From mboxrd@z Thu Jan 1 00:00:00 1970 From: Daniel Mack Subject: Re: Appended DTB files for multi-machine kernels Date: Fri, 05 Jul 2013 01:02:25 +0200 Message-ID: <51D5FF01.3060104@gmail.com> References: <51D5A938.30607@gmail.com> <20130704171148.GJ27646@sirena.org.uk> <201307042334.37161.arnd@arndb.de> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <201307042334.37161.arnd-r2nGTMty4D4@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: devicetree-discuss-bounces+gldd-devicetree-discuss=m.gmane.org-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org Sender: "devicetree-discuss" To: Arnd Bergmann Cc: stigge-uj/7R2tJ6VmzQB+pC5nmwQ@public.gmane.org, Stephen Warren , Magnus Damm , "devicetree-discuss-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org" , Sven Neumann , Mark Brown , "linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org" List-Id: devicetree@vger.kernel.org Hi Arnd, On 04.07.2013 23:34, Arnd Bergmann wrote: > On Thursday 04 July 2013, Mark Brown wrote: >> Another way of skinning this would be for either the kernel to contain >> a set of machine ID to compatible string mappings or for the device >> trees for the boards to have an additional properties giving the machine >> IDs that the boards match. The kernel could then look for multiple DTBs >> appended to the image and try to pick one based on ATAGs. > > IIRC there is actually an unused field in the dtb header that could > be used to match a board ID. While that would help many users, it doesn't cover our case where different board revisions require different DTBs to be loaded, depending on the supplied ATAG. I think I'll go for Nicolas Pitre's suggestion as first step. He's right that's it's a hack anyway, and we're just dealing with legacy systems here, and hence it might not even be worth caring too much about a proper solution. Thanks for all the answers, Daniel