/*      $NetBSD: cninit.c,v 1.14 2020/07/29 01:55:58 uwe Exp $  */

/*
* Copyright (c) 1988 University of Utah.
* Copyright (c) 1990, 1993
*      The Regents of the University of California.  All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* the Systems Programming Group of the University of Utah Computer
* Science Department.
*
* 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. Neither the name of the University nor the names of its contributors
*    may be used to endorse or promote products derived from this software
*    without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``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 REGENTS OR CONTRIBUTORS 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.
*
* from: Utah $Hdr: cons.c 1.7 92/01/21$
*
*      @(#)cons.c      8.2 (Berkeley) 1/12/94
*/

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: cninit.c,v 1.14 2020/07/29 01:55:58 uwe Exp $");

#include <sys/param.h>
#include <sys/proc.h>
#include <sys/systm.h>
#include <sys/buf.h>
#include <sys/ioctl.h>
#include <sys/tty.h>
#include <sys/file.h>
#include <sys/conf.h>
#include <sys/vnode.h>

#include <dev/cons.h>

void
cninit(void)
{
       struct consdev *bestMatch;
       struct consdev *cp;

       /*
        * Collect information about all possible consoles
        * and find the one with highest priority
        */
       bestMatch = NULL;
       for (cp = constab; cp->cn_probe; cp++) {
               (*cp->cn_probe)(cp);
               if (cp->cn_pri > CN_DEAD &&
                   (bestMatch == NULL || cp->cn_pri > bestMatch->cn_pri)) {
                       bestMatch = cp;
               }
       }

       /*
        * No console, we can handle it
        */
       if (bestMatch == NULL)
               return;

       /*
        * Turn on console
        */
       {
               struct consdev *old_cn_tab = cn_tab;

               /* cn_init may set cn_tab to self */
               (*bestMatch->cn_init)(bestMatch);

               /*
                * Now let everyone know we have an active console they can
                * use for diagnostics. If we use cn_tab in the search loop
                * then interrupts from the ethernet at boot may cause system
                * hang.
                */
               if (cn_tab == old_cn_tab) /* if cn_init didn't, set it */
                       cn_tab = bestMatch;
       }
}