Broadband Router Embedded Operating System Improvements

The embedded software is the soul of embedded system, and the embedded OS is the kernel of the embedded software. So the key of embedded system' s development is the development of embedded software, especially the embedded OS. Compared with the traditional operating system, the embedded OS has some specifications, such as real time, high efficiency, hardware dependency, fixed software, etc. And to be based on Internet and special application is the trade of the embedded OS' development.With the improvement of life and the rapid development of Internet, network has become the necessary in people's life and work. Some serious problems come out with the explosion of the Internet: one of these is that IP addresses(Ipv4) available for allocating is too limited contrasting to potential needs.Broad band router is such a product that targeting this application. It supports Internet' s connection sharing and provides some functions as a router. As an embedded product, Broad band router has some specifications, such as real time, busy handling network packets, simple structure, etc. And the focus of implementation of the Broad band router' s software is the embedded OS.Work of the thesis is based on 'Nanos, the embedded OS of the broad band router' ,which has elementary functions of router. The thesis analyzes the problems and limitation of the embedded OS and puts forward the related solutions. Added PCI bus driver and realtek 8139 100M NIC driver to Nanos, and adjusted the interface of drivers. Then advanced Half-Polling technic for farther efficiency. In order to perfecting NAT, ping and ftp PORT mode are supported.Finally, compositive tests and evaluation are made between the system and Linux. The results show that the system has obviously more efficient than Linux . Although the system runs well, there are still plentyof work to be done to improve the system and make it more mature.