I started create a small board support layer  for yocto (aka
angstrom) because we use yocto/angstrom for all our boards and the
available beagle bsp is loveless or unmaintained. So far images are
working very nice with kernel 4.1 (beagleboard/rnelson source).
Now my question: At what folder does kernel expect the devicetree
Overlays generally go init /lib/firmware. Some of the official distributions put copies in initrd. Older kernels have some overlays built-in. These tend to get in the way (e.g. if you have an overlay file with the same name in /lib/firmware and built into the kernel, the built-in one takes precedence. It's terrible).