Migrating BSP 2.8.6 to BSP 5.x


We have been using so far BSP 2.8.x with rt kernel patch.
We were building a customized lxde image with kernel version 4.9.166-rt-125-2.8.6 . With BSP 5.x,
we would like to do the same by building “tdx-xwayland-rt” reference image from the source. The image gets build fine and the board is booting. But I am not sure whether it is applying the rt kernel patches. Also, I could not find a recipe for the rt kernel. I was expecting a recipe file like “linux-toradex-rt-*.bb” like it was the case in the olde BSP. I only found the “linux-toradex_5.4-2.3.x.bb” for the standard kernel.

Am I doing something wrong here ? Which recipe actually applies the rt patches ? Also, a guide to customize the device tree on this new BSP will be very helpful in this regard.

Toradex Colibri iMX7 Dual 1GB Emmc
Custom Carrierboard
BSP 5.x

Hi @xdaco !

For the BSP 5, there are no specific rt recipes.

You can see in the meta-toradex-distro layer that e.g. the tdx-wayland-upstream-rt.conf configuration file set some variables that will activate the PREEMPT-RT patches.

Take a look at the Real-Time Linux article to see how to check PREEMPT-RT capabilities.

Best regards,

Thanks @henrique.tx for the clarification. This also means that I need to modify linux-toradex_5.4-2.3.x.bb in order to achieve our required kernel customisation for the rt variant too. Is this assumption correct?

Hi @xdaco !

You shouldn’t need to tweak any recipes in order to apply the PREMPT_RT patch.

Take a look at the Distro section of the OpenEmbedded (core) - Toradex System/Computer on Modules article.

In order to get the PREEMPT_RT in your final image, you only need to set the DISTRO variable (e.g. in your local.conf file) to the distro that will apply the patch (currently tdx-xwayland-rt or tdx-xwayland-upstream-rt)

Makes sense to you?

Best regards,