1 /* $NetBSD: cninit.c,v 1.14 2020/07/29 01:55:58 uwe 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. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * from: Utah $Hdr: cons.c 1.7 92/01/21$ 37 * 38 * @(#)cons.c 8.2 (Berkeley) 1/12/94 39 */ 40 41 #include <sys/cdefs.h> 42 __KERNEL_RCSID(0, "$NetBSD: cninit.c,v 1.14 2020/07/29 01:55:58 uwe Exp $"); 43 44 #include <sys/param.h> 45 #include <sys/proc.h> 46 #include <sys/systm.h> 47 #include <sys/buf.h> 48 #include <sys/ioctl.h> 49 #include <sys/tty.h> 50 #include <sys/file.h> 51 #include <sys/conf.h> 52 #include <sys/vnode.h> 53 54 #include <dev/cons.h> 55 56 void 57 cninit(void) 58 { 59 struct consdev *bestMatch; 60 struct consdev *cp; 61 62 /* 63 * Collect information about all possible consoles 64 * and find the one with highest priority 65 */ 66 bestMatch = NULL; 67 for (cp = constab; cp->cn_probe; cp++) { 68 (*cp->cn_probe)(cp); 69 if (cp->cn_pri > CN_DEAD && 70 (bestMatch == NULL || cp->cn_pri > bestMatch->cn_pri)) { 71 bestMatch = cp; 72 } 73 } 74 75 /* 76 * No console, we can handle it 77 */ 78 if (bestMatch == NULL) 79 return; 80 81 /* 82 * Turn on console 83 */ 84 { 85 struct consdev *old_cn_tab = cn_tab; 86 87 /* cn_init may set cn_tab to self */ 88 (*bestMatch->cn_init)(bestMatch); 89 90 /* 91 * Now let everyone know we have an active console they can 92 * use for diagnostics. If we use cn_tab in the search loop 93 * then interrupts from the ethernet at boot may cause system 94 * hang. 95 */ 96 if (cn_tab == old_cn_tab) /* if cn_init didn't, set it */ 97 cn_tab = bestMatch; 98 } 99 } 100