boot/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.
 *
 * $FreeBSD: src/sys/boot/common/console.c,v 1.6 2003/08/25 23:30:41 obrien Exp $
 * $DragonFly: src/sys/boot/common/console.c,v 1.5 2004/06/26 02:26:20 dillon Exp $
 */

#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);

/*
 * Detect possible console(s) to use.  The first probed console
 * is marked active.  Also create the console variable.
 *
 * XXX Add logic for multiple console support.
 */
void
cons_probe(void)
{
    int	cons;
    int	active;
    char *prefconsole;

    /*
     * Probe all available consoles
     */
    for (cons = 0; consoles[cons] != NULL; cons++) {
	consoles[cons]->c_flags = 0;
 	consoles[cons]->c_probe(consoles[cons]);
    }

    /*
     * Get our console preference.  If there is no preference, all
     * available consoles will be made active in parallel.  Otherwise
     * only the specified console is activated.
     */
    active = -1;
    if ((prefconsole = getenv("console")) != NULL) {
	for (cons = 0; consoles[cons] != NULL; cons++) {
	    if (strcmp(prefconsole, consoles[cons]->c_name) == 0) {
		if (consoles[cons]->c_flags & (C_PRESENTIN | C_PRESENTOUT))
		    active = cons;
	    }
	}
	unsetenv("console");
	if (active >= 0) {
	    env_setenv("console", EV_VOLATILE, consoles[active]->c_name,
			cons_set, env_nounset);
	}
    }

    /*
     * Active the active console or all consoles if active is -1.
     */
    for (cons = 0; consoles[cons] != NULL; cons++) {
	if ((active == -1 || cons == active) &&
	    (consoles[cons]->c_flags & (C_PRESENTIN|C_PRESENTOUT))
	) {
	    consoles[cons]->c_flags |= (C_ACTIVEIN | C_ACTIVEOUT);
	    consoles[cons]->c_init(0);
	    printf("Console: %s\n", consoles[cons]->c_desc);
	}
    }
}

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_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_ACTIVEIN) &&
	    (consoles[cons]->c_ready() != 0))
		return(1);
    return(0);
}

#ifdef COMCONSOLE_DEBUG

static int
isa_inb(int port)
{
    u_char      data;

    if (__builtin_constant_p(port) &&
        (((port) & 0xffff) < 0x100) &&
        ((port) < 0x10000)) {
        __asm __volatile("inb %1,%0" : "=a" (data) : "id" ((u_short)(port)));
    } else {
        __asm __volatile("inb %%dx,%0" : "=a" (data) : "d" (port));
    }
    return(data);
}

static void
isa_outb(int port, int value)
{
    u_char      al = value;

    if (__builtin_constant_p(port) &&
        (((port) & 0xffff) < 0x100) &&
        ((port) < 0x10000)) {
        __asm __volatile("outb %0,%1" : : "a" (al), "id" ((u_short)(port)));
    } else {
        __asm __volatile("outb %0,%%dx" : : "a" (al), "d" (port));
    }
}

#endif

void
putchar(int c)
{
    int		cons;

#ifdef COMCONSOLE_DEBUG
    if ((consoles[1]->c_flags & C_ACTIVEOUT) == 0) {
	while ((isa_inb(0x3f8+5) & 0x20) == 0)	/* wait tx ready */
	    ;
	isa_outb(0x3f8, c);				/* output */
    }
#endif

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

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

static int
cons_find(const char *name)
{
    int		cons;

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


/*
 * Select a console.
 *
 * XXX Note that the console system design allows for some extension
 *     here (eg. multiple consoles, input/output only, etc.)
 */
static int
cons_set(struct env_var *ev, int flags, const void *value)
{
    int		cons, active;

    if ((value == NULL) || ((active = cons_find(value)) == -1)) {
	if (value != NULL)
	    printf("no such console '%s'\n", (char *)value);
	printf("Available consoles:\n");
	for (cons = 0; consoles[cons] != NULL; cons++)
	    printf("    %s\n", consoles[cons]->c_name);
	return(CMD_ERROR);
    }

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

    /* enable selected console */
    consoles[active]->c_flags |= C_ACTIVEIN | C_ACTIVEOUT;
    consoles[active]->c_init(0);

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