8.4.1.1 Hardware

TrustZone enables a single physical processor core to execute code safely and efficiently from both the Normal world and the Secure world. This removes the need for a dedicated security processor core, saving silicon area and power, and allowing high performance security software to run alongside the Normal world operating environment.

The two virtual processors switch contexts via Monitor mode when changing the currently running virtual processor.

See the following figure.

Figure 8-2. TrustZone Hardware Implementation