rather disk 0x81)
using BIOS calls. Then execute it.

The Linix boot stuff ought to take the disk number from register 'dl'.
If it is hard coded into the sectors you need (somehow) to set the loader
up while it is disk 1.
Dunno enough about Lilo and Linux install to help.

(I think I know how netbsd (i386) finds it's boot disk - tis trully
nasty!)

    David