As ARM now also moved to device tree it look like in future we will have more kernels that are using device tree then ones that are not. As far as I understand currently the generation of device trees is controlled via KERNEL_DEVICETREE and is handled in via an include file recipes-kernel/linux/linux-dtb.inc.
I was thinking about moving this include into a class so it becomes easier to use. Before I dive into implementing something I would like some feedback from the community.
I have the following variant in mind.
Add the device tree generation to the current kernel.bbclass (or let kernel.bblcass inherit from a kernel-dtb.bbclass). This way all kernels would automatically be DT enabled. The class would check if KERNEL_DEVICETREE is set and generate device trees based on this information. For boards that don't have KERNEL_DEVICETREE set the class would do nothing and the behavior is like before. The advantage I see with this approach is that the only thing a user needs to do is to set KERNEL_DEVICETREE in the board and make sure the device trees are available in the kernel they like to build.
