Migration And Optimization Of Windows CE On The Platform Of Loongson

With the development of information technology, the research and development of embeddedoperating system has become the new direction.Owning the advantages of simple operation, friendlyinterface and supporting a variety of file formats, the embedded operating system Windows CE has beenused in embedded system field widely.This paper achieves the transplantation and optimization ofWindowsCEonLoongsonplatformbasedontheLoongson2Eprocessor.In the process of the Windows CE transplantation and Optimization, developing the BSP (BoardSupportPackage)isthepivotandalsothe mainworkoftheresearchatthesame time.TheBSPisalayerof software systemwhich is between the hardware platformand the Windows CE operating system, and isapartoftheoperatingsystem.OneofthemainfunctionsofBSPistoabstractouttheinterfaceswheretheWindows CE operating system interacts with the hardware platform as a single layer of functions so thatthe operating system may not access the hardware platform directly when accessing the bottomhardware.The BSPis mainlycomposed of 4 parts, the OEM Abstraction Layer (OAL), the Boot Loader,the Device Drivers and the Configuration Files.The main task of developing BSP is the design andimplementation of the BootLoader and the OAL.The basic function ofBoot Loader in the Windows CEoperatingsystemistoinitializethehardwareplatformandloadtheoperatingsystemimagefiles.Themainfunction of OAL in Windows CE operating system is to abstract out the way that the operating systemkernel accesses the hardware so as to form a number of interface functions and libraries, which can bedirectly called when the operating system needs to access the hardware.To generate the Windows CEoperating system image file in developing environment through compiling, needs to write thenecessary .BIB, .REG, Source and DIRS configuration files, then to customize the platform, necessarymodules of the operating system according to the features of the Loongson's hardware platform, andeventually to generate the final operating system image file in the developing environment throughcompilingandlinking.Combined with the Loongson 2E processor architecture and the page management feature of Windows CE, this paper achieves the implementation and optimization on the platform of Loongson 2Eprocessor cache management.The overall performance of the optimized system and application programhas been improved by about 20% and satisfactory result has been got by the implementation andoptimizationofLoongson2Eplatformcachemanagement.In this paper, Windows CE embedded operating system has operated stably and efficiently on theLoongson 2E develop board, which has wide application value and directive significance for expansion ofLoongsonprocessinembeddedsystemfield.