console.c revision 278602 
1/*-
2 * Copyright (c) 1998 Michael Smith <msmith@freebsd.org>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27#include <sys/cdefs.h>
28__FBSDID("$FreeBSD: stable/10/sys/boot/common/console.c 278602 2015-02-11 22:55:24Z ian $");
29
30#include <stand.h>
31#include <string.h>
32
33#include "bootstrap.h"
34/*
35 * Core console support
36 */
37
38static int	cons_set(struct env_var *ev, int flags, const void *value);
39static int	cons_find(const char *name);
40static int	cons_check(const char *string);
41static void	cons_change(const char *string);
42static int	twiddle_set(struct env_var *ev, int flags, const void *value);
43
44/*
45 * Detect possible console(s) to use.  If preferred console(s) have been
46 * specified, mark them as active. Else, mark the first probed console
47 * as active.  Also create the console variable.
48 */
49void
50cons_probe(void)
51{
52    int			cons;
53    int			active;
54    char		*prefconsole;
55
56    /* We want a callback to install the new value when this var changes. */
57    env_setenv("twiddle_divisor", EV_VOLATILE, "1", twiddle_set, env_nounset);
58
59    /* Do all console probes */
60    for (cons = 0; consoles[cons] != NULL; cons++) {
61	consoles[cons]->c_flags = 0;
62 	consoles[cons]->c_probe(consoles[cons]);
63    }
64    /* Now find the first working one */
65    active = -1;
66    for (cons = 0; consoles[cons] != NULL && active == -1; cons++) {
67	consoles[cons]->c_flags = 0;
68 	consoles[cons]->c_probe(consoles[cons]);
69	if (consoles[cons]->c_flags == (C_PRESENTIN | C_PRESENTOUT))
70	    active = cons;
71    }
72    /* Force a console even if all probes failed */
73    if (active == -1)
74	active = 0;
75
76    /* Check to see if a console preference has already been registered */
77    prefconsole = getenv("console");
78    if (prefconsole != NULL)
79	prefconsole = strdup(prefconsole);
80    if (prefconsole != NULL) {
81	unsetenv("console");		/* we want to replace this */
82	cons_change(prefconsole);
83    } else {
84	consoles[active]->c_flags |= C_ACTIVEIN | C_ACTIVEOUT;
85	consoles[active]->c_init(0);
86	prefconsole = strdup(consoles[active]->c_name);
87    }
88
89    printf("Consoles: ");
90    for (cons = 0; consoles[cons] != NULL; cons++)
91	if (consoles[cons]->c_flags & (C_ACTIVEIN | C_ACTIVEOUT))
92	    printf("%s  ", consoles[cons]->c_desc);
93    printf("\n");
94
95    if (prefconsole != NULL) {
96	env_setenv("console", EV_VOLATILE, prefconsole, cons_set,
97	    env_nounset);
98	free(prefconsole);
99    }
100}
101
102int
103getchar(void)
104{
105    int		cons;
106    int		rv;
107
108    /* Loop forever polling all active consoles */
109    for(;;)
110	for (cons = 0; consoles[cons] != NULL; cons++)
111	    if ((consoles[cons]->c_flags & (C_PRESENTIN | C_ACTIVEIN)) ==
112		(C_PRESENTIN | C_ACTIVEIN) &&
113		((rv = consoles[cons]->c_in()) != -1))
114		return(rv);
115}
116
117int
118ischar(void)
119{
120    int		cons;
121
122    for (cons = 0; consoles[cons] != NULL; cons++)
123	if ((consoles[cons]->c_flags & (C_PRESENTIN | C_ACTIVEIN)) ==
124	    (C_PRESENTIN | C_ACTIVEIN) &&
125	    (consoles[cons]->c_ready() != 0))
126		return(1);
127    return(0);
128}
129
130void
131putchar(int c)
132{
133    int		cons;
134
135    /* Expand newlines */
136    if (c == '\n')
137	putchar('\r');
138
139    for (cons = 0; consoles[cons] != NULL; cons++)
140	if ((consoles[cons]->c_flags & (C_PRESENTOUT | C_ACTIVEOUT)) ==
141	    (C_PRESENTOUT | C_ACTIVEOUT))
142	    consoles[cons]->c_out(c);
143}
144
145/*
146 * Find the console with the specified name.
147 */
148static int
149cons_find(const char *name)
150{
151    int		cons;
152
153    for (cons = 0; consoles[cons] != NULL; cons++)
154	if (!strcmp(consoles[cons]->c_name, name))
155	    return (cons);
156    return (-1);
157}
158
159/*
160 * Select one or more consoles.
161 */
162static int
163cons_set(struct env_var *ev, int flags, const void *value)
164{
165    int		cons;
166
167    if ((value == NULL) || (cons_check(value) == -1)) {
168	if (value != NULL)
169	    printf("no such console!\n");
170	printf("Available consoles:\n");
171	for (cons = 0; consoles[cons] != NULL; cons++)
172	    printf("    %s\n", consoles[cons]->c_name);
173	return(CMD_ERROR);
174    }
175
176    cons_change(value);
177
178    env_setenv(ev->ev_name, flags | EV_NOHOOK, value, NULL, NULL);
179    return(CMD_OK);
180}
181
182/*
183 * Check that all of the consoles listed in *string are valid consoles
184 */
185static int
186cons_check(const char *string)
187{
188    int		cons;
189    char	*curpos, *dup, *next;
190
191    dup = next = strdup(string);
192    cons = -1;
193    while (next != NULL) {
194	curpos = strsep(&next, " ,");
195	if (*curpos != '\0') {
196	    cons = cons_find(curpos);
197	    if (cons == -1)
198		break;
199	}
200    }
201
202    free(dup);
203    return (cons);
204}
205
206/*
207 * Activate all of the consoles listed in *string and disable all the others.
208 */
209static void
210cons_change(const char *string)
211{
212    int		cons;
213    char	*curpos, *dup, *next;
214
215    /* Disable all consoles */
216    for (cons = 0; consoles[cons] != NULL; cons++) {
217	consoles[cons]->c_flags &= ~(C_ACTIVEIN | C_ACTIVEOUT);
218    }
219
220    /* Enable selected consoles */
221    dup = next = strdup(string);
222    while (next != NULL) {
223	curpos = strsep(&next, " ,");
224	if (*curpos == '\0')
225		continue;
226	cons = cons_find(curpos);
227	if (cons >= 0) {
228	    consoles[cons]->c_flags |= C_ACTIVEIN | C_ACTIVEOUT;
229	    consoles[cons]->c_init(0);
230	    if ((consoles[cons]->c_flags & (C_PRESENTIN | C_PRESENTOUT)) !=
231		(C_PRESENTIN | C_PRESENTOUT))
232		printf("console %s failed to initialize\n",
233		    consoles[cons]->c_name);
234	}
235    }
236
237    free(dup);
238}
239
240/*
241 * Change the twiddle divisor.
242 *
243 * The user can set the twiddle_divisor variable to directly control how fast
244 * the progress twiddle spins, useful for folks with slow serial consoles.  The
245 * code to monitor changes to the variable and propagate them to the twiddle
246 * routines has to live somewhere.  Twiddling is console-related so it's here.
247 */
248static int
249twiddle_set(struct env_var *ev, int flags, const void *value)
250{
251    u_long tdiv;
252    char * eptr;
253
254    tdiv = strtoul(value, &eptr, 0);
255    if (*(const char *)value == 0 || *eptr != 0) {
256	printf("invalid twiddle_divisor '%s'\n", (const char *)value);
257	return (CMD_ERROR);
258    }
259    twiddle_divisor((u_int)tdiv);
260    env_setenv(ev->ev_name, flags | EV_NOHOOK, value, NULL, NULL);
261
262    return(CMD_OK);
263}
264