> Another module that is not available in sparc64 is the xserver-xorg-video-sunffb package.
> https://packages.debian.org/wheezy/sparc/xserver-xorg- video-sunffb/download
> It was last available for wheezy.
That driver was completely removed from Debian. I'm not sure whether it's
still maintained upstream, I think it was removed.
Might be possible that you can use xf86-video-modesetting together with
the right kernel module on these machines these days. Dave Miller probably
knows more, he's on the sparclinux kernel mailing list.