Comment by transpute

There's a direct line between the Microsoft/AMD Xbox SoC corporate contract and Pluton in 2022 Ryzen consumer CPUs, as described in the videos linked above. It's not in Intel's interest to make Microsoft-AMD designed Pluton into the exclusive silicon RoT provider for Intel CPUs.

Another candidate for "Open RoT" is Google's OpenTitan, https://opentitan.org.

Open-Source FPGA Foundation: https://osfpga.org/