| 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... |
PDF Full Text Request