make
insmod cpucycles4ns.ko
dmesg | grep cpucycles4ns
This should print something like mknod /dev/cpucycles4ns c 253 0. Run that command.
Based on http://bench.cr.yp.to/cpucycles/n810.html which appears to have been written by D.J. Bernstein (according to the paper "SHA3 on ARM11 processors" by Peter Schwabe, Bo-Yin Yang and Shang-Yi Yang).