Embedded Real-time Operating System Research

With the development of computer technology, embedded micro computer system is becoming more and more popular, its performance is becoming higher and higher——speed is going faster and memory is going larger, also the peripherals are getting more and more complex. The embedded system is coming more like the common personal computer system, meanwhile the embedded system has low power consumption, small body and good stability. As this, the embedded real time operation system—core of the embedded system—will run the same way as the desktop operation system. Currently, there are three main embedded operation systems: embedded Linux, Symbian and Windows Embedded CE. Embedded Linux was loved by Linux developers and consumer electronics developers; Symbian was mostly used by Nokia in smart phone, covered about 70% market share of smart phone; Windows Embedded CE is the base of Windows Mobile, it covered about 90% market share of GPS devices and Windows Mobile covered about 20% market share of smart phone.This article will focus on the embedded real time operation system kernel research, including process and thread, memory management, information protection and security, scheduler and resource management, to analyze the theory of these modules, implementation of these modules and excellence and shortcoming of these modules. In order to meet the requirement of the target product, some changes should be made to Windows Embedded CE 5.0's virtual memory management; this will help us to get better performance with lower bom cost.This article is based on a common crossover product platform project, hardware is PXA270—an Intel latest Xscale serial processor and the latest mobile graphics video accelerator chip—Intel 2700G, software platform is Windows Embedded CE 5.0. The goal is to learn embedded real time operation knowledge and to understand the theory of RTOS, and to make changes to virtual memory management of Windows Embedded CE 5.0 in order to make Windows Embedded CE 5.0 support external storage based virtual memory, this will help us to develop more stable and better performance embedded products since we got knowledge of such Embedded OS.