By default, Digi Embedded Yocto uses the Digi Linux kernel. Digi recommends you use this vendor kernel, as it offers full support for all interfaces and features available on Digi system-on-modules and SBCs, has been tested extensively with Digi hardware, and allows you to leverage Digi support and updates.

As an alternative to using the Digi Linux kernel, you can also use a mainline kernel. However, mainline kernels typically only support a subset of the functionality of a system-on-module or SBC, and you must rely on support from the wider Linux kernel community.

The mainline support is available on the meta-freescale-3rdparty Yocto Project layer, so you need to clone this layer into the sources folder and checkout to a compatible branch:

$ cd </path/to/dey/installation>/sources/
$ git clone https://github.com/Freescale/meta-freescale-3rdparty.git
$ cd </path/to/dey/installation>/sources/meta-freescale-3rdparty
$ git checkout -b thud origin/thud

And add the meta-freescale-3rdparty layer to your conf/bblayers.conf configuration file:

--- a/bblayers.conf  2019-04-03 17:00:30.289689618 +0200
+++ b/bblayers.conf  2019-03-29 14:42:25.899222140 +0100
@@ -19,4 +19,5 @@
   /usr/local/ssd/dey-2.6/sources/meta-fsl-demos \
   /usr/local/ssd/dey-2.6/sources/meta-digi/meta-digi-arm \
   /usr/local/ssd/dey-2.6/sources/meta-digi/meta-digi-dey \
+  /usr/local/ssd/dey-2.6/sources/meta-freescale-3rdparty \
   "

Finally, to build images with a mainline kernel, configure the following in your project’s conf/local.conf configuration file:

MACHINEOVERRIDES .= ":use-mainline-bsp"

You can then build any supported Digi Embedded Yocto image as usual.