From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dmitry Eremin-Solenikov Subject: Re: [PATCH 0/3] patches to allow DTB to be appended to the ARM zImage Date: Mon, 13 Jun 2011 20:19:46 +0000 (UTC) Message-ID: 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> <20110612104048.GE10283@n2100.arm.linux.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: 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: devicetree-discuss-mnsaURCQ41sdnm+yROfE0A@public.gmane.org Cc: linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org List-Id: devicetree@vger.kernel.org Russell King - ARM Linux wrote: > 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. ... exactly like cuboot* preloaders are patching dtb on the powerpc systems, where U-Boot doesn't understand dtb. -- With best wishes Dmitry