From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758998AbZE1OkJ (ORCPT ); Thu, 28 May 2009 10:40:09 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754878AbZE1Oj7 (ORCPT ); Thu, 28 May 2009 10:39:59 -0400 Received: from yw-out-2324.google.com ([74.125.46.30]:11932 "EHLO yw-out-2324.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753421AbZE1Oj6 (ORCPT ); Thu, 28 May 2009 10:39:58 -0400 MIME-Version: 1.0 In-Reply-To: <9e4733910905280547w7ee65d40yb4b3ab9559e14dae@mail.gmail.com> References: <1243408083.13460.14.camel@debian-nb> <20090527150527.GK6805@pengutronix.de> <87vdnm8sec.fsf@macbook.be.48ers.dk> <4A1D6901.2090508@freescale.com> <20090527175609.GB31861@flint.arm.linux.org.uk> <1243496236.3171.140.camel@pasglop> <20090528091513.GA14789@n2100.arm.linux.org.uk> <9e4733910905280547w7ee65d40yb4b3ab9559e14dae@mail.gmail.com> From: Grant Likely Date: Thu, 28 May 2009 08:39:40 -0600 Message-ID: Subject: Re: [RFC] [PATCH] Device Tree on ARM platform To: Jon Smirl Cc: Russell King - ARM Linux , Benjamin Herrenschmidt , Scott Wood , devicetree-discuss , linux-kernel@vger.kernel.org, Timur Tabi , Janboe Ye , linux-arm-kernel@lists.arm.linux.org.uk Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, May 28, 2009 at 6:47 AM, Jon Smirl wrote: > On Thu, May 28, 2009 at 5:15 AM, Russell King - ARM Linux > For ARM the model could be to use the machine number to load a device > tree built into the kernel (these trees would slowly migrate into the > firmware). After the device tree is selected the machine specific code > would add the override function pointers. Unified OF aware device > drivers would load using the device tree. These drivers would find the > function pointers and use them to implement machine specific features. Nagging point: it is not encouraged to move the device tree into the firmware. It is useful to *pass* the device tree via the kernel, but hard linking it in is the way of pain because it makes updates hard. This is probably what you meant, but I wanted to clarify. g. -- Grant Likely, B.Sc., P.Eng. Secret Lab Technologies Ltd. From mboxrd@z Thu Jan 1 00:00:00 1970 From: Grant Likely Subject: Re: [RFC] [PATCH] Device Tree on ARM platform Date: Thu, 28 May 2009 08:39:40 -0600 Message-ID: References: <1243408083.13460.14.camel@debian-nb> <20090527150527.GK6805@pengutronix.de> <87vdnm8sec.fsf@macbook.be.48ers.dk> <4A1D6901.2090508@freescale.com> <20090527175609.GB31861@flint.arm.linux.org.uk> <1243496236.3171.140.camel@pasglop> <20090528091513.GA14789@n2100.arm.linux.org.uk> <9e4733910905280547w7ee65d40yb4b3ab9559e14dae@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <9e4733910905280547w7ee65d40yb4b3ab9559e14dae-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: devicetree-discuss-bounces+gldd-devicetree-discuss=m.gmane.org-mnsaURCQ41sdnm+yROfE0A@public.gmane.org Errors-To: devicetree-discuss-bounces+gldd-devicetree-discuss=m.gmane.org-mnsaURCQ41sdnm+yROfE0A@public.gmane.org To: Jon Smirl Cc: devicetree-discuss , Russell King - ARM Linux , linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-arm-kernel-xIg/pKzrS19vn6HldHNs0ANdhmdF6hFW@public.gmane.org, Scott Wood , Janboe Ye , Timur Tabi List-Id: devicetree@vger.kernel.org On Thu, May 28, 2009 at 6:47 AM, Jon Smirl wrote: > On Thu, May 28, 2009 at 5:15 AM, Russell King - ARM Linux > For ARM the model could be to use the machine number to load a device > tree built into the kernel (these trees would slowly migrate into the > firmware). After the device tree is selected the machine specific code > would add the override function pointers. Unified OF aware device > drivers would load using the device tree. These drivers would find the > function pointers and use them to implement machine specific features. Nagging point: it is not encouraged to move the device tree into the firmware. It is useful to *pass* the device tree via the kernel, but hard linking it in is the way of pain because it makes updates hard. This is probably what you meant, but I wanted to clarify. g. -- Grant Likely, B.Sc., P.Eng. Secret Lab Technologies Ltd.