1.\" 2.\" Copyright (c) 1992, 1993, 1994 3.\" The Regents of the University of California. All rights reserved. 4.\" All rights reserved. 5.\" 6.\" This code is derived from software donated to Berkeley by 7.\" Jan-Simon Pendry. 8.\" 9.\" %sccs.include.redist.roff% 10.\" 11.\" @(#)mount_kernfs.8 8.2 (Berkeley) 03/27/94 12.\" 13.\" 14.Dd 15.Dt MOUNT_KERNFS 8 16.Os BSD 4.4 17.Sh NAME 18.Nm mount_kernfs 19.Nd mount the /kern file system 20.Sh SYNOPSIS 21.Nm mount_kernfs 22.Op Fl o Ar options 23.Ar /kern 24.Ar mount_point 25.Sh DESCRIPTION 26The 27.Nm mount_kern 28command attaches an instance of the kernel parameter 29namespace to the global filesystem namespace. 30The conventional mount point is 31.Pa /kern . 32This command is normally executed by 33.Xr mount 8 34at boot time. 35.Pp 36The filesystem includes several regular files which can be read, 37some of which can also be written. 38The contents of the files is in a machine-independent format, 39either a string, or an integer in decimal ASCII. 40Where numbers are returned, a trailing newline character is also added. 41.Pp 42The options are as follows: 43.Bl -tag -width indent 44.It Fl o 45Options are specified with a 46.Fl o 47flag followed by a comma separated string of options. 48See the 49.Xr mount 8 50man page for possible options and their meanings. 51.El 52.Sh FILES 53.Bl -tag -width copyright -compact 54.It Pa boottime 55the time at which the system was last booted (decimal ASCII). 56.It Pa copyright 57kernel copyright message. 58.It Pa hostname 59the hostname, with a trailing newline. 60The hostname can be changed by writing to this file. 61A trailing newline will be stripped from the hostname being written. 62.It Pa hz 63the frequency of the system clock (decimal ASCII). 64.It Pa loadavg 65the 1, 5 and 15 minute load average in kernel fixed-point format. 66The final integer is the fix-point scaling factor. 67All numbers are in decimal ASCII. 68.It Pa pagesize 69the machine pagesize (decimal ASCII). 70.It Pa physmem 71the number of pages of physical memory in the machine (decimal ASCII). 72.It Pa root 73the system root directory. 74In a chroot'ed environment, 75.Nm 76can be used to create a new 77.Pa /kern 78mount point. 79.Pa /kern/root 80will then refer to the system global root, not the current process root. 81.It Pa rootdev 82the root device. 83.It Pa rrootdev 84the raw root device. 85.It Pa time 86the second and microsecond value of the system clock. 87Both numbers are in decimal ASCII. 88.It Pa version 89the kernel version string. 90The head line for 91.Pa /etc/motd 92can be generated by running: 93.Dq Ic "sed 1q /kern/version" 94.El 95.Sh SEE ALSO 96.Xr mount 2 , 97.Xr unmount 2 , 98.Xr fstab 5 , 99.Xr mount 8 100.Sh CAVEATS 101This filesystem may not be NFS-exported. 102.Sh HISTORY 103The 104.Nm mount_kernfs 105utility first appeared in 4.4BSD. 106