MAKE AND IMPROVEMENT OF EMBEDDED LINUX ROOT FILE SYSTEM CRAMFS BASED ON S3C2440

Root file system is an important component of Linux embedded system. It is the beginning point of all files and device modules, and the key whether the system can have a normal start. Combined with the characteristics of the embedded system, this paper introduces how to use Busybox tool to construct embedded root file system whose name is Cramfs and how to transplant Cramfs to a concrete ARM development platform. Simultaneously, we proposed a new approach to configure the root file system. And this approach can support requirements of reading and writing based on applications, it doesn't need to add extra file system, but only use own characteristics of root file system to construct a partial writable root file system. Finally, it is tested in the actual development board that verified the new root file system generated validity and reliability.