From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1NMNnA-0005Od-36 for qemu-devel@nongnu.org; Sun, 20 Dec 2009 10:33:56 -0500 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1NMNn5-0005Kx-A5 for qemu-devel@nongnu.org; Sun, 20 Dec 2009 10:33:55 -0500 Received: from [199.232.76.173] (port=53030 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1NMNn5-0005Kq-35 for qemu-devel@nongnu.org; Sun, 20 Dec 2009 10:33:51 -0500 Received: from mx1.redhat.com ([209.132.183.28]:2220) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1NMNn4-0007Wg-LR for qemu-devel@nongnu.org; Sun, 20 Dec 2009 10:33:50 -0500 Date: Sun, 20 Dec 2009 17:33:47 +0200 From: Gleb Natapov Message-ID: <20091220153347.GN4490@redhat.com> References: <1261134074-11795-1-git-send-email-kraxel@redhat.com> <20091220083857.GE4490@redhat.com> <4B2E381A.4080804@codemonkey.ws> <20091220145200.GA6706@redhat.com> <4B2E3BA0.7080004@codemonkey.ws> <20091220150751.GL4490@redhat.com> <4B2E3E96.7090708@codemonkey.ws> <20091220152346.GM4490@redhat.com> <4B2E42A2.6030600@codemonkey.ws> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4B2E42A2.6030600@codemonkey.ws> Subject: [Qemu-devel] Re: [SeaBIOS] [PATCH 0/8] option rom loading overhaul. List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Anthony Liguori Cc: Gerd Hoffmann , qemu-devel@nongnu.org On Sun, Dec 20, 2009 at 09:28:34AM -0600, Anthony Liguori wrote: > Gleb Natapov wrote: > >On Sun, Dec 20, 2009 at 09:11:18AM -0600, Anthony Liguori wrote: > >>Gleb Natapov wrote: > >>>On Sun, Dec 20, 2009 at 08:58:40AM -0600, Anthony Liguori wrote: > >>>>No. You have to physically shut down and start up again. That's > >>>>the right semantics IMHO. > >>>> > >>>Reset is equivalent (or should be) to shut down and start up again. > >>Not at all. Reset can happen in a lot of different ways, some that > >We support only one way of reset: hard reset. It equivalent to full > >HW power cycling. ACPI spec define ACPI reset as equivalent to HW power > >cycling too BTW (see 4.7.3.6). > > For every system periphereal? To cite ACPI spec : "From an OSPM perspective, asserting the reset mechanism is the logical equivalent to power cycling the machine." > For instance, memory contents survive > a reset whereas they won't survive a hard power down. > We cannot rely on memory content after such reset. > More importantly though, what's the use-case here? > Use-case for what? This just what need to be done for correct HW emulation. > >This will work only if we assume that rom file size doesn't shrink, > > Well the easy thing to do is hard code the rom size into qemu and > throw an error if the rom size increases. That way, if a rom does > shrink, we're safe and if a rom size increases, we get an immediate > run time error that gives the contributor feed back that they need > to bump the constant. > -- Gleb.