Cooperative Scheduling Method With Hardware And Software For Heterogeneous Multi-core In Embedded System

As the development of semiconductor technology, IP based SoC system is becoming popular in the embedded system field. One is the heterogeneous multi-core system in the master/slave model. The general processor core as master is responsible for the controlling of system while the slave processor cores which are designed for specific purpose.The operating system for this architecture is running on the master core, and the part in the application with large computation is running in the slave cores. For the slave cores, device driver or system call can be used as a interface for application. But they are not applicable when there are more than one application in the system.This paper designs a hardware scheduler to reinforce the general software scheduler in the operating system for heterogeneous multi-core architecture.In this paper the task for slave core is design in three parts, the pre-processing, running, post-processing. Pre-processing part is responsible for the creating of the context of the slave task, including the code and data, and the post-processing part is responsible for processing the results of computation. The running part, the computing of data is the core of slave task, is scheduled by the hardware scheduler while the pre-processing and post-processing running in the master core is scheduled by the software scheduler.The hardware scheduler this paper designed is support first come fist service (FCFS) and dynamic priority scheduling strategies.With this hardware-software co-schedule method, after testing and analyzing, the slave tasks throughput in the system is increased 8.1%, and the scheduling time for slave tasks is reduced 7.8%, than the general scheduling method in software.In short, the method that hardware-software co-schedule method, hardware scheduler reinforce the software scheduler, can be flexible and efficient support the task scheduling of heterogeneous multi-core system.