The embedded system, installed in the micro electronic products, is used widely in our daily life. The paper illustrates the process of building a scalable embedded system on the ARM platform effectively. In the beginning, the theory of u-boot and Linux kernel is introduced. Then, the paper gives some details about u-boot, such as initialization, adjusting and so on. After that, the process of building a root file system is given as well. Finally, an experimental embedded Linux system based on ARM SBC2410 platform is constructed successfully.