From mboxrd@z Thu Jan 1 00:00:00 1970 From: Russell King - ARM Linux Subject: Re: [PATCH 0/3] patches to allow DTB to be appended to the ARM zImage Date: Sun, 12 Jun 2011 11:40:48 +0100 Message-ID: <20110612104048.GE10283@n2100.arm.linux.org.uk> References: <1307858800-16712-1-git-send-email-nicolas.pitre@linaro.org> <20110612081541.GA10283@n2100.arm.linux.org.uk> <20110612083414.GA29516@S2100-06.ap.freescale.net> <20110612092131.GC10283@n2100.arm.linux.org.uk> <20110612095217.GD10283@n2100.arm.linux.org.uk> <20110612104215.GC29516@S2100-06.ap.freescale.net> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <20110612104215.GC29516-+NayF8gZjK2ctlrPMvKcciBecyulp+rMXqFh9Ls21Oc@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-bounces+gldd-devicetree-discuss=m.gmane.org-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org To: Shawn Guo Cc: Nicolas Pitre , Tony Lindgren , devicetree-discuss-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org List-Id: devicetree@vger.kernel.org On Sun, Jun 12, 2011 at 06:42:16PM +0800, Shawn Guo wrote: > On Sun, Jun 12, 2011 at 10:52:17AM +0100, Russell King - ARM Linux wrote: > > On Sun, Jun 12, 2011 at 05:38:23PM +0800, Shawn Guo wrote: > > > On Sun, Jun 12, 2011 at 10:21:31AM +0100, Russell King - ARM Linux wrote: > > > > What if your platform doesn't use uboot? > > > > > > Add dtb parsing support with the help from libfdt, I guess. It is > > > some amount of work, but it's not a rewrite of bootloader, IMHO. > > > > I guess you're suggesting that this wrapper uses libfdt to merge > > the ATAGs with the DT info? > > > No, ATAGs does not play at all in this case. For u-boot example > again, if it boots a dt kernel, dtb will be parsed to get cmdline > node overwritten as bootargs env value, and then it boots the dt > kernel with this updated dtb. You've missed my point entirely. What you're saying is that we have to re-build and replace the boot loader in order to pass a command line into a kernel using the DT wrapper. I'm saying that you shouldn't have to, and the kernel should accept the memory size and command line from the ATAGs _in addition_ to the appended DT blob, and the ATAGs in that case should take precidence.