Very few people are getting viruses because someone has come into their house, connected the DRAM bus on their PC to a logic analyzer, and injected malicious code directly into memory. Instead, the malicious code is coming in through trusted code the user is running (web browser, faulty samba server), which encrypted memory does nothing to protect against.
I believe ARM has had this in the form of TrustZone for a while.
Very few people are getting viruses because someone has come into their house, connected the DRAM bus on their PC to a logic analyzer, and injected malicious code directly into memory. Instead, the malicious code is coming in through trusted code the user is running (web browser, faulty samba server), which encrypted memory does nothing to protect against.
I believe ARM has had this in the form of TrustZone for a while.