Research Of Embedded Linux Character Device Drivers Based On ARM

Embedded technology has obtained broad space of development, along with thedevelopment of information, networking, intelligent. Linux has become mainstreamembedded development platform rapidly depends on its tiny kernel, cutting free,open source, reliable security and multi-platform. A wide variety of embeddeddevices show up and most of them applicated in character devices. The devicedrivers occupy a pivotal position in the embedded systems. Therefore this articleresearch aim at principles and methods of embedded Linux character drivers designs.First of all, this paper introduces embedded system development environment tobuild. The content includes host Linux system to build, the kernel source tree,cross-compiler tool chain of production, synopsis of S3C2410platform, cutting andtransplantation of the Linux kernel, the BootLoader and the Root Filesytem.Secondly, Focus on the key technology of Linux device drivers. In-depthunderstanding of the kernel concurrency techniques such as semaphore and spinlock,the kernel timers including tasklet mechanism and workqueues technology, thehardware communication of I/O memory and I/O port technology, the interrupthandling and debugging techniques.Furthermore, Study of the basic principles and methods of character devicedrivers. Introduction of the kernel module development technology, including themodule initialization and shutdown, error handling, and module parameters. Focuson the character device numbers and device registration, and important data structureon the character device, and the method of read and write, ioctl interface andblocking and non-blocking technologies, etc.Finally, Application the device driver technology in the USB keyboard. Thispaper introduces the core data structures and basic methods of USB keyboard driver.