Device node
User-space programs access the PRNG device through a device node, /dev/prandom.
Your distribution might create this device node for you, or provide udev to create it (see Device nodes provided by udev).
If no device node is created for you, you must create it yourself, for example, with the mknod command. See the mknod man page for further details.
The PRNG device driver registers a misc character device node. During load, a sysfs directory, /sys/devices/virtual/misc/prandom, is created. This directory contains a dev attribute with the major and minor number of the PRNG device.