FreeBSD/Linux Kernel Cross Reference
sys/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.
     */
    
    #include <sys/cdefs.h>
    __FBSDID("$FreeBSD: releng/8.2/sys/boot/common/console.c 148516 2005-07-29 12:47:42Z brian $");
    
    #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 void     cons_change(const char *string);
    
    /*
     * 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;
        
        /* 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);
        }
    }
    
    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);
   }
   
   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_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))
               return (cons);
       return (-1);
   }
   
   /*
    * Select one or more consoles.
    */
   static int
   cons_set(struct env_var *ev, int flags, const void *value)
   {
       int         cons;
   
       if ((value == NULL) || (cons_check(value) == -1)) {
           if (value != NULL) 
               printf("no such console!\n");
           printf("Available consoles:\n");
           for (cons = 0; consoles[cons] != NULL; cons++)
               printf("    %s\n", consoles[cons]->c_name);
           return(CMD_ERROR);
       }
   
       cons_change(value);
   
       env_setenv(ev->ev_name, flags | EV_NOHOOK, value, NULL, NULL);
       return(CMD_OK);
   }
   
   /*
    * Check that all of the consoles listed in *string are valid consoles
    */
   static int
   cons_check(const char *string)
   {
       int         cons;
       char        *curpos, *dup, *next;
   
       dup = next = strdup(string);
       cons = -1;
       while (next != NULL) {
           curpos = strsep(&next, " ,");
           if (*curpos != '\0') {
               cons = cons_find(curpos);
               if (cons == -1)
                   break;
           }
       }
   
       free(dup);
       return (cons);
   }
   
   /*
    * Activate all of the consoles listed in *string and disable all the others.
    */
   static void
   cons_change(const char *string)
   {
       int         cons;
       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);
       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);
           }
       }
   
       free(dup);
   }

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