Original patch submitted in FreeBSD SVN
https://svnweb.freebsd.org/base?view=revision&revision=261266
by Alexander Leidinger aka netchild
http://www.leidinger.net/blog/2007/04/07/a-desktop-environment-in-a-jail/
https://lists.freebsd.org/pipermail/svn-src-head/2014-January/055578.html
sys/dev/drm/drmP.h
sys/dev/drm2/drm_os_freebsd.h
sys/kern/kern_jail.c
sys/sys/jail.h
usr.sbin/jail/jail.8