Rosenzweig: Writing an open source GPU driver – without the hardware

Here's awar story from Alyssa Rosenzweig on the process of writing a freedriver for Arm's "Valhall" GPUs without having the hardware to test it on.

In 2021, there were no Valhall devices running mainlineLinux. While a lack of devices poses an obvious obstacle to devicedriver development, there is no better time to write drivers thanbefore hardware reaches end-users. Developing and distributingproduction-quality drivers takes time, and we don't want users tobe reliant on closed source blobs. If development doesn't startuntil a device hits shelves, that device could reach end-of-life"by the time there are mature open drivers. But with a head start,we can have drivers ready by the time devices reach end users.