Exploiting asymmetric CPU performance for fast startup of subsystem in mobile smart devices

Fast startup of a subsystem, such as an image subsystem, is important in mobile smart devices because the startup time is directly related to the responsiveness of applications, such as a camera. This paper proposes a CPU switch method that offloads the long initialization phase from the subsystem to the fast main CPU in an application processor. By providing a consistent execution environment in the main CPU, the subsystem software can be easily ported without significant engineering costs. The evaluation results show that the proposed scheme greatly reduces the startup time of the image subsystem by up to 78%¹.