Radeon Video
The following instructions are for modern AMD GPU chipsets covered by the radeon and amdgpu drivers.
Firmware
    
For RDNA and later, the linux-firmware-amdgpu package is required. Otherwise, the linux-firmware-radeon should be used.
See the relevant section on the Gentoo Wiki for a more granular list of product names and microarchitecture names.
Kernel Modesetting (KMS)
    
To enable KMS at boot:
- Add the 
radeonoramdgpuandfbconmodules to /etc/modules:$ echo radeon >> /etc/modules
or
$ echo fbcon >> /etc/modules$ echo amdgpu >> /etc/modules
$ echo fbcon >> /etc/modules - Install 
mkinitfs:apk add mkinitfs
 - Enable the 
kmsfeature in themkinitfsconfiguration by adding it to the features variable, e.g.,Contents of /etc/mkinitfs/mkinitfs.conf
features="keymap cryptsetup kms ata base ide scsi usb virtio ext4" - Run 
mkinitfs. - Reboot to test the configuration.
 
Wayland
    
Install the following packages as needed:
mesa-dri-gallium: necessary Mesa drivers.mesa-va-gallium: VA-API drivers, for hardware accelerated video encoding and decoding
If driver auto-selection does not work, e.g. no mouse cursor under Sway, manual driver selection might be needed:
export MESA_LOADER_DRIVER_OVERRIDE=r300: for AMD's Radeon R300, R400, and R500 GPUs.export MESA_LOADER_DRIVER_OVERRIDE=r600: for AMD's Radeon R600 GPUs up to Northern Islands. Officially supported by AMD.export MESA_LOADER_DRIVER_OVERRIDE=radeonsi: for AMD's Southern Island GPUs and later. Officially supported by AMD.
For VA-API:
export LIBVA_DRIVER_NAME=r600export LIBVA_DRIVER_NAME=radeonsi
Xorg
    
Install either the Free Software driver xf86-video-ati or the proprietary amdgpu firmware linux-firmware-amdgpu.
modprobe fbcon might be needed to avoid black screen when leaving Xorg.