sys/dev/cninit.c

   1 /*      $NetBSD: cninit.c,v 1.9 2008/03/11 05:31:00 matt 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 1.9 2008/03/11 05:31:00 matt Exp $");
  82
  83 #include <sys/param.h>
  84 #include <sys/proc.h>
  85 #include <sys/systm.h>
  86 #include <sys/buf.h>
  87 #include <sys/ioctl.h>
  88 #include <sys/tty.h>
  89 #include <sys/file.h>
  90 #include <sys/conf.h>
  91 #include <sys/vnode.h>
  92
  93 #include <dev/cons.h>
  94
  95 void
  96 cninit(void)
  97 {
  98         struct consdev *cp;
  99         struct consdev *bestMatch;
 100
 101         bestMatch = cn_tab = NULL;
 102         /*
 103          * Collect information about all possible consoles
 104          * and find the one with highest priority
 105          */
 106         for (cp = constab; cp->cn_probe; cp++) {
 107                 (*cp->cn_probe)(cp);
 108                 if (cp->cn_pri > CN_DEAD &&
 109                     (bestMatch == NULL || cp->cn_pri > bestMatch->cn_pri)) {
 110                         bestMatch = cp;
 111                 }
 112         }
 113         /*
 114          * No console, we can handle it
 115          */
 116         if ((cp = bestMatch) == NULL)
 117                 return;
 118         /*
 119          * Turn on console
 120          */
 121         {
 122                 struct consdev *old_cn_tab = cn_tab;
 123
 124                 (*cp->cn_init)(cp);
 125                 /*
 126                  * Now let everyone know we have an active console they can
 127                  * use for diagnostics. If we use cn_tab in the search loop
 128                  * then interrupts from the ethernet at boot may cause system
 129                  * hang.
 130                  */
 131                 if (cn_tab == old_cn_tab)
 132                         cn_tab = bestMatch;
 133         }
 134 }