Subject: Re: NetBSD + LINUX
To: None <>
From: David Laight <>
List: netbsd-users
Date: 01/09/2002 22:37:26
> > 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.
> No, you can "install lilo in the MBR", that it install in the MBR the code
> that will load lilo from disk.

I've not dumped out lilo, but it'll be a VERY tight squeeze.....

The netbsd pbr code rereads a longer copy of itself - sitting in spare
sectors after the pbr and netbsd 'disklabel' before the filesystem data.
This 4th bootstrap [1] reads in the boot program - that will give you a
directory listing etc.


[1] netbsd bootstraps:
1) ROM bios code
2) mbr - read from sector 0 of the disk
3) pbr - read from sector 0 of the active/selected partition
4) xxx - read from sectors 2-n of the partion the pbr thinks it was read from
5) yyy - read from filestore using a list of sectors encoded (by installboot)
   into xxx.
6) now running netbsd - guesses the active/selected partition to find the
(I've forgotten thenames of xxx and yyy)