Speeding up open-source GPU driver development with unit tests, drm-shim, and code reuse

Getting an Arm platform that works with mainline Linux may take several years as the work is often done by third parties, and the silicon vendor has its own Linux tree. That means in many cases, the software is ready when the platform is obsolete or soon will be. It would be nice to start software development before the hardware is ready. It may seem like a crazy idea, but that’s what the team at Collabora has done to add support for Arm “Valhall” GPUs (Mali-G57, Mali-G78) to the Panfrost open-source GPU driver.