Graphics, sound and multimedia • Re: Map of RPi5 HVS registers

I still haven't quite got my head around how/why the RPi5 splits the video hardware across multiple `dri` cards/devices

i think the pi5 has at least 3 dri devices

one is the 3d core, all it does is turn textures+shaders+polygons into 2d images
one is the bcm2712 2d core, it deals with the HVS, pixel valves, and hdmi
and one is the RP1 2d core (check the RP1 datasheet), it deals with DSI, DPI, and VEC(ntsc/pal)

BCM2712 has 2 - v3d for 3D rendering, and vc4 for the 2D HDMI (and writeback) pipeline. Most ARM based platforms now adopt that strategy as there are only a few 3D engines to choose from, whilst there are a larger number of options for display pipelines.

RP1 has 4 separate blocks used for DSI (x2), DPI, and VEC that will be instantiated when enabled.

I would ask why you're trying to drive the HVS directly when you can achieve the same things described in that article through the DRM/KMS API? Hacking directly risks getting trampled by the vc4 DRM driver if it chooses to update anything.

Statistics: Posted by 6by9 — Tue Aug 13, 2024 2:01 pm

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