From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:54190) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VQyBq-0000Tu-Le for qemu-devel@nongnu.org; Tue, 01 Oct 2013 07:32:36 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1VQyBk-0000ji-No for qemu-devel@nongnu.org; Tue, 01 Oct 2013 07:32:30 -0400 Received: from mail-la0-f51.google.com ([209.85.215.51]:65264) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VQyBk-0000iv-HZ for qemu-devel@nongnu.org; Tue, 01 Oct 2013 07:32:24 -0400 Received: by mail-la0-f51.google.com with SMTP id es20so5712067lab.38 for ; Tue, 01 Oct 2013 04:32:23 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <1380626523.5280.27.camel@nilsson.home.kraxel.org> References: <1380620399-9907-1-git-send-email-kraxel@redhat.com> <1380626523.5280.27.camel@nilsson.home.kraxel.org> From: Peter Maydell Date: Tue, 1 Oct 2013 20:32:02 +0900 Message-ID: Content-Type: text/plain; charset=UTF-8 Subject: Re: [Qemu-devel] [PATCH] turn firmware image filename into a machine option List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Gerd Hoffmann Cc: Mark Langsdorf , QEMU Developers , Fabien Chouteau , Alexander Graf , Blue Swirl , Michael Walle , =?UTF-8?Q?Herv=C3=A9_Poussineau?= , Paul Brook , Anthony Liguori , "open list:New World" , =?UTF-8?Q?Andreas_F=C3=A4rber?= , Aurelien Jarno , Richard Henderson On 1 October 2013 20:22, Gerd Hoffmann wrote: > On Di, 2013-10-01 at 19:55 +0900, Peter Maydell wrote: >> No documentation or definition of what the semantics of >> specifying a "firmware image" filename are? > > "-machine firmware=$file" has the same effect as "-bios $file", which is > simliar to '-machine kernel=$file' and '-kernel $file'. It's similar in that it has semantics that might vary between target cpu architecture or even between target machines, and which aren't very well documented... -bios we're stuck with because it's a legacy option, but if we're going to change/augment the syntax here it would be good to be sure that we end up with something that's (a) consistent across boards/architectures (b) not going to turn into another awkward legacy option. >> Why is this a machine option rather than a property of >> the ROM/flash device? > > Not all machines have a flash device. No, but they must have *something* that the firmware code lives in... > Also flash drives don't want a > simple (readonly) image file but a (writable) blockdev as backing > storage, at least the pflash device emulation I've briefly looked at. ...so how does this work for machines where the firmware lives in a flash device? Does -firmware=foo override setting the backing image for the flash device, or vice versa, or do machines with flash devices not support -firmware=foo, or something else? -- PMM