What you can do with a trusted CPU domain is use FDE. FDE is standard practice for anyone even remotely concerned about security in the first place. So the fi

What you can do with a trusted CPU domain is use FDE. FDE is standard practice for anyone even remotely concerned about security in the first place. So the firmware that matters -- the firmware that can subvert the system due to privilege level, etc. -- is open. No other vendor aside from some lower end ARM toy SoCs can say that.