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cninit.c revision 1.7
      1 /*	$NetBSD: cninit.c,v 1.7 2005/02/27 00:26:58 perry Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1990, 1993
      5  *	The Regents of the University of California.  All rights reserved.
      6  *
      7  * This code is derived from software contributed to Berkeley by
      8  * the Systems Programming Group of the University of Utah Computer
      9  * Science Department.
     10  *
     11  * Redistribution and use in source and binary forms, with or without
     12  * modification, are permitted provided that the following conditions
     13  * are met:
     14  * 1. Redistributions of source code must retain the above copyright
     15  *    notice, this list of conditions and the following disclaimer.
     16  * 2. Redistributions in binary form must reproduce the above copyright
     17  *    notice, this list of conditions and the following disclaimer in the
     18  *    documentation and/or other materials provided with the distribution.
     19  * 3. Neither the name of the University nor the names of its contributors
     20  *    may be used to endorse or promote products derived from this software
     21  *    without specific prior written permission.
     22  *
     23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     33  * SUCH DAMAGE.
     34  *
     35  * from: Utah $Hdr: cons.c 1.7 92/01/21$
     36  *
     37  *	@(#)cons.c	8.2 (Berkeley) 1/12/94
     38  */
     39 
     40 /*
     41  * Copyright (c) 1988 University of Utah.
     42  *
     43  * This code is derived from software contributed to Berkeley by
     44  * the Systems Programming Group of the University of Utah Computer
     45  * Science Department.
     46  *
     47  * Redistribution and use in source and binary forms, with or without
     48  * modification, are permitted provided that the following conditions
     49  * are met:
     50  * 1. Redistributions of source code must retain the above copyright
     51  *    notice, this list of conditions and the following disclaimer.
     52  * 2. Redistributions in binary form must reproduce the above copyright
     53  *    notice, this list of conditions and the following disclaimer in the
     54  *    documentation and/or other materials provided with the distribution.
     55  * 3. All advertising materials mentioning features or use of this software
     56  *    must display the following acknowledgement:
     57  *	This product includes software developed by the University of
     58  *	California, Berkeley and its contributors.
     59  * 4. Neither the name of the University nor the names of its contributors
     60  *    may be used to endorse or promote products derived from this software
     61  *    without specific prior written permission.
     62  *
     63  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     64  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     65  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     66  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     67  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     68  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     69  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     70  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     71  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     72  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     73  * SUCH DAMAGE.
     74  *
     75  * from: Utah $Hdr: cons.c 1.7 92/01/21$
     76  *
     77  *	@(#)cons.c	8.2 (Berkeley) 1/12/94
     78  */
     79 
     80 #include <sys/cdefs.h>
     81 __KERNEL_RCSID(0, "$NetBSD: cninit.c,v 1.7 2005/02/27 00:26:58 perry Exp $");
     82 
     83 #include <sys/param.h>
     84 #include <sys/proc.h>
     85 #include <sys/user.h>
     86 #include <sys/systm.h>
     87 #include <sys/buf.h>
     88 #include <sys/ioctl.h>
     89 #include <sys/tty.h>
     90 #include <sys/file.h>
     91 #include <sys/conf.h>
     92 #include <sys/vnode.h>
     93 
     94 #include <dev/cons.h>
     95 
     96 void
     97 cninit()
     98 {
     99 	struct consdev *cp;
    100 	struct consdev *bestMatch;
    101 
    102 	bestMatch = cn_tab = NULL;
    103 	/*
    104 	 * Collect information about all possible consoles
    105 	 * and find the one with highest priority
    106 	 */
    107 	for (cp = constab; cp->cn_probe; cp++) {
    108 		(*cp->cn_probe)(cp);
    109 		if (cp->cn_pri > CN_DEAD &&
    110 		    (bestMatch == NULL || cp->cn_pri > bestMatch->cn_pri)) {
    111 			bestMatch = cp;
    112 		}
    113 	}
    114 	/*
    115 	 * No console, we can handle it
    116 	 */
    117 	if ((cp = bestMatch) == NULL)
    118 		return;
    119 	/*
    120 	 * Turn on console
    121 	 */
    122 	{
    123 		struct consdev *old_cn_tab = cn_tab;
    124 
    125  		(*cp->cn_init)(cp);
    126 		/*
    127 		 * Now let everyone know we have an active console they can
    128 		 * use for diagnostics. If we use cn_tab in the search loop
    129 		 * then interrupts from the ethernet at boot may cause system
    130 		 * hang.
    131 		 */
    132 		if (cn_tab == old_cn_tab)
    133 			cn_tab = bestMatch;
    134 	}
    135 }
    136