Analysis And Innovation Of An Embedded Graphic System

With embedded system more expanding in the computer, communication and consumption field, and the hardware development, a graphic user interface which is suitable for the embedded Chinese situation is very needed by embedded system. The embedded graphic system -- Nano-X adopts layered architecture and client-server module with stabilization and requiring low expense.The server of Nano-X can support more than one client application at the same time, but requires that each application only has one thread. Otherwise, accessing the critical resources including requesting buffer, network socket and event queue will result in collision. Analysis the interaction of clients and server through requests responsions and events, use different policy in synchronous and asynchronous procedures to make Nano-X support multi-threading application.The clients and server communicate with each other through network socket, for each time translating date from client to server, there are two copy process: first from client buffer to kernel space, then from kernel space to server space. This will result in large system expense problem, especially when translating large data. A sharing memory method is put forward to enhance communication efficiency and the two methods can be dynamically switched.Aim at the Nano-X in short supporting chinese characters environment, discuss the lattice font object. Adding a vectorial font object and using the FreeType2 library to realize display of the vectorial chinese characters. Capture Nano-X keyboad input events, and then convert the number key to chinese characters code through the input method; finally send the chinese characters code to the application. By this means, user can input chinese characters.