Is there documentation somewhere to help folks develop their own UEFI/EBBR/SBBR to get rid of U-Boot?

Hi there,

I have not yet understood what "Arm Server Ready" means and what are its main advantages, but it looks like it is tightly linked to UEFI/SBBR.
I have seen that some people were trying to create UEFI for the Raspberry Pi, so there must be a good incentive to do so.
Sometimes, U-Boot is seen as tinkering and not as a robust system, so it's maybe time to shift to UEFI/SBBR.
I have quite a few 64 bits boards, and even if it looks like a daunting tasks, where should I start if I ever felt like doing it?
Would anyone have a few hints, a documentation, or at least a few pointers so that I can better understand the whole ecosystem?

Thanks a bunch.