Research And Implementation Of The Frame Buffer Display Module For Embedded System

With the development of embedded technology, it has been widely used in various industries, and the central processor has also been upgraded from8bit,16bit,32bit to64bit, embedded system development is also deeply affecting and changing the development of the industy. The development of the embedded display system has went through many stages. The early character interface such as a pager could only display numbers, English and Chinese characters. Afterwards the black and white display system of the early mobild phone was able to showsimple graphics. At present more and more embedded systems use LCD (Liquid Crystal Display) as the display device, such as modern mobile phones and navigators etc. They can display pictures, or play video. The entire display system needs collaborative work from chip design, hardware design, Linux kernel driver design and user space design. In these devices, frame buffer is widely used as an interface between hardware and application software.The purpose of this thesis is to design and implement a frame buffer display technology solution which are used by the embedded system. Its main job is to design and implement a frame buffer display driver and integrate it into the commonly used embedded system. Finally a practical frame buffer display module for embedded system is implemented based on above solution. Following main works are included:1) Selection of hardware and LCD panelInvestigate the LCD related hardware design, including selecting the appropriate size according to the requirements, the choice of the bus between LCD and CPU, e.g. CPU interface bus, RGB bus, DSI bus. The choive is according to the amount of data transmission, the data transfer rate and the cost.2) The design and implementation of the frame buffer driver in embedded kernelDiscuss the display driver architecture and principle of the kernel, interrupt handle and user space interface. Investigate the technologies and their implementation of the whole frame buffer architecture, display process, device management, interruption processing and so on.3) Design of the user space display architectureResearch on the basic technical principles and graphical interface development technologies of the user space in the kernel, design the user space display architecture, including device driver layer, the middle engine core layer andAPI interface layer. Focuse on the implementation of the bottom layer interface call and interaction process.Compared to the existing technical solution, the solution of the embedded system frame buffer display module presented in this thesis has the features such as open source, strong portability, structure clear, easy maintenance and so on. Meanwhile, the cost is also under control.