In recent years, the embedded system is becoming more and more important in various areas of the society, with the development of the software and hardware of computers, especially with the spread of the networking application. As the base of embedded system, embedded operating system has a significant effect on the system performance, development, and application.Consequently, embedded operating system has been a focus of embedded system research. Because Linux is an open source operating system, more and more people has began to research how to use Linux in the embedded system. However, for Linux is not designed for the embedded system, many special problems should be resolved in the course of using Linux in the embedded system.The embedded application generally needs to run in a real-time environment, and require the devices with small volume, small weight, and low power consumption. All these characteristics make the design of embedded operating systems different and even more difficult compared with the general operating systems. This paper introduces the principles and the properties of existing embedded operating system. The advantages and disadvantages for Linux to be used in embedded operating system are also analyzed. And the paper presents the design method of the driver of the peripheral equipment.In the specific design on XScale hardware platform realize and aim at the optimization of hardware platform, which can support various embedded devices of the platform and satisfy the requirements of most embedded applications, then gives the design method about driver of periphery equipments.A platform of XScale PXA255 is built and designed. Firstly, the paper introduces the structure of PXA255, its applications and properties in detail. Secondly, the paper presents the module of the clock & power management in the hardware platform, the module of the system control, the module of periphery control, the detailed realization of the universal board, the choice of Flash, SDRAM, FPGA ,USB and other type of specific device, and its circuit. Thirdly, the paper pointes out the design skills of the print circuit board (PCB), the emphasizes , the difficulties, and the other important points in designing. Finally the paper presents the quick design of PCB, the quick choice of the chips, the countercheck of EMI, the integrity of the signal design, andthe skills of the circuit design.The embedded system can be used in some areas: Network communication & communication security products, such as firewall, router, safe gateway, switching equipment, and Network computers. Industrial control application products, the embedded computers which can offer industrial control in single board, and the control center of the numerical system.Wireless terminal products, it can offer complete wireless dial sustain and data transmission to GPRS/CDMA. Multi-media terminal products, such as the visualable telephone based on ADSL, the box above digital TVs based on wired & wireless network, video meeting system, and the visualable speaking system based on IP. Portable apparatus products, it can offer the development platform of SmartPhone and PDA, and the solving scheme in detail .It can be applied in intelligent mobile telephones, mobile business to enterprises, traffic systematic, etc.The research result of this paper can be used in embedded system, and it offers the support for developing work in the level of operating system. It has accumulated the development experiences of the embedded system, and found the base to the future design and application of the system. |