Use kunbus linux kernel 4.9 instead of 4.14, and use their skb branch.

[MathiasKoch]

revpi-core-3.conf:

• Add PREFERRED_VERSION_linux-raspberrypi to override kernel version to 4.9.%
• Remove bcm2710-rpi-3-b-plus.dtb from device tree, as it is not included in kernel repo. See note below.

linux-kunbus.bb:

• Add LINUX_KERNEL_TYPE = "preempt-rt".
• Allow for easy change between 4.9 and 4.14, for easy upgrade later on.

linux-kunbus.bbappend:

• Add kernel configuration, similar to what kunbus configures in https://github.com/RevolutionPi/imagebakery to build as fully preemptive RT, with all the required drivers.

picontrol.bb:

• Allow for easy change between 4.9 and 4.14, for easy upgrade later on.

[Issue #24 ]

• Use kernel 4.9 instead of 4.14, as 4.14 still timeouts, even when built as preemptive RT.
• Build the kernel as a fully preemptive RT build.
• Allow quickly changing between 4.9-skb and 4.14, by just changing PREFERRED_VERSION_linux-raspberrypi in revpi-core-3.conf

NOTE: Maybe we should consider adding bcm2710-rpi-3-b-plus.dtb through a patch, instead of removing it from the device tree? Perhaps someone with the yocto knowledge to do this, can assist with it?

Signed-off-by: Mathias Koch mk@blackbird.online

[floion]

Hi, we have deprecated this repository. We instead use https://github.com/balena-os/balena-raspberrypi We'll be switching the kernel to 4.9 in that repo for the revpi

[MathiasKoch]

Alright! sounds great.

Should i add a PR for the kernel change, and the config in that repo? or will you change it? Also, when can we expect to see a new image online, with these changes, for a BalenaOS host Update?