1/*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 1999 Assar Westerlund
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 *
28 * $FreeBSD$
29 */
30
31#include <sys/param.h>
32#include <sys/proc.h>
33#include <sys/module.h>
34#include <sys/sysproto.h>
35#include <sys/sysent.h>
36#include <sys/kernel.h>
37#include <sys/systm.h>
38
39/*
40 * The function for implementing the syscall.
41 */
42static int
43hello(struct thread *td, void *arg)
44{
45
46	printf("hello kernel\n");
47	return (0);
48}
49
50/*
51 * The `sysent' for the new syscall
52 */
53static struct sysent hello_sysent = {
54	0,			/* sy_narg */
55	hello			/* sy_call */
56};
57
58/*
59 * The offset in sysent where the syscall is allocated.
60 */
61static int offset = NO_SYSCALL;
62
63/*
64 * The function called at load/unload.
65 */
66static int
67load(struct module *module, int cmd, void *arg)
68{
69	int error = 0;
70
71	switch (cmd) {
72	case MOD_LOAD :
73		printf("syscall loaded at %d\n", offset);
74		break;
75	case MOD_UNLOAD :
76		printf("syscall unloaded from %d\n", offset);
77		break;
78	default :
79		error = EOPNOTSUPP;
80		break;
81	}
82	return (error);
83}
84
85SYSCALL_MODULE(syscall, &offset, &hello_sysent, load, NULL);
86