xref: /netbsd-src/sys/dev/cninit.c (revision 5e4c038a45edbc7d63b7c2daa76e29f88b64a4e3)
1 /*	$NetBSD: cninit.c,v 1.4 2001/11/13 05:32:50 lukem Exp $	*/
2 
3 /*
4  * Copyright (c) 1988 University of Utah.
5  * Copyright (c) 1990, 1993
6  *	The Regents of the University of California.  All rights reserved.
7  *
8  * This code is derived from software contributed to Berkeley by
9  * the Systems Programming Group of the University of Utah Computer
10  * Science Department.
11  *
12  * Redistribution and use in source and binary forms, with or without
13  * modification, are permitted provided that the following conditions
14  * are met:
15  * 1. Redistributions of source code must retain the above copyright
16  *    notice, this list of conditions and the following disclaimer.
17  * 2. Redistributions in binary form must reproduce the above copyright
18  *    notice, this list of conditions and the following disclaimer in the
19  *    documentation and/or other materials provided with the distribution.
20  * 3. All advertising materials mentioning features or use of this software
21  *    must display the following acknowledgement:
22  *	This product includes software developed by the University of
23  *	California, Berkeley and its contributors.
24  * 4. Neither the name of the University nor the names of its contributors
25  *    may be used to endorse or promote products derived from this software
26  *    without specific prior written permission.
27  *
28  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
29  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
30  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
31  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
32  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
33  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
34  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
35  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
36  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
37  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
38  * SUCH DAMAGE.
39  *
40  * from: Utah $Hdr: cons.c 1.7 92/01/21$
41  *
42  *	@(#)cons.c	8.2 (Berkeley) 1/12/94
43  */
44 
45 #include <sys/cdefs.h>
46 __KERNEL_RCSID(0, "$NetBSD: cninit.c,v 1.4 2001/11/13 05:32:50 lukem Exp $");
47 
48 #include <sys/param.h>
49 #include <sys/proc.h>
50 #include <sys/user.h>
51 #include <sys/systm.h>
52 #include <sys/buf.h>
53 #include <sys/ioctl.h>
54 #include <sys/tty.h>
55 #include <sys/file.h>
56 #include <sys/conf.h>
57 #include <sys/vnode.h>
58 
59 #include <dev/cons.h>
60 
61 extern struct consdev constab[];
62 
63 extern struct	consdev *cn_tab;	/* physical console device info */
64 
65 void
66 cninit()
67 {
68 	struct consdev *cp;
69 	struct consdev *bestMatch;
70 
71 	bestMatch = cn_tab = NULL;
72 	/*
73 	 * Collect information about all possible consoles
74 	 * and find the one with highest priority
75 	 */
76 	for (cp = constab; cp->cn_probe; cp++) {
77 		(*cp->cn_probe)(cp);
78 		if (cp->cn_pri > CN_DEAD &&
79 		    (bestMatch == NULL || cp->cn_pri > bestMatch->cn_pri)) {
80 			bestMatch = cp;
81 		}
82 	}
83 	/*
84 	 * No console, we can handle it
85 	 */
86 	if ((cp = bestMatch) == NULL)
87 		return;
88 	/*
89 	 * Turn on console
90 	 */
91 	{
92 		struct consdev *old_cn_tab = cn_tab;
93 
94  		(*cp->cn_init)(cp);
95 		/*
96 		 * Now let everyone know we have an active console they can
97 		 * use for diagnostics. If we use cn_tab in the search loop
98 		 * then interrupts from the ethernet at boot may cause system
99 		 * hang.
100 		 */
101 		if (cn_tab == old_cn_tab)
102 			cn_tab = bestMatch;
103 	}
104 }
105