Subject: Re: sysinstall "local" tarball
To: Charles M. Hannum <>
From: David Brownlee <>
List: tech-install
Date: 09/20/1998 20:10:20
	Would including the drive's capacity in the table help the
	matches? (Assuming both NetBSD and the BIOS can both correctly get
	this value). Standard disclaimer about working around BIOS
	braimdamage of clipped values :)

On Sun, 20 Sep 1998, Charles M. Hannum wrote:

> So I suggest a completely different mechanism.
> At boot time, before doing anything else, we do two BIOS calls for
> each disk (say, up to 16 disks).  The first loads the first block
> (MBR) of the disk, and the second gets the BIOS disk description.  We
> store these (or maybe just the geometry and a hash of the first block)
> away.
> During autoconfig, when we find a disk, we read the first block, look
> it up in the table we stashed away, and if found use the geometry we
> got from the BIOS.  (If there are multiple matches with different BIOS
> geometries, we arbitrarily pick one and warn the user.)
> This data is then used to calculate the default label.  If there is a
> label present already, we use that instead.
> Alternatively, we could have the table passed in from the boot block.
> Old users (with old boot blocks) are going to have this right by now
> anyway.


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