基于Linux的嵌入式系统研究及防火墙应用

【作者】 王华萍；

【导师】 凌明芳； 冉立新；

【作者基本信息】 浙江大学 ， 电子科学与技术， 2002， 硕士

【摘要】 在以计算机技术、通讯技术相结合的信息时代的快速发展和互联网的广泛应用的形势下，3C(Computer、Communication、Consumer)合一的趋势已经形成，其结果必然就是将计算机工业的中心从计算产品转移到信息产品，从而出现信息电器的概念。在信息电器的应用开发领域，由于功能的不断增加，嵌入式系统也就将成为软件业的新宠儿。同时在计算机本身的领域里面，微型化和专业化成了发展的新趋势，同样也需要嵌入式系统的支持。因此，研究与嵌入式系统有关的关键技术——嵌入式系统有着相当重要的实际意义。 利用Linux构建嵌入式系统是近年来出现的一种令人振奋的设计方案。而嵌入式Linux的主要挑战是把系统资源的需求减少，以适应于诸如内存、固态电子盘容量、处理器速度、以及节能、节省成本的限制。基于此，本文提出了基于Linux的嵌入式系统研究，直接从RedHat6.2发行版本瘦身定制了一个小型Linux系统，将其嵌入一容量为8M的DiskOnChip。为了验证系统的可行性，论文还按照防火墙的标准定制系统，实现了一个简单的防火墙应用。系统可稳定地运行于低功耗6×86单板机上。 在构建嵌入式Linux系统时采用了两种方法：一种是根据RedHat6.2对内核和系统文件进行个性化定制；另一种直接利用已开发的嵌入式Linux系统对其进行功能特定化。第一种方法能对整个系统有更全面的了解，从而对进一步的研究开发很有价值；第二种方法具有设计周期短、产品见效快的优点，对项目的短期开发很有利。 本文利用嵌入式这种先进的技术，低成本、高效率地实现了防火墙的应用。与现成的技术相比，在大规模生产中，具有节省成本、节省开发时间的优势。更多还原

【Abstract】 With the development of Computer technology and Communication technology in Information times and the board application of Internet, it is clear that 3C (Computer, Communication and Consumer) will converge in the near future which will lead the focus of Computer Industry from the Compute product to Information product. It is the concept of Information Appliance. In the application and development field of Information Appliance, Embedded System will be the most favorite thing in Software Development field. At the same time, in the field of computer science itself, the micromation and specialization is the new direction of the computer world. It also needs the support of Embedded System. So, the research of the key technique of embedded system Embedded System is ~e most important thing.One of the most promising emerging areas seems to be running Linux in these environments. But the main challenge for embedded Linux is how to save the requirement of system source to adapt the restrictions such as memorycapacitance -. speed of CPU and cost .Based on this, We designed a diminutive Linux system and implemented the firewall function on this system, then embedded the system to a DiskOnChip whose capacity is SM.In this paper, we adapted two means to design the diminutive Linux system: one method is to customize system directly from RedHat6.2 ,the other is to use the Embedded Linux system in web .The first method can make us have a fair understanding of system and is suitable for in-depth research. The second method has the timesaving virtue and has rivalrousness in shortdated development of items.In this paper, we used advanced Embedded technique to implement the firewall function with low cost and high efficiency. Compared with the ready technique, it has the character of saving time and cost.更多还原