1.\" 2.\" Copyright (c) 1992, 1993 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 8.1 (Berkeley) 06/09/93 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 F Ar fsoptions 23.Pa /kern 24.Pa 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.Sh FILES 42.Bl -tag -width copyright -compact 43.It Pa boottime 44the time at which the system was last booted (decimal ASCII). 45.It Pa copyright 46kernel copyright message. 47.It Pa hostname 48the hostname, with a trailing newline. 49The hostname can be changed by writing to this file. 50A trailing newline will be stripped from the hostname being written. 51.It Pa hz 52the frequency of the system clock (decimal ASCII). 53.It Pa loadavg 54the 1, 5 and 15 minute load average in kernel fixed-point format. 55The final integer is the fix-point scaling factor. 56All numbers are in decimal ASCII. 57.It Pa pagesize 58the machine pagesize (decimal ASCII). 59.It Pa physmem 60the number of pages of physical memory in the machine (decimal ASCII). 61.It Pa root 62the system root directory. 63In a chroot'ed environment, 64.Nm 65can be used to create a new 66.Pa /kern 67mount point. 68.Pa /kern/root 69will then refer to the system global root, not the current process root. 70.It Pa rootdev 71the root device. 72.It Pa rrootdev 73the raw root device. 74.It Pa time 75the second and microsecond value of the system clock. 76Both numbers are in decimal ASCII. 77.It Pa version 78the kernel version string. 79The head line for 80.Pa /etc/motd 81can be generated by running: 82.Dq Ic "sed 1q /kern/version" 83.El 84.Sh SEE ALSO 85.Xr mount 2 , 86.Xr unmount 2 , 87.Xr fstab 5 88.Sh CAVEATS 89This filesystem may not be NFS-exported. 90.Sh HISTORY 91The 92.Nm mount_kernfs 93utility first appeared in 4.4BSD. 94