【作者】 梁志刚；

【导师】 顾伟驷；

【作者基本信息】 浙江工业大学 ， 控制理论与控制工程， 2009， 硕士

【摘要】 ARM微处理器和嵌入式Linux操作系统由于其高性能、高可靠性、实时性、低成本越来越多地在工业控制领域中得到了应用。本文所研究的课题是作为“基于Linux操作系统的模块化高性能数控系统”项目的重要组成部分,设计了基于AT91SAM9261 ARM微控制器的数控系统主板硬件,详细地研究了基于该硬件平台的Linux操作系统移植过程,并在此基础上开发了底层驱动程序、相关支持库及数控系统的一个功能模块。首先,设计数控系统的主板,介绍了主要的元件的接口电路和功能,设计了电路原理图,通过这个过程详细地阐述了项目硬件的开发过程。然后,系统地研究了Linux系统平台的创建过程。根据本项目主板硬件的特点对启动装载程序(U-BOOT)进行了针对性的移植和研究,改进了U-BOOT源代码,使之支持YAFFS(文件系统)映像文件下载。接着在目标板上移植了Linux-2.6内核,根据目标板硬件对Linux内核驱动程序做了针对性的修改,使Linux内核稳定地运行于本项目特定的硬件平台上,在Linux的移植、配置、裁剪过程中给出了作者独特的建议。另外具体地阐述了嵌入式Linux根文件系统制作的方法和注意事项,在数控主板上实现了Cramfs(只读)+Yaffs(可读写)形式的根文件系统。在此基础上,作者开发数控系统软件。先对Linux设备驱动程序的开发进行了阐述、分析,实现了数控系统键盘的驱动程序。并移植了用于显示美观中英文字体的FreeType库以及开发了一套可用于上层应用程序调用的通用图形子系统函数库。这个图形子系统开发过程具有指导性,可以指引读者创建自己的函数库,并且图形子系统本身具有通用性,可应用于今后程序开发中,提高了嵌入式系统的开发效率。在以上软硬件的基础上开发了应用程序:数控系统文本编辑器。本文的研究为进一步开发高性能数控系统打下坚实的基础。更多还原

【Abstract】 The embedded system (ARM microcontroller and Linux operating system), due to its high performance, reliability, real timing, low cost, are widely used in industrial field. Therefore, the research of embedded systems in industrial field is of great significance. This paper, as an important module of advanced numerical control system, based on AT91SAM9261 ARM microcontroller and Linux-2.6 kernel, design the main board, study the embedded system development process carefully, develop keyboard driver and user-defined function library, and realize a functional module of a numerical control machine.In this paper, firstly, the author design the main board, introduce the interface circuit and the usage of every component, illustrate the hardware development process of this project.Secondly, the author study systematically on how to build an embedded operating system platform step by step on a bare target board. According to the project hardware, transplant and improve the boot loader program(U-BOOT), and make it have the ability of writing the YAFFS filesystem to nand flash. Analyze carefully of the kernel’s architecture, and transplant the Linux kernel to the target board, in this protess, the author put forward his own proposals on kernel configuration and kernel reduction. And then illustrate the important technology of creating root file system, and realize a Cramfs(read only)+Yaffs(read and write) root file system.Thirdly, based on the platform, the author develop the application software. Programme a Linux device driver of the keyboard. In oder to display beautiful font on LCD, transplanted the font engine—FreeType and create a graphics subsystem. This subsystem, is structional and practical, can be used in later project. Finally, based on all the work that mentioned above, the author development and realize a typical application example of an editer. All this, laid a solid foundation of developing high-performance numerical control system更多还原