[U-Boot] dt overlays raspberry pi

[Waldemar Brodkorb]

Hi U-boot hackers,

we like to use u-boot as intermediate bootloader to
create a raspberry pi based system with fallback partitions.
This worked fine in the first tests.

Recently the raspberry pi project switched to Linux Kernel
3.18.x and a device tree enabled kernel.
I added fdtfile and stuff to load the dtb (bcm2708-rpi-b.dtb)
into my u-boot environment and this works fine.

But we are using a rpi-proto audio chip (something like a hifiberry
i2s connected daughterboard) which is enbaled in the Broadcom
Bootloader via a Device Tree Overlay.

Is there any support for device tree overlays in u-boot for
raspberry pi?

https://github.com/raspberrypi/firmware/blob/master/boot/overlays/README

Is anyone working on this?

Thanks in advance
 Waldemar