Holidays are here and I have time to look back at 2023. For six months I have been working for Igalia and what should I say?
I ❤️ it!
This was the best decision to leave my comfort zone of a normal 9-5 job. I am so proud to work on open source GPU drivers and I am able to spend much of my work time on etnaviv.
Driver maintenance
Before adding any new feature I thought it would be great idea to improve the current state of etnaviv’s gallium driver. Therefor I reworked some general driver code to be more consistent and to have a more modern feeling, and made it possible to drop some hand-rolled conversion helpers by switching to already existing solutions (U_FIXED(..), S_FIXED(..), float_to_ubyte(..)).
I worked through the low hanging fruits of crashes seen in CI runs and fixed many of them.
Feature wise, I also looked at some easy to implement extensions like GL_NV_conditional_render and GL_OES_texture_half_float_linear.
Besides the gallium driver I also worked on some NIR and isaspec features that are beneficial for etnaviv.
XDC2023
A personal highlight was to give a talk about etnaviv at XDC2023 in person.
You might wonder what happened since mid October in etnaviv land.
GLES3
I worked on some features that are needed to expose GLES3 and it turned out that an easy to maintain, extend and test compiler backend is needed. Sadly etnaviv’s current backend compiler does not check any of these boxes. It is so fragile that I only added some needed lowerings to pass some of the dEQP-GLES3.functional.shaders.texture_functions.* tests.
Some more fun work regarding some feature emulation is on the horizon and it’s blocked again by the current compiler.
Backend Compiler
etnaviv includes an isaspec powered disassembler now - a small step towards a new backend compiler. Next on the road to success is the etnaviv backend IR with an assembler.
The new backend compiler is able to run OpenCL kernels with the help of rusticl but I want to land the new backend compiler in smaller chunks that are easier to review.
Multiple Render Targets
During my XDC presentation I talked about a feature I got working on GC7000L - Multiple Render Targets (MRT). At this point it was more or less a proof-of-concept regarding the gallium drivers. There were some missing bits and register for full support on more GPU models and therefore more reverse engineering work was needed. Also the gallium driver needed lots of work to add support for MRT.
Some weeks later I had MRT working on a wider range of Vivante GPUs that are supporting this feature. This includes GC2000, GC3000 and GC7000 models among others. As etnaviv makes heavy use of GPU features it should work on even more models.
Looking forward to 2024
I am really confident that we will see GLES3 and OpenCL for etnaviv. As driver testing is quite important for my work I will expand my current board farm and will look into the new star in CI world - ci-tron.
With that, have a happy holiday season and we’ll be back with more improvements in 2024!