I've just done a 1.6.1 release of radeontool from my personal repo, it contains both
radeontool and avivotool, and is probably full of ugly but whats in distros now is older
radeontool (and avivotool) are lowlevel tools to tweak register and dump state on radeon
GPUs, they also can parse parts of the BIOS data tables.
Tarballs are at
r128 support from Jonathan Nieder
Some new legacy table decoding added