Use mdev to automatically generate the device node

in the init script, e.g: rc.local

cat etc/init.d/rcS 
#!/bin/sh 
 
 
mount -o sys /sys 
mount -o proc /proc 
 
 
echo "----------mount /sys as sysfs" 
mount -t tmpfs mdev /dev 
echo "----------Starting mdev......" 
echo /sbin/mdev > /proc/sys/kernel/hotplug 
mdev -s