Question regarding bootfiles/overlays

[LouDou]

Description

Hi,

I'm struggling to understand how to append additional overlay files into the image build for my application. Specifically, I have a device with an Audioinjector Ultra and a Waveshare 5" HDMI touchscreen.

I have all the lines I need added to config.txt, but the required devicetree overlay files are not included by default in the build. These overlay files are available in https://github.com/raspberrypi/firmware, but only a subset of these get included in the build.

They seem to be selected via the RPI_KERNEL_DEVICETREE_OVERLAYS variable. I understand that perhaps not all files are included for size/space efficiency.

I'd like to extend this variable to add the files that I required. I cannot find any working examples or documentation for how to do this.

My application layer image config is here: https://bitbucket.org/doughammond/meta-rpi-guitar-pedal/src/1a510e86e62cc43a3e68087f06e8121aac7d709c There's not a lot in there yet, as I'm still trying to get the basics correct before adding the actual apps on top.

Could you please advise?

Thanks, Doug.

Steps to reproduce the issue:

1. build core-image-minimal for any rpi machine

Describe the results you received:

observe that not all overlays available in raspberrypi/firmware are not included in the final sd image files

Describe the results you expected:

Either:

• All overlay files include OR
• Configuration available to select which overlays to include in the build

Additional information you deem important (e.g. issue happens only occasionally):

None.

Additional details (revisions used, host distro, etc.):

distro: poky version: dunfell

[agherzan]

Is the overlay currently built by all the kernel versions we have in the layer now? If yes, we could enable it by default. Otherwise you can just append it to RPI_KERNEL_DEVICETREE_OVERLAYS as part of your local.conf for example.

[mterwoord]

I'm on thud. I'm appending to RPI_KERNEL_DEVICETREE_OVERLAYS using:

RPI_KERNEL_DEVICETREE_OVERLAYS += " \
    overlays/uart1.dtbo \
    "

But now my overlays folder only contains the uart1 file, not the rest of the set. To me it seems conf/machine/include/rpi-base.inc should set RPI_KERNEL_DEVICETREE_OVERLAYS using the += operator to make appending (like you suggest) working?

[kraj]

use RPI_KERNEL_DEVICETREE_OVERLAYS_append = " overlays/uart1.dtbo"

[mterwoord]

Thanks. Not sure how I missed that.

[LouDou]

Thanks. Not sure how I missed that.

Me neither - I guess that adequately resolves this issue.