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diff --git a/share/man/man4/devfs.4 b/share/man/man4/devfs.4 new file mode 100644 index 000000000000..c90835570127 --- /dev/null +++ b/share/man/man4/devfs.4 @@ -0,0 +1,147 @@ +.\" Copyright (c) 1996 +.\" Mike Pritchard <mpp@FreeBSD.org>. All rights reserved. +.\" +.\" Copyright (c) 1992, 1993, 1994 +.\" The Regents of the University of California. All rights reserved. +.\" All rights reserved. +.\" +.\" This code is derived from software donated to Berkeley by +.\" Jan-Simon Pendry. +.\" +.\" 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. +.\" 3. Neither the name of the University nor the names of its contributors +.\" may be used to endorse or promote products derived from this software +.\" without specific prior written permission. +.\" +.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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. +.\" +.Dd June 30, 2022 +.Dt DEVFS 4 +.Os +.Sh NAME +.Nm devfs +.Nd device file system +.Sh SYNOPSIS +.Bd -literal +devfs /dev devfs rw 0 0 +.Ed +.Sh DESCRIPTION +The device file system, or +.Nm , +provides access to kernel's device +namespace in the global file system namespace. +The conventional mount point is +.Pa /dev . +.Pp +The file system includes several directories, links, symbolic links +and devices, some of which can also be written. +In a chroot'ed +environment, +.Xr devfs 8 +can be used to create a new +.Pa /dev +mount point. +.Pp +The +.Xr mknod 8 +tool can be used to recover deleted device entries under +.Nm . +.Pp +The +.Xr fdescfs 5 +filesystem is an alternate means for populating +.Pa /dev/fd . +The character devices that both +.Nm +and +.Xr fdescfs 5 +present in +.Pa /dev/fd +correspond to the open file descriptors of the process +accessing the directory. +.Nm +only creates files for the standard file descriptors +.Pa 0 , +.Pa 1 +and +.Pa 2 . +.Xr fdescfs 5 +creates files for all open descriptors. +.Pp +The options are as follows: +.Bl -tag -width indent +.It Fl o Ar options +Use the specified mount +.Ar options , +as described in +.Xr mount 8 . +The following devfs file system-specific options are available: +.Bl -tag -width indent +.It Cm ruleset Ns No = Ns Ar ruleset +Set ruleset number +.Ar ruleset +as the current ruleset for the mount-point and apply all its rules. +If the ruleset number +.Ar ruleset +does not exist, an empty ruleset with the number +.Ar ruleset +is created. +See +.Xr devfs 8 +for more information on working with devfs rulesets. +.El +.El +.Sh FILES +.Bl -tag -width /dev/XXXX -compact +.It Pa /dev +The normal +.Nm +mount point. +.El +.Sh EXAMPLES +To mount a +.Nm +volume located on +.Pa /mychroot/dev : +.Pp +.Dl "mount -t devfs devfs /mychroot/dev" +.Sh SEE ALSO +.Xr fdescfs 5 , +.Xr devfs 8 , +.Xr mount 8 , +.Xr make_dev 9 +.Sh HISTORY +The +.Nm +file system first appeared in +.Fx 2.0 . +It became the preferred method for accessing devices in +.Fx 5.0 +and the only method in +.Fx 6.0 . +The +.Nm +manual page first appeared in +.Fx 2.2 . +.Sh AUTHORS +The +.Nm +manual page was written by +.An Mike Pritchard Aq Mt mpp@FreeBSD.org . |