1 /*-
2  * Copyright (c) 1999 Assar Westerlund
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  * $FreeBSD: src/share/examples/kld/syscall/module/syscall.c,v 1.2 1999/08/28 00:19:23 peter Exp $
27  * $DragonFly: src/share/examples/kld/syscall/module/syscall.c,v 1.2 2003/06/17 04:36:57 dillon Exp $
28  */
29 
30 #include <sys/types.h>
31 #include <sys/param.h>
32 #include <sys/proc.h>
33 #include <sys/module.h>
34 #include <sys/sysent.h>
35 #include <sys/kernel.h>
36 #include <sys/systm.h>
37 
38 /*
39  * The function for implementing the syscall.
40  */
41 
42 static int
43 hello (struct proc *p, void *arg)
44 {
45 	kprintf ("hello kernel\n");
46 	return 0;
47 }
48 
49 /*
50  * The `sysent' for the new syscall
51  */
52 
53 static 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  */
61 
62 static int offset = NO_SYSCALL;
63 
64 /*
65  * The function called at load/unload.
66  */
67 
68 static int
69 load (struct module *module, int cmd, void *arg)
70 {
71 	int error = 0;
72 
73 	switch (cmd) {
74 	case MOD_LOAD :
75 		kprintf ("syscall loaded at %d\n", offset);
76 		break;
77 	case MOD_UNLOAD :
78 		kprintf ("syscall unloaded from %d\n", offset);
79 		break;
80 	default :
81 		error = EINVAL;
82 		break;
83 	}
84 	return error;
85 }
86 
87 SYSCALL_MODULE(syscall, &offset, &hello_sysent, load, NULL);
88