Embedded Linux Porting And Driver Design In Smart Home

Smart home is a living environment, which is installed as a platform for a residential smart home system. It is a blend of embedded technology, the Internet of things technology, the Internet and other technologies. On the basis of previous research, this project designs an smart home system framework based on the embedded technology and Zig Bee technology, it has completed the clipping and porting of u-boot and Linux kernel which are based on Exynos 4412 platform, and uses multi-process/multi-thread technology to achieve multi-task parallel operation. In this paper, main works are as follows:(1)This paper has completed the clipping and porting of embedded Linux system and the construction of the server which are based on Exynos 4412 platform, mainly including the clipping and porting of u-boot, the clipping and porting of Linux kernel, the root file system. And according to the functional requirements of smart home system, the embedded web server mjpg-streamer video server and embedded database SQLite are built on this platform to achieve remote monitoring, data storage and other functions.(2)Using modular programming ideas, This paper uses multi-process/multi-thread technology to divide the various subsystems of smart home into several task modules. The user communicates with the main process through the CGI process in a message queue; The main process creates a various of functional threads, and the method of communication between threads by the way of shared memory. The client request thread wakes up the corresponding thread, according to the CGI data which from the main process. The data receiving thread the data updating thread and the data updating thread cooperate with each other to complete the work of environmental data acquisition of Zigbee module. The database thread mainly completes the work of saving the information form Zigbee module and user. Led thread, buzzer thread and motor control thread complete the work of turning on/off led, buzzer, curtains,and the camera threads complete video surveillance.(3)This paper has completed the design of character device driver in embedded Linux, and writes the driver and testing procedures of LED, buzzer, DC motor; also includes the corresponding CGI, web program. Platform bus is used to improve the portability of the code when designing the character device driver.