xref: /openbsd-src/sys/dev/cninit.c (revision a28daedfc357b214be5c701aa8ba8adb29a7f1c2)
1 /*	$OpenBSD: cninit.c,v 1.8 2008/01/23 16:37:55 jsing Exp $	*/
2 /*	$NetBSD: cninit.c,v 1.2 1995/04/11 22:08:10 pk Exp $	*/
3 
4 /*
5  * Copyright (c) 1988 University of Utah.
6  * Copyright (c) 1990, 1993
7  *	The Regents of the University of California.  All rights reserved.
8  *
9  * This code is derived from software contributed to Berkeley by
10  * the Systems Programming Group of the University of Utah Computer
11  * Science Department.
12  *
13  * Redistribution and use in source and binary forms, with or without
14  * modification, are permitted provided that the following conditions
15  * are met:
16  * 1. Redistributions of source code must retain the above copyright
17  *    notice, this list of conditions and the following disclaimer.
18  * 2. Redistributions in binary form must reproduce the above copyright
19  *    notice, this list of conditions and the following disclaimer in the
20  *    documentation and/or other materials provided with the distribution.
21  * 3. Neither the name of the University nor the names of its contributors
22  *    may be used to endorse or promote products derived from this software
23  *    without specific prior written permission.
24  *
25  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
26  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
27  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
28  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
29  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
30  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
31  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
32  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
33  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
34  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35  * SUCH DAMAGE.
36  *
37  * from: Utah $Hdr: cons.c 1.7 92/01/21$
38  *
39  *	@(#)cons.c	8.2 (Berkeley) 1/12/94
40  */
41 
42 #include <sys/param.h>
43 #include <sys/systm.h>
44 #include <sys/proc.h>
45 #include <sys/user.h>
46 #include <sys/buf.h>
47 #include <sys/ioctl.h>
48 #include <sys/tty.h>
49 #include <sys/file.h>
50 #include <sys/conf.h>
51 #include <sys/vnode.h>
52 
53 #include <dev/cons.h>
54 
55 void
56 cninit()
57 {
58 	struct consdev *cp;
59 
60 	/*
61 	 * Collect information about all possible consoles
62 	 * and find the one with highest priority.
63 	 */
64 	for (cp = constab; cp->cn_probe; cp++) {
65 		(*cp->cn_probe)(cp);
66 		if (cp->cn_pri != CN_DEAD &&
67 		    (cn_tab == NULL || cp->cn_pri > cn_tab->cn_pri))
68 			cn_tab = cp;
69 	}
70 
71 	/*
72 	 * No console, we can handle it.
73 	 */
74 	if ((cp = cn_tab) == NULL)
75 		return;
76 
77 	/*
78 	 * Turn on console.
79 	 */
80 	(*cp->cn_init)(cp);
81 }
82 
83 int
84 cnset(dev)
85 	dev_t dev;
86 {
87 	struct consdev *cp;
88 
89 	/*
90 	 * Look for the specified console device and use it.
91 	 */
92 	for (cp = constab; cp->cn_probe; cp++) {
93 		if (major(cp->cn_dev) == major(dev)) {
94 			/* Short-circuit noop. */
95 			if (cp == cn_tab && cp->cn_dev == dev)
96 				return (0);
97 			if (cp->cn_pri != CN_DEAD) {
98 				cn_tab = cp;
99 				cp->cn_dev = dev;
100 				/* Turn it on.  */
101 				(*cp->cn_init)(cp);
102 				return (0);
103 			}
104 			break;
105 		}
106 	}
107 	return (1);
108 }
109