From mboxrd@z Thu Jan 1 00:00:00 1970 From: Grant Likely Subject: Re: [PATCH 0/3] patches to allow DTB to be appended to the ARM zImage Date: Mon, 13 Jun 2011 09:17:49 -0600 Message-ID: References: <20110612112219.GD16318@ibawizard.net> <20110612115820.GF10283@n2100.arm.linux.org.uk> <201106121615.24059.arnd@arndb.de> <20110612145751.GA4013@ponder.secretlab.ca> <20110612151931.GK10283@n2100.arm.linux.org.uk> <20110612155940.GM10283@n2100.arm.linux.org.uk> <20110613095142.GA10951@atomide.com> <20110613142044.GC13643@n2100.arm.linux.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-arm-kernel-bounces@lists.infradead.org Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: Nicolas Pitre Cc: Russell King - ARM Linux , Arnd Bergmann , Tony Lindgren , devicetree-discuss@lists.ozlabs.org, John Bonesio , =?UTF-8?Q?Petr_=C5=A0tetiar?= , linux-arm-kernel@lists.infradead.org List-Id: devicetree@vger.kernel.org On Mon, Jun 13, 2011 at 9:14 AM, Nicolas Pitre w= rote: > On Mon, 13 Jun 2011, Russell King - ARM Linux wrote: > >> On Mon, Jun 13, 2011 at 10:14:07AM -0400, Nicolas Pitre wrote: >> > On Mon, 13 Jun 2011, Tony Lindgren wrote: >> > >> > > I agree that we need to parse the user configurable ATAGs to support >> > > existing hardware properly. Otherwise we have edit the .dts for each= board >> > > to change the user configurable things, which is not nice for distro= s. >> > >> > You mean "existing bootloaders", right? >> > >> > Updated bootloaders should translate user configurable information into >> > proper DT records and pass the resulting DTB to the kernel separately. >> >> OMAP is one of the code bases where this really matters - they have a >> _lot_ of existing platforms with boot loaders which do the ATAG stuff. >> They also have a lot of code in arch/arm that needs to be converted to >> a DT representation. > > Yes, agreed. =A0I just wanted to make the situation clear above, so people > aren't confused in believing that the DT data is always static. =A0New > bootloaders should have the same ability to dynamically change some of > the parameters passed to the kernel. =A0So the issue is not about existing > hardware, but rather about existing bootloaders. > >> With the current situation where you can have either ATAGs or DT but >> not both, they're currently facing either having to break all the >> existing platforms by ignoring the ATAGs _or_ keeping two copies of >> a considerable amount of data - one in DT form and one in its existing >> form. >> >> At present, DT can only be used sensibly on brand new SoCs where there >> are no existing platforms with ATAG based boot loaders to worry about. >> As things stand at present, even with your patch series, existing SoCs >> have no viable path to transition to DT. > > As I said, I'm now convinced that the patch adding a shim to translate > ATAGs into DT entries should be added to this series. =A0I was reluctant > initially for insentive purposes, but your argument clearly tilted the > balance the other way. John Bonesio was the author of that patch. John, can you dust of the ATAGs-->DT conversion patch and get it rebased to my current devicetree/test branch? I've picked up Nicolas' 3 patch series which includes your dtb append patch into devicetree/test. g. -- = Grant Likely, B.Sc., P.Eng. Secret Lab Technologies Ltd.