From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1LXmDA-0003y8-VE for qemu-devel@nongnu.org; Thu, 12 Feb 2009 19:47:21 -0500 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1LXmD9-0003wl-Ja for qemu-devel@nongnu.org; Thu, 12 Feb 2009 19:47:19 -0500 Received: from [199.232.76.173] (port=59181 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1LXmD9-0003wi-EA for qemu-devel@nongnu.org; Thu, 12 Feb 2009 19:47:19 -0500 Received: from mx20.gnu.org ([199.232.41.8]:20250) by monty-python.gnu.org with esmtps (TLS-1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.60) (envelope-from ) id 1LXmD9-0004df-0J for qemu-devel@nongnu.org; Thu, 12 Feb 2009 19:47:19 -0500 Received: from mail2.shareable.org ([80.68.89.115]) by mx20.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1LXmD8-0000HR-9n for qemu-devel@nongnu.org; Thu, 12 Feb 2009 19:47:18 -0500 Date: Fri, 13 Feb 2009 00:47:07 +0000 From: Jamie Lokier Subject: Re: [Qemu-devel] [RFC] Machine description as data Message-ID: <20090213004707.GE805@shareable.org> References: <20090212040138.GD31142@yookeroo.seuss> <20090212.094613.514366467.imp@bsdimp.com> <4994B22E.6060608@gmx.net> <200902122358.25864.paul@codesourcery.com> <4994BF93.2070409@gmx.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4994BF93.2070409@gmx.net> Reply-To: qemu-devel@nongnu.org List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: devicetree-discuss@ozlabs.org, Paul Brook , hollisb@us.ibm.com Carl-Daniel Hailfinger wrote: > I'm a bit surprised by the lack of automatically detectable features in > embedded systems. Wouldn't automatic detection allow reusing whole OS > images on slighly different systems and thus lower development cost? Where systems are slightly different, what often happens is the boot firmware (boot loader, whatever you want to call it) has different parameters patched in. They might be compiled in differently or different values in a small config block. That only applies to different versions of the same product though. Among embedded systems generally there are huge differences between them. In the OS image, you often have only drivers for devices on the board, to keep the OS as small as possible, so it's customised for each board anyway, except being shared between minor revisions. There are often a few custom devices and kernel patches too. -- Jamie