Add missing usfs manual page.

Suggested by:	Sascha Wildner <swildner@gmail.com>
MFC after:	1 week

share/man/man4/Makefile

@@ -540,6 +540,7 @@ MAN=	aac.4 \
 	usb_template.4 \
 	usb_quirk.4 \
 	uslcom.4 \
+	usfs.4 \
 	utopia.4 \
 	uvisor.4 \
 	uvscom.4 \

share/man/man4/usfs.4

@@ -0,0 +1,62 @@
+.\"
+.\" Copyright (c) 2014 Hans Petter Selasky
+.\" All rights reserved.
+.\"
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions
+.\" are met:
+.\" 1. Redistributions of source code must retain the above copyright
+.\"    notice, this list of conditions and the following disclaimer.
+.\" 2. Redistributions in binary form must reproduce the above copyright
+.\"    notice, this list of conditions and the following disclaimer in the
+.\"    documentation and/or other materials provided with the distribution.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
+.\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+.\" TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+.\" PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
+.\" BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+.\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+.\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+.\" POSSIBILITY OF SUCH DAMAGE.
+.\"
+.\" $FreeBSD$
+.\"
+.Dd March 18, 2014
+.Dt USFS 4
+.Os
+.Sh NAME
+.Nm usfs
+.Nd USB device side support for bulk only transport mass storage
+.Sh SYNOPSIS
+To compile this driver into the kernel,
+place the following lines in your
+kernel configuration file:
+.Bd -ragged -offset indent
+.Cd "device usb"
+.Cd "device usfs"
+.Ed
+.Pp
+Alternatively, to load the driver as a
+module at boot time, place the following line in
+.Xr loader.conf 5 :
+.Bd -literal -offset indent
+usfs_load="YES"
+.Ed
+.Sh DESCRIPTION
+The
+.Nm
+driver provides support for emulating an USB mass storage device when
+the USB stack is activated in USB device side mode.
+.Pp
+Upon attach the driver creates a RAM disk which can be read and written.
+.Sh SEE ALSO
+.Xr umass 4
+.Xr usb 4
+.Sh HISTORY
+The
+.Nm
+driver appeared in FreeBSD 8.