Android4.0 开放Root权限

system/extras/su/

1>Android.mk:

                    添加： ifeq ($(strip $(TARGET_OPEN_ROOT)),true)
                                 LOCAL_CFLAGS += -DOPEN_ROOT=1
                                 endif

2>su.c:

         /* Until we have something better, only root and the shell can use su. */
         myuid = getuid();
#if OPEN_ROOT
#else
          if (myuid != AID_ROOT && myuid != AID_SHELL) {
              fprintf(stderr,"su: uid %d not allowed to su\n", myuid);
              return 1;
          }  
#endif 

3>init.rc:

           chown root root /system/xbin/su
           chmod 4755 /system/xbin/su

4>删除busybox里面的su