Research Of Critical Technologies In Embedded Linux System Based On ARM Processor

With the development of computer technology, microprocessor technology and integratedcircuit technology, Embedded system has become an important part of computer applications in21st century. Due to the characteristics of its open source code, the kernel stability efficiently,supporting a wide range of processor architecture and hardware platforms, especially the rapiddevelopment of Linux2.6kernel, embedded Linux has become more and more popular applied inthe embedded field. Based on32-bit core arm embedded processor, which has the characteristicsof high performance, low power consumption and so on, has been widely used and has occupiedthe vast majority of the market share of the32-bit embedded microprocessors. Thecombination of embedded Linux and ARM processor is a mainstream solution for embedded tec-hnologies. Building embedded Linux system on ARM processor has great practical value.The embedded system, which is composed by a combination of hardware and software, isan independent system with specific functions used for specific occasions. The specialrequirements of size, power consumption and cost, etc of embedded system decides its softwaresystems which must be customized according to the requirements of hardware and application inthe design and development of embedded systems. A typical embedded system software isusually constituted by three basic parts of Bootloader, embedded operating system kernel androot file system. The three basic parts must be designed and configured reasonably according tothe hardware and the demand of application in the embedded systems development process, inorder to achieve the purpose of meeting the application requirements of the software system in aparticular hardware environment.This paper studies and discusses the key technologies of embedded Linux system based onARM processor. First of all, the paper studied the building of cross compile environment, usingcrosstool scripting tools to make a one-off cross compile tool chain. Then the paper analyzes therealization of the principle of the system boot program which is called Bootloader, and studiedthe subject of the using of the structure and the realization of the U-Boot, finally expanded theway of the embedded Linux boot. Next the kernel source code tree structure of Linux2.6arediscussed, in order to determine the modules and files which need to be modified and cut, aimingatthenew2.6version of the Linux kernel source code to configure,compile and transplantation.At last the creation of embedded Linux root file system is discussed, and produced a file systembased on cramfs as the root file system for the embedded systems whose size are shrunk by usingBusyBox and μClibc. Through the methods and techniques,which are discussed in this paper,can be convenient to build an embedded Linux system based on ARM.