.\"-
.\" Copyright (c) 2001 Boris Popov
.\" Copyright (c) 2001 Dag-Erling Coïdan Smørgrav
.\" 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.
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.\" $FreeBSD$
.\"
.Dd February 25, 2023
.Dt KLDXREF 8
.Os
.Sh NAME
.Nm kldxref
.Nd generate hints for the kernel loader
.Sh SYNOPSIS
.Nm
.Op Fl Rdv
.Op Fl f Ar hintsfile
.Ar path ...
.Sh DESCRIPTION
The
.Nm
utility is used to generate hint files which list modules, their
version numbers, and the files that contain them.
These hints are used by the kernel loader to determine where to find a
particular KLD module.
.Pp
A separate hint file is generated for each directory listed on the
command line that contains modules.
If no hint records are generated for a particular directory, no hint
file is created, and the preexisting hint file (if there was one in
that directory) is removed.
.Pp
.Nm
ignores files with at least two "."s in the filename, such as
.Pa foo.ko.debug
or
.Pa bar.ko.pkgsave .
Note that this means that modules cannot have names such as
.Pa foo.bar.ko .
This limitation however, has been lived practice since the beginning of
FreeBSD's kernel modules.
.Pp
The following options are available:
.Bl -tag -width indent
.It Fl R
Recurse into subdirectories.
.It Fl d
Do not generate a hint file, but print module metadata on standard
output.
.It Fl f Ar hintsfile
Specify a different name for the hints files than
.Pa linker.hints .
.It Fl v
Operate in verbose mode.
.El
.Sh EXAMPLES
To build hint files for both standard and add-on modules:
.Pp
.Dl "kldxref /boot/kernel /boot/modules"
.Pp
To build hint files for all installed kernels:
.Pp
.Dl "kldxref -R /boot"
.Sh SEE ALSO
.Xr kld 4 ,
.Xr kldconfig 8 ,
.Xr kldload 8 ,
.Xr kldstat 8 ,
.Xr kldunload 8
.Sh HISTORY
The
.Nm
utility first appeared in
.Fx 5.0 .
.Sh AUTHORS
.An -nosplit
The
.Nm
utility was implemented by
.An Boris Popov Aq Mt bp@FreeBSD.org .
This manual page was written by
.An Boris Popov Aq Mt bp@FreeBSD.org
and
.An Dag-Erling Sm\(/orgrav Aq Mt des@FreeBSD.org .