An Embedded Network Downloader Based On PowerPC (FTP And HTTP Section)

With the rapid development of nowadays digital information and network technology, the efficiency and convenience of data resource's downloading, storage, management, sharing and exchanging are gradually coming into people's sight. Despite the good performance of existing NAS, large size, high price and poor user interface are still the main barriers for personal or home users, and even for some small enterprises.Meanwhile, in nowadays information society, various types of data are increasing at a geometric progression, therefore, downloading them from Internet with a desktop is often time-consuming and often involves resource waste and safety problem.This project aims to design an embedded network downloader suitable for personal users. It is embedded application oriented and simple-structured with low cost and power, supporting long-time online work. As a network downloader for specified resource acquisition as well as an NAS, it can automatically start downloading and is compatible with many transfer protocols.The paper is mainly about what I do in this project. According to the nominal development procedure and method of embedded system, different common embedded processors and embedded operation systems are compared for the requirements of our downloader product, and the general design scheme is introduced. Then, an FTP and an HTTP client are designed by the analysis of FTP and HTTP. The implementation procedure and method is expounded. Flow chart and key function's code are presented. Finally, the porting and testing issues are introduced.The FTP and HTTP clients implemented in this project are suitable for embedded system. They have powerful task management function, and multiple tasks multiple threads download function, which can increase download speed and shorten download time obviously. The implementation of download resuming is also introduced in the paper.