Setting ThinkPad TrackPoint

Whatever I try, the rc.local still won't work when it boots or reboots.
That's mean I need to run the command manually to change trackpoint speed, sensitivity.

#!/bin/bash
echo -n xxx > /sys/devices/platform/i8042/serio1/speed
echo -n yyy > /sys/devices/platform/i8042/serio1/sensitivity
exit 0

put this shell in /bin/xxx.sh is a little more convenient to use.