Pseudo-device drivers are parts of the kernel that act like device drivers but do not correspond to any actual hardware in the machine. The network-related pseudo-devices are in that section, while the remainder are here.
gzip allows you to run FreeBSD programs
that have been compressed with gzip. The
programs in /stand are compressed so it
is a good idea to have this option in your kernel.
log is used for logging of kernel error
messages. Mandatory.
pty is a ``pseudo-terminal'' or simulated
login port. It's used by incoming telnet
and rlogin sessions, xterm, and some other
applications such as emacs. The number
indicates the number of ptys to create.
If you need more than GENERIC default of 16
simultaneous xterm windows and/or remote logins, be
sure to increase this number accordingly, up to a
maximum of 64.
Snoop device. This pseudo-device allows one
terminal session to watch another using the
watch(8) command. Note that
implementation of this capability has important
security and privacy implications. The
number after snp is the total number of
simultaneous snoop sessions. Optional.
Vnode driver. Allows a file to be treated as a
device after being set up with the
vnconfig(8) command. This driver can be
useful for manipulating floppy disk images and
using a file as a swap device (e.g. an MS Windows
swap file). Optional.