NetBSD-5.0.2/sys/lkm/misc/example/example_misc.c

/*
 * misccall.c
 *
 * 05 Jun 93	Terry Lambert		Split out of newsyscall.c
 *
 * Copyright (c) 1993 Terrence R. Lambert.
 * 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.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by Terrence R. Lambert.
 * 4. The name Terrence R. Lambert may not be used to endorse or promote
 *    products derived from this software without specific prior written
 *    permission.
 *
 * THIS SOFTWARE IS PROVIDED BY TERRENCE R. LAMBERT ``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 TERRENCE R. LAMBERT 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.
 *
 *	$NetBSD: example_misc.c,v 1.5 2007/12/19 20:31:39 dsl Exp $
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: example_misc.c,v 1.5 2007/12/19 20:31:39 dsl Exp $");

#include <sys/param.h>
#include <sys/ioctl.h>
#include <sys/systm.h>

int misccall(struct lwp *, void *, register_t *);

/*
 * This is the actual code for system call...  it can be static because
 * we've externed it up above... the only plae it needs to be referenced
 * is the sysent we are interested in.
 *
 * To write your own system call using this as a template, you could strip
 * out this code and use the rest as a prototype module, changing only the
 * function names and the number of arguments to the call in the module
 * specific "sysent".
 *
 * You would have to use the "-R" option of "ld" to ensure a linkable file
 * if you were to do this, since you would need to combine multiple ".o"
 * files into a single ".o" file for use by "modload".
 */
int
misccall(l, uap, retval)
	struct lwp	*l;
	void		*uap;
	register_t	retval[];
{
	/*
	 * Our new system call simply prints a message; it takes no
	 * arguments.
	 */

	printf( "\nI am a loaded system call using the miscellaneous\n");
	printf( "module loader interface and a kernel printf!\n");
	printf( "I will print this message each time I am called!\n");

	return( 0);	/* success (or error code from errno.h)*/
}

/*
 * EOF -- This file has not been truncated.
 */