1.\" 2.\" Copyright (c) 1999 Chris Costello 3.\" All rights reserved. 4.\" 5.\" Redistribution and use in source and binary forms, with or without 6.\" modification, are permitted provided that the following conditions 7.\" are met: 8.\" 1. Redistributions of source code must retain the above copyright 9.\" notice, this list of conditions and the following disclaimer. 10.\" 2. Redistributions in binary form must reproduce the above copyright 11.\" notice, this list of conditions and the following disclaimer in the 12.\" documentation and/or other materials provided with the distribution. 13.\" 14.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24.\" SUCH DAMAGE. 25.\" 26.Dd March 26, 2026 27.Dt KLDLOAD 2 28.Os 29.Sh NAME 30.Nm kldload 31.Nd load KLD files into the kernel 32.Sh LIBRARY 33.Lb libc 34.Sh SYNOPSIS 35.In sys/linker.h 36.Ft int 37.Fn kldload "const char *file" 38.Sh DESCRIPTION 39The 40.Fn kldload 41system call 42loads a kld file specified by 43.Fa file 44into the kernel using the kernel linker (see 45.Xr kld 4 ) . 46The 47.Fa file 48can be specified as a full or relative path, or otherwise is searched 49within the module path as defined by the 50loader tunable and sysctl variable 51.Va kern.module_path . 52The .ko 53extension for 54.Fa file 55is not mandatory. 56.Sh RETURN VALUES 57The 58.Fn kldload 59system call 60returns the fileid of the kld file which was loaded into the kernel. 61If an error occurs, 62.Fn kldload 63will return -1 and set 64.Va errno 65to indicate the error. 66.Sh ERRORS 67The named file is loaded unless: 68.Bl -tag -width Er 69.It Bq Er EPERM 70You do not have access to read the file or link it with the kernel. 71You should be the root user to be able to use the 72.Nm kld 73system calls. 74.It Bq Er EFAULT 75Bad address encountered when adding kld info into the kernel space. 76.It Bq Er ENOMEM 77There is no memory to load the file into the kernel. 78.It Bq Er ENOENT 79The file was not found. 80.It Bq Er ENOEXEC 81The file format of 82.Fa file 83was unrecognized. 84.It Bq Er EEXIST 85The supplied 86.Fa file 87has already been loaded. 88.El 89.Sh SEE ALSO 90.Xr kldfind 2 , 91.Xr kldfirstmod 2 , 92.Xr kldnext 2 , 93.Xr kldstat 2 , 94.Xr kldsym 2 , 95.Xr kldunload 2 , 96.Xr modfind 2 , 97.Xr modfnext 2 , 98.Xr modnext 2 , 99.Xr modstat 2 , 100.Xr kld 4 , 101.Xr kldload 8 102.Sh HISTORY 103The 104.Nm kld 105interface first appeared in 106.Fx 3.0 . 107