| 摘要 |
A system (100) comprising a processor adapted to activate multiple privilege levels for the system, a monitoring unit coupled to the processor and employing security rules pertaining to the multiple privilege levels, and a memory management unit (MMU) (22) coupled to the monitoring unit and adapted to partition memory into public and secure memories. If the processor switches privilege levels while the MMU is disabled, the monitoring unit restricts usage of the system. If the processor accesses the public memory while in a privilege level not authorized by the security rales, the monitoring unit restricts usage of the system. |
