From owner-freebsd-hackers Mon Aug 21 20:14:33 1995 Return-Path: hackers-owner Received: (from majordom@localhost) by freefall.FreeBSD.org (8.6.11/8.6.6) id UAA27700 for hackers-outgoing; Mon, 21 Aug 1995 20:14:33 -0700 Received: from godzilla.zeta.org.au (godzilla.zeta.org.au [203.2.228.34]) by freefall.FreeBSD.org (8.6.11/8.6.6) with ESMTP id UAA27693 for ; Mon, 21 Aug 1995 20:14:16 -0700 Received: (from bde@localhost) by godzilla.zeta.org.au (8.6.9/8.6.9) id NAA20592; Tue, 22 Aug 1995 13:09:36 +1000 Date: Tue, 22 Aug 1995 13:09:36 +1000 From: Bruce Evans Message-Id: <199508220309.NAA20592@godzilla.zeta.org.au> To: msmith@atrad.adelaide.edu.au, terry@cs.weber.edu Subject: Re: Install issues (was: State of the union speech Cc: bde@zeta.org.au, freebsd-hackers@FreeBSD.org, roberto@keltia.frmug.fr.net Sender: hackers-owner@FreeBSD.org Precedence: bulk >What we are interested in is a sector offset and length on the physical >device being exported as a device to the /dev namespace. This is different I.e., a slice. >This actually strikes at the heart of what I think is wrong with the >current disklabel code. You mean the current slice code. Disklabels are layered under slices so they are irrelevant to this discussion. I think labels should go away eventually. The current slice code is too closely tied to a particular initialization routine (the only one implemented). >The PowerPC under a PReP/OpenFirmware implementation assumes a DOS >partitioning scheme, but uses the sector offset field rather than the >C/H/S field -- 4GB worth of 512 byte sectors, or 2TB of disk. So does FreeBSD. >They look for the AA55 signature, and if it isn't present, they assume >that the physical device constitutes a single partition. This is their So does FreeBSD. This doesn't work too well in practice, since some BIOSes require AA55 for booting, so the default bootblock has to have it, so you get an unwanted signature when you write the bootblock. Bruce