1.\" Copyright (c) 2002 Gordon Tetlow 2.\" All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 13.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 14.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 15.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 16.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 17.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 18.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 19.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 20.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 21.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 22.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 23.\" SUCH DAMAGE. 24.\" 25.\" $FreeBSD$ 26.\" 27.Dd November 4, 2002 28.Dt NEXTBOOT 8 29.Os 30.Sh NAME 31.Nm nextboot 32.Nd "specify an alternate kernel and boot flags for the next reboot" 33.Sh SYNOPSIS 34.Nm 35.Op Fl f 36.Op Fl o Ar options 37.Fl k Ar kernel 38.Nm 39.Fl D 40.Sh DESCRIPTION 41The 42.Nm 43utility allows specifying an alternate kernel and/or boot flags for the 44next time the machine is booted. 45Once the 46.Xr loader 8 47loads in the new kernel 48information, it is deleted so in case the new kernel hangs the machine, 49once it is rebooted, the machine will automatically revert to its previous 50configuration. 51.Pp 52The options are as follows: 53.Bl -tag -width ".Fl o Ar options" 54.It Fl D 55Invoking 56.Nm 57with this 58option removes an existing 59.Nm 60configuration. 61.It Fl f 62This 63option disables the sanity checking which checks if the kernel really exists 64before writing the 65.Nm 66configuration. 67.It Fl k Ar kernel 68This option specifies a kernel directory relative to 69.Pa /boot 70to load the kernel and any modules from. 71.It Fl o Ar options 72This option 73allows the passing of kernel flags for the next boot. 74.El 75.Sh FILES 76.Bl -tag -width ".Pa /boot/nextboot.conf" -compact 77.It Pa /boot/nextboot.conf 78The configuration file that the 79.Nm 80configuration is written into. 81.El 82.Sh EXAMPLES 83To boot the 84.Pa GENERIC 85kernel with the 86.Nm 87command: 88.Pp 89.Dl "nextboot -k GENERIC" 90.Pp 91To enable into single user mode with the normal kernel: 92.Pp 93.Dl "nextboot -o ""-s"" -k kernel" 94.Pp 95To remove an existing nextboot configuration: 96.Pp 97.Dl "nextboot -D" 98.Sh SEE ALSO 99.Xr boot 8 , 100.Xr loader 8 101.Sh HISTORY 102The original 103.Nm 104manual page first appeared in 105.Fx 2.2 . 106It used a very different interface to achieve similar results. 107.Pp 108The current incarnation of 109.Nm 110appeared in 111.Fx 5.0 . 112.Sh AUTHORS 113This manual page was written by 114.An Gordon Tetlow Aq gordon@FreeBSD.org . 115.Sh BUGS 116The 117.Nm 118code is implemented in the 119.Xr loader 8 . 120It is not the most throughly tested code. 121It is also my first attempt to write in Forth. 122.Pp 123Finally, it does some evil things like writing to the file system before it 124has been checked. 125If it scrambles your file system, do not blame me. 126