Copyright2010SonyCorporation

《Copyright2010SonyCorporation》由会员上传分享，免费在线阅读，更多相关内容在教育资源-天天文库。

1、ImprovingAndroidBootupTimeTimBirdSonyNetworkEntertainment,Inc.Copyright2010SonyCorporationOverviewAndroidbootsequenceMeasuringbootuptimeProblemareasIncludingsomegorydetailsIdeasforimprovementsConclusionsResourcesCopyright2010SonyCorporationAndroidBootSequenceBoot

2、loaderKernelInitLoadsseveraldaemonsandservices,includingzygoteSee/init.rcand/init..rcZygotePreloadsclassesStartspackagemanagerServicemanagerStartsservicesCopyright2010SonyCorporationMeasuringboottimeSystemsMeasuredAndroidDeveloperPhone(ADP1)QualcommMSM7201at528MHzwith192MRAMRun

3、ningDonut(1.6)Nexus1Qualcomm8250at1GHzwith512RAMRunningEclair(2.1)OMAPEvaluationModuleTIOMAP3530at600MHzwith128MRAMRunningEclairCopyright2010SonyCorporationToolsusedStopwatchIt'skindofsadthatittakessolongthatyoucanuseastopwatchMessageloggersGrabserialPrintktimesAndroidsystemlogBootchartS

4、traceDalvikmethodtracer*Ftrace*GrabserialToolformeasuringtimeofprintoutsonaserialport,fromahostmachineOnlyusefulwithEVMboard,whichhasserialconsoleShowstimestampforeachlinereceivedoverserialconsoleSeehttp://elinux.org/GrabserialCopyright2010SonyCorporationPrintk-timesKerneloptionforadding

5、timestamptoeachprintkSetCONFIG_PRINTK_TIME=yOptionison"Kernelhacking"menu,"Showtiminginformationonprintks"Cansaveviewonserialconsole,orafterbootwith‘dmesg’Canturnon'initcall_debug'onkernelcommandlineSeehttp://elinux.org/Printk_TimesInitprogramalsooutputsto/dev/kmsgCanadjustloglevelof'ini

6、t'programChange“loglevel3”to“loglevel7”in/init.rcCopyright2010SonyCorporationBootchart'init'gathersdataonstartupMustre-compile'init'withsupportforbootchartdatacollectionAtoolonthehostproducesanicegraphicSeehttp://elinux.org/Bootchartandhttp://elinux.org/Using_Bootchart_on_AndroidStraceSh

7、owssystemcallsforaprocess(orsetofprocesses)IspartofAOSPsinceEclairCanaddtoinit.rctotraceinitialization.Forexample,totracezygotestartup,in/init.rcchange:toservicezygote/system/xbin/strace-tt-o/data/boot.strace/system/bin/app_process-Xzygote/system/bin--zygote--start-system