Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933154AbZJLTTf (ORCPT ); Mon, 12 Oct 2009 15:19:35 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S933082AbZJLTTd (ORCPT ); Mon, 12 Oct 2009 15:19:33 -0400 Received: from mx3.mail.elte.hu ([157.181.1.138]:47334 "EHLO mx3.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933044AbZJLTTc (ORCPT ); Mon, 12 Oct 2009 15:19:32 -0400 Date: Mon, 12 Oct 2009 21:18:24 +0200 From: Ingo Molnar To: Carl-Daniel Hailfinger Cc: David Woodhouse , Artem Bityutskiy , LKML , "Koskinen Aaro (Nokia-D/Helsinki)" , linux-mtd , Simon Kagstrom , Andrew Morton , Linus Torvalds , Alan Cox Subject: Re: [PATCH] panic.c: export panic_on_oops Message-ID: <20091012191824.GL17138@elte.hu> References: <20091012120951.GA16799@elte.hu> <20091012142714.56362465@marrow.netinsight.se> <20091012123210.GB22766@elte.hu> <20091012140821.5dfa1598@lxorguk.ukuu.org.uk> <20091012132503.GD25464@elte.hu> <1255354342.30919.17.camel@macbook.infradead.org> <20091012142634.GB4565@elte.hu> <1255358181.9111.14.camel@macbook.infradead.org> <20091012151431.GC14004@elte.hu> <4AD3763C.70307@gmx.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4AD3763C.70307@gmx.net> User-Agent: Mutt/1.5.18 (2008-05-17) X-ELTE-SpamScore: -1.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.5 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.5 -1.5 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1628 Lines: 38 * Carl-Daniel Hailfinger wrote: > > I wish it worked on any of the 10+ x86 systems i have. Is there > > anyone who'd be interested in exploring whether warm BIOS reboots > > work _anywhere_? > > AFAIK memory clearing is default off in coreboot for non-ECC RAM and > default on for ECC RAM (to avoid parity errors on read, but that can > probably be worked around). Unless I'm mistaken, the SeaBIOS BIOS > compatibility layer on top of coreboot doesn't erase RAM at all, so > contents can survive. > > No idea about classic AMI/Award/Phoenix/Insyde/whatever BIOS, though. I wouldnt mind to support this for coreboot too, but it will only be practical if there's at least one standard BIOS out of the many i run that supports warm reboot in practice ... Can try a test-patch on all of those systems btw. - we do support warm-reboot on x86 in arch/x86/kernel/reboot.c: /* Write 0x1234 to absolute memory location 0x472. The BIOS reads this on booting to tell it to "Bypass memory test (also warm boot)". This seems like a fairly standard thing that gets set by REBOOT.COM programs, and the previous reset routine did this too. */ *((unsigned short *)0x472) = reboot_mode; But someone would have to come up with a test-patch to prove whether it works really works. Ingo -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/