I build the evil binary blob firmware into the kernel,
CONFIG_EXTRA_FIRMWARE="radeon/R600_rlc.bin radeon/RS780_pfp.bin radeon/RS780_me.bin"
so make sure you have these evil binary blobs in your /lib/firmware. I could scp those too there but you generally want to grab such blobs from a more safe source than some random long-haried hippie on the internets.
you can put the blobs in initrd or whatever instead, I just push'it into the kernel and it's there and it works.