Design And Implementation Of A New Embedded Operating System For MCUs Using ARM Cortex-M3/4 Instruction Set

With the development of Industry 4.0 in automation,Internet of Things and other fields,intelligent devices with embedded processors have been widely used.As a software development platform for intelligent devices,embedded operating system(EOS)is paid more and more attention by system developers.However,the existing embedded operating systems do not provide the embedded application developing mode that does not depend on the specific hardwires.The developers not only have to master the working principle and development process of the EOS,but also have to develop the hardware interface program by themselves.It further leads to the duplication of hardware related development resources and poor software reuse.To solve this contradiction,this thesis develops a new EOS design method,which provides a common interface to the embedded application.Therefore,the developers can focus on their embedded application,since the hardware is separated by the new EOS.It reduces the difficulty of the development of embedded software,and makes the embedded software development similar as the PC software development.The new EOS design method is applied to the Microcontroller Unit(MCU)using ARM Cortex-M3/4 instruction set.The new embedded operating system and Applications(APPs)are developed.The test results show that the system can still ensure the real-time performance of applications.This design mode of the embedded operating system shows that the application development like PC can also be achieved in the embedded field under the premise of ensuring real-time performance,thus simplifying the development process of embedded software.This thesis considers the design and implementation of a new embedded operating system for MCU using ARM Cortex-M3/4instruction set and the main contents include the following parts:Firstly,this thesis describes the research background and significance of a new EOS for MCUs using ARM Cortex-M3/4 instruction set,and summarizes the fundamental knowledge and research of embedded operating system in recent years.Based on the analysis and comparison of several typical embedded real-time operating systems(ERTOS)and timesharing operating systems,the specific functional requirements of the new embedded operating system are proposed.Secondly,the overall design method of the new EOS for MCUs using ARM Cortex-M3/4instruction set is presented to meet the above requirements including the separation of the EOS and APPs,and the functions for downloadable APPs.By designing the memory storage management module,the EOS can directly manage the physical memory,and assign the loading address to APP.By designing the system timer,it provides the time reference for APP scheduling.By designing system call interface,the communication mechanism between APP and EOS is established.Then,aiming at the requirements of APP download and management,the APP management module of the EOS is designed to realize multiple APP download functions.Through the APP initialization module,some relevant variables can be initialized before the APP runs and the running environment can be prepared.Furthermore,the communication data management module is designed inside the operating system to realize the data interaction between APPs and MCU hardware.Finally,the thesis provides a way to design and realize APP of the new ERTOS based on MATLAB,and carries out a performance test in the designed new ERTOS.The test results show that compared with the traditional ERTOS,the new ERTOS retains the characteristics of micro-kernel and good real-time performance,and is more convenient in embedded application development.In conclusion,the new ERTOS developed in this thesis for MCU using ARM Cortex-M3/4instruction set not only inherits the characteristics of the traditional ERTOS system such as good real-time performance,but also has the advantages of system and application separation and convenient application development,which provides a useful reference for modern embedded system development.