From mboxrd@z Thu Jan 1 00:00:00 1970 From: Grant Likely Subject: Re: [U-Boot] dtb vs. kernel command line arguments Date: Mon, 15 Apr 2013 14:37:18 +0100 Message-ID: <20130415133718.E5DEB3E0AA8@localhost> References: <5134E855.7070908@cumulusnetworks.com> <20130304180323.80ef2597c60455f3a358bd79@freescale.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20130304180323.80ef2597c60455f3a358bd79-KZfg59tc24xl57MIdRCFDg@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: Kim Phillips , Curt Brune Cc: u-boot-0aAXYlwwYIKGBzrmiIFOJg@public.gmane.org, devicetree-discuss-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org List-Id: devicetree@vger.kernel.org On Mon, 4 Mar 2013 18:03:23 -0600, Kim Phillips wrote: > On Mon, 4 Mar 2013 10:30:45 -0800 > Curt Brune wrote: > > > Hello - > > > > I want to pass a number of arguments from u-boot to the booted kernel. > > The arguments are needed by user space applications, not the kernel. > > > > I can think of two ways: > > > > 1. append args by setting "bootargs". > > 2. add nodes to the dtb before booting. > > > > Is there a preferred way to pass information like this? > > > > Like I said the arguments are not needed by the kernel device drivers, > > but by user space applications. > > > > I like the structure of nodes in the dtb. > > please don't dual-purpose device trees as a mechanism of getting > arguments through the kernel into userspace - device trees strictly > describe the hardware. Why not? The chosen node in particular is for software configuration. I don't have any problem with passing U-Boot extra data through the chosen node. Just don't go crazy and please document it. g.