A dual-kernel scheduling scheme based on TrustZone

With the continuous improvement of the performance of embedded hardware platforms, in the fields of aviation and automotive electronics, an important development direction is to concentrate functions including real-time control, information visualization and human-computer interaction into the same hardware platform. Because of its preemptive design and customized drivers for real-time scenarios, RTOS can meet the requirements of real-time control for hard real-time. However, in terms of the functions related to user experience such as human-computer interaction, the mainstream general operating system (GPOS) such as Windows and Linux is obviously a more suitable choice. In TZDKS architecture, with the help of TrustZone technology under AArch64 architecture, RTOS and GPOS are integrated into the same SoC platform, which can run real-time tasks and common tasks at the same time. However, the Idle scheduling scheme of TZDKS makes the responsiveness of GPOS completely sacrificed when the real-time kernel load is heavy. To solve this problem, this paper uses Sporadic Server algorithm to replace Idle scheduling scheme, and significantly improves the response capability of GPOS while ensuring hard real-time tasks in RTOS.