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To: Michael Smith <msmith@atrad.adelaide.edu.au>
cc: bde@zeta.org.au, jkh@time.cdrom.com, freebsd-hackers@freebsd.org,
        obrien@cs.ucdavis.edu
Subject: Re: X for install 
In-reply-to: Your message of "Wed, 03 Jan 1996 22:50:41 +1030."
             <199601031220.WAA07603@genesis.atrad.adelaide.edu.au> 
Date: Wed, 03 Jan 1996 13:46:20 +0100
Message-ID: <1255.820673180@critter.tfs.com>
From: Poul-Henning Kamp <phk@critter.tfs.com>
Sender: owner-hackers@freebsd.org
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> Poul-Henning Kamp stands accused of saying:
> > > Erm, the BIOS geometry problem is entirely in software, and "probing" of
> > > the BIOS geometry has already been implemented by someone named phk :-).
> > > (The problem is that association of BIOS disk numbers with FreeBSD
> > > disk names isn't really implemented.)
> > 
> > And cannot be done reliably, unless you can actually read a couple
> > of sectors using the bios :-)
> 
> THe problem is not reading the sectors, but which sectors to read.
> 0 is obviously a good choice, but 1..(s-1) are boring, and from there in it's
 
> a tough call.  
> 
> There are a few "better" ways perhaps to look for more unique things,
> but you'll still be screwed by two identical disks with identical
> contents 8(

Well my idea was something like:

	sector = 0
	while (1)
		for all disks the bios knows about
			read $sector
			update checksum[disk]
		if checksums differ
			store checksum[] & $sector
		sector++
		
--
Poul-Henning Kamp           | phk@FreeBSD.ORG       FreeBSD Core-team.
http://www.freebsd.org/~phk | phk@login.dknet.dk    Private mailbox.
whois: [PHK]                | phk@ref.tfs.com       TRW Financial Systems, Inc.
Future will arrive by its own means, progress not so.