AMD Radeon Graphics Driver "AMDGPU" Ported To DragonFlyBSD
Open-source developer Sergey Zigachev has ported the AMDGPU kernel driver from Linux to DragonFlyBSD and as of today is now in that open-source operating system's upstream code-base.
The massive port pulls in the AMDGPU driver as of the state found in Linux 4.19. Yes, Linux 4.19 is rather dated in being three years old now, but DragonFlyBSD and the BSDs more broadly trail the Linux kernel in their DRM driver ports due to different kernel interface changes and other alterations needed to get going. So with this older port, it still won't work for the latest generation AMD Radeon graphics cards today, but it's a start and will at least begin working with older generations of AMD GCN graphics cards.
The DragonFlyBSD port also required updating its TTM code for memory management to match the state of Linux 4.19.
Among the caveats is no GCN 1.0/1.1 support (Southern Islands and Sea Islands) which is treated as experimental support on Linux, thus this AMDGPU driver support starts with GCN 1.2. Other caveats include potentially needing "amdgpu_hw_i2c=1" module option to avoid a kernel panic at boot, Thunderbolt support is disabled, and trace infrastructure is not implemented.
DragonFlyBSD has already had a port of the "Radeon" DRM driver for supporting pre-GCN 1.2 GPUs back through old ATI Radeon era graphics processors. It's great that finally now the AMDGPU kernel driver from Linux is ported over to DragonFlyBSD for supporting newer graphics. In user-space, Mesa continues to be available on DragonFlyBSD. FreeBSD from which DragonFlyBSD was originally forked has offered an AMDGPU kernel driver port for a while.