freebsd-nq/stand/common/console.c

/*-
 * Copyright (c) 1998 Michael Smith <msmith@freebsd.org>
 * All rights reserved.
 *
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
 */

#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");

#include <stand.h>
#include <string.h>

#include "bootstrap.h"
/*
 * Core console support
 */

static int	cons_set(struct env_var *ev, int flags, const void *value);
static int	cons_find(const char *name);
static int	cons_check(const char *string);
static int	cons_change(const char *string);
static int	twiddle_set(struct env_var *ev, int flags, const void *value);

/*
 * Detect possible console(s) to use.  If preferred console(s) have been
 * specified, mark them as active. Else, mark the first probed console
 * as active.  Also create the console variable.
 */
void
cons_probe(void)
{
	int	cons;
	int	active;
	char	*prefconsole;

	TSENTER();

	/* We want a callback to install the new value when this var changes. */
	env_setenv("twiddle_divisor", EV_VOLATILE, "1", twiddle_set,
	    env_nounset);

	/* Do all console probes */
	for (cons = 0; consoles[cons] != NULL; cons++) {
		consoles[cons]->c_flags = 0;
		consoles[cons]->c_probe(consoles[cons]);
	}
	/* Now find the first working one */
	active = -1;
	for (cons = 0; consoles[cons] != NULL && active == -1; cons++) {
		consoles[cons]->c_flags = 0;
		consoles[cons]->c_probe(consoles[cons]);
		if (consoles[cons]->c_flags == (C_PRESENTIN | C_PRESENTOUT))
			active = cons;
	}
	/* Force a console even if all probes failed */
	if (active == -1)
		active = 0;

	/* Check to see if a console preference has already been registered */
	prefconsole = getenv("console");
	if (prefconsole != NULL)
		prefconsole = strdup(prefconsole);
	if (prefconsole != NULL) {
		unsetenv("console");		/* we want to replace this */
		cons_change(prefconsole);
	} else {
		consoles[active]->c_flags |= C_ACTIVEIN | C_ACTIVEOUT;
		consoles[active]->c_init(0);
		prefconsole = strdup(consoles[active]->c_name);
	}

	printf("Consoles: ");
	for (cons = 0; consoles[cons] != NULL; cons++)
		if (consoles[cons]->c_flags & (C_ACTIVEIN | C_ACTIVEOUT))
			printf("%s  ", consoles[cons]->c_desc);
	printf("\n");

	if (prefconsole != NULL) {
		env_setenv("console", EV_VOLATILE, prefconsole, cons_set,
		    env_nounset);
		free(prefconsole);
	}

	TSEXIT();
}

int
getchar(void)
{
	int	cons;
	int	rv;

	/* Loop forever polling all active consoles */
	for (;;) {
		for (cons = 0; consoles[cons] != NULL; cons++) {
			if ((consoles[cons]->c_flags &
			    (C_PRESENTIN | C_ACTIVEIN)) ==
			    (C_PRESENTIN | C_ACTIVEIN) &&
			    ((rv = consoles[cons]->c_in()) != -1))
				return (rv);
		}
	}
}

int
ischar(void)
{
	int	cons;

	for (cons = 0; consoles[cons] != NULL; cons++)
		if ((consoles[cons]->c_flags & (C_PRESENTIN | C_ACTIVEIN)) ==
		    (C_PRESENTIN | C_ACTIVEIN) &&
		    (consoles[cons]->c_ready() != 0))
			return (1);
	return (0);
}

void
putchar(int c)
{
	int	cons;

	/* Expand newlines */
	if (c == '\n')
		putchar('\r');

	for (cons = 0; consoles[cons] != NULL; cons++) {
		if ((consoles[cons]->c_flags & (C_PRESENTOUT | C_ACTIVEOUT)) ==
		    (C_PRESENTOUT | C_ACTIVEOUT))
			consoles[cons]->c_out(c);
	}
}

/*
 * Find the console with the specified name.
 */
static int
cons_find(const char *name)
{
	int	cons;

	for (cons = 0; consoles[cons] != NULL; cons++)
		if (strcmp(consoles[cons]->c_name, name) == 0)
			return (cons);
	return (-1);
}

/*
 * Select one or more consoles.
 */
static int
cons_set(struct env_var *ev, int flags, const void *value)
{
	int	ret;

	if ((value == NULL) || (cons_check(value) == 0)) {
		/*
		 * Return CMD_OK instead of CMD_ERROR to prevent forth syntax
		 * error, which would prevent it processing any further
		 * loader.conf entries.
		 */
		return (CMD_OK);
	}

	ret = cons_change(value);
	if (ret != CMD_OK)
		return (ret);

	env_setenv(ev->ev_name, flags | EV_NOHOOK, value, NULL, NULL);
	return (CMD_OK);
}

/*
 * Check that at least one the consoles listed in *string is valid
 */
static int
cons_check(const char *string)
{
	int	cons, found, failed;
	char	*curpos, *dup, *next;

	dup = next = strdup(string);
	found = failed = 0;
	while (next != NULL) {
		curpos = strsep(&next, " ,");
		if (*curpos != '\0') {
			cons = cons_find(curpos);
			if (cons == -1) {
				printf("console %s is invalid!\n", curpos);
				failed++;
			} else {
				found++;
			}
		}
	}

	free(dup);

	if (found == 0)
		printf("no valid consoles!\n");

	if (found == 0 || failed != 0) {
		printf("Available consoles:\n");
		for (cons = 0; consoles[cons] != NULL; cons++)
			printf("    %s\n", consoles[cons]->c_name);
	}

	return (found);
}

/*
 * Activate all the valid consoles listed in *string and disable all others.
 */
static int
cons_change(const char *string)
{
	int	cons, active;
	char	*curpos, *dup, *next;

	/* Disable all consoles */
	for (cons = 0; consoles[cons] != NULL; cons++) {
		consoles[cons]->c_flags &= ~(C_ACTIVEIN | C_ACTIVEOUT);
	}

	/* Enable selected consoles */
	dup = next = strdup(string);
	active = 0;
	while (next != NULL) {
		curpos = strsep(&next, " ,");
		if (*curpos == '\0')
			continue;
		cons = cons_find(curpos);
		if (cons >= 0) {
			consoles[cons]->c_flags |= C_ACTIVEIN | C_ACTIVEOUT;
			consoles[cons]->c_init(0);
			if ((consoles[cons]->c_flags &
			    (C_PRESENTIN | C_PRESENTOUT)) ==
			    (C_PRESENTIN | C_PRESENTOUT)) {
				active++;
				continue;
			}

			if (active != 0) {
				/*
				 * If no consoles have initialised we
				 * wouldn't see this.
				 */
				printf("console %s failed to initialize\n",
				    consoles[cons]->c_name);
			}
		}
	}

	free(dup);

	if (active == 0) {
		/*
		 * All requested consoles failed to initialise,
		 * try to recover.
		 */
		for (cons = 0; consoles[cons] != NULL; cons++) {
			consoles[cons]->c_flags |= C_ACTIVEIN | C_ACTIVEOUT;
			consoles[cons]->c_init(0);
			if ((consoles[cons]->c_flags &
			    (C_PRESENTIN | C_PRESENTOUT)) ==
			    (C_PRESENTIN | C_PRESENTOUT))
				active++;
		}

		if (active == 0)
			return (CMD_ERROR); /* Recovery failed. */
	}

	return (CMD_OK);
}

/*
 * Change the twiddle divisor.
 *
 * The user can set the twiddle_divisor variable to directly control how fast
 * the progress twiddle spins, useful for folks with slow serial consoles.  The
 * code to monitor changes to the variable and propagate them to the twiddle
 * routines has to live somewhere.  Twiddling is console-related so it's here.
 */
static int
twiddle_set(struct env_var *ev, int flags, const void *value)
{
	u_long tdiv;
	char *eptr;

	tdiv = strtoul(value, &eptr, 0);
	if (*(const char *)value == 0 || *eptr != 0) {
		printf("invalid twiddle_divisor '%s'\n", (const char *)value);
		return (CMD_ERROR);
	}
	twiddle_divisor((u_int)tdiv);
	env_setenv(ev->ev_name, flags | EV_NOHOOK, value, NULL, NULL);

	return (CMD_OK);
}