From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261606AbVHDRSA (ORCPT ); Thu, 4 Aug 2005 13:18:00 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261487AbVHDRQT (ORCPT ); Thu, 4 Aug 2005 13:16:19 -0400 Received: from scl-ims.phoenix.com ([216.148.212.222]:15647 "EHLO scl-exch2k.phoenix.com") by vger.kernel.org with ESMTP id S261512AbVHDRPy convert rfc822-to-8bit (ORCPT ); Thu, 4 Aug 2005 13:15:54 -0400 X-MimeOLE: Produced By Microsoft Exchange V6.5.7226.0 Content-class: urn:content-classes:message MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT Subject: RE: IDE disk and HPA Date: Thu, 4 Aug 2005 10:15:49 -0700 Message-ID: <0EF82802ABAA22479BC1CE8E2F60E8C341EB82@scl-exch2k3.phoenix.com> X-MS-Has-Attach: X-MS-TNEF-Correlator: Thread-Topic: IDE disk and HPA thread-index: AcWY7nw+Viy9EnTtQrWYAOu2Hp5JkQAKGNaw From: "Aleksey Gorelov" To: , X-OriginalArrivalTime: 04 Aug 2005 17:15:50.0034 (UTC) FILETIME=[29415720:01C59918] Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org >-----Original Message----- >From: linux-kernel-owner@vger.kernel.org >[mailto:linux-kernel-owner@vger.kernel.org] On Behalf Of >Etienne Lorrain >Sent: Thursday, August 04, 2005 5:11 AM >To: linux-kernel@vger.kernel.org >Subject: Re: IDE disk and HPA > >> > > My question is now: why is an HPA disabled i.e. disprotected when >> > > detected? Why not let the HPA alone, because a certain >set of disk >> > > sectors shall not be accessible by the OS? >> > >> > Because the HPA is most commonly used to hide all but a >fraction of a >> > disk to work with older BIOSes. >> >> But as to my knowledge, the HPA was had been introduced to allow HW >> vendors to store things like diagnostic programs in a part of the >> disk protected from partitioning and filesystems. >> The point is, IF there is an HPA, there MIGHT be a partitioning >> scheme and some filesystems on the disk which rely on the size of >> disk being the native size MINUS the HPA. > > If those HW vendors want to store software in the HPA of the IDE > hard disk, and they employ people able to read the IDE specifications, > they know that this HPA can be protected by password and so Linux > just display a failure when trying to restore the capacity of the > Hard Disk - because it lacks the unlocking password. Yep, you are right. When used by BIOS/firmware, it is usually protected by password. And interesting enough, as in this particular case, they employ people to not only read them, but to write them as well ;) However, if not protected by the password, it is probably Ok to make it visible (as things currently are). > > Note that this HPA is a good place to store a bootloader too, in fact > I like to think of it as the big floppy drive of the PC which no more > have any floppy drive: create a FAT filesystem of 64 Mbytes there and > copy all the floppy you used to have there. Your bootloader, if it > is good enough, will be able to run software from this area. If your bootloader if the first thing to run in the system, you can use & protect portion of your hardrive for yourself - just make sure you lock with set max with password when passing control to 'normal' OS/loader. Aleks.