> Turns out there is some pretty good architecture documentation: https://docs.broadcom.com/doc/12358545 https://docs.broadcom.com/doc/12358545 .. but that only

> Turns out there is some pretty good architecture documentation: https://docs.broadcom.com/doc/12358545 https://docs.broadcom.com/doc/12358545 .. but that only describes the 3D capabilities, not the whole register map. This documentation is for the VideoCore IV. The BCM2711 SOC that is used in the Raspberry Pi 4 has a VideoCore VI.