Former Nouveau developer Lucas Stach has been one of the main developers working on this reverse-engineered Vivante 3D graphics stack for Linux systems. With Linux 4.5, there's the DRM driver ready to go and present in the code-base. During this past weekend's FOSDEM conference he shared more about the work on this community-based driver project.
This new DRM Etnaviv driver is only around 7,000 lines of code compared to the 60,000+ lines of code via Vivante's official "fat and obfuscated" kernel driver. Now that the kernel driver is mainlined, the Etnaviv developers will be spending more time working on the user-space portion.
The Etnaviv Mesa driver is Gallium3D-based and coming up this German developer will be working to rebase the code against mainline and continue refactoring the driver. There are more bugs to fix and so far the Etnaviv code has around a 80% pass-rate for the Piglit OpenGL regression tests. Once everything is stabilized, they are planning to merge his Etnaviv support into the Mesa repository as well as libdrm. There's also more work to be done on improving the performance and exposing more OpenGL features. There is also work to be done for ensuring Etnaviv will properly handle Wayland.
More details on the Etnaviv state for starting off 2016 can be found via Stach's PDF slides.