ATI OpenGL on Gentoo
From DWIKI
Compile kernel with DRM support.
emerge xf86-video-ati
TO /etc/make.conf add:
VIDEO_CARDS="radeon"
Then:
emerge mesa
In /etc/X11/xorg make sure you have:
Section "Device" Driver "radeon" EndSection
Section "Extensions" Option "Composite" "1" EndSection
Section "ServerFlags" Option "AIGLX" "On" EndSection