From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark Lord Subject: Re: hdparm-9.2 now available: w/ DCO and firmware support Date: Tue, 04 Nov 2008 14:13:34 -0500 Message-ID: <49109EDE.1020803@rtr.ca> References: <490F4030.5030709@rtr.ca> <87f94c370811041001ucd76d27lc948c553ad2a381e@mail.gmail.com> <49108F96.8010902@rtr.ca> <87f94c370811041023s3de41ec9o66614bf3f0fdb63c@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from rtr.ca ([76.10.145.34]:50369 "EHLO mail.rtr.ca" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756968AbYKDTMy (ORCPT ); Tue, 4 Nov 2008 14:12:54 -0500 In-Reply-To: <87f94c370811041023s3de41ec9o66614bf3f0fdb63c@mail.gmail.com> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Greg Freemyer Cc: IDE/ATA development list Greg Freemyer wrote: > On Tue, Nov 4, 2008 at 1:08 PM, Mark Lord wrote: .. >> Mmm.. never thought about that much before now, >> but DCO is a nifty way to hide much of a drive from prying eyes. >> Eg. Use DCO to restrict the drive to LBA28 accessible sectors >> and also turn off LBA48 support, and then a lot of space becomes "hidden". >> Until now! > > Yeah, combine that with some HPA shenanigans and you can create two > complete disk partition layouts on one drive. > > ie. Two partition tables, the normal partition table for the first 128 > GiB is in sector 1. The partition table for the rest of the disk is > at sector 128 GiB + 1. Then use DCO to totally hide the upper section > of the drive. > > When you want access, use DCO commands to expose it, and then HPA > commands to make only the sectors beyond 128 GiB accessible. .. Now that one has me stumped. The only HPA commands I know of, permit setting only the maximum-LBA, not the minimum. Or is this a newish ATA9 (or last-minute ATA8) sort of thing ? .. > to the end of the disk, then issue a "hpa swap" command. That will > hide the first 128 GiB and expose the rest of the disk. .. Yeah.. what's this "hpa swap" ? Possibly a vendor-specific op, perhaps? Cheers