From owner-freebsd-current Tue Oct 13 19:44:08 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id TAA21251 for freebsd-current-outgoing; Tue, 13 Oct 1998 19:44:08 -0700 (PDT) (envelope-from owner-freebsd-current@FreeBSD.ORG) Received: from firewall.scitec.com.au (fgate.scitec.com.au [203.17.180.68]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id TAA21246 for ; Tue, 13 Oct 1998 19:44:05 -0700 (PDT) (envelope-from john.saunders@scitec.com.au) Received: by firewall.scitec.com.au; id MAA26176; Wed, 14 Oct 1998 12:43:49 +1000 (EST) Received: from mailhub.scitec.com.au(203.17.180.131) by fgate.scitec.com.au via smap (3.2) id xma026135; Wed, 14 Oct 98 12:43:26 +1000 Received: from saruman (saruman.scitec.com.au [203.17.182.108]) by mailhub.scitec.com.au (8.6.12/8.6.9) with SMTP id MAA15831 for ; Wed, 14 Oct 1998 12:43:25 +1000 Received: by localhost with Microsoft MAPI; Wed, 14 Oct 1998 12:43:25 +1000 Message-ID: <01BDF770.3BFBAFB0.john.saunders@scitec.com.au> From: John Saunders To: "freebsd-current@FreeBSD.ORG" Subject: RE: bitten 3 times already. Date: Wed, 14 Oct 1998 12:43:23 +1000 Organization: SCITEC LIMITED X-Mailer: Microsoft Internet E-mail/MAPI - 8.0.0.4211 MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG Soren Schmidt [SMTP:sos@FreeBSD.ORG] wrote: > In reply to Marius Bendiksen who wrote: > > I haven't been tracking this too closely, but doesn't such a thing as Soren > > Schmidt suggested (removing LBA support) mean that people with LBA drives > > will end up in heaps of trouble? I have 8.4 + 3.2 gigs on LBA-formatted IDE > > drives, and would certainly not appreciate losing those. > > You dont need to run the drive in LBA mode to coexist with DOS or whatever. > Also you dont need to run the drive in LBA mode to use >8G, infact using > LBA has nothing to do with >8G support. >8G support has something to do > with us probing the drive correctly and using it that way. I think people are confusing operating the physical interface to the drive (IDE interface) in LBA mode, and using the partition geometry calculated by the BIOS in LBA mode. >From what I can understand, FreeBSD uses the sector addresses rather than the CHS addresses in the partition table to determine where it's partition lives. It is then free to either put the drive into LBA mode or CHS mode as long as it ends up reading and writing to the correct sectors. If it leaves the drive in CHS mode, then it has to make absolutely sure it knows the correct geometry for the drive so it can convert the sector addresses into the exact CHS values for the drive when doing IO. P.S. The above view is based on observation of installing FreeBSD on many machines, and "manager level" IDE/ATAPI knowledge, rather than intimate knowledge of the IDE driver source code. So feel free to correct me if needed :-) Cheers. -- . +-------------------------------------------------------+ ,--_|\ | John Saunders mailto:John.Saunders@scitec.com.au | / Oz \ | SCITEC LIMITED Phone +61294289563 Fax +61294289933 | \_,--\_/ | "By the time you make ends meet, they move the ends." | v +-------------------------------------------------------+ To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message