ARM vs x86 privacy/security?

[z4v4l]

TrustZone, Secure Monitor, EL3 Secure World OS, entirely hidden of and inaccessible by the ordinary OS, run in the EL1, it even has its own system address space, set of "secure" peripherals, it's a system in the system and if the vendor locks it, you will never have a chance to get into that, except what the vendor has exposed to you through the gateway, that still never will show you what's inside. And every armv7 and armv8 SoC nowadays has Secure World included. So, only a tin foil hat, my friend.