AXI Protocol, difference between secure and non-secure transactions

Question

Just wanted to ask, what is the difference between secure and non-secure transactions when it comes to AXI bus transactions?

What are the performance implications of either transaction?

Answer 1

Trusted transactions are a part of ARM's TrustZone policy. It requires an additional pin to indicate a secure connection. It only allows communication with the secure section of the processor. It is a software solution to restrict access to hardware in the case of root access on the OS. It acts as a firewall in the event a hacker takes control of the OS. It does not guard against hardware hacking.

As far a performance, the hardware bandwidth is unaffected, but the extra step in the secure processor does incur a performance penalty.