启动Service保存系统log

1、在产品目录的init.XXX.rc文件中，添加相应的service

service logcat_service /system/bin/logcat -b system -b events -b main
 -b radio -k -n 10 -v threadtime -r5000 -f /data/Logs/Log.0/logcat.log
    user root
    group log system
    class main
    disabled

2、启动服务的方式
命令行启动

setprop ctl.start logcat_service 
or
start logcat_service 

代码启动

c++
property_set("ctl.start","logcat_service");