Research And Design Of The Bootloader In Embedded System Based On S3C2410and μC/OS-Ⅱ

With the rapid development of computer technology and the continuous progressof chip manufacturing technology, the applications of embedded system areincreasing day by day. From personal consumer products to Aerospace ControlSystem, embedded system is everywhere. In most of embedded system, embeddedreal-time operating system is used to achieve many complex functions. Therefore,how to start an embedded real-time operating system becomes the first issue inembedded system development.This paper mainly analyses and designs the Bootloader which is based on ARM9processor. After power up the system, operating system can not run immediately, itneeds a small process to do some prepared work, such as initialize the hardwareequipment, set up the memory space map, and the software and hardwareenvironment of the system is set in a suitable state, after those we can call theoperating system kernel and the users’ applicating programs can be run. The smallprocess is called boot load program, we can also call it Bootloader. An embeddedsystem is a special computer system, it is different from general computer system, itis designed to meet certain functions. So the Bootloader in embedded system isspecial too, its characteristics are simple and efficient.In this paper, the content can be divided into three parts, the first part is theorybasis, the research background and the research situation are introduced in the chapterone; the working principle of ARM9processor, such as working status, workingmode, and exceptions. In this chapter, NAND Flash and NOR Flash are introduced,two kinds of developing-boards’ starting methods are introduced too. The workingmechanism of μC/OS-Ⅱ operating system is explained in the third chapter. Thesecond part is designing, in the forth chapter, working process and actual workingprocess of Bootloader are analyzed. In the fifth part, according to the environment ofsofeware and hardware, Bootloader is designed. The last part is verification, in thesixth chapter, the μC/OS-Ⅱ real-time operating system is ported to S3C2410successfully, the correctness of the Bootloader is verificated. In this paper, μC/OS-Ⅱ and ARM9processor are combinated, on thedeveloping-board which is based on ARM9processor, Bootloader is designedspecifically. The result of this paper is that μC/OS-Ⅱ operating system can be startedon the S3C2410developing-board. Bootloaders which have already existed aresuitable to many kinds of processors, they are general, but their numbers of codes arelarge, their file-systems are complex, and they are hard to understand, but theBootloader which is designed in this paper targets to ARM9processor specifically,this is Bootloader’s specificity, in this kind of Bootloader, the number of codes issmall, file-system is simple, and it is easy to understand. The system which uses thiskind of Bootloader can improve the run-speed, save run-time，and can save valuablesystem storage space. This is the innovation of this paper. If we want to design aspecifical Bootloader, we must have a complete knowledge of structure, we mustknow the hardware, grasp the principle of the operating system, this is the difficultyin this paper. The purpose of this paper is to understand and master the workingprinciple of the software and the hardware in the embedded system starting process,and the actual working process.