As the author of the NetBSD Wii and Wii U ports, congrats! I’m looking forward to seeing how you solved some of the problems that I faced along the way.
72 karma · joined November 6, 2014
Look at ports/sysutils/u-boot-cubieboard2 for a template on how to build a suitable U-Boot, and sys/boot/fdt/dts/arm/cubieboard2.dts for a template for your dtb.
For a detailed list of supported hardware, have a look at the wiki: https://wiki.freebsd.org/FreeBSD/arm/Allwinner