From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jan =?ISO-8859-1?Q?L=FCbbe?= Subject: Re: [PATCH v4 3/3] dtc: Document the dynamic plugin internals Date: Tue, 03 Mar 2015 14:42:52 +0100 Message-ID: <1425390172.3668.196.camel@pengutronix.de> References: <1425063346-14554-1-git-send-email-pantelis.antoniou@konsulko.com> <1425063346-14554-4-git-send-email-pantelis.antoniou@konsulko.com> Mime-Version: 1.0 Content-Transfer-Encoding: 8BIT Return-path: In-Reply-To: <1425063346-14554-4-git-send-email-pantelis.antoniou-OWPKS81ov/FWk0Htik3J/w@public.gmane.org> Sender: devicetree-compiler-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: Content-Type: text/plain; charset="us-ascii" To: Pantelis Antoniou Cc: Jon Loeliger , Grant Likely , Rob Herring , devicetree-compiler-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org Hi Pantelis, On Fr, 2015-02-27 at 20:55 +0200, Pantelis Antoniou wrote: > +3.b) The Device Tree fragments must be compiled with the same option but they > +must also have a tag (/plugin/) that allows undefined references to labels > +that are not present at compilation time to be recorded so that the runtime > +loader can fix them. > + > +So the bar peripheral's DTS format would be of the form: > + > +/plugin/; /* allow undefined label references and record them */ > +/ { > + .... /* various properties for loader use; i.e. part id etc. */ > + fragment@0 { > + target = <&ocp>; > + __overlay__ { > + /* bar peripheral */ > + bar { > + compatible = "corp,bar"; > + ... /* various properties and child nodes */ > + } > + }; > + }; > +}; > + > +Note that there's a target property that specifies the location where the > +contents of the overlay node will be placed, and it references the label > +in the foo.dts file. The kernel overlay code also supports using 'target-path="/path";' instead of 'target=;' to work with base DTBs which have no __symbols__ node. Shouldn't this be mentioned here as well? Thanks, Jan -- Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | -- To unsubscribe from this list: send the line "unsubscribe devicetree-compiler" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html