OpenIndiana Distribution

AMDgpu is a family of open source graphics drivers for newer AMD/ATI Radeon graphics cards based on the Southern Islands, Sea Islands, Volcanic Islands, and Arctic Islands chipsets.

Feature support
Family Chipset name Product name OpenGL OpenGL ES VIDEO_CARDS
Southern Islands CAPE VERDE, PITCAIRN, TAHITI, OLAND, HAINAN HD7750-HD7970, R9 270, R9 280, R9 370X, R7 240, R7 250 4.1 3.0 amdgpu radeonsi
Sea Islands BONAIRE, KABINI, KAVERI, HAWAII, MULLINS HD7790, R7 260, R9 290, R7 360, R9 390 4.3 3.1 amdgpu radeonsi
Volcanic Islands CARRIZO, FIJI, STONEY, TONGA, TOPAZ R9 285, R9 380, R9 380X, R9 Fury, R9 Nano, R9 Fury X, Pro Duo 4.3 3.1 amdgpu radeonsi
Arctic Islands POLARIS10, POLARIS11 RX 460, RX 470, RX 480 4.3 3.1 amdgpu radeonsi

Base Feature Support:

Supported APIs:
            OpenGL 4.5 and GLX 1.4
            OpenCL 1.2
            Vulkan 1.0
            VDPAU
            Vulkan support for DOTA2

Also;
Glamor - OpenGL 2D acceleration

At the moment there is support for Volcanic Islands (VI) and experimental support for Sea Islands (CI) and Southern Islands (SI) cards. AMD has absolutely no plans for supporting the pre-GCN GPUs.

Owners of unsupported AMD/ATI video cards may use the Radeon open source or AMD's proprietary driver instead.

If you want manual configuration, create /etc/X11/xorg.conf.d/20-amdgpu.conf, and add the following:
Section "Device"
Identifier "AMD"
Driver "amdgpu"
EndSection