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- .\" Copyright (c) 2002 Gordon Tetlow
- .\" All rights reserved.
- .\"
- .\" 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.
- .\"
- .\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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 March 29, 2022
- .Dt NEXTBOOT 8
- .Os
- .Sh NAME
- .Nm nextboot
- .Nd "specify an alternate kernel and boot flags for the next reboot"
- .Sh SYNOPSIS
- .Nm
- .Op Fl af
- .Op Fl e Ar variable=value
- .Op Fl k Ar kernel
- .Op Fl o Ar options
- .Nm
- .Fl D
- .Sh DESCRIPTION
- The
- .Nm
- utility allows specifying some combination of an alternate kernel, boot
- flags, and kernel environment for the next time the machine is booted.
- Once the
- .Xr loader 8
- loads in the new kernel information from the
- .Pa /boot/nextboot.conf
- file, it is disabled so in case the new kernel hangs the machine, once
- it is rebooted, the machine will automatically revert to its previous
- configuration.
- .Pp
- The options are as follows:
- .Bl -tag -width ".Fl o Ar options"
- .It Fl a
- This option causes
- .Nm
- to append to an existing configuration in
- .Pa /boot/nextboot.conf .
- By default any existing configuration is overwritten.
- .It Fl D
- Invoking
- .Nm
- with this
- option removes an existing
- .Nm
- configuration.
- .It Fl e Ar variable=value
- This option adds the provided variable and value to the kernel environment.
- The value is quoted when written to the
- .Nm
- configuration.
- .It Fl f
- This
- option disables the sanity checking which checks if the kernel really exists
- before writing the
- .Nm
- configuration.
- .It Fl k Ar kernel
- This option specifies a kernel directory relative to
- .Pa /boot
- to load the kernel and any modules from.
- .It Fl o Ar options
- This option
- allows the passing of kernel flags for the next boot.
- .El
- .Sh FILES
- .Bl -tag -width ".Pa /boot/nextboot.conf" -compact
- .It Pa /boot/nextboot.conf
- The configuration file that the
- .Nm
- configuration is written into.
- .El
- .Sh EXAMPLES
- To boot the
- .Pa GENERIC
- kernel with the
- .Nm
- command:
- .Pp
- .Dl "nextboot -k GENERIC"
- .Pp
- To enable into single user mode with the normal kernel:
- .Pp
- .Dl "nextboot -o ""-s"" -k kernel"
- .Pp
- To remove an existing nextboot configuration:
- .Pp
- .Dl "nextboot -D"
- .Sh SEE ALSO
- .Xr boot 8 ,
- .Xr freebsd-update 8 ,
- .Xr loader 8
- .Sh HISTORY
- The original
- .Nm
- manual page first appeared in
- .Fx 2.2 .
- It used a very different interface to achieve similar results.
- .Pp
- The current incarnation of
- .Nm
- appeared in
- .Fx 5.0 .
- .Sh AUTHORS
- This manual page was written by
- .An Gordon Tetlow Aq Mt gordon@FreeBSD.org .
- .Sh BUGS
- The
- .Nm
- code is implemented in the
- .Xr loader 8 .
- It is not the most thoroughly tested code.
- It is also my first attempt to write in Forth.
- .Pp
- Finally, it does some evil things like writing to the file system before it
- has been checked.
- If it scrambles your file system, do not blame me.
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