Mesa's Asahi/AGX Gallium3D Driver Makes Early Prep Changes For WIP Kernel Driver

Mesa's AGX "Asahi" Gallium3D driver for providing OpenGL / GLES support on Apple M1/M2 SoCs has begun making some early preparatory changes for eventually supporting the in-development DRM/KMS kernel driver. The kernel driver is still a work-in-progress and not close to being merged yet and the user-space API not yet set in stone, but some early changes in better preparing the Mesa driver for actually running on the Apple Silicon hardware under Linux have been merged.

Being worked on simultaneously for the open-source Apple Silicon graphics support on Linux is the DRM/KMS kernel driver and then in user-space is the Mesa driver. The kernel driver is being written in Rust and is making progress although it may still be a while before being merged, likely some point later in 2023 at least. But at least Alyssa Rosenzweig has begun making preparations for quickly making use of that kernel driver when ready.

Code merged today to the Mesa 23.0 development tree was noted by Alyssa:

@asahilina has been working on a branch that integrates Mesa with her new UAPI to run the Asahi driver on Linux. Today's project was cleaning up that branch as I took the shiny new driver for a spin. https://gitlab.freedesktop.org/alyssa/mesa/-/tree/asahi/rebased contains the fruit of that effort. Unfortunately, we can't merge Linux UAPI code until the corresponding code is merged into the upstream Linux kernel, which could take a long time. In the interest of reducing rebase pain in the mean time, this series contains the non-UAPI bits, some of which will be immediately useful.

That landed code is 576 lines of new code and around 123 lines dropped. In the meantime until the DRM driver is mainlined there is this out-of-tree work happening and Alyssa continuing to work on the AGX Gallium3D code under macOS. She hopes to see around OpenGL 2.1 by the end of the year. Vulkan API support has yet to be tackled.