How to specify which kernel to build with bitbake/yocto

Question

I am working on generating a new BSP using yocto daisy. When I build my image I get these warnings:

NOTE: Resolving any missing task queue dependencies
NOTE: multiple providers are available for virtual/kernel (my-kernel, linux-dummy)
NOTE: consider defining a PREFERRED_PROVIDER entry to match virtual/kernel
NOTE: multiple providers are available for runtime kernel-modules (my-kernel, linux-dummy)
NOTE: consider defining a PREFERRED_PROVIDER entry to match kernel-modules

I can't understand how to define my preferred provider for the kernel. From what I have read I should just need to add it to the meta-myLayer/conf/machine/myMachine.conf Which I did, as such:

KERNEL_IMAGETYPE = "zImage"
KERNEL_DEVICETREE = "${S}/arch/arm/boot/dts/myTree.dtb"
KERNEL_EXTRA_ARGS += "LOADADDR=${UBOOT_ENTRYPOINT}"
#  use this kernel and version
PREFERRED_PROVIDER_virtual/kernel = "linux-yocto"
PREFERRED_VERSION_linux-yocto = "3.14%"

Yocto/bitbake seem to be ignoring these lines.
Also, to be clear I also have the machine name set correctly in build/conf/local.conf

Is there something else I need to change to get this to work? Or is Yocto just that broken?

Mycenae

You have the preferred kernel provider set as linux-yocto, but it's saying only my-kernel and linux-dummy are available. Are you sure you have the poky/meta-yocto and poky/meta-yocto-bsp layers added to your bblayers.conf? – Doane

@Doane Yes my bblayers includes meta-yocto and met-yocot-bsp in the BBLAYERS variable. – Mycenae

Answer 1

Like E-rich wrote, the build system does only see my-kernel and linux-dummy as available providers for virtual/kernel. Thus, I'd guess that you'd actually want to build one of them?

The reason that linux-yocto isn't available is likely that your machine isn't in the COMPATIBLE_MACHINE regexp in linux-yocto_3.14.bb. Thus, if you want to use linux-yocto, you should bbappend that recipe in your own layer, and add your machine to COMPATIBLE_MACHINE. (You will also likely need to supply some more parameters, SRCREV, KBRANCH, etc.)

Mehalek

This was it. Thank you for pointing me in the right direction. Yocto is so much harder to use than BuildRoot. If it wasn't a requirement to use yocto, I would switch to BR. – Mycenae