From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by yocto-www.yoctoproject.org (Postfix, from userid 118) id 80905E009F0; Fri, 31 Jul 2015 06:29:35 -0700 (PDT) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on yocto-www.yoctoproject.org X-Spam-Level: X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00,HTML_MESSAGE, RCVD_IN_DNSWL_NONE autolearn=ham version=3.3.1 X-Spam-HAM-Report: * -0.0 RCVD_IN_DNSWL_NONE RBL: Sender listed at http://www.dnswl.org/, no * trust * [195.74.38.225 listed in list.dnswl.org] * -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% * [score: 0.0000] * 0.0 HTML_MESSAGE BODY: HTML included in message Received: from bin-vsp-out-05.atm.binero.net (vsp-unauthed01.binero.net [195.74.38.225]) by yocto-www.yoctoproject.org (Postfix) with ESMTP id B747AE009E5 for ; Fri, 31 Jul 2015 06:29:30 -0700 (PDT) X-Halon-ID: 3150d0b2-3788-11e5-8d95-005056916f53 Authorized-sender: petter@technux.se Received: from [192.168.1.82] (unknown [81.229.90.163]) by bin-vsp-out-05.atm.binero.net (Halon Mail Gateway) with ESMTPSA; Fri, 31 Jul 2015 15:29:38 +0200 (CEST) Message-ID: <55BB7830.8010909@technux.se> Date: Fri, 31 Jul 2015 15:29:20 +0200 From: =?windows-1252?Q?Petter_Mab=E4cker?= User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.7.0 MIME-Version: 1.0 To: Herve Jourdain , francois@concept-embarque.fr, Andrei Gherzan References: <086901d0ca77$9e8f1300$dbad3900$@neuf.fr> In-Reply-To: <086901d0ca77$9e8f1300$dbad3900$@neuf.fr> Cc: yocto@yoctoproject.org Subject: Re: [meta-raspberrypi] Adding an additional device tree overlay in the SDCard X-BeenThere: yocto@yoctoproject.org X-Mailman-Version: 2.1.13 Precedence: list List-Id: Discussion of all things Yocto Project List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 31 Jul 2015 13:29:35 -0000 Content-Type: multipart/alternative; boundary="------------030002070405070402030408" --------------030002070405070402030408 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 8bit Hi Herve, See inline answers. BR, Petter On 07/30/2015 05:27 AM, Herve Jourdain wrote: > > Hello, > > I’m trying to add a specific .dts file to the raspberrypi. > > Therefore, in my own layer, I have made a > linux-raspberrypi_3.%.bbappend, that applies a patch to the > arch/arm/boot/dts makefile to add my own layer, and a new rule that > copies my specific .dts file to the kernel source directory. > > And, initially, I had also defined KERNEL_DEVICETREE += > “myown-overlay.dtb” in there. > > It definitely compiles well, installation process is smooth, I get the > Image-myown-overlay.dtb in tmp/deploy/raspberrypi2. > > BUT when I flash my SDCard, it does NOT appear in the “overlays” > directory of the DOS partition! > > If I add it manually, everything works fine, so I know my overlay has > been correctly generated and is working. > > What I discovered is that, the sdcard_image_rpi class takes the list > of .dtb to be considered from split_overlays(), which is defined in > linux-raspberrypi-base class. > > And split_overlays() basically gets the value of KERNEL_DEVICETREE > (dts = d.getVar("KERNEL_DEVICETREE", True)). > > But when I set KERNEL_DEVICETREE in linux-raspberrypi_3.%.bbappend, it > seems the additional value it defines is NOT taken into account when > linux-raspberry-class evaluates the value of KERNEL_DEVICETREE. > > I’ve checked in the create_image.rpi-sdimg script created, it does not > appear in DTS nor DT_OVERLAYS. > > But when I define KERNEL_DEVICETREE in my distro.conf, THEN it is > taken into account… > > My goal would be to add that overlay by NOT modifying distro.conf > (distros are not necessarily RaspberryPi centric) nor in the raspberry > machine files (or local.conf). > > This leads me to several questions: > > #1 Is there a specific reason why my addition to KERNEL_DEVICETREE > gets lost when creating the image? I mean, is it normal, or are there > some steps I missed there? > Yes, in the current solution KERNEL_DEVICETREE is needed in both the kernel recipe and image creation context. When appending KERNEL_DEVICETREE in linux-raspberrypi_3.%.bbappend your new overlay will only be visible within the linux-raspberrypi scope and NOT within the image class. > #2 Is there a way that I could achieve adding my .dtb overlay in the > sdcard image only from my linux kernel bbappend? > If I remember the code correct within the kernel scope we are only interesting if device tree should be used. At least in theory (assuming you are using a >= 3.18 kernel since then KERNEL_DEVICETREE will bve set by default) you should be able to skip the KERNEL_DEVICETREE += code in linux-raspberrypi_3.%.bbappend (since it will be set any way and the overlays themselves isn't really used in here..) then append the KERNEL_DEVICETREE within the image scope. If you don't want to put this into the layer.conf or similiar in your own layer I guess it should work to "prepend" for example the IMAGE_CMD. But in the current solution I guess local.conf, layer.conf (in your own layer) or rpi-base.inc (in meta-raspberrypi) is the easiest options.. > #3 On a more general note, wouldn’t it be simpler (better?) to just > add all the .dtb that are found in the deploy/images/ directory to the > DOS partition of the SDCard? After all, the .dtb need to be compiled > from a .dts, so all the .dtb that appear in deploy/images are “legit”. > That might perhaps be a better solution. Have you tried it out? Andrei or Francois might have some comments about this? > > Herve > > > --------------030002070405070402030408 Content-Type: text/html; charset=windows-1252 Content-Transfer-Encoding: 8bit
Hi Herve,

See inline answers.

BR,
Petter

On 07/30/2015 05:27 AM, Herve Jourdain wrote:

Hello,

 

I’m trying to add a specific .dts file to the raspberrypi.

Therefore, in my own layer, I have made a linux-raspberrypi_3.%.bbappend, that applies a patch to the arch/arm/boot/dts makefile to add my own layer, and a new rule that copies my specific .dts file to the kernel source directory.

And, initially, I had also defined KERNEL_DEVICETREE += “myown-overlay.dtb” in there.

 

It definitely compiles well, installation process is smooth, I get the Image-myown-overlay.dtb in tmp/deploy/raspberrypi2.

 

BUT when I flash my SDCard, it does NOT appear in the “overlays” directory of the DOS partition!

 

If I add it manually, everything works fine, so I know my overlay has been correctly generated and is working.

 

What I discovered is that, the sdcard_image_rpi class takes the list of .dtb to be considered from split_overlays(), which is defined in linux-raspberrypi-base class.

And split_overlays() basically  gets the value of KERNEL_DEVICETREE (dts = d.getVar("KERNEL_DEVICETREE", True)).

 

But when I set KERNEL_DEVICETREE in linux-raspberrypi_3.%.bbappend, it seems the additional value it defines is NOT taken into account when linux-raspberry-class evaluates the value of KERNEL_DEVICETREE.

I’ve checked in the create_image.rpi-sdimg script created, it does not appear in DTS nor DT_OVERLAYS.

 

But when I define KERNEL_DEVICETREE in my distro.conf, THEN it is taken into account…

 

My goal would be to add that overlay by NOT modifying distro.conf (distros are not necessarily RaspberryPi centric) nor in the raspberry machine files (or local.conf).

This leads me to several questions:

#1 Is there a specific reason why my addition to KERNEL_DEVICETREE gets lost when creating the image? I mean, is it normal, or are there some steps I missed there?

Yes, in the current solution KERNEL_DEVICETREE is needed in both the kernel recipe and image creation context. When appending KERNEL_DEVICETREE in linux-raspberrypi_3.%.bbappend your new overlay will only be visible within the linux-raspberrypi scope and NOT within the image class.

#2 Is there a way that I could achieve adding my .dtb overlay in the sdcard image only from my linux kernel bbappend?


If I remember the code correct within the kernel scope we are only interesting if device tree should be used. At least in theory (assuming you are using a >= 3.18 kernel since then KERNEL_DEVICETREE will bve set by default) you should be able to skip the KERNEL_DEVICETREE += code in linux-raspberrypi_3.%.bbappend (since it will be set any way and the overlays themselves isn't really used in here..) then append the KERNEL_DEVICETREE within the image scope. If you don't want to put this into the layer.conf or similiar in your own layer I guess it should work to "prepend" for example the IMAGE_CMD. But in the current solution I guess local.conf, layer.conf (in your own layer) or rpi-base.inc (in meta-raspberrypi) is the easiest options..

#3 On a more general note, wouldn’t it be simpler (better?) to just add all the .dtb that are found in the deploy/images/ directory to the DOS partition of the SDCard? After all, the .dtb need to be compiled from a .dts, so all the .dtb that appear in deploy/images are “legit”.


That might perhaps be a better solution. Have you tried it out? Andrei or Francois might have some comments about this?

 

Herve




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