From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([140.186.70.92]:55481) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1R49ja-0003Kj-5F for qemu-devel@nongnu.org; Thu, 15 Sep 2011 07:03:59 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1R49jX-0003iE-Rp for qemu-devel@nongnu.org; Thu, 15 Sep 2011 07:03:58 -0400 Date: Thu, 15 Sep 2011 21:03:35 +1000 From: David Gibson Message-ID: <20110915110335.GW9025@yookeroo.fritz.box> References: <1315989802-18753-1-git-send-email-agraf@suse.de> <1315989802-18753-29-git-send-email-agraf@suse.de> <20110915031932.GU9025@yookeroo.fritz.box> <25DA59E2-0AA8-486E-A129-2016EAC99CC6@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <25DA59E2-0AA8-486E-A129-2016EAC99CC6@suse.de> Subject: Re: [Qemu-devel] [Qemu-ppc] [PATCH 28/58] device tree: give dt more size List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Alexander Graf Cc: qemu-ppc@nongnu.org, qemu-devel Developers On Thu, Sep 15, 2011 at 09:37:48AM +0200, Alexander Graf wrote: > > On 15.09.2011, at 05:19, David Gibson wrote: > > > On Wed, Sep 14, 2011 at 10:42:52AM +0200, Alexander Graf wrote: > >> We currently load a device tree blob and then just take its size x2 to > >> account for modifications we do inside. While this is nice and great, > >> it fails when we have a small device tree as blob and lots of nodes added > >> in machine init code. > >> > >> So for now, just make it 20k bigger than it was before. We maybe want to > >> be more clever about this later. > > > > In fact, one of the few things I can think of that might justify > > qemu's "abstraction" of the libfdt interface, is that the wrappers > > could be modified to detect -FDT_ERR_NOSPACE and realloc() > > appropriately. > > Oh, yeah, that sounds like a very good idea! > > > Otherwise the wrappers, which are limited and not notably simpler to > > use than the raw libfdt functions seem pretty pointless to me. > > > > Not that I'm biased as the author of libfdt or anything :). > > I agree that the wrappers are not all that overly useful atm. I was > actually very close to just ripping them out completely instead of > extending them for new functionality. I did have the feeling that > wrapping libfdt would give us a few benefits, maybe even the chance > of getting rid of #ifdefs in target code. Hrm, maybe. Can't really see it. Of course, my preference would be to get rid of those #ifdefs by embedding libfdt in qemu so it's always there. > Could you please put this on your todo list? We should probably > force every target code in QEMU to only use the wrappers and > dynamically realloc() in them. Uh, sure, but it's a long list and it won't be near the top. The wrappers would need to be a lot more extensive to do this. I use libfdt directly in the spapr code for a reason. -- David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson