Being a TPM is one of the Intel ME and PSP’s functionalities. Making a TPM that’d be secure against custom firmware is possible, but isn’t very implemented acro

Being a TPM is one of the Intel ME and PSP’s functionalities. Making a TPM that’d be secure against custom firmware is possible, but isn’t very implemented across the industry. It’d need measuring the hash of the loaded firmware itself to hardware managed PCRs that affect the hardware crypto engines. Something that’s done on the Secure Enclave for Apple A13 onwards AFAIK. (also… managing DRM systems, they’ll have to be put on a coprocessor somewhere.)