Research And Implemention Of The System Consistency Based On Fast Boot Technique Of Android

Android is one operating system aimed at the mobile terminal devices, which was developed by Google and the Open Handset Alliance. Its complicated architecture, open source code, open platform, and its strong developing environment and tools supply developers and users infinite convenience, and help Android achieve the great success in the mobile market. However, it also brings a huge problem, which is that the average booting time for Android devices is more than 45 seconds. The endless booting has seriously bad influence on users’ experience.Home and overseas researchers and companies put forward and complished some methods to solve the problem. Among these methods, the Android fast boot method based on Linux Suspend/Resume technique has great advantage in both theory and practical effect. Though this method indeed reduces the booting time, the system inconsistency is brought as well for the same image is used to restore the system during every booting procedure. The system inconsistency problem causes much inconvenience to users and would be one obstacle to the promotion of Android. This thesis studied and achieved how to reduce the booting time and guaranteed the system inconsistency on the basis of current fast booting methods.Aimed at the inconsistency problem brought by the current fast boot method, this thesis solved it in two sides. One side is the Linux level whose problem is to solve the filesystem inconsistency and the filesystem contains Virtual Filesystem Switch and the bottom physical file system which is Yaffs2 discussed in this thesis. The other one is the Android level, whose problem is to solve the inconsistency problem of Android services and applications. The thesis first introduced the corresponding theory foundation of the fast boot method including the method of Suspend/Resume and the frameworks of Android, at the same time analyzed the procedure of Android booting in details. Then the reason which causes the inconsistency of filesystem, Android services and applications was analyzed in details. Based on the analysis of the system inconsistency, the concrete scheme achieving the consistency of filesystem, Android services and applications was approved. In the last, we tested and evaluated the schema in the scientific way. Adopted the normal boot procedure, it takes 45 seconds to boot up at least. In our fast boot schema the time is only 23 seconds, which is the half of the normal boot, and the system consistency is achieved at the same time. So the system consistency schema based on the Android fast boot method achieves the goal of fast booting and the system consistency.