VIDEO_CARDS setting: AMDGPU is an Open Source graphics driver developed by AMD that supports the latest AMD Radeon graphics cards (GCN 1.2, HD 7xxxx+). It is typically used in conjunction with Mesa's
radeonsi driver which provides OpenGL support. There is a kernel-space part and a user-space part (in
x11-drivers/xf86-video-amdgpu to this driver.