Design And Impiementation Of Android Smart Phone Based On Qualcomm MSM7227

In recent years, China’s demand for smartphones is in accelerated growth. In orderto meet the market demand, each major manufacturer of mobile terminals focuses on themobile smart devices based on Android.Once, the author worked in AnKeXin Communications Co., Ltd. Suzhou as anintern. The company is a provider of mobile solutions. This paper based on thecompany’s I820project of Android smartphone builds the hardware platform by usingthe hardware solution of the project, and completes the transplantation of Android2.1system by designing and implementing the device driver and hardware abstraction layerof Android2.1system.As input device, touch screen and optical mouse’s drivers are implemented byusing input subsystem drivers of Linux kernel; Vibrator, as timed output device, itsdriver is implemented by using Timed Output driver framework defined by Androidkernel; Sensor, as I2C device, the implementation of its I2C device driver does notcomply with the architecture of Linux I2C driver, but deal with the sensor asmiscellaneous character device; Camera, also as I2C device, the implementation of itsdriver is similar with sensor, but the difference is that a camera is registered as a threecharacter device; Bluetooth driver realizes its management of chip’s power by standardLinux rfkill interfaces.According to the special module’s hardware abstraction layer’s interface mode andthe interfaces, the hardware abstraction layer is implemented. The hardware abstractionlayer interface of display module and sensor module uses the way of hardware module,and the implementation of their hardware abstraction layer needs implement and extendthe structures in interface; The hardware abstraction layer interface of vibrator moduleand GPS module uses the way of direct interface, and the implementation of theirhardware abstraction layer needs directly implement the independent interfaces whichare provided by hardware_legacy library; The hardware abstraction layer interface ofaudio module and camera module uses the way of C++class inheritance, and theimplementation of their hardware abstraction layer needs inherit the classes in interfaceand implement the functions in class.At present, Android smartphones have been put into mass production implementedbased on this paper’s design. According to the customers’ feedback, this kind of smartphone has good performance.