From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1NDZDj-00038o-0a for qemu-devel@nongnu.org; Thu, 26 Nov 2009 02:56:55 -0500 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1NDZDe-00033z-Dp for qemu-devel@nongnu.org; Thu, 26 Nov 2009 02:56:54 -0500 Received: from [199.232.76.173] (port=53081 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1NDZDe-00033w-A3 for qemu-devel@nongnu.org; Thu, 26 Nov 2009 02:56:50 -0500 Received: from mx20.gnu.org ([199.232.41.8]:62332) by monty-python.gnu.org with esmtps (TLS-1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.60) (envelope-from ) id 1NDZDd-0003UA-Og for qemu-devel@nongnu.org; Thu, 26 Nov 2009 02:56:49 -0500 Received: from mx1.redhat.com ([209.132.183.28]) by mx20.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1NDZDd-0007Ox-0U for qemu-devel@nongnu.org; Thu, 26 Nov 2009 02:56:49 -0500 Date: Thu, 26 Nov 2009 09:56:42 +0200 From: Gleb Natapov Subject: Re: [Qemu-devel] Re: POST failure (loop) with isapc and seabios Message-ID: <20091126075642.GW2999@redhat.com> References: <20091124143812.GA27783@shareable.org> <20091124144044.GJ2999@redhat.com> <20091125060951.GA17203@shareable.org> <20091125122039.GM2999@redhat.com> <20091125225349.GA18812@morn.localdomain> <20091126064925.GS2999@redhat.com> <20091126071527.GA29003@morn.localdomain> <20091126072034.GA1990@redhat.com> <20091126074846.GA32741@morn.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20091126074846.GA32741@morn.localdomain> List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Kevin O'Connor Cc: qemu-devel@nongnu.org, Sebastian Herbszt On Thu, Nov 26, 2009 at 02:48:46AM -0500, Kevin O'Connor wrote: > On Thu, Nov 26, 2009 at 09:20:34AM +0200, Gleb Natapov wrote: > > On Thu, Nov 26, 2009 at 02:15:27AM -0500, Kevin O'Connor wrote: > > > Now, if the bios is reloaded, the jump to the resume vector will skip > > > ide, bios table, and other internal state setup. So, later calls to > > > the bios will likely fail. > > > > > Seabios stores .bss and .data section in BIOS segments? > > Yes. > > >If this is the > > case that you are right. Can we move them somewhere else and add it to > > e820 map? > > That would significantly complicate the code, and it wouldn't truly > solve the issue as some data needs to be stored in the f-segment (eg, > smbios anchor). And I don't think support of switching to rm with triple fault worth complication at all. BTW is seams QEMU doesn't event support 286 where this is needed. > > >Although event then switching to real mode using triple fault > > after migration to newer BIOS will not work properly. > > IMO, migrating to a new bios doesn't make sense - the bios is an > application with state - one can't just replace the code. > You don't migrate to a new BIOS. You migrate to a new QEMU that happens to have a new BIOS. And ability to migrate to a newer QEMU is a must. -- Gleb.