The Improvement And Implementation Of OTA Differential Upgrade Mode Based On Linux System

Smart TVs need to fix problems and update functions by OTA(Over The Air Technology)upgrade.If upgrade by whole package.Not only the download and upgrade time is long,but also the equipment provider's server is under pressure.At the same time,the existing OTA differential upgrade mechanism is not perfect enough,Failures are easily occur during the upgrade process.For example,an unexpected power-off or insufficient space during the upgrade process will result in the upgrade failure.And the existing modular differential upgrades have not been truly lightweight.This thesis proposes the following improvements for the current status of OTA upgrades:1.This thesis studies the OTA differential upgrade of the smart TV based on Linux platform.Aiming at the problem that the unexpected power-off during the upgrade of the smart TV causes smart TV fail to turn on.Then propose the solution two-channel upgrade.According to the start-up procedure of the television,the smart TV sets two start up channels,one for normal operation of the television and the other as a dedicated channel for upgrading.Only the operating channels and system files are upgraded,the contents of the upgrade channels are not changed during upgrade process.Therefore,the problems can be avoided.At the same time,this thesis adds fault-tolerance mechanisms for the processes where is prone to trouble in the upgrade process,so that it can effectively improve security and stability.2.This thesis studies the differential upgrade method and proposes a differential method based on file system.According to whether the file supports partitioning of the file system,the upgrade partition is divided into two parts: the operation kernel partition and the support file system partition.The bsdiff algorithm is used to perform the difference and this thesis mainly designed from the aspects of differential packet generation,differential packet synthesis and differential packet upgrade.At the same time,file cutting is performed on large files to reduce the memory space's requirement during the upgrade.Achieve more lightweight upgrade while maintaining security.This thesis achieve the program based on MTK5658 and MSD6586 platform,The test results show the feasibility of the program.It can effectively avoid the problems that unexpected power-off caused the TV can not turn on,through the improvement anddesign of the OTA differential upgrade mode.And can reduce the size of differential packet and upgrade time.The addition of fault-tolerance mechanisms can also improve differential upgrade security and user experience.