FreeTEE: When real-time and security meet

The pervasive use of embedded computing systems in modern societies altogether with the industry trend towards consolidating workloads, openness and interconnectedness, have raised security, safety, and real-time concerns. Virtualization has been used as an enabler for safety and security, but research works have proven that it must be extended and improved with hardware-based security foundations. ARM Trustzone has been used for the realization of Trusted Environments, however in this case real-time requirements are completely disregarded. This work in progress paper presents FreeTEE, an embedded architecture that emphasizes and preserves the real-time properties of the system but still guarantees security from the outset. TrustZone technology is exploited to implement the basic building blocks of a Trusted Execution Environment (TEE) as a lower-priority thread of a RTOS. Preliminary results demonstrated that the real-time properties of the RTOS remain practically intact.