[PennRobotics]

Pluton is separate from TZ.

Pluton is another core which is a security module---in this case, a Microsoft product. TZ splits data and instruction access into insecure and secure classes on the original core---letting a little information pass from one side to the other without revealing the inner functionality.

There are plenty of Arm SoCs with Cortex-A cores plus an onboard Cortex-M-based trusted platform module (TPM). There are also already Arm chips using Pluton, such as the MediaTek MT3620.