AMD has something similar: a small ARM cpu inside their Ryzen series
running a Trusted Execution Environment OS called tbase (teebase?) on a
platform called TrustZone.
We do not yet know what it can do exactly, but we do know that it
has high-speed access to at least memory, firmware and the rest of the
cpu and it can run at least two different kinds of programs (trustlets
and services) with different security levels depending on how it
downloaded them and who signed them. It also has a small amount of RAM
and non-volatile storage as well as a unique hardware identifier.
The entire system goes under the name Platform Security Processor.