1.\" $NetBSD: mount_kernfs.8,v 1.18 2012/03/22 21:47:20 wiz Exp $ 2.\" 3.\" Copyright (c) 1992, 1993, 1994 4.\" The Regents of the University of California. All rights reserved. 5.\" All rights reserved. 6.\" 7.\" This code is derived from software donated to Berkeley by 8.\" Jan-Simon Pendry. 9.\" 10.\" Redistribution and use in source and binary forms, with or without 11.\" modification, are permitted provided that the following conditions 12.\" are met: 13.\" 1. Redistributions of source code must retain the above copyright 14.\" notice, this list of conditions and the following disclaimer. 15.\" 2. Redistributions in binary form must reproduce the above copyright 16.\" notice, this list of conditions and the following disclaimer in the 17.\" documentation and/or other materials provided with the distribution. 18.\" 3. Neither the name of the University nor the names of its contributors 19.\" may be used to endorse or promote products derived from this software 20.\" without specific prior written permission. 21.\" 22.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32.\" SUCH DAMAGE. 33.\" 34.\" @(#)mount_kernfs.8 8.2 (Berkeley) 3/27/94 35.\" 36.Dd March 22, 2012 37.Dt MOUNT_KERNFS 8 38.Os 39.Sh NAME 40.Nm mount_kernfs 41.Nd mount the /kern file system 42.Sh SYNOPSIS 43.Nm 44.Op Fl o Ar options 45.Ar /kern 46.Ar mount_point 47.Sh DESCRIPTION 48The 49.Nm 50command attaches an instance of the kernel parameter 51namespace to the global filesystem namespace. 52The conventional mount point is 53.Pa /kern . 54The directory specified by 55.Ar mount_point 56is converted to an absolute path before use. 57This command is normally executed by 58.Xr mount 8 59at boot time. 60.Pp 61The filesystem includes several regular files which can be read, 62some of which can also be written. 63The contents of the files is in a machine-independent format, 64either a string, or an integer in decimal ASCII. 65Where numbers are returned, a trailing newline character is also added. 66.Pp 67The options are as follows: 68.Bl -tag -width indent 69.It Fl o 70Options are specified with a 71.Fl o 72flag followed by a comma separated string of options. 73See the 74.Xr mount 8 75man page for possible options and their meanings. 76.El 77.Sh FILES 78.Bl -tag -width copyright -compact 79.It Pa boottime 80the time at which the system was last booted (decimal ASCII). 81.It Pa copyright 82kernel copyright message. 83.It Pa hostname 84the hostname, with a trailing newline. 85The hostname can be changed by writing to this file. 86A trailing newline will be stripped from the hostname being written. 87.It Pa hz 88the frequency of the system clock (decimal ASCII). 89.It Pa loadavg 90the 1, 5 and 15 minute load average in kernel fixed-point format. 91The final integer is the fix-point scaling factor. 92All numbers are in decimal ASCII. 93.It Pa msgbuf 94the kernel message buffer, also read by 95.Xr syslogd 8 , 96through the 97.Pa log 98device, and by 99.Xr dmesg 8 . 100.It Pa pagesize 101the machine pagesize (decimal ASCII). 102.It Pa physmem 103the number of pages of physical memory in the machine (decimal ASCII). 104.\" .It Pa root 105.\" the system root directory. 106.\" In a chroot'ed environment, 107.\" .Nm 108.\" can be used to create a new 109.\" .Pa /kern 110.\" mount point. 111.\" .Pa /kern/root 112.\" will then refer to the system global root, not the current process root. 113.It Pa rootdev 114the root device. 115.It Pa rrootdev 116the raw root device. 117.It Pa time 118the second and microsecond value of the system clock. 119Both numbers are in decimal ASCII. 120.It Pa version 121the kernel version string. 122The head line for 123.Pa /etc/motd 124can be generated by running: 125.Dq Ic "sed 1q /kern/version" 126.El 127.Sh SEE ALSO 128.Xr mount 2 , 129.Xr unmount 2 , 130.Xr fstab 5 , 131.Xr dmesg 8 , 132.Xr mount 8 , 133.Xr setkey 8 , 134.Xr syslogd 8 135.Sh HISTORY 136The 137.Nm 138utility first appeared in 139.Bx 4.4 . 140.Sh BUGS 141This filesystem may not be NFS-exported. 142