The Raspberry Pi VC4 Graphics Driver You Won't Find In Linux 4.0
Due to being very busy working on the new server farm, it escaped my mind yesterday when writing about "missing features" of Linux 4.0. Eric Anholt at Broadcom has been making great progress on his fully open-source VC4 graphics driver stack for Linux, but the VC4 DRM driver has yet to be merged.
The VC4 stack is comprised of the DRM kernel driver and the new VC4 Gallium3D driver for providing open-source OpenGL support on the different Raspberry Pi models, including the new Raspberry Pi 2.
Those wishing to try out the new driver stack need to use Eric Anholt's kernel tree that contains the VC4 DRM driver. As of writing this article the kernel is currently based on the Linux 3.15 code and the last work by Eric to the VC4 kernel code was in early January.
A majority of Eric's focus is currently on the VC4 Gallium3D code as shown by this Git search with there being new patches frequently going into this driver part of mainline Mesa. New features continue to be implemented for this basic Gallium3D driver, including work towards using NIR.
Hopefully in Linux 4.1 or another kernel release not too far out we'll see the VC4 DRM driver merged into at least the staging area for lowering the barrier to using this new driver stack for the millions of Raspberry Pi owners. For those wanting more on the Raspberry Pi VC4 driver, visit the FreeDesktop.org project page.