[gj_78]

Raspberry Pi is not marketed for graphics as nvidia is doing with their GPUs. What I mean is that firmware is running on a usually small cpu and memory that is sold as a part of the GPU. No security issues here as the main security issue is to plug the whole GPU inside your PC.

[my123]

With the complexity of GPU driver stacks, what you are asking for is not firmware, but a multi GHz+ set of CPUs just for that purpose.

+ RPC needed all the time... with its latency would tank the performance

It'd also be not tinkerable at all unlike what we have today, it's exactly advocating for the opposite of open.