3. Secure Boot : The purpose of Secure Boot it
to bring the system to a known and trusted state. The Secure Boot routine is a ROM-based routine, so that an attacker cannot intercept the procedure. Additional features are required in order to provide a complete Secure Boot solution. These include the ability for software update at any point in time i.e. a Software Version Revocation mechanism for system advancement to a new version of the software image with prevention of roll-back to an older version is a must.