From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1L12sH-0004yo-Sb for qemu-devel@nongnu.org; Fri, 14 Nov 2008 12:54:30 -0500 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1L12sG-0004xF-4q for qemu-devel@nongnu.org; Fri, 14 Nov 2008 12:54:29 -0500 Received: from [199.232.76.173] (port=59381 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1L12sF-0004x2-S5 for qemu-devel@nongnu.org; Fri, 14 Nov 2008 12:54:27 -0500 Received: from rn-out-0910.google.com ([64.233.170.191]:61981) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1L12sF-0002T9-MK for qemu-devel@nongnu.org; Fri, 14 Nov 2008 12:54:27 -0500 Received: by rn-out-0910.google.com with SMTP id m61so1346423rnd.8 for ; Fri, 14 Nov 2008 09:54:25 -0800 (PST) Message-ID: Date: Fri, 14 Nov 2008 11:54:24 -0600 From: "Hollis Blanchard" Sender: slightlyunconventional@gmail.com Subject: Re: [Qemu-devel] Machine config files In-Reply-To: <200811140332.14093.paul@codesourcery.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <200811140332.14093.paul@codesourcery.com> 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 On Thu, Nov 13, 2008 at 9:32 PM, Paul Brook wrote: > It's come up in other contexts recently, so I think it's worth mentioning that > I am currently working on adding a machine config file support to qemu. > > I am focusing on the board setup side of things, rather than the user-level > config side. My goal is to come up with a system that will allow e.g. the > entirety of realview.c and gumstix.c to be eliminated. Currently this is > based this round Flattened Device Trees (as used by ppc-linux). > > I have looked at the bits that Fabrice did a while ago. While that contains > some good ideas (which I will probably steal!) it is approaching the problem > from a somewhat different direction. FTDs are a much better fit for some of > my requirements (e.g. being able to pass the config through to the guest OS). > > I haven't entirely figured out how this will interact with user config (in > particular user-pluggable devices like PCI NICs), but I think I can come up > with something fairly sensible. Sounds great! For what it's worth, in the PowerPC KVM patches that I'll be posting here soon, we also use a flat device tree and pass it to the guest. We start with a template .dtb file in pc-bios/, then modify things like memory nodes at runtime based on qemu's command line options. One practical consideration is that libfdt isn't generally available as a standalone package. I requested that Debian and Fedora create packages for it, and they agreed, but those obviously aren't available in older versions or other Linux distributions. In the meantime, we could either include a libfdt snapshot in qemu (which is how it was originally intended to be used), or require users to build and install the package from source. -Hollis