Research Of Embedded UClinux Porting Technology

After entering the 21st century, embedded linux operating system has been widly used in embedded field. uClinux is a kind of embedded linux operating system specialed for no MMU cpu and has many virtues such as light-weight, full functions, easy to customization and easy used by applications. The research of porting uClinux to the target board based on ADSP-BF561 includes developing the bootloader, porting uCinux kernel, building the file system and developing device drviers of related peripherals.Bootloader is used to initialize the hardware and boot the operating system. There are many differences between the implementation of dual core processor's bootloader and one core processor's bootloader. It is needed analyzing boot modes of ADSP-BF561, and select a suitable mode to boot dual core in right orders. In order to support the further development, some auxiliary functions such as user interface, downloading files to Flash, hardware self-inspection are provided. The bootloader is designed to two modules, boot module and intercross module, to support two parts of functions.After analyzing the architecture of the processor, porting the uClinux kernel need to modify the code releated to the entry of kernel, interrupt dispatching and processing, system real-time clock. In order to raise the reliability of file system and also to solve the wear leveling problem existing in store equipment of embedded system, a file system solution based on JFFS2, cramfs and tmpfs file systems is provided.Used the standard procedure supplied by uClinux system to research and develop drivers of related peripherals, such as high performance NIC and video decoding chip. In order to support the high performance requirement of the project, NIC drivers is optimizated by a improved transmit methods and providing a stable, high performance application development environment.