【作者】 张俊；

【导师】 卞佳丽；

【作者基本信息】 北京邮电大学 ， 计算机技术（专业学位）， 2013， 硕士

【摘要】 当今社会,手机、家电、汽车、先进的医疗设备、网络通信设备及其它带有数字接口的器材设备得到了飞速发展,嵌入式系统技术在其中起到了关键的作用。而网络通信功能则是嵌入式设备中最基本最重要的功能之一。因此,在嵌入式平台基础上,对实时嵌入式操作系统RTEMS(Real Time Executive for Multiprocessor Systems)的网络功能进行扩展,具有重要的现实意义。RTEMS是一个免费开源的嵌入式实时操作系统,最早服务于美国国防事业,至1994年起一直由OAR公司负责版本开发与维护工作。它具有体积小、实时性强、源代码公开等优点,在众多领域得到了广泛应用。课题对RTEMS操作系统网络功能的扩展实现,依托实验室GX2410BP硬件开发平台。GX2410_BP是一款基于三星S3C2410X处理器(ARM920T)的针对高校嵌入式教学和科研实验的平台,集成了丰富的外围设备,相应配套软件完善,为在该平台基础上扩展出一个网络语音传输系统提供了可能。本课题在深入学习网络语音传输系统原理、嵌入式系统相关技术和SIP(Session Initialization Protocol)办议标准的基础上,研究并实现一个具有放音、录音、通过网络远程传输音频数据的网络语音系统基础平台。结合网络语音传输系统的需求和功能,开发了RTEMS系统针对GX2410BP的板级支持包(Board Support Package);开发了UDA1341音频芯片驱动程序,以达到可以录音、放音的目的；开发了DM9000网络芯片驱动,为音频数据在网络上传输提供保障。实现中采用PJSIP作为本系统的SIP协议栈,PJSIP是一个开源的SIP协议库,提供非常清晰的API和技术文档,并具有非常好的移植性。课题最后在应用层开发了相应程序对该系统进行了验证,并指出了本设计的一些不足之处,提出了相应改进意见。更多还原

【Abstract】 Nowadays, the embedded system technology is closely linked to a series of devices including cell phones, household appliances, automobiles, advanced medical equipment, network equipment and other equipments with digital interface. And the network communication is one of the most important and fundamental function of these embedded equipment. Therefore, it is of great practical significance to extend the network function of RTEMS OS on the basis of embedded system.RTEMS is a duty-free and open-source embedded real-time operating system. It was firstly used for National Defense System in the United States, and has been developed and maintained by OAR corporation from1994. It has lots of advantages, such as small in size, real-time, source code-open, and it is widely used in many fields.This project, which extended the network function of RTEMS, based on our library’s GX2410_BP hardware platform. GX2410_BP is a platform for embedded system teaching and studying, it bases on Sumsung S3C2410X processor(ARM920T), and integrates abundant peripheral equipment. It also has lots of corresponding software kit, which makes the extention of a network phonetic transmission system on this platform possible.This project, realized a basic network phonetic system platform for playing, recording and teletransmission of audio data by network. By combining the needs and functions of network phonetic transmission system, this project developed BSP(Board Support Package) of RTEMS used for GX2410_BP hardware development platform; developed Philips’UDA1341audio driver program to record and play audio materials and DM9000network chips drive program to ensure the network transmission of audio data. This system uses PJSIP as its’ SIP protocol stack, which is a source-open protocal library to provide clear API and technology files, and has a good portability. At last, this project provedes corresponding application programs on application layer to tests the system, and then points out the characteristics and disadvantages, also provides advices to make improvements.更多还原