From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from majordomo by infradead.org with local (Exim 3.20 #2) id 14rh8c-0005kW-00 for mtd-list@infradead.org; Mon, 23 Apr 2001 15:16:26 +0100 Received: from ns.sysgo.de ([213.68.67.98] helo=rob.devdep.sysgo.de) by infradead.org with esmtp (Exim 3.20 #2) id 14rh8Z-0005kO-00 for mtd@infradead.org; Mon, 23 Apr 2001 15:16:24 +0100 From: Robert Kaiser Reply-To: rob@sysgo.de To: "Alex Lennon" Subject: RE: Elan SC520 - problem with MTD Date: Mon, 23 Apr 2001 15:54:52 +0200 Content-Type: text/plain References: In-Reply-To: Cc: MIME-Version: 1.0 Message-Id: <01042316161301.01109@rob> Content-Transfer-Encoding: 8bit Sender: owner-mtd@infradead.org List-ID: On Mon, 23 Apr 2001 you wrote: > >> However, if you want to get rid of the BIOS, you have to write your own > startup > >> code for the board, which is not a trivial task. Actually, I'm currently > >> working on something like that, but it is not ready for release yet and > I'm > >> making only slow progress as I have about a hundred other things to do. > >> However, I believe, Vipin Malik has gotten this to work for himself. > Maybe if > >> you ask him nicely... > > I this BIOS compressed ? If not you should be able to write a simple BIOS > extension > to hook INT13h or INT19h. Then when your BIOS proper executes the interrupt > your > custom BIOS extension code loads your kernel out of linear flash - or do you > see a > problem with this approach ? Interesting idea -- a bit like the DOC approach ;-) Though I'm not sure if I understand that BIOS extension part right. As far as I can tell, the BIOS is not compressed, but it occupies the only ROM socket on the board. A BIOS extension would have to be put in a seperate ROM, along with an 0xaa55 header and a checksum so the BIOS calls it, right ? In principle this could work. One would basically have to put part of the MTD code into the BIOS extension to do the flash accesses. Keep in mind though that the BIOS must be entered and left in real-mode (i.e. no access beyond 1MB), so the BIOS extension would have to make the transition to protected mode and back. I've done this a couple of times but this stuff is sooo ugly that I always want to forget all about it immediately after the job is done ;-) To be honest, I don't think this is worth the trouble, I'd rather dump the BIOS completely and write my own startup code. Rob ---------------------------------------------------------------- Robert Kaiser email: rkaiser@sysgo.de SYSGO RTS GmbH Am Pfaffenstein 14 phone: (49) 6136 9948-762 D-55270 Klein-Winternheim / Germany fax: (49) 6136 9948-10 To unsubscribe, send "unsubscribe mtd" to majordomo@infradead.org