Based On Digital Tv Platform Android Customization And Optimization

A great success has been acquired by android since it entered the mobile terminalmarket. As a new platform with features of exploitability, free and convenient toolsoffered to application developers, Android operating system is now being applied todigital TV and tablet pc fields. Android os was designed for mobile platform. Itscomplicated software stack architecture can yield great return for hardware and supplyrich software services. These advantages also delay the boot-up time of android devicesbeing sold on the market up to an average of35s. In order to use android os on digitalTV platform, manufactures have to customize android os according to their hardwarefeatures and optimize the boot-up time of android devices.To make android os fit for digital TV platform, this paper studied androidarchitecture, boot-up procedure of android os, the registration of android native servicesand android services and analyzed part of the android os core services in detail. On thatbase, this paper customized android os according to the application requirements ofdigital TV by pruning unnecessary android services including native services andandroid services. Running results of customized android os proved that operatingsystem performed well and the boot-up time, usages of memory and flash disk havebeen decreased accordingly. The customized android os can support accessing ofnetwork and installation of game apks in the on-line market.In order to meet the boot-up time requirement of digital TV, this paper studied theframework of Linux power management and came up with a scheme of android fastboot, which stores boot-up system state of android os to an I/O device and directlyrestores system state from the storage device when booting up next time. Results ofboot-up experiment show that android fast boot technology can boot up an androiddevice within10s and the boot-up time depends on the read-write speed of the I/Odevice bing used, which means boot-up time will be decreased to less than3s if moreadvanced I/O devices like SSD or devices support the USB3.0standards were used.Android fast boot technology has dramatically reduced boot-up time of androiddevices. However, it led to the file system inconsistency problem when used in practice. In order to solve the file system inconsistency problem, in the first place, this paperanalyzed the reason that led to the problem in detail, and then studied the criticalstructures as well as the scanning procedure of file system partition on NAND Flashdevice of yaffs2file system. On that base, this paper came up with a scheme of updatingandroid file system based on yaffs2, which updates file system data in memoryaccording to new states on NAND Flash partitions correspondingly after android fastboot technology restored android os state from system image stored on the storagedevice. The comparison of info of super block structures in memory before and after filesystem updating proved that this method can guarantee the file system consistency inthe android fast boot technology.