Research On Porting And Reduction Of Embedded Linux Based On ARM

With the rapid development of computer technology and micro-electronics, embedded system is widely applied to many fields, such as scientific research, engineering design, military technology, and kinds of business applications. Embedded system is defined as a professional computer system based on computer technology which aims at applications. Its software and hardware can bu cut down. It also meets the specifical requirement, such as function, reliability, cost, volume, power dissipation. At the present time, because of lower power dissipation and lower cost of ARM's strong suit, many manufacturers use it. ARM is more successful than other embedded processor of 32-bits. On the other hand, linux is open-sourced, easy to port and has powerful function so that it turns into the first choice of embedded system. Therefore building embedded linux system is popular.Firstly, the thesis summarizes the features of the ARM architecture. The AT91RM9200 board that based on ARM920T is choosen to be the aim platform. Afterward the Bootloader of embedded linux system is introduced. U-Boot is then ported to the aim platform. Then the thesis makes a detailed analysis at the linux kernel, and ports the kernel to the aim platform. After comprehensive analysis of the current methods to reduce Linux and considering that embedded system is the application-special system that the hardware and software are fixed in design period and almost never changed, an application-oriented method is put forward. This method is code-level so that it could remove the unused code. It is then tested in the experiment about an embedded Linux CD player system. Through the test we get the conclusion that there will be a higher reduction rate using this method than others, thus it can be more effectively to reduce the size of embedded Linux system.At last the process of building an embedded linux system on SkyEye simulator in Fedora Core 4 system is discussed, including configuring SkyEye simulator, building the embedded cross-compile environment in Fedora Core 4 system and making the root filesystem. Ultimately the embedded system ported and reduced before runs successfully.