Design Of An Embedded OS Kernel Facing C8051F

Embedded operating system appeares in the 1980s,it makes the embedded computer systems applied in various fields such as national defense and civil use.The embedded operating system(EOS) has been used widely.EOS reduces the intensity of system development significantly and shortens the development cycle.It is advantageous not only for system maintenance and secondary development,but for improving the stability and reliability of the embedded system.The research contents of this dissertation is to design an embedded operating system for specific hardware environment.It researched and analyzed the structure of real-time operating system kernelμC/OS-Ⅱ,and also improved the kernel structure.The dissertation designed and implemented an embedded operating system kernel named micro-K facing C8O51F Single Chip Microcomputer.The micro-K OS which had compact structure could be applied in small or medium control system.It was compatible,portable and extensional.In the design process of micro-K,the dissertation analyzed the task management ofμC/OS-Ⅱreal-time kernel in detail,and optimized the priority bitmap scheduling algorithm.Under the premise of ensuring the features and advantages ofμC/OS-Ⅱkernel was not affected,the dissertation extended the kernel's priority numbers from 64 supporting byμC/OS-Ⅱkernel to 128 required by micro-K kernel.Based on the analysis of the original task scheduling algorithm and the classical scheduling strategy,the dissertation improvedμC/OS-Ⅱkernel's scheduling mechanism,optimized the task priority allocation strategy ofμC/OS-Ⅱ,proposed HP algorithm for micro-K kernel.HP algorithm allowed multiple tasks with the same priority,and the different level of tasks used the original static scheduling while at the same level of tasks was to be handled adopting dynamic dispatching mechanism.The algorithm not only solved the priority inversion,but also improved task scheduling performance.Micro-K was just a preemptive kernel,and it only owned some basic functions such as process scheduling,memory management and task management.As the kernel did not have user interface,document management and network communication,there would be the need for kernel function expansion.The dissertation designed peripheral driver management (PDML) for micro-K kernel to realize the unified equipment management,and tested micro-K kernel on C8051F120 hardware platform.The experiments showed that in addition to possessing the advantages of preemptive kernel,micro-K kernel's function was more perfect,and the kernel was more flexible and efficient.