FreeBSD/Linux Kernel Cross Reference
sys/pc98/pc98/syscons.c

     /*-
      * Copyright (c) 1992-1998 Sen Schmidt
      * 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,
     *    without modification, immediately at the beginning of the file.
     * 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.
     * 3. The name of the author may not be used to endorse or promote products
     *    derived from this software without specific prior written permission.
     *
     * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 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: releng/5.0/sys/pc98/pc98/syscons.c 105319 2002-10-17 12:51:43Z nyan $
     */
    
    #include "opt_syscons.h"
    #include "opt_splash.h"
    #include "opt_ddb.h"
    
    #include <sys/param.h>
    #include <sys/systm.h>
    #include <sys/conf.h>
    #include <sys/cons.h>
    #include <sys/consio.h>
    #include <sys/eventhandler.h>
    #include <sys/fbio.h>
    #include <sys/kbio.h>
    #include <sys/kernel.h>
    #include <sys/lock.h>
    #include <sys/malloc.h>
    #include <sys/mutex.h>
    #include <sys/proc.h>
    #include <sys/random.h>
    #include <sys/reboot.h>
    #include <sys/signalvar.h>
    #include <sys/sysctl.h>
    #include <sys/tty.h>
    #include <sys/power.h>
    
    #include <machine/clock.h>
    #include <machine/pc/display.h>
    #ifdef __i386__
    #include <machine/psl.h>
    #include <machine/apm_bios.h>
    #include <machine/frame.h>
    #endif
    
    #include <dev/kbd/kbdreg.h>
    #include <dev/fb/fbreg.h>
    #include <dev/fb/splashreg.h>
    #include <dev/syscons/syscons.h>
    
    #define COLD 0
    #define WARM 1
    
    #define DEFAULT_BLANKTIME       (5*60)          /* 5 minutes */
    #define MAX_BLANKTIME           (7*24*60*60)    /* 7 days!? */
    
    #define KEYCODE_BS              0x0e            /* "<-- Backspace" key, XXX */
    
    typedef struct default_attr {
            int             std_color;              /* normal hardware color */
            int             rev_color;              /* reverse hardware color */
    } default_attr;
    
    static default_attr user_default = {
        SC_NORM_ATTR,
        SC_NORM_REV_ATTR,
    };
    
    static default_attr kernel_default = {
        SC_KERNEL_CONS_ATTR,
        SC_KERNEL_CONS_REV_ATTR,
    };
    
    static  int             sc_console_unit = -1;
    static  int             sc_saver_keyb_only;
    static  scr_stat        *sc_console;
    static  struct tty      *sc_console_tty;
    static  void            *kernel_console_ts;
    
    static  char            init_done = COLD;
    static  char            shutdown_in_progress = FALSE;
    static  char            sc_malloc = FALSE;
   
   static  int             saver_mode = CONS_NO_SAVER; /* LKM/user saver */
   static  int             run_scrn_saver = FALSE; /* should run the saver? */
   static  long            scrn_blank_time = 0;    /* screen saver timeout value */
   #ifdef DEV_SPLASH
   static  int             scrn_blanked;           /* # of blanked screen */
   static  int             sticky_splash = FALSE;
   
   static  void            none_saver(sc_softc_t *sc, int blank) { }
   static  void            (*current_saver)(sc_softc_t *, int) = none_saver;
   #endif
   
   SYSCTL_NODE(_hw, OID_AUTO, syscons, CTLFLAG_RD, 0, "syscons");
   SYSCTL_NODE(_hw_syscons, OID_AUTO, saver, CTLFLAG_RD, 0, "saver");
   SYSCTL_INT(_hw_syscons_saver, OID_AUTO, keybonly, CTLFLAG_RW,
       &sc_saver_keyb_only, 0, "screen saver interrupted by input only");
   #if !defined(SC_NO_FONT_LOADING) && defined(SC_DFLT_FONT)
   #include "font.h"
   #endif
   
           d_ioctl_t       *sc_user_ioctl;
   
   static  bios_values_t   bios_value;
   
   static  int             enable_panic_key;
   SYSCTL_INT(_machdep, OID_AUTO, enable_panic_key, CTLFLAG_RW, &enable_panic_key,
              0, "");
   
   #define SC_CONSOLECTL   255
   
   #define VIRTUAL_TTY(sc, x) (SC_DEV((sc), (x)) != NULL ? \
           SC_DEV((sc), (x))->si_tty : NULL)
   #define ISTTYOPEN(tp)   ((tp) && ((tp)->t_state & TS_ISOPEN))
   
   static  int             debugger;
   
   /* prototypes */
   static int scvidprobe(int unit, int flags, int cons);
   static int sckbdprobe(int unit, int flags, int cons);
   static void scmeminit(void *arg);
   static int scdevtounit(dev_t dev);
   static kbd_callback_func_t sckbdevent;
   static int scparam(struct tty *tp, struct termios *t);
   static void scstart(struct tty *tp);
   static void scinit(int unit, int flags);
   #if __i386__
   static void scterm(int unit, int flags);
   #endif
   static void scshutdown(void *arg, int howto);
   static u_int scgetc(sc_softc_t *sc, u_int flags);
   #define SCGETC_CN       1
   #define SCGETC_NONBLOCK 2
   static int sccngetch(int flags);
   static void sccnupdate(scr_stat *scp);
   static scr_stat *alloc_scp(sc_softc_t *sc, int vty);
   static void init_scp(sc_softc_t *sc, int vty, scr_stat *scp);
   static timeout_t scrn_timer;
   static int and_region(int *s1, int *e1, int s2, int e2);
   static void scrn_update(scr_stat *scp, int show_cursor);
   
   #ifdef DEV_SPLASH
   static int scsplash_callback(int event, void *arg);
   static void scsplash_saver(sc_softc_t *sc, int show);
   static int add_scrn_saver(void (*this_saver)(sc_softc_t *, int));
   static int remove_scrn_saver(void (*this_saver)(sc_softc_t *, int));
   static int set_scrn_saver_mode(scr_stat *scp, int mode, u_char *pal, int border);
   static int restore_scrn_saver_mode(scr_stat *scp, int changemode);
   static void stop_scrn_saver(sc_softc_t *sc, void (*saver)(sc_softc_t *, int));
   static int wait_scrn_saver_stop(sc_softc_t *sc);
   #define scsplash_stick(stick)           (sticky_splash = (stick))
   #else /* !DEV_SPLASH */
   #define scsplash_stick(stick)
   #endif /* DEV_SPLASH */
   
   static int do_switch_scr(sc_softc_t *sc, int s);
   static int vt_proc_alive(scr_stat *scp);
   static int signal_vt_rel(scr_stat *scp);
   static int signal_vt_acq(scr_stat *scp);
   static int finish_vt_rel(scr_stat *scp, int release, int *s);
   static int finish_vt_acq(scr_stat *scp);
   static void exchange_scr(sc_softc_t *sc);
   static void update_cursor_image(scr_stat *scp);
   static void change_cursor_shape(scr_stat *scp, int flags, int base, int height);
   static int save_kbd_state(scr_stat *scp);
   static int update_kbd_state(scr_stat *scp, int state, int mask);
   static int update_kbd_leds(scr_stat *scp, int which);
   static timeout_t blink_screen;
   
   #define CDEV_MAJOR      12
   
   static cn_probe_t       sccnprobe;
   static cn_init_t        sccninit;
   static cn_getc_t        sccngetc;
   static cn_checkc_t      sccncheckc;
   static cn_putc_t        sccnputc;
   static cn_dbctl_t       sccndbctl;
   static cn_term_t        sccnterm;
   
   #if __alpha__
   void sccnattach(void);
   #endif
   
   CONS_DRIVER(sc, sccnprobe, sccninit, sccnterm, sccngetc, sccncheckc, sccnputc,
               sccndbctl);
   
   static  d_open_t        scopen;
   static  d_close_t       scclose;
   static  d_read_t        scread;
   static  d_ioctl_t       scioctl;
   static  d_mmap_t        scmmap;
   
   static struct cdevsw sc_cdevsw = {
           /* open */      scopen,
           /* close */     scclose,
           /* read */      scread,
           /* write */     ttywrite,
           /* ioctl */     scioctl,
           /* poll */      ttypoll,
           /* mmap */      scmmap,
           /* strategy */  nostrategy,
           /* name */      "sc",
           /* maj */       CDEV_MAJOR,
           /* dump */      nodump,
           /* psize */     nopsize,
           /* flags */     D_TTY | D_KQFILTER,
           /* kqfilter */  ttykqfilter
   };
   
   int
   sc_probe_unit(int unit, int flags)
   {
       if (!scvidprobe(unit, flags, FALSE)) {
           if (bootverbose)
               printf("sc%d: no video adapter found.\n", unit);
           return ENXIO;
       }
   
       return ((sckbdprobe(unit, flags, FALSE)) ? 0 : ENXIO);
   }
   
   /* probe video adapters, return TRUE if found */ 
   static int
   scvidprobe(int unit, int flags, int cons)
   {
       /*
        * Access the video adapter driver through the back door!
        * Video adapter drivers need to be configured before syscons.
        * However, when syscons is being probed as the low-level console,
        * they have not been initialized yet.  We force them to initialize
        * themselves here. XXX
        */
       vid_configure(cons ? VIO_PROBE_ONLY : 0);
   
       return (vid_find_adapter("*", unit) >= 0);
   }
   
   /* probe the keyboard, return TRUE if found */
   static int
   sckbdprobe(int unit, int flags, int cons)
   {
       /* access the keyboard driver through the backdoor! */
       kbd_configure(cons ? KB_CONF_PROBE_ONLY : 0);
   
       return (kbd_find_keyboard("*", unit) >= 0);
   }
   
   static char
   *adapter_name(video_adapter_t *adp)
   {
       static struct {
           int type;
           char *name[2];
       } names[] = {
           { KD_MONO,      { "MDA",        "MDA" } },
           { KD_HERCULES,  { "Hercules",   "Hercules" } },
           { KD_CGA,       { "CGA",        "CGA" } },
           { KD_EGA,       { "EGA",        "EGA (mono)" } },
           { KD_VGA,       { "VGA",        "VGA (mono)" } },
           { KD_PC98,      { "PC-98x1",    "PC-98x1" } },
           { KD_TGA,       { "TGA",        "TGA" } },
           { -1,           { "Unknown",    "Unknown" } },
       };
       int i;
   
       for (i = 0; names[i].type != -1; ++i)
           if (names[i].type == adp->va_type)
               break;
       return names[i].name[(adp->va_flags & V_ADP_COLOR) ? 0 : 1];
   }
   
   int
   sc_attach_unit(int unit, int flags)
   {
       sc_softc_t *sc;
       scr_stat *scp;
   #ifdef SC_PIXEL_MODE
       video_info_t info;
   #endif
       int vc;
       dev_t dev;
   
       flags &= ~SC_KERNEL_CONSOLE;
   
       if (sc_console_unit == unit) {
           /*
            * If this unit is being used as the system console, we need to
            * adjust some variables and buffers before and after scinit().
            */
           /* assert(sc_console != NULL) */
           flags |= SC_KERNEL_CONSOLE;
           scmeminit(NULL);
   
           scinit(unit, flags);
   
           if (sc_console->tsw->te_size > 0) {
               /* assert(sc_console->ts != NULL); */
               kernel_console_ts = sc_console->ts;
               sc_console->ts = malloc(sc_console->tsw->te_size,
                                       M_DEVBUF, M_WAITOK);
               bcopy(kernel_console_ts, sc_console->ts, sc_console->tsw->te_size);
               (*sc_console->tsw->te_default_attr)(sc_console,
                                                   user_default.std_color,
                                                   user_default.rev_color);
           }
       } else {
           scinit(unit, flags);
       }
   
       sc = sc_get_softc(unit, flags & SC_KERNEL_CONSOLE);
       sc->config = flags;
       scp = SC_STAT(sc->dev[0]);
       if (sc_console == NULL)     /* sc_console_unit < 0 */
           sc_console = scp;
   
   #ifdef SC_PIXEL_MODE
       if ((sc->config & SC_VESA800X600)
           && ((*vidsw[sc->adapter]->get_info)(sc->adp, M_VESA_800x600, &info) == 0)) {
   #ifdef DEV_SPLASH
           if (sc->flags & SC_SPLASH_SCRN)
               splash_term(sc->adp);
   #endif
           sc_set_graphics_mode(scp, NULL, M_VESA_800x600);
           sc_set_pixel_mode(scp, NULL, COL, ROW, 16);
           sc->initial_mode = M_VESA_800x600;
   #ifdef DEV_SPLASH
           /* put up the splash again! */
           if (sc->flags & SC_SPLASH_SCRN)
               splash_init(sc->adp, scsplash_callback, sc);
   #endif
       }
   #endif /* SC_PIXEL_MODE */
   
       /* initialize cursor */
       if (!ISGRAPHSC(scp))
           update_cursor_image(scp);
   
       /* get screen update going */
       scrn_timer(sc);
   
       /* set up the keyboard */
       kbd_ioctl(sc->kbd, KDSKBMODE, (caddr_t)&scp->kbd_mode);
       update_kbd_state(scp, scp->status, LOCK_MASK);
   
       printf("sc%d: %s <%d virtual consoles, flags=0x%x>\n",
              unit, adapter_name(sc->adp), sc->vtys, sc->config);
       if (bootverbose) {
           printf("sc%d:", unit);
           if (sc->adapter >= 0)
               printf(" fb%d", sc->adapter);
           if (sc->keyboard >= 0)
               printf(", kbd%d", sc->keyboard);
           if (scp->tsw)
               printf(", terminal emulator: %s (%s)",
                      scp->tsw->te_name, scp->tsw->te_desc);
           printf("\n");
       }
   
       /* register a shutdown callback for the kernel console */
       if (sc_console_unit == unit)
           EVENTHANDLER_REGISTER(shutdown_pre_sync, scshutdown, 
                                 (void *)(uintptr_t)unit, SHUTDOWN_PRI_DEFAULT);
   
       for (vc = 0; vc < sc->vtys; vc++) {
           dev = make_dev(&sc_cdevsw, vc + unit * MAXCONS,
               UID_ROOT, GID_WHEEL, 0600, "ttyv%r", vc + unit * MAXCONS);
           sc->dev[vc] = dev;
           /*
            * The first vty already has struct tty and scr_stat initialized
            * in scinit().  The other vtys will have these structs when
            * first opened.
            */
       }
   
       dev = make_dev(&sc_cdevsw, SC_CONSOLECTL,
                      UID_ROOT, GID_WHEEL, 0600, "consolectl");
       dev->si_tty = sc_console_tty = ttymalloc(sc_console_tty);
       SC_STAT(dev) = sc_console;
   
       return 0;
   }
   
   static void
   scmeminit(void *arg)
   {
       if (sc_malloc)
           return;
       sc_malloc = TRUE;
   
       /*
        * As soon as malloc() becomes functional, we had better allocate
        * various buffers for the kernel console.
        */
   
       if (sc_console_unit < 0)    /* sc_console == NULL */
           return;
   
       /* copy the temporary buffer to the final buffer */
       sc_alloc_scr_buffer(sc_console, FALSE, FALSE);
   
   #ifndef SC_NO_CUTPASTE
       sc_alloc_cut_buffer(sc_console, FALSE);
   #endif
   
   #ifndef SC_NO_HISTORY
       /* initialize history buffer & pointers */
       sc_alloc_history_buffer(sc_console, 0, 0, FALSE);
   #endif
   }
   
   /* XXX */
   SYSINIT(sc_mem, SI_SUB_KMEM, SI_ORDER_ANY, scmeminit, NULL);
   
   static int
   scdevtounit(dev_t dev)
   {
       int vty = SC_VTY(dev);
   
       if (vty == SC_CONSOLECTL)
           return ((sc_console != NULL) ? sc_console->sc->unit : -1);
       else if ((vty < 0) || (vty >= MAXCONS*sc_max_unit()))
           return -1;
       else
           return vty/MAXCONS;
   }
   
   static int
   scopen(dev_t dev, int flag, int mode, struct thread *td)
   {
       int unit = scdevtounit(dev);
       sc_softc_t *sc;
       struct tty *tp;
       scr_stat *scp;
       keyarg_t key;
       int error;
   
       DPRINTF(5, ("scopen: dev:%d,%d, unit:%d, vty:%d\n",
                   major(dev), minor(dev), unit, SC_VTY(dev)));
   
       sc = sc_get_softc(unit, (sc_console_unit == unit) ? SC_KERNEL_CONSOLE : 0);
       if (sc == NULL)
           return ENXIO;
   
       tp = dev->si_tty = ttymalloc(dev->si_tty);
       tp->t_oproc = scstart;
       tp->t_param = scparam;
       tp->t_stop = nottystop;
       tp->t_dev = dev;
       if (!ISTTYOPEN(tp)) {
           ttychars(tp);
           /* Use the current setting of the <-- key as default VERASE. */  
           /* If the Delete key is preferable, an stty is necessary     */
           if (sc->kbd != NULL) {
               key.keynum = KEYCODE_BS;
               kbd_ioctl(sc->kbd, GIO_KEYMAPENT, (caddr_t)&key);
               tp->t_cc[VERASE] = key.key.map[0];
           }
           tp->t_iflag = TTYDEF_IFLAG;
           tp->t_oflag = TTYDEF_OFLAG;
           tp->t_cflag = TTYDEF_CFLAG;
           tp->t_lflag = TTYDEF_LFLAG;
           tp->t_ispeed = tp->t_ospeed = TTYDEF_SPEED;
           scparam(tp, &tp->t_termios);
           (*linesw[tp->t_line].l_modem)(tp, 1);
       }
       else
           if (tp->t_state & TS_XCLUDE && suser(td))
               return(EBUSY);
   
       error = (*linesw[tp->t_line].l_open)(dev, tp);
   
       scp = SC_STAT(dev);
       if (scp == NULL) {
           scp = SC_STAT(dev) = alloc_scp(sc, SC_VTY(dev));
           if (ISGRAPHSC(scp))
               sc_set_pixel_mode(scp, NULL, COL, ROW, 16);
       }
       if (!tp->t_winsize.ws_col && !tp->t_winsize.ws_row) {
           tp->t_winsize.ws_col = scp->xsize;
           tp->t_winsize.ws_row = scp->ysize;
       }
   
       return error;
   }
   
   static int
   scclose(dev_t dev, int flag, int mode, struct thread *td)
   {
       struct tty *tp = dev->si_tty;
       scr_stat *scp;
       int s;
   
       if (SC_VTY(dev) != SC_CONSOLECTL) {
           scp = SC_STAT(tp->t_dev);
           /* were we in the middle of the VT switching process? */
           DPRINTF(5, ("sc%d: scclose(), ", scp->sc->unit));
           s = spltty();
           if ((scp == scp->sc->cur_scp) && (scp->sc->unit == sc_console_unit))
               cons_unavail = FALSE;
           if (finish_vt_rel(scp, TRUE, &s) == 0)  /* force release */
               DPRINTF(5, ("reset WAIT_REL, "));
           if (finish_vt_acq(scp) == 0)            /* force acknowledge */
               DPRINTF(5, ("reset WAIT_ACQ, "));
   #if not_yet_done
           if (scp == &main_console) {
               scp->pid = 0;
               scp->proc = NULL;
               scp->smode.mode = VT_AUTO;
           }
           else {
               sc_vtb_destroy(&scp->vtb);
               sc_vtb_destroy(&scp->scr);
               sc_free_history_buffer(scp, scp->ysize);
               SC_STAT(dev) = NULL;
               free(scp, M_DEVBUF);
           }
   #else
           scp->pid = 0;
           scp->proc = NULL;
           scp->smode.mode = VT_AUTO;
   #endif
           scp->kbd_mode = K_XLATE;
           if (scp == scp->sc->cur_scp)
               kbd_ioctl(scp->sc->kbd, KDSKBMODE, (caddr_t)&scp->kbd_mode);
           DPRINTF(5, ("done.\n"));
       }
       spltty();
       (*linesw[tp->t_line].l_close)(tp, flag);
       ttyclose(tp);
       spl0();
       return(0);
   }
   
   static int
   scread(dev_t dev, struct uio *uio, int flag)
   {
       if (!sc_saver_keyb_only)
           sc_touch_scrn_saver();
       return ttyread(dev, uio, flag);
   }
   
   static int
   sckbdevent(keyboard_t *thiskbd, int event, void *arg)
   {
       sc_softc_t *sc;
       struct tty *cur_tty;
       int c; 
       size_t len;
       u_char *cp;
   
       sc = (sc_softc_t *)arg;
       /* assert(thiskbd == sc->kbd) */
   
       switch (event) {
       case KBDIO_KEYINPUT:
           break;
       case KBDIO_UNLOADING:
           sc->kbd = NULL;
           sc->keyboard = -1;
           kbd_release(thiskbd, (void *)&sc->keyboard);
           return 0;
       default:
           return EINVAL;
       }
   
       /* 
        * Loop while there is still input to get from the keyboard.
        * I don't think this is nessesary, and it doesn't fix
        * the Xaccel-2.1 keyboard hang, but it can't hurt.         XXX
        */
       while ((c = scgetc(sc, SCGETC_NONBLOCK)) != NOKEY) {
   
           cur_tty = VIRTUAL_TTY(sc, sc->cur_scp->index);
           if (!ISTTYOPEN(cur_tty)) {
               cur_tty = sc_console_tty;
               if (!ISTTYOPEN(cur_tty))
                   continue;
           }
   
           if ((*sc->cur_scp->tsw->te_input)(sc->cur_scp, c, cur_tty))
               continue;
   
           switch (KEYFLAGS(c)) {
           case 0x0000: /* normal key */
               (*linesw[cur_tty->t_line].l_rint)(KEYCHAR(c), cur_tty);
               break;
           case FKEY:  /* function key, return string */
               cp = kbd_get_fkeystr(thiskbd, KEYCHAR(c), &len);
               if (cp != NULL) {
                   while (len-- >  0)
                       (*linesw[cur_tty->t_line].l_rint)(*cp++, cur_tty);
               }
               break;
           case MKEY:  /* meta is active, prepend ESC */
               (*linesw[cur_tty->t_line].l_rint)(0x1b, cur_tty);
               (*linesw[cur_tty->t_line].l_rint)(KEYCHAR(c), cur_tty);
               break;
           case BKEY:  /* backtab fixed sequence (esc [ Z) */
               (*linesw[cur_tty->t_line].l_rint)(0x1b, cur_tty);
               (*linesw[cur_tty->t_line].l_rint)('[', cur_tty);
               (*linesw[cur_tty->t_line].l_rint)('Z', cur_tty);
               break;
           }
       }
   
   #ifndef SC_NO_CUTPASTE
       if (sc->cur_scp->status & MOUSE_VISIBLE) {
           sc_remove_mouse_image(sc->cur_scp);
           sc->cur_scp->status &= ~MOUSE_VISIBLE;
       }
   #endif /* SC_NO_CUTPASTE */
   
       return 0;
   }
   
   static int
   scparam(struct tty *tp, struct termios *t)
   {
       tp->t_ispeed = t->c_ispeed;
       tp->t_ospeed = t->c_ospeed;
       tp->t_cflag = t->c_cflag;
       return 0;
   }
   
   static int
   scioctl(dev_t dev, u_long cmd, caddr_t data, int flag, struct thread *td)
   {
       int error;
       int i;
       struct tty *tp;
       sc_softc_t *sc;
       scr_stat *scp;
       int s;
   
       tp = dev->si_tty;
   
       /* If there is a user_ioctl function call that first */
       if (sc_user_ioctl) {
           error = (*sc_user_ioctl)(dev, cmd, data, flag, td);
           if (error != ENOIOCTL)
               return error;
       }
   
       error = sc_vid_ioctl(tp, cmd, data, flag, td);
       if (error != ENOIOCTL)
           return error;
   
   #ifndef SC_NO_HISTORY
       error = sc_hist_ioctl(tp, cmd, data, flag, td);
       if (error != ENOIOCTL)
           return error;
   #endif
   
   #ifndef SC_NO_SYSMOUSE
       error = sc_mouse_ioctl(tp, cmd, data, flag, td);
       if (error != ENOIOCTL)
           return error;
   #endif
   
       scp = SC_STAT(tp->t_dev);
       /* assert(scp != NULL) */
       /* scp is sc_console, if SC_VTY(dev) == SC_CONSOLECTL. */
       sc = scp->sc;
   
       if (scp->tsw) {
           error = (*scp->tsw->te_ioctl)(scp, tp, cmd, data, flag, td);
           if (error != ENOIOCTL)
               return error;
       }
   
       switch (cmd) {              /* process console hardware related ioctl's */
   
       case GIO_ATTR:              /* get current attributes */
           /* this ioctl is not processed here, but in the terminal emulator */
           return ENOTTY;
   
       case GIO_COLOR:             /* is this a color console ? */
           *(int *)data = (sc->adp->va_flags & V_ADP_COLOR) ? 1 : 0;
           return 0;
   
       case CONS_BLANKTIME:        /* set screen saver timeout (0 = no saver) */
           if (*(int *)data < 0 || *(int *)data > MAX_BLANKTIME)
               return EINVAL;
           s = spltty();
           scrn_blank_time = *(int *)data;
           run_scrn_saver = (scrn_blank_time != 0);
           splx(s);
           return 0;
   
       case CONS_CURSORTYPE:       /* set cursor type (obsolete) */
           s = spltty();
           *(int *)data &= CONS_CURSOR_ATTRS;
           sc_change_cursor_shape(scp, *(int *)data, -1, -1);
           splx(s);
           return 0;
   
       case CONS_GETCURSORSHAPE:   /* get cursor shape (new interface) */
           if (((int *)data)[0] & CONS_LOCAL_CURSOR) {
               ((int *)data)[0] = scp->curr_curs_attr.flags;
               ((int *)data)[1] = scp->curr_curs_attr.base;
               ((int *)data)[2] = scp->curr_curs_attr.height;
           } else {
               ((int *)data)[0] = sc->curs_attr.flags;
               ((int *)data)[1] = sc->curs_attr.base;
               ((int *)data)[2] = sc->curs_attr.height;
           }
           return 0;
   
       case CONS_SETCURSORSHAPE:   /* set cursor shape (new interface) */
           s = spltty();
           sc_change_cursor_shape(scp, ((int *)data)[0],
               ((int *)data)[1], ((int *)data)[2]);
           splx(s);
           return 0;
   
       case CONS_BELLTYPE:         /* set bell type sound/visual */
           if ((*(int *)data) & 0x01)
               sc->flags |= SC_VISUAL_BELL;
           else
               sc->flags &= ~SC_VISUAL_BELL;
           if ((*(int *)data) & 0x02)
               sc->flags |= SC_QUIET_BELL;
           else
               sc->flags &= ~SC_QUIET_BELL;
           return 0;
   
       case CONS_GETINFO:          /* get current (virtual) console info */
       {
           vid_info_t *ptr = (vid_info_t*)data;
           if (ptr->size == sizeof(struct vid_info)) {
               ptr->m_num = sc->cur_scp->index;
               ptr->font_size = scp->font_size;
               ptr->mv_col = scp->xpos;
               ptr->mv_row = scp->ypos;
               ptr->mv_csz = scp->xsize;
               ptr->mv_rsz = scp->ysize;
               ptr->mv_hsz = (scp->history != NULL) ? scp->history->vtb_rows : 0;
               /*
                * The following fields are filled by the terminal emulator. XXX
                *
                * ptr->mv_norm.fore
                * ptr->mv_norm.back
                * ptr->mv_rev.fore
                * ptr->mv_rev.back
                */
               ptr->mv_grfc.fore = 0;      /* not supported */
               ptr->mv_grfc.back = 0;      /* not supported */
               ptr->mv_ovscan = scp->border;
               if (scp == sc->cur_scp)
                   save_kbd_state(scp);
               ptr->mk_keylock = scp->status & LOCK_MASK;
               return 0;
           }
           return EINVAL;
       }
   
       case CONS_GETVERS:          /* get version number */
           *(int*)data = 0x200;    /* version 2.0 */
           return 0;
   
       case CONS_IDLE:             /* see if the screen has been idle */
           /*
            * When the screen is in the GRAPHICS_MODE or UNKNOWN_MODE,
            * the user process may have been writing something on the
            * screen and syscons is not aware of it. Declare the screen
            * is NOT idle if it is in one of these modes. But there is
            * an exception to it; if a screen saver is running in the 
            * graphics mode in the current screen, we should say that the
            * screen has been idle.
            */
           *(int *)data = (sc->flags & SC_SCRN_IDLE)
                          && (!ISGRAPHSC(sc->cur_scp)
                              || (sc->cur_scp->status & SAVER_RUNNING));
           return 0;
   
       case CONS_SAVERMODE:        /* set saver mode */
           switch(*(int *)data) {
           case CONS_NO_SAVER:
           case CONS_USR_SAVER:
               /* if a LKM screen saver is running, stop it first. */
               scsplash_stick(FALSE);
               saver_mode = *(int *)data;
               s = spltty();
   #ifdef DEV_SPLASH
               if ((error = wait_scrn_saver_stop(NULL))) {
                   splx(s);
                   return error;
               }
   #endif
               run_scrn_saver = TRUE;
               if (saver_mode == CONS_USR_SAVER)
                   scp->status |= SAVER_RUNNING;
               else
                   scp->status &= ~SAVER_RUNNING;
               scsplash_stick(TRUE);
               splx(s);
               break;
           case CONS_LKM_SAVER:
               s = spltty();
               if ((saver_mode == CONS_USR_SAVER) && (scp->status & SAVER_RUNNING))
                   scp->status &= ~SAVER_RUNNING;
               saver_mode = *(int *)data;
               splx(s);
               break;
           default:
               return EINVAL;
           }
           return 0;
   
       case CONS_SAVERSTART:       /* immediately start/stop the screen saver */
           /*
            * Note that this ioctl does not guarantee the screen saver 
            * actually starts or stops. It merely attempts to do so...
            */
           s = spltty();
           run_scrn_saver = (*(int *)data != 0);
           if (run_scrn_saver)
               sc->scrn_time_stamp -= scrn_blank_time;
           splx(s);
           return 0;
   
       case CONS_SCRSHOT:          /* get a screen shot */
       {
           int retval, hist_rsz;
           size_t lsize, csize;
           vm_offset_t frbp, hstp;
           unsigned lnum;
           scrshot_t *ptr = (scrshot_t *)data;
           void *outp = ptr->buf;
   
           s = spltty();
           if (ISGRAPHSC(scp)) {
               splx(s);
               return EOPNOTSUPP;
           }
           hist_rsz = (scp->history != NULL) ? scp->history->vtb_rows : 0;
           if ((ptr->x + ptr->xsize) > scp->xsize ||
               (ptr->y + ptr->ysize) > (scp->ysize + hist_rsz)) {
               splx(s);
               return EINVAL;
           }
   
           lsize = scp->xsize * sizeof(u_int16_t);
           csize = ptr->xsize * sizeof(u_int16_t);
           /* Pointer to the last line of framebuffer */
           frbp = scp->vtb.vtb_buffer + scp->ysize * lsize + ptr->x *
                  sizeof(u_int16_t);
           /* Pointer to the last line of target buffer */
           (vm_offset_t)outp += ptr->ysize * csize;
           /* Pointer to the last line of history buffer */
           if (scp->history != NULL)
               hstp = scp->history->vtb_buffer + sc_vtb_tail(scp->history) *
                   sizeof(u_int16_t) + ptr->x * sizeof(u_int16_t);
           else
               hstp = 0;
   
           retval = 0;
           for (lnum = 0; lnum < (ptr->y + ptr->ysize); lnum++) {
               if (lnum < scp->ysize) {
                   frbp -= lsize;
               } else {
                   hstp -= lsize;
                   if (hstp < scp->history->vtb_buffer)
                       hstp += scp->history->vtb_rows * lsize;
                   frbp = hstp;
               }
               if (lnum < ptr->y)
                   continue;
               (vm_offset_t)outp -= csize;
               retval = copyout((void *)frbp, outp, csize);
               if (retval != 0)
                   break;
           }
           splx(s);
           return retval;
       }
   
       case VT_SETMODE:            /* set screen switcher mode */
       {
           struct vt_mode *mode;
           struct proc *p1;
   
           mode = (struct vt_mode *)data;
           DPRINTF(5, ("sc%d: VT_SETMODE ", sc->unit));
           if (scp->smode.mode == VT_PROCESS) {
               p1 = pfind(scp->pid);
               if (scp->proc == p1 && scp->proc != td->td_proc) {
                   if (p1)
                       PROC_UNLOCK(p1);
                   DPRINTF(5, ("error EPERM\n"));
                   return EPERM;
               }
               if (p1)
                   PROC_UNLOCK(p1);
           }
           s = spltty();
           if (mode->mode == VT_AUTO) {
               scp->smode.mode = VT_AUTO;
               scp->proc = NULL;
               scp->pid = 0;
               DPRINTF(5, ("VT_AUTO, "));
               if ((scp == sc->cur_scp) && (sc->unit == sc_console_unit))
                   cons_unavail = FALSE;
               /* were we in the middle of the vty switching process? */
               if (finish_vt_rel(scp, TRUE, &s) == 0)
                   DPRINTF(5, ("reset WAIT_REL, "));
               if (finish_vt_acq(scp) == 0)
                   DPRINTF(5, ("reset WAIT_ACQ, "));
           } else {
               if (!ISSIGVALID(mode->relsig) || !ISSIGVALID(mode->acqsig)
                   || !ISSIGVALID(mode->frsig)) {
                   splx(s);
                   DPRINTF(5, ("error EINVAL\n"));
                   return EINVAL;
               }
               DPRINTF(5, ("VT_PROCESS %d, ", td->td_proc->p_pid));
               bcopy(data, &scp->smode, sizeof(struct vt_mode));
               scp->proc = td->td_proc;
               scp->pid = scp->proc->p_pid;
               if ((scp == sc->cur_scp) && (sc->unit == sc_console_unit))
                   cons_unavail = TRUE;
           }
           splx(s);
           DPRINTF(5, ("\n"));
           return 0;
       }
   
       case VT_GETMODE:            /* get screen switcher mode */
           bcopy(&scp->smode, data, sizeof(struct vt_mode));
           return 0;
   
       case VT_RELDISP:            /* screen switcher ioctl */
           s = spltty();
           /*
            * This must be the current vty which is in the VT_PROCESS
            * switching mode...
            */
           if ((scp != sc->cur_scp) || (scp->smode.mode != VT_PROCESS)) {
               splx(s);
               return EINVAL;
           }
           /* ...and this process is controlling it. */
           if (scp->proc != td->td_proc) {
               splx(s);
               return EPERM;
           }
           error = EINVAL;
           switch(*(int *)data) {
           case VT_FALSE:          /* user refuses to release screen, abort */
               if ((error = finish_vt_rel(scp, FALSE, &s)) == 0)
                   DPRINTF(5, ("sc%d: VT_FALSE\n", sc->unit));
               break;
           case VT_TRUE:           /* user has released screen, go on */
               if ((error = finish_vt_rel(scp, TRUE, &s)) == 0)
                   DPRINTF(5, ("sc%d: VT_TRUE\n", sc->unit));
               break;
           case VT_ACKACQ:         /* acquire acknowledged, switch completed */
               if ((error = finish_vt_acq(scp)) == 0)
                   DPRINTF(5, ("sc%d: VT_ACKACQ\n", sc->unit));
               break;
           default:
               break;
           }
           splx(s);
           return error;
   
       case VT_OPENQRY:            /* return free virtual console */
           for (i = sc->first_vty; i < sc->first_vty + sc->vtys; i++) {
               tp = VIRTUAL_TTY(sc, i);
               if (!ISTTYOPEN(tp)) {
                   *(int *)data = i + 1;
                   return 0;
               }
           }
           return EINVAL;
   
       case VT_ACTIVATE:           /* switch to screen *data */
           i = (*(int *)data == 0) ? scp->index : (*(int *)data - 1);
           s = spltty();
           sc_clean_up(sc->cur_scp);
           splx(s);
          return sc_switch_scr(sc, i);
  
      case VT_WAITACTIVE:         /* wait for switch to occur */
          i = (*(int *)data == 0) ? scp->index : (*(int *)data - 1);
          if ((i < sc->first_vty) || (i >= sc->first_vty + sc->vtys))
              return EINVAL;
          s = spltty();
          error = sc_clean_up(sc->cur_scp);
          splx(s);
          if (error)
              return error;
          scp = SC_STAT(SC_DEV(sc, i));
          if (scp == scp->sc->cur_scp)
              return 0;
          while ((error=tsleep((caddr_t)&scp->smode, PZERO|PCATCH,
                               "waitvt", 0)) == ERESTART) ;
          return error;
  
      case VT_GETACTIVE:          /* get active vty # */
          *(int *)data = sc->cur_scp->index + 1;
          return 0;
  
      case VT_GETINDEX:           /* get this vty # */
          *(int *)data = scp->index + 1;
          return 0;
  
      case VT_LOCKSWITCH:         /* prevent vty switching */
          if ((*(int *)data) & 0x01)
              sc->flags |= SC_SCRN_VTYLOCK;
          else
              sc->flags &= ~SC_SCRN_VTYLOCK;
          return 0;
  
      case KDENABIO:              /* allow io operations */
          error = suser(td);
          if (error != 0)
              return error;
          error = securelevel_gt(td->td_ucred, 0);
          if (error != 0)
              return error;
  #ifdef __i386__
          td->td_frame->tf_eflags |= PSL_IOPL;
  #endif
          return 0;
  
      case KDDISABIO:             /* disallow io operations (default) */
  #ifdef __i386__
          td->td_frame->tf_eflags &= ~PSL_IOPL;
  #endif
          return 0;
  
      case KDSKBSTATE:            /* set keyboard state (locks) */
          if (*(int *)data & ~LOCK_MASK)
              return EINVAL;
          scp->status &= ~LOCK_MASK;
          scp->status |= *(int *)data;
          if (scp == sc->cur_scp)
              update_kbd_state(scp, scp->status, LOCK_MASK);
          return 0;
  
      case KDGKBSTATE:            /* get keyboard state (locks) */
          if (scp == sc->cur_scp)
              save_kbd_state(scp);
          *(int *)data = scp->status & LOCK_MASK;
          return 0;
  
      case KDGETREPEAT:           /* get keyboard repeat & delay rates */
      case KDSETREPEAT:           /* set keyboard repeat & delay rates (new) */
          error = kbd_ioctl(sc->kbd, cmd, data);
          if (error == ENOIOCTL)
              error = ENODEV;
          return error;
  
      case KDSETRAD:              /* set keyboard repeat & delay rates (old) */
          if (*(int *)data & ~0x7f)
              return EINVAL;
          error = kbd_ioctl(sc->kbd, cmd, data);
          if (error == ENOIOCTL)
              error = ENODEV;
          return error;
  
      case KDSKBMODE:             /* set keyboard mode */
          switch (*(int *)data) {
          case K_XLATE:           /* switch to XLT ascii mode */
          case K_RAW:             /* switch to RAW scancode mode */
          case K_CODE:            /* switch to CODE mode */
              scp->kbd_mode = *(int *)data;
              if (scp == sc->cur_scp)
                  kbd_ioctl(sc->kbd, cmd, data);
              return 0;
          default:
              return EINVAL;
          }
          /* NOT REACHED */
  
      case KDGKBMODE:             /* get keyboard mode */
          *(int *)data = scp->kbd_mode;
          return 0;
  
      case KDGKBINFO:
          error = kbd_ioctl(sc->kbd, cmd, data);
          if (error == ENOIOCTL)
              error = ENODEV;
          return error;
  
      case KDMKTONE:              /* sound the bell */
          if (*(int*)data)
              sc_bell(scp, (*(int*)data)&0xffff,
                      (((*(int*)data)>>16)&0xffff)*hz/1000);
          else
              sc_bell(scp, scp->bell_pitch, scp->bell_duration);
          return 0;
  
      case KIOCSOUND:             /* make tone (*data) hz */
          if (scp == sc->cur_scp) {
              if (*(int *)data)
                  return sc_tone(*(int *)data);
              else
                  return sc_tone(0);
          }
          return 0;
  
      case KDGKBTYPE:             /* get keyboard type */
          error = kbd_ioctl(sc->kbd, cmd, data);
          if (error == ENOIOCTL) {
              /* always return something? XXX */
              *(int *)data = 0;
          }
          return 0;
  
      case KDSETLED:              /* set keyboard LED status */
          if (*(int *)data & ~LED_MASK)   /* FIXME: LOCK_MASK? */
              return EINVAL;
          scp->status &= ~LED_MASK;
          scp->status |= *(int *)data;
          if (scp == sc->cur_scp)
              update_kbd_leds(scp, scp->status);
          return 0;
  
      case KDGETLED:              /* get keyboard LED status */
          if (scp == sc->cur_scp)
              save_kbd_state(scp);
          *(int *)data = scp->status & LED_MASK;
          return 0;
  
      case CONS_SETKBD:           /* set the new keyboard */
          {
              keyboard_t *newkbd;
  
              s = spltty();
              newkbd = kbd_get_keyboard(*(int *)data);
              if (newkbd == NULL) {
                  splx(s);
                  return EINVAL;
              }
              error = 0;
              if (sc->kbd != newkbd) {
                  i = kbd_allocate(newkbd->kb_name, newkbd->kb_unit,
                                   (void *)&sc->keyboard, sckbdevent, sc);
                  /* i == newkbd->kb_index */
                  if (i >= 0) {
                      if (sc->kbd != NULL) {
                          save_kbd_state(sc->cur_scp);
                          kbd_release(sc->kbd, (void *)&sc->keyboard);
                      }
                      sc->kbd = kbd_get_keyboard(i); /* sc->kbd == newkbd */
                      sc->keyboard = i;
                      kbd_ioctl(sc->kbd, KDSKBMODE,
                                (caddr_t)&sc->cur_scp->kbd_mode);
                      update_kbd_state(sc->cur_scp, sc->cur_scp->status,
                                       LOCK_MASK);
                  } else {
                      error = EPERM;      /* XXX */
                  }
              }
              splx(s);
              return error;
          }
  
      case CONS_RELKBD:           /* release the current keyboard */
          s = spltty();
          error = 0;
          if (sc->kbd != NULL) {
              save_kbd_state(sc->cur_scp);
              error = kbd_release(sc->kbd, (void *)&sc->keyboard);
              if (error == 0) {
                  sc->kbd = NULL;
                  sc->keyboard = -1;
              }
          }
          splx(s);
          return error;
  
      case CONS_GETTERM:          /* get the current terminal emulator info */
          {
              sc_term_sw_t *sw;
  
              if (((term_info_t *)data)->ti_index == 0) {
                  sw = scp->tsw;
              } else {
                  sw = sc_term_match_by_number(((term_info_t *)data)->ti_index);
              }
              if (sw != NULL) {
                  strncpy(((term_info_t *)data)->ti_name, sw->te_name, 
                          sizeof(((term_info_t *)data)->ti_name));
                  strncpy(((term_info_t *)data)->ti_desc, sw->te_desc, 
                          sizeof(((term_info_t *)data)->ti_desc));
                  ((term_info_t *)data)->ti_flags = 0;
                  return 0;
              } else {
                  ((term_info_t *)data)->ti_name[0] = '\0';
                  ((term_info_t *)data)->ti_desc[0] = '\0';
                  ((term_info_t *)data)->ti_flags = 0;
                  return EINVAL;
              }
          }
  
      case CONS_SETTERM:          /* set the current terminal emulator */
          s = spltty();
          error = sc_init_emulator(scp, ((term_info_t *)data)->ti_name);
          /* FIXME: what if scp == sc_console! XXX */
          splx(s);
          return error;
  
      case GIO_SCRNMAP:           /* get output translation table */
          bcopy(&sc->scr_map, data, sizeof(sc->scr_map));
          return 0;
  
      case PIO_SCRNMAP:           /* set output translation table */
          bcopy(data, &sc->scr_map, sizeof(sc->scr_map));
          for (i=0; i<sizeof(sc->scr_map); i++) {
              sc->scr_rmap[sc->scr_map[i]] = i;
          }
          return 0;
  
      case GIO_KEYMAP:            /* get keyboard translation table */
      case PIO_KEYMAP:            /* set keyboard translation table */
      case GIO_DEADKEYMAP:        /* get accent key translation table */
      case PIO_DEADKEYMAP:        /* set accent key translation table */
      case GETFKEY:               /* get function key string */
      case SETFKEY:               /* set function key string */
          error = kbd_ioctl(sc->kbd, cmd, data);
          if (error == ENOIOCTL)
              error = ENODEV;
          return error;
  
  #ifndef SC_NO_FONT_LOADING
  
      case PIO_FONT8x8:           /* set 8x8 dot font */
          if (!ISFONTAVAIL(sc->adp->va_flags))
              return ENXIO;
          bcopy(data, sc->font_8, 8*256);
          sc->fonts_loaded |= FONT_8;
          /*
           * FONT KLUDGE
           * Always use the font page #0. XXX
           * Don't load if the current font size is not 8x8.
           */
          if (ISTEXTSC(sc->cur_scp) && (sc->cur_scp->font_size < 14))
              sc_load_font(sc->cur_scp, 0, 8, sc->font_8, 0, 256);
          return 0;
  
      case GIO_FONT8x8:           /* get 8x8 dot font */
          if (!ISFONTAVAIL(sc->adp->va_flags))
              return ENXIO;
          if (sc->fonts_loaded & FONT_8) {
              bcopy(sc->font_8, data, 8*256);
              return 0;
          }
          else
              return ENXIO;
  
      case PIO_FONT8x14:          /* set 8x14 dot font */
          if (!ISFONTAVAIL(sc->adp->va_flags))
              return ENXIO;
          bcopy(data, sc->font_14, 14*256);
          sc->fonts_loaded |= FONT_14;
          /*
           * FONT KLUDGE
           * Always use the font page #0. XXX
           * Don't load if the current font size is not 8x14.
           */
          if (ISTEXTSC(sc->cur_scp)
              && (sc->cur_scp->font_size >= 14)
              && (sc->cur_scp->font_size < 16))
              sc_load_font(sc->cur_scp, 0, 14, sc->font_14, 0, 256);
          return 0;
  
      case GIO_FONT8x14:          /* get 8x14 dot font */
          if (!ISFONTAVAIL(sc->adp->va_flags))
              return ENXIO;
          if (sc->fonts_loaded & FONT_14) {
              bcopy(sc->font_14, data, 14*256);
              return 0;
          }
          else
              return ENXIO;
  
      case PIO_FONT8x16:          /* set 8x16 dot font */
          if (!ISFONTAVAIL(sc->adp->va_flags))
              return ENXIO;
          bcopy(data, sc->font_16, 16*256);
          sc->fonts_loaded |= FONT_16;
          /*
           * FONT KLUDGE
           * Always use the font page #0. XXX
           * Don't load if the current font size is not 8x16.
           */
          if (ISTEXTSC(sc->cur_scp) && (sc->cur_scp->font_size >= 16))
              sc_load_font(sc->cur_scp, 0, 16, sc->font_16, 0, 256);
          return 0;
  
      case GIO_FONT8x16:          /* get 8x16 dot font */
          if (!ISFONTAVAIL(sc->adp->va_flags))
              return ENXIO;
          if (sc->fonts_loaded & FONT_16) {
              bcopy(sc->font_16, data, 16*256);
              return 0;
          }
          else
              return ENXIO;
  
  #endif /* SC_NO_FONT_LOADING */
  
  #ifdef PC98
      case ADJUST_CLOCK: /* /dev/rtc for 98note resume */
          inittodr(0);
          return 0;
  #endif
  
      default:
          break;
      }
  
      error = (*linesw[tp->t_line].l_ioctl)(tp, cmd, data, flag, td);
      if (error != ENOIOCTL)
          return(error);
      error = ttioctl(tp, cmd, data, flag);
      if (error != ENOIOCTL)
          return(error);
      return(ENOTTY);
  }
  
  static void
  scstart(struct tty *tp)
  {
      struct clist *rbp;
      int s, len;
      u_char buf[PCBURST];
      scr_stat *scp = SC_STAT(tp->t_dev);
  
      if (scp->status & SLKED || scp->sc->blink_in_progress)
          return;
      s = spltty();
      if (!(tp->t_state & (TS_TIMEOUT | TS_BUSY | TS_TTSTOP))) {
          tp->t_state |= TS_BUSY;
          rbp = &tp->t_outq;
          while (rbp->c_cc) {
              len = q_to_b(rbp, buf, PCBURST);
              splx(s);
              sc_puts(scp, buf, len);
              s = spltty();
          }
          tp->t_state &= ~TS_BUSY;
          ttwwakeup(tp);
      }
      splx(s);
  }
  
  static void
  sccnprobe(struct consdev *cp)
  {
  #if __i386__
      int unit;
      int flags;
  
      cp->cn_pri = sc_get_cons_priority(&unit, &flags);
  
      /* a video card is always required */
      if (!scvidprobe(unit, flags, TRUE))
          cp->cn_pri = CN_DEAD;
  
      /* syscons will become console even when there is no keyboard */
      sckbdprobe(unit, flags, TRUE);
  
      if (cp->cn_pri == CN_DEAD)
          return;
  
      /* initialize required fields */
      cp->cn_dev = makedev(CDEV_MAJOR, SC_CONSOLECTL);
  #endif /* __i386__ */
  
  #if __alpha__
      /*
       * alpha use sccnattach() rather than cnprobe()/cninit()/cnterm()
       * interface to install the console.  Always return CN_DEAD from
       * here.
       */
      cp->cn_pri = CN_DEAD;
  #endif /* __alpha__ */
  }
  
  static void
  sccninit(struct consdev *cp)
  {
  #if __i386__
      int unit;
      int flags;
  
      sc_get_cons_priority(&unit, &flags);
      scinit(unit, flags | SC_KERNEL_CONSOLE);
      sc_console_unit = unit;
      sc_console = SC_STAT(sc_get_softc(unit, SC_KERNEL_CONSOLE)->dev[0]);
  #endif /* __i386__ */
  
  #if __alpha__
      /* SHOULDN'T REACH HERE */
  #endif /* __alpha__ */
  }
  
  static void
  sccnterm(struct consdev *cp)
  {
      /* we are not the kernel console any more, release everything */
  
      if (sc_console_unit < 0)
          return;                 /* shouldn't happen */
  
  #if __i386__
      scterm(sc_console_unit, SC_KERNEL_CONSOLE);
      sc_console_unit = -1;
      sc_console = NULL;
  #endif /* __i386__ */
  
  #if __alpha__
      /* do nothing XXX */
  #endif /* __alpha__ */
  }
  
  #ifdef __alpha__
  
  void
  sccnattach(void)
  {
      static struct consdev consdev;
      int unit;
      int flags;
  
      bcopy(&sc_consdev, &consdev, sizeof(sc_consdev));
      consdev.cn_pri = sc_get_cons_priority(&unit, &flags);
  
      /* a video card is always required */
      if (!scvidprobe(unit, flags, TRUE))
          consdev.cn_pri = CN_DEAD;
  
      /* alpha doesn't allow the console being without a keyboard... Why? */
      if (!sckbdprobe(unit, flags, TRUE))
          consdev.cn_pri = CN_DEAD;
  
      if (consdev.cn_pri == CN_DEAD)
          return;
  
      scinit(unit, flags | SC_KERNEL_CONSOLE);
      sc_console_unit = unit;
      sc_console = SC_STAT(sc_get_softc(unit, SC_KERNEL_CONSOLE)->dev[0]);
      consdev.cn_dev = makedev(CDEV_MAJOR, 0);
      cnadd(&consdev);
  }
  
  #endif /* __alpha__ */
  
  static void
  sccnputc(dev_t dev, int c)
  {
      u_char buf[1];
      scr_stat *scp = sc_console;
      void *save;
  #ifndef SC_NO_HISTORY
      struct tty *tp;
  #endif /* !SC_NO_HISTORY */
      int s;
  
      /* assert(sc_console != NULL) */
  
  #ifndef SC_NO_HISTORY
      if (scp == scp->sc->cur_scp && scp->status & SLKED) {
          scp->status &= ~SLKED;
          update_kbd_state(scp, scp->status, SLKED);
          if (scp->status & BUFFER_SAVED) {
              if (!sc_hist_restore(scp))
                  sc_remove_cutmarking(scp);
              scp->status &= ~BUFFER_SAVED;
              scp->status |= CURSOR_ENABLED;
              sc_draw_cursor_image(scp);
          }
          tp = VIRTUAL_TTY(scp->sc, scp->index);
          if (ISTTYOPEN(tp))
              scstart(tp);
      }
  #endif /* !SC_NO_HISTORY */
  
      save = scp->ts;
      if (kernel_console_ts != NULL)
          scp->ts = kernel_console_ts;
      buf[0] = c;
      sc_puts(scp, buf, 1);
      scp->ts = save;
  
      s = spltty();       /* block sckbdevent and scrn_timer */
      sccnupdate(scp);
      splx(s);
  }
  
  static int
  sccngetc(dev_t dev)
  {
      return sccngetch(0);
  }
  
  static int
  sccncheckc(dev_t dev)
  {
      return sccngetch(SCGETC_NONBLOCK);
  }
  
  static void
  sccndbctl(dev_t dev, int on)
  {
      /* try to switch to the kernel console screen */
      if (on && debugger == 0) {
          /*
           * TRY to make sure the screen saver is stopped, 
           * and the screen is updated before switching to 
           * the vty0.
           */
          scrn_timer(NULL);
          if (!cold
              && sc_console->sc->cur_scp->smode.mode == VT_AUTO
              && sc_console->smode.mode == VT_AUTO) {
              ++debugger;         /* XXX */
              sc_switch_scr(sc_console->sc, sc_console->index);
              --debugger;         /* XXX */
          }
      }
      if (on)
          ++debugger;
      else
          --debugger;
  }
  
  static int
  sccngetch(int flags)
  {
      static struct fkeytab fkey;
      static int fkeycp;
      scr_stat *scp;
      u_char *p;
      int cur_mode;
      int s = spltty();   /* block sckbdevent and scrn_timer while we poll */
      int c;
  
      /* assert(sc_console != NULL) */
  
      /* 
       * Stop the screen saver and update the screen if necessary.
       * What if we have been running in the screen saver code... XXX
       */
      sc_touch_scrn_saver();
      scp = sc_console->sc->cur_scp;      /* XXX */
      sccnupdate(scp);
  
      if (fkeycp < fkey.len) {
          splx(s);
          return fkey.str[fkeycp++];
      }
  
      if (scp->sc->kbd == NULL) {
          splx(s);
          return -1;
      }
  
      /* 
       * Make sure the keyboard is accessible even when the kbd device
       * driver is disabled.
       */
      kbd_enable(scp->sc->kbd);
  
      /* we shall always use the keyboard in the XLATE mode here */
      cur_mode = scp->kbd_mode;
      scp->kbd_mode = K_XLATE;
      kbd_ioctl(scp->sc->kbd, KDSKBMODE, (caddr_t)&scp->kbd_mode);
  
      kbd_poll(scp->sc->kbd, TRUE);
      c = scgetc(scp->sc, SCGETC_CN | flags);
      kbd_poll(scp->sc->kbd, FALSE);
  
      scp->kbd_mode = cur_mode;
      kbd_ioctl(scp->sc->kbd, KDSKBMODE, (caddr_t)&scp->kbd_mode);
      kbd_disable(scp->sc->kbd);
      splx(s);
  
      switch (KEYFLAGS(c)) {
      case 0:     /* normal char */
          return KEYCHAR(c);
      case FKEY:  /* function key */
          p = kbd_get_fkeystr(scp->sc->kbd, KEYCHAR(c), (size_t *)&fkeycp);
          fkey.len = fkeycp;
          if ((p != NULL) && (fkey.len > 0)) {
              bcopy(p, fkey.str, fkey.len);
              fkeycp = 1;
              return fkey.str[0];
          }
          return c;       /* XXX */
      case NOKEY:
      case ERRKEY:
      default:
          return -1;
      }
      /* NOT REACHED */
  }
  
  static void
  sccnupdate(scr_stat *scp)
  {
      /* this is a cut-down version of scrn_timer()... */
  
      if (scp->sc->font_loading_in_progress || scp->sc->videoio_in_progress)
          return;
  
      if (debugger > 0 || panicstr || shutdown_in_progress) {
          sc_touch_scrn_saver();
      } else if (scp != scp->sc->cur_scp) {
          return;
      }
  
      if (!run_scrn_saver)
          scp->sc->flags &= ~SC_SCRN_IDLE;
  #ifdef DEV_SPLASH
      if ((saver_mode != CONS_LKM_SAVER) || !(scp->sc->flags & SC_SCRN_IDLE))
          if (scp->sc->flags & SC_SCRN_BLANKED)
              stop_scrn_saver(scp->sc, current_saver);
  #endif
  
      if (scp != scp->sc->cur_scp || scp->sc->blink_in_progress
          || scp->sc->switch_in_progress)
          return;
      /*
       * FIXME: unlike scrn_timer(), we call scrn_update() from here even
       * when write_in_progress is non-zero.  XXX
       */
  
      if (!ISGRAPHSC(scp) && !(scp->sc->flags & SC_SCRN_BLANKED))
          scrn_update(scp, TRUE);
  }
  
  static void
  scrn_timer(void *arg)
  {
  #ifndef PC98
      static int kbd_interval = 0;
  #endif
      struct timeval tv;
      sc_softc_t *sc;
      scr_stat *scp;
      int again;
      int s;
  
      again = (arg != NULL);
      if (arg != NULL)
          sc = (sc_softc_t *)arg;
      else if (sc_console != NULL)
          sc = sc_console->sc;
      else
          return;
  
      /* don't do anything when we are performing some I/O operations */
      if (sc->font_loading_in_progress || sc->videoio_in_progress) {
          if (again)
              timeout(scrn_timer, sc, hz / 10);
          return;
      }
      s = spltty();
  
  #ifndef PC98
      if ((sc->kbd == NULL) && (sc->config & SC_AUTODETECT_KBD)) {
          /* try to allocate a keyboard automatically */
          if (++kbd_interval >= 25) {
              sc->keyboard = kbd_allocate("*", -1, (void *)&sc->keyboard,
                                          sckbdevent, sc);
              if (sc->keyboard >= 0) {
                  sc->kbd = kbd_get_keyboard(sc->keyboard);
                  kbd_ioctl(sc->kbd, KDSKBMODE,
                            (caddr_t)&sc->cur_scp->kbd_mode);
                  update_kbd_state(sc->cur_scp, sc->cur_scp->status,
                                   LOCK_MASK);
              }
              kbd_interval = 0;
          }
      }
  #endif /* PC98 */
  
      /* find the vty to update */
      scp = sc->cur_scp;
  
      /* should we stop the screen saver? */
      getmicrouptime(&tv);
      if (debugger > 0 || panicstr || shutdown_in_progress)
          sc_touch_scrn_saver();
      if (run_scrn_saver) {
          if (tv.tv_sec > sc->scrn_time_stamp + scrn_blank_time)
              sc->flags |= SC_SCRN_IDLE;
          else
              sc->flags &= ~SC_SCRN_IDLE;
      } else {
          sc->scrn_time_stamp = tv.tv_sec;
          sc->flags &= ~SC_SCRN_IDLE;
          if (scrn_blank_time > 0)
              run_scrn_saver = TRUE;
      }
  #ifdef DEV_SPLASH
      if ((saver_mode != CONS_LKM_SAVER) || !(sc->flags & SC_SCRN_IDLE))
          if (sc->flags & SC_SCRN_BLANKED)
              stop_scrn_saver(sc, current_saver);
  #endif
  
      /* should we just return ? */
      if (sc->blink_in_progress || sc->switch_in_progress
          || sc->write_in_progress) {
          if (again)
              timeout(scrn_timer, sc, hz / 10);
          splx(s);
          return;
      }
  
      /* Update the screen */
      scp = sc->cur_scp;          /* cur_scp may have changed... */
      if (!ISGRAPHSC(scp) && !(sc->flags & SC_SCRN_BLANKED))
          scrn_update(scp, TRUE);
  
  #ifdef DEV_SPLASH
      /* should we activate the screen saver? */
      if ((saver_mode == CONS_LKM_SAVER) && (sc->flags & SC_SCRN_IDLE))
          if (!ISGRAPHSC(scp) || (sc->flags & SC_SCRN_BLANKED))
              (*current_saver)(sc, TRUE);
  #endif
  
      if (again)
          timeout(scrn_timer, sc, hz / 25);
      splx(s);
  }
  
  static int
  and_region(int *s1, int *e1, int s2, int e2)
  {
      if (*e1 < s2 || e2 < *s1)
          return FALSE;
      *s1 = imax(*s1, s2);
      *e1 = imin(*e1, e2);
      return TRUE;
  }
  
  static void 
  scrn_update(scr_stat *scp, int show_cursor)
  {
      int start;
      int end;
      int s;
      int e;
  
      /* assert(scp == scp->sc->cur_scp) */
  
      ++scp->sc->videoio_in_progress;
  
  #ifndef SC_NO_CUTPASTE
      /* remove the previous mouse pointer image if necessary */
      if ((scp->status & (MOUSE_VISIBLE | MOUSE_MOVED))
          == (MOUSE_VISIBLE | MOUSE_MOVED)) {
          /* FIXME: I don't like this... XXX */
          sc_remove_mouse_image(scp);
          if (scp->end >= scp->xsize*scp->ysize)
              scp->end = scp->xsize*scp->ysize - 1;
      }
  #endif /* !SC_NO_CUTPASTE */
  
  #if 1
      /* debug: XXX */
      if (scp->end >= scp->xsize*scp->ysize) {
          printf("scrn_update(): scp->end %d > size_of_screen!!\n", scp->end);
          scp->end = scp->xsize*scp->ysize - 1;
      }
      if (scp->start < 0) {
          printf("scrn_update(): scp->start %d < 0\n", scp->start);
          scp->start = 0;
      }
  #endif
  
      /* update screen image */
      if (scp->start <= scp->end)  {
          if (scp->mouse_cut_end >= 0) {
              /* there is a marked region for cut & paste */
              if (scp->mouse_cut_start <= scp->mouse_cut_end) {
                  start = scp->mouse_cut_start;
                  end = scp->mouse_cut_end;
              } else {
                  start = scp->mouse_cut_end;
                  end = scp->mouse_cut_start - 1;
              }
              s = start;
              e = end;
              /* does the cut-mark region overlap with the update region? */
              if (and_region(&s, &e, scp->start, scp->end)) {
                  (*scp->rndr->draw)(scp, s, e - s + 1, TRUE);
                  s = 0;
                  e = start - 1;
                  if (and_region(&s, &e, scp->start, scp->end))
                      (*scp->rndr->draw)(scp, s, e - s + 1, FALSE);
                  s = end + 1;
                  e = scp->xsize*scp->ysize - 1;
                  if (and_region(&s, &e, scp->start, scp->end))
                      (*scp->rndr->draw)(scp, s, e - s + 1, FALSE);
              } else {
                  (*scp->rndr->draw)(scp, scp->start,
                                     scp->end - scp->start + 1, FALSE);
              }
          } else {
              (*scp->rndr->draw)(scp, scp->start,
                                 scp->end - scp->start + 1, FALSE);
          }
      }
  
      /* we are not to show the cursor and the mouse pointer... */
      if (!show_cursor) {
          scp->end = 0;
          scp->start = scp->xsize*scp->ysize - 1;
          --scp->sc->videoio_in_progress;
          return;
      }
  
      /* update cursor image */
      if (scp->status & CURSOR_ENABLED) {
          /* did cursor move since last time ? */
          if (scp->cursor_pos != scp->cursor_oldpos) {
              /* do we need to remove old cursor image ? */
              if (scp->cursor_oldpos < scp->start ||
                  scp->cursor_oldpos > scp->end) {
                  sc_remove_cursor_image(scp);
              }
              sc_draw_cursor_image(scp);
          }
          else {
              /* cursor didn't move, has it been overwritten ? */
              if (scp->cursor_pos >= scp->start && scp->cursor_pos <= scp->end) {
                  sc_draw_cursor_image(scp);
              } else {
                  /* if its a blinking cursor, we may have to update it */
                  if (scp->curs_attr.flags & CONS_BLINK_CURSOR)
                      (*scp->rndr->blink_cursor)(scp, scp->cursor_pos,
                                                 sc_inside_cutmark(scp,
                                                          scp->cursor_pos));
              }
          }
      }
  
  #ifndef SC_NO_CUTPASTE
      /* update "pseudo" mouse pointer image */
      if (scp->status & MOUSE_VISIBLE) {
          /* did mouse move since last time ? */
          if (scp->status & MOUSE_MOVED) {
              /* the previous pointer image has been removed, see above */
              scp->status &= ~MOUSE_MOVED;
              sc_draw_mouse_image(scp);
          } else {
              /* mouse didn't move, has it been overwritten ? */
              if (scp->mouse_pos + scp->xsize + 1 >= scp->start &&
                  scp->mouse_pos <= scp->end) {
                  sc_draw_mouse_image(scp);
              } else if (scp->cursor_pos == scp->mouse_pos ||
                  scp->cursor_pos == scp->mouse_pos + 1 ||
                  scp->cursor_pos == scp->mouse_pos + scp->xsize ||
                  scp->cursor_pos == scp->mouse_pos + scp->xsize + 1) {
                  sc_draw_mouse_image(scp);
              }
          }
      }
  #endif /* SC_NO_CUTPASTE */
  
      scp->end = 0;
      scp->start = scp->xsize*scp->ysize - 1;
  
      --scp->sc->videoio_in_progress;
  }
  
  #ifdef DEV_SPLASH
  static int
  scsplash_callback(int event, void *arg)
  {
      sc_softc_t *sc;
      int error;
  
      sc = (sc_softc_t *)arg;
  
      switch (event) {
      case SPLASH_INIT:
          if (add_scrn_saver(scsplash_saver) == 0) {
              sc->flags &= ~SC_SAVER_FAILED;
              run_scrn_saver = TRUE;
              if (cold && !(boothowto & (RB_VERBOSE | RB_CONFIG))) {
                  scsplash_stick(TRUE);
                  (*current_saver)(sc, TRUE);
              }
          }
          return 0;
  
      case SPLASH_TERM:
          if (current_saver == scsplash_saver) {
              scsplash_stick(FALSE);
              error = remove_scrn_saver(scsplash_saver);
              if (error)
                  return error;
          }
          return 0;
  
      default:
          return EINVAL;
      }
  }
  
  static void
  scsplash_saver(sc_softc_t *sc, int show)
  {
      static int busy = FALSE;
      scr_stat *scp;
  
      if (busy)
          return;
      busy = TRUE;
  
      scp = sc->cur_scp;
      if (show) {
          if (!(sc->flags & SC_SAVER_FAILED)) {
              if (!(sc->flags & SC_SCRN_BLANKED))
                  set_scrn_saver_mode(scp, -1, NULL, 0);
              switch (splash(sc->adp, TRUE)) {
              case 0:             /* succeeded */
                  break;
              case EAGAIN:        /* try later */
                  restore_scrn_saver_mode(scp, FALSE);
                  sc_touch_scrn_saver();          /* XXX */
                  break;
              default:
                  sc->flags |= SC_SAVER_FAILED;
                  scsplash_stick(FALSE);
                  restore_scrn_saver_mode(scp, TRUE);
                  printf("scsplash_saver(): failed to put up the image\n");
                  break;
              }
          }
      } else if (!sticky_splash) {
          if ((sc->flags & SC_SCRN_BLANKED) && (splash(sc->adp, FALSE) == 0))
              restore_scrn_saver_mode(scp, TRUE);
      }
      busy = FALSE;
  }
  
  static int
  add_scrn_saver(void (*this_saver)(sc_softc_t *, int))
  {
  #if 0
      int error;
  
      if (current_saver != none_saver) {
          error = remove_scrn_saver(current_saver);
          if (error)
              return error;
      }
  #endif
      if (current_saver != none_saver)
          return EBUSY;
  
      run_scrn_saver = FALSE;
      saver_mode = CONS_LKM_SAVER;
      current_saver = this_saver;
      return 0;
  }
  
  static int
  remove_scrn_saver(void (*this_saver)(sc_softc_t *, int))
  {
      if (current_saver != this_saver)
          return EINVAL;
  
  #if 0
      /*
       * In order to prevent `current_saver' from being called by
       * the timeout routine `scrn_timer()' while we manipulate 
       * the saver list, we shall set `current_saver' to `none_saver' 
       * before stopping the current saver, rather than blocking by `splXX()'.
       */
      current_saver = none_saver;
      if (scrn_blanked)
          stop_scrn_saver(this_saver);
  #endif
  
      /* unblank all blanked screens */
      wait_scrn_saver_stop(NULL);
      if (scrn_blanked)
          return EBUSY;
  
      current_saver = none_saver;
      return 0;
  }
  
  static int
  set_scrn_saver_mode(scr_stat *scp, int mode, u_char *pal, int border)
  {
      int s;
  
      /* assert(scp == scp->sc->cur_scp) */
      s = spltty();
      if (!ISGRAPHSC(scp))
          sc_remove_cursor_image(scp);
      scp->splash_save_mode = scp->mode;
      scp->splash_save_status = scp->status & (GRAPHICS_MODE | PIXEL_MODE);
      scp->status &= ~(GRAPHICS_MODE | PIXEL_MODE);
      scp->status |= (UNKNOWN_MODE | SAVER_RUNNING);
      scp->sc->flags |= SC_SCRN_BLANKED;
      ++scrn_blanked;
      splx(s);
      if (mode < 0)
          return 0;
      scp->mode = mode;
      if (set_mode(scp) == 0) {
          if (scp->sc->adp->va_info.vi_flags & V_INFO_GRAPHICS)
              scp->status |= GRAPHICS_MODE;
  #ifndef SC_NO_PALETTE_LOADING
          if (pal != NULL)
              load_palette(scp->sc->adp, pal);
  #endif
          sc_set_border(scp, border);
          return 0;
      } else {
          s = spltty();
          scp->mode = scp->splash_save_mode;
          scp->status &= ~(UNKNOWN_MODE | SAVER_RUNNING);
          scp->status |= scp->splash_save_status;
          splx(s);
          return 1;
      }
  }
  
  static int
  restore_scrn_saver_mode(scr_stat *scp, int changemode)
  {
      int mode;
      int status;
      int s;
  
      /* assert(scp == scp->sc->cur_scp) */
      s = spltty();
      mode = scp->mode;
      status = scp->status;
      scp->mode = scp->splash_save_mode;
      scp->status &= ~(UNKNOWN_MODE | SAVER_RUNNING);
      scp->status |= scp->splash_save_status;
      scp->sc->flags &= ~SC_SCRN_BLANKED;
      if (!changemode) {
          if (!ISGRAPHSC(scp))
              sc_draw_cursor_image(scp);
          --scrn_blanked;
          splx(s);
          return 0;
      }
      if (set_mode(scp) == 0) {
  #ifndef SC_NO_PALETTE_LOADING
          load_palette(scp->sc->adp, scp->sc->palette);
  #endif
          --scrn_blanked;
          splx(s);
          return 0;
      } else {
          scp->mode = mode;
          scp->status = status;
          splx(s);
          return 1;
      }
  }
  
  static void
  stop_scrn_saver(sc_softc_t *sc, void (*saver)(sc_softc_t *, int))
  {
      (*saver)(sc, FALSE);
      run_scrn_saver = FALSE;
      /* the screen saver may have chosen not to stop after all... */
      if (sc->flags & SC_SCRN_BLANKED)
          return;
  
      mark_all(sc->cur_scp);
      if (sc->delayed_next_scr)
          sc_switch_scr(sc, sc->delayed_next_scr - 1);
      if (debugger == 0)
          wakeup((caddr_t)&scrn_blanked);
  }
  
  static int
  wait_scrn_saver_stop(sc_softc_t *sc)
  {
      int error = 0;
  
      while (scrn_blanked > 0) {
          run_scrn_saver = FALSE;
          if (sc && !(sc->flags & SC_SCRN_BLANKED)) {
              error = 0;
              break;
          }
          error = tsleep((caddr_t)&scrn_blanked, PZERO | PCATCH, "scrsav", 0);
          if ((error != 0) && (error != ERESTART))
              break;
      }
      run_scrn_saver = FALSE;
      return error;
  }
  #endif /* DEV_SPLASH */
  
  void
  sc_touch_scrn_saver(void)
  {
      scsplash_stick(FALSE);
      run_scrn_saver = FALSE;
  }
  
  int
  sc_switch_scr(sc_softc_t *sc, u_int next_scr)
  {
      scr_stat *cur_scp;
      struct tty *tp;
      struct proc *p;
      int s;
  
      DPRINTF(5, ("sc0: sc_switch_scr() %d ", next_scr + 1));
  
      /* prevent switch if previously requested */
      if (sc->flags & SC_SCRN_VTYLOCK) {
              sc_bell(sc->cur_scp, sc->cur_scp->bell_pitch,
                  sc->cur_scp->bell_duration);
              return EPERM;
      }
  
      /* delay switch if the screen is blanked or being updated */
      if ((sc->flags & SC_SCRN_BLANKED) || sc->write_in_progress
          || sc->blink_in_progress || sc->videoio_in_progress) {
          sc->delayed_next_scr = next_scr + 1;
          sc_touch_scrn_saver();
          DPRINTF(5, ("switch delayed\n"));
          return 0;
      }
  
      s = spltty();
      cur_scp = sc->cur_scp;
  
      /* we are in the middle of the vty switching process... */
      if (sc->switch_in_progress
          && (cur_scp->smode.mode == VT_PROCESS)
          && cur_scp->proc) {
          p = pfind(cur_scp->pid);
          if (cur_scp->proc != p) {
              if (p)
                  PROC_UNLOCK(p);
              /* 
               * The controlling process has died!!.  Do some clean up.
               * NOTE:`cur_scp->proc' and `cur_scp->smode.mode' 
               * are not reset here yet; they will be cleared later.
               */
              DPRINTF(5, ("cur_scp controlling process %d died, ",
                 cur_scp->pid));
              if (cur_scp->status & SWITCH_WAIT_REL) {
                  /*
                   * Force the previous switch to finish, but return now 
                   * with error.
                   */
                  DPRINTF(5, ("reset WAIT_REL, "));
                  finish_vt_rel(cur_scp, TRUE, &s);
                  splx(s);
                  DPRINTF(5, ("finishing previous switch\n"));
                  return EINVAL;
              } else if (cur_scp->status & SWITCH_WAIT_ACQ) {
                  /* let's assume screen switch has been completed. */
                  DPRINTF(5, ("reset WAIT_ACQ, "));
                  finish_vt_acq(cur_scp);
              } else {
                  /* 
                   * We are in between screen release and acquisition, and
                   * reached here via scgetc() or scrn_timer() which has 
                   * interrupted exchange_scr(). Don't do anything stupid.
                   */
                  DPRINTF(5, ("waiting nothing, "));
              }
          } else {
              if (p)
                  PROC_UNLOCK(p);
              /*
               * The controlling process is alive, but not responding... 
               * It is either buggy or it may be just taking time.
               * The following code is a gross kludge to cope with this
               * problem for which there is no clean solution. XXX
               */
              if (cur_scp->status & SWITCH_WAIT_REL) {
                  switch (sc->switch_in_progress++) {
                  case 1:
                      break;
                  case 2:
                      DPRINTF(5, ("sending relsig again, "));
                      signal_vt_rel(cur_scp);
                      break;
                  case 3:
                      break;
                  case 4:
                  default:
                      /*
                       * Act as if the controlling program returned
                       * VT_FALSE.
                       */
                      DPRINTF(5, ("force reset WAIT_REL, "));
                      finish_vt_rel(cur_scp, FALSE, &s);
                      splx(s);
                      DPRINTF(5, ("act as if VT_FALSE was seen\n"));
                      return EINVAL;
                  }
              } else if (cur_scp->status & SWITCH_WAIT_ACQ) {
                  switch (sc->switch_in_progress++) {
                  case 1:
                      break;
                  case 2:
                      DPRINTF(5, ("sending acqsig again, "));
                      signal_vt_acq(cur_scp);
                      break;
                  case 3:
                      break;
                  case 4:
                  default:
                       /* clear the flag and finish the previous switch */
                      DPRINTF(5, ("force reset WAIT_ACQ, "));
                      finish_vt_acq(cur_scp);
                      break;
                  }
              }
          }
      }
  
      /*
       * Return error if an invalid argument is given, or vty switch
       * is still in progress.
       */
      if ((next_scr < sc->first_vty) || (next_scr >= sc->first_vty + sc->vtys)
          || sc->switch_in_progress) {
          splx(s);
          sc_bell(cur_scp, bios_value.bell_pitch, BELL_DURATION);
          DPRINTF(5, ("error 1\n"));
          return EINVAL;
      }
  
      /*
       * Don't allow switching away from the graphics mode vty
       * if the switch mode is VT_AUTO, unless the next vty is the same 
       * as the current or the current vty has been closed (but showing).
       */
      tp = VIRTUAL_TTY(sc, cur_scp->index);
      if ((cur_scp->index != next_scr)
          && ISTTYOPEN(tp)
          && (cur_scp->smode.mode == VT_AUTO)
          && ISGRAPHSC(cur_scp)) {
          splx(s);
          sc_bell(cur_scp, bios_value.bell_pitch, BELL_DURATION);
          DPRINTF(5, ("error, graphics mode\n"));
          return EINVAL;
      }
  
      /*
       * Is the wanted vty open? Don't allow switching to a closed vty.
       * If we are in DDB, don't switch to a vty in the VT_PROCESS mode.
       * Note that we always allow the user to switch to the kernel 
       * console even if it is closed.
       */
      if ((sc_console == NULL) || (next_scr != sc_console->index)) {
          tp = VIRTUAL_TTY(sc, next_scr);
          if (!ISTTYOPEN(tp)) {
              splx(s);
              sc_bell(cur_scp, bios_value.bell_pitch, BELL_DURATION);
              DPRINTF(5, ("error 2, requested vty isn't open!\n"));
              return EINVAL;
          }
          if ((debugger > 0) && (SC_STAT(tp->t_dev)->smode.mode == VT_PROCESS)) {
              splx(s);
              DPRINTF(5, ("error 3, requested vty is in the VT_PROCESS mode\n"));
              return EINVAL;
          }
      }
  
      /* this is the start of vty switching process... */
      ++sc->switch_in_progress;
      sc->delayed_next_scr = 0;
      sc->old_scp = cur_scp;
      sc->new_scp = SC_STAT(SC_DEV(sc, next_scr));
      if (sc->new_scp == sc->old_scp) {
          sc->switch_in_progress = 0;
          /*
           * XXX wakeup() calls mtx_lock(&sched_lock) which will hang if
           * sched_lock is in an in-between state, e.g., when we stop at
           * a breakpoint at fork_exit.  It has always been wrong to call
           * wakeup() when the debugger is active.  In RELENG_4, wakeup()
           * is supposed to be locked by splhigh(), but the debugger may
           * be invoked at splhigh().
           */
          if (debugger == 0)
              wakeup((caddr_t)&sc->new_scp->smode);
          splx(s);
          DPRINTF(5, ("switch done (new == old)\n"));
          return 0;
      }
  
      /* has controlling process died? */
      vt_proc_alive(sc->old_scp);
      vt_proc_alive(sc->new_scp);
  
      /* wait for the controlling process to release the screen, if necessary */
      if (signal_vt_rel(sc->old_scp)) {
          splx(s);
          return 0;
      }
  
      /* go set up the new vty screen */
      splx(s);
      exchange_scr(sc);
      s = spltty();
  
      /* wake up processes waiting for this vty */
      if (debugger == 0)
          wakeup((caddr_t)&sc->cur_scp->smode);
  
      /* wait for the controlling process to acknowledge, if necessary */
      if (signal_vt_acq(sc->cur_scp)) {
          splx(s);
          return 0;
      }
  
      sc->switch_in_progress = 0;
      if (sc->unit == sc_console_unit)
          cons_unavail = FALSE;
      splx(s);
      DPRINTF(5, ("switch done\n"));
  
      return 0;
  }
  
  static int
  do_switch_scr(sc_softc_t *sc, int s)
  {
      vt_proc_alive(sc->new_scp);
  
      splx(s);
      exchange_scr(sc);
      s = spltty();
      /* sc->cur_scp == sc->new_scp */
      wakeup((caddr_t)&sc->cur_scp->smode);
  
      /* wait for the controlling process to acknowledge, if necessary */
      if (!signal_vt_acq(sc->cur_scp)) {
          sc->switch_in_progress = 0;
          if (sc->unit == sc_console_unit)
              cons_unavail = FALSE;
      }
  
      return s;
  }
  
  static int
  vt_proc_alive(scr_stat *scp)
  {
      struct proc *p;
  
      if (scp->proc) {
          if ((p = pfind(scp->pid)) != NULL)
              PROC_UNLOCK(p);
          if (scp->proc == p)
              return TRUE;
          scp->proc = NULL;
          scp->smode.mode = VT_AUTO;
          DPRINTF(5, ("vt controlling process %d died\n", scp->pid));
      }
      return FALSE;
  }
  
  static int
  signal_vt_rel(scr_stat *scp)
  {
      if (scp->smode.mode != VT_PROCESS)
          return FALSE;
      scp->status |= SWITCH_WAIT_REL;
      PROC_LOCK(scp->proc);
      psignal(scp->proc, scp->smode.relsig);
      PROC_UNLOCK(scp->proc);
      DPRINTF(5, ("sending relsig to %d\n", scp->pid));
      return TRUE;
  }
  
  static int
  signal_vt_acq(scr_stat *scp)
  {
      if (scp->smode.mode != VT_PROCESS)
          return FALSE;
      if (scp->sc->unit == sc_console_unit)
          cons_unavail = TRUE;
      scp->status |= SWITCH_WAIT_ACQ;
      PROC_LOCK(scp->proc);
      psignal(scp->proc, scp->smode.acqsig);
      PROC_UNLOCK(scp->proc);
      DPRINTF(5, ("sending acqsig to %d\n", scp->pid));
      return TRUE;
  }
  
  static int
  finish_vt_rel(scr_stat *scp, int release, int *s)
  {
      if (scp == scp->sc->old_scp && scp->status & SWITCH_WAIT_REL) {
          scp->status &= ~SWITCH_WAIT_REL;
          if (release)
              *s = do_switch_scr(scp->sc, *s);
          else
              scp->sc->switch_in_progress = 0;
          return 0;
      }
      return EINVAL;
  }
  
  static int
  finish_vt_acq(scr_stat *scp)
  {
      if (scp == scp->sc->new_scp && scp->status & SWITCH_WAIT_ACQ) {
          scp->status &= ~SWITCH_WAIT_ACQ;
          scp->sc->switch_in_progress = 0;
          return 0;
      }
      return EINVAL;
  }
  
  static void
  exchange_scr(sc_softc_t *sc)
  {
      scr_stat *scp;
  
      /* save the current state of video and keyboard */
      sc_move_cursor(sc->old_scp, sc->old_scp->xpos, sc->old_scp->ypos);
      if (!ISGRAPHSC(sc->old_scp))
          sc_remove_cursor_image(sc->old_scp);
      if (sc->old_scp->kbd_mode == K_XLATE)
          save_kbd_state(sc->old_scp);
  
      /* set up the video for the new screen */
      scp = sc->cur_scp = sc->new_scp;
  #ifdef PC98
      if (sc->old_scp->mode != scp->mode || ISUNKNOWNSC(sc->old_scp) || ISUNKNOWNSC(sc->new_scp))
  #else
      if (sc->old_scp->mode != scp->mode || ISUNKNOWNSC(sc->old_scp))
  #endif
          set_mode(scp);
      else
          sc_vtb_init(&scp->scr, VTB_FRAMEBUFFER, scp->xsize, scp->ysize,
                      (void *)sc->adp->va_window, FALSE);
      sc_move_cursor(scp, scp->xpos, scp->ypos);
      if (!ISGRAPHSC(scp))
          sc_set_cursor_image(scp);
  #ifndef SC_NO_PALETTE_LOADING
      if (ISGRAPHSC(sc->old_scp))
          load_palette(sc->adp, sc->palette);
  #endif
      sc_set_border(scp, scp->border);
  
      /* set up the keyboard for the new screen */
      if (sc->old_scp->kbd_mode != scp->kbd_mode)
          kbd_ioctl(sc->kbd, KDSKBMODE, (caddr_t)&scp->kbd_mode);
      update_kbd_state(scp, scp->status, LOCK_MASK);
  
      mark_all(scp);
  }
  
  void
  sc_puts(scr_stat *scp, u_char *buf, int len)
  {
  #ifdef DEV_SPLASH
      /* make screensaver happy */
      if (!sticky_splash && scp == scp->sc->cur_scp && !sc_saver_keyb_only)
          run_scrn_saver = FALSE;
  #endif
  
      if (scp->tsw)
          (*scp->tsw->te_puts)(scp, buf, len);
  
      if (scp->sc->delayed_next_scr)
          sc_switch_scr(scp->sc, scp->sc->delayed_next_scr - 1);
  }
  
  void
  sc_draw_cursor_image(scr_stat *scp)
  {
      /* assert(scp == scp->sc->cur_scp); */
      ++scp->sc->videoio_in_progress;
      (*scp->rndr->draw_cursor)(scp, scp->cursor_pos,
                                scp->curs_attr.flags & CONS_BLINK_CURSOR, TRUE,
                                sc_inside_cutmark(scp, scp->cursor_pos));
      scp->cursor_oldpos = scp->cursor_pos;
      --scp->sc->videoio_in_progress;
  }
  
  void
  sc_remove_cursor_image(scr_stat *scp)
  {
      /* assert(scp == scp->sc->cur_scp); */
      ++scp->sc->videoio_in_progress;
      (*scp->rndr->draw_cursor)(scp, scp->cursor_oldpos,
                                scp->curs_attr.flags & CONS_BLINK_CURSOR, FALSE,
                                sc_inside_cutmark(scp, scp->cursor_oldpos));
      --scp->sc->videoio_in_progress;
  }
  
  static void
  update_cursor_image(scr_stat *scp)
  {
      /* assert(scp == scp->sc->cur_scp); */
      sc_remove_cursor_image(scp);
      sc_set_cursor_image(scp);
      sc_draw_cursor_image(scp);
  }
  
  void
  sc_set_cursor_image(scr_stat *scp)
  {
      scp->curs_attr.flags = scp->curr_curs_attr.flags;
      if (scp->curs_attr.flags & CONS_HIDDEN_CURSOR) {
          /* hidden cursor is internally represented as zero-height underline */
          scp->curs_attr.flags = CONS_CHAR_CURSOR;
          scp->curs_attr.base = scp->curs_attr.height = 0;
      } else if (scp->curs_attr.flags & CONS_CHAR_CURSOR) {
          scp->curs_attr.base = imin(scp->curr_curs_attr.base,
                                    scp->font_size - 1);
          scp->curs_attr.height = imin(scp->curr_curs_attr.height,
                                      scp->font_size - scp->curs_attr.base);
      } else {    /* block cursor */
          scp->curs_attr.base = 0;
          scp->curs_attr.height = scp->font_size;
      }
  
      /* assert(scp == scp->sc->cur_scp); */
      ++scp->sc->videoio_in_progress;
      (*scp->rndr->set_cursor)(scp, scp->curs_attr.base, scp->curs_attr.height,
                               scp->curs_attr.flags & CONS_BLINK_CURSOR);
      --scp->sc->videoio_in_progress;
  }
  
  static void
  change_cursor_shape(scr_stat *scp, int flags, int base, int height)
  {
      if ((scp == scp->sc->cur_scp) && !ISGRAPHSC(scp))
          sc_remove_cursor_image(scp);
  
      if (base >= 0)
          scp->curr_curs_attr.base = base;
      if (height >= 0)
          scp->curr_curs_attr.height = height;
      if (flags & CONS_RESET_CURSOR)
          scp->curr_curs_attr = scp->dflt_curs_attr;
      else
          scp->curr_curs_attr.flags = flags & CONS_CURSOR_ATTRS;
  
      if ((scp == scp->sc->cur_scp) && !ISGRAPHSC(scp)) {
          sc_set_cursor_image(scp);
          sc_draw_cursor_image(scp);
      }
  }
  
  void
  sc_change_cursor_shape(scr_stat *scp, int flags, int base, int height)
  {
      sc_softc_t *sc;
      dev_t dev;
      int s;
      int i;
  
      s = spltty();
      if ((flags != -1) && (flags & CONS_LOCAL_CURSOR)) {
          /* local (per vty) change */
          change_cursor_shape(scp, flags, base, height);
          splx(s);
          return;
      }
  
      /* global change */
      sc = scp->sc;
      if (base >= 0)
          sc->curs_attr.base = base;
      if (height >= 0)
          sc->curs_attr.height = height;
      if (flags != -1) {
          if (flags & CONS_RESET_CURSOR)
              sc->curs_attr = sc->dflt_curs_attr;
          else
              sc->curs_attr.flags = flags & CONS_CURSOR_ATTRS;
      }
  
      for (i = sc->first_vty; i < sc->first_vty + sc->vtys; ++i) {
          if ((dev = SC_DEV(sc, i)) == NODEV)
              continue;
          if ((scp = SC_STAT(dev)) == NULL)
              continue;
          scp->dflt_curs_attr = sc->curs_attr;
          change_cursor_shape(scp, CONS_RESET_CURSOR, -1, -1);
      }
      splx(s);
  }
  
  static void
  scinit(int unit, int flags)
  {
      /*
       * When syscons is being initialized as the kernel console, malloc()
       * is not yet functional, because various kernel structures has not been
       * fully initialized yet.  Therefore, we need to declare the following
       * static buffers for the console.  This is less than ideal, 
       * but is necessry evil for the time being.  XXX
       */
      static scr_stat main_console;
      static dev_t main_devs[MAXCONS];
      static struct tty main_tty;
  #ifndef PC98
      static u_short sc_buffer[ROW*COL];  /* XXX */
  #else
      static u_short sc_buffer[ROW*COL*2];/* XXX */
  #endif
  #ifndef SC_NO_FONT_LOADING
      static u_char font_8[256*8];
      static u_char font_14[256*14];
      static u_char font_16[256*16];
  #endif
  
      sc_softc_t *sc;
      scr_stat *scp;
      video_adapter_t *adp;
      int col;
      int row;
      int i;
  
      /* one time initialization */
      if (init_done == COLD)
          sc_get_bios_values(&bios_value);
      init_done = WARM;
  
      /*
       * Allocate resources.  Even if we are being called for the second
       * time, we must allocate them again, because they might have 
       * disappeared...
       */
      sc = sc_get_softc(unit, flags & SC_KERNEL_CONSOLE);
      adp = NULL;
      if (sc->adapter >= 0) {
          vid_release(sc->adp, (void *)&sc->adapter);
          adp = sc->adp;
          sc->adp = NULL;
      }
      if (sc->keyboard >= 0) {
          DPRINTF(5, ("sc%d: releasing kbd%d\n", unit, sc->keyboard));
          i = kbd_release(sc->kbd, (void *)&sc->keyboard);
          DPRINTF(5, ("sc%d: kbd_release returned %d\n", unit, i));
          if (sc->kbd != NULL) {
              DPRINTF(5, ("sc%d: kbd != NULL!, index:%d, unit:%d, flags:0x%x\n",
                  unit, sc->kbd->kb_index, sc->kbd->kb_unit, sc->kbd->kb_flags));
          }
          sc->kbd = NULL;
      }
      sc->adapter = vid_allocate("*", unit, (void *)&sc->adapter);
      sc->adp = vid_get_adapter(sc->adapter);
      /* assert((sc->adapter >= 0) && (sc->adp != NULL)) */
      sc->keyboard = kbd_allocate("*", unit, (void *)&sc->keyboard,
                                  sckbdevent, sc);
      DPRINTF(1, ("sc%d: keyboard %d\n", unit, sc->keyboard));
      sc->kbd = kbd_get_keyboard(sc->keyboard);
      if (sc->kbd != NULL) {
          DPRINTF(1, ("sc%d: kbd index:%d, unit:%d, flags:0x%x\n",
                  unit, sc->kbd->kb_index, sc->kbd->kb_unit, sc->kbd->kb_flags));
      }
  
      if (!(sc->flags & SC_INIT_DONE) || (adp != sc->adp)) {
  
          sc->initial_mode = sc->adp->va_initial_mode;
  
  #ifndef SC_NO_FONT_LOADING
          if (flags & SC_KERNEL_CONSOLE) {
              sc->font_8 = font_8;
              sc->font_14 = font_14;
              sc->font_16 = font_16;
          } else if (sc->font_8 == NULL) {
              /* assert(sc_malloc) */
              sc->font_8 = malloc(sizeof(font_8), M_DEVBUF, M_WAITOK);
              sc->font_14 = malloc(sizeof(font_14), M_DEVBUF, M_WAITOK);
              sc->font_16 = malloc(sizeof(font_16), M_DEVBUF, M_WAITOK);
          }
  #endif
  
          /* extract the hardware cursor location and hide the cursor for now */
          (*vidsw[sc->adapter]->read_hw_cursor)(sc->adp, &col, &row);
          (*vidsw[sc->adapter]->set_hw_cursor)(sc->adp, -1, -1);
  
          /* set up the first console */
          sc->first_vty = unit*MAXCONS;
          sc->vtys = MAXCONS;             /* XXX: should be configurable */
          if (flags & SC_KERNEL_CONSOLE) {
              sc->dev = main_devs;
              sc->dev[0] = makedev(CDEV_MAJOR, unit*MAXCONS);
              sc->dev[0]->si_tty = &main_tty;
              ttyregister(&main_tty);
              scp = &main_console;
              init_scp(sc, sc->first_vty, scp);
              sc_vtb_init(&scp->vtb, VTB_MEMORY, scp->xsize, scp->ysize,
                          (void *)sc_buffer, FALSE);
              if (sc_init_emulator(scp, SC_DFLT_TERM))
                  sc_init_emulator(scp, "*");
              (*scp->tsw->te_default_attr)(scp,
                                           kernel_default.std_color,
                                           kernel_default.rev_color);
          } else {
              /* assert(sc_malloc) */
              sc->dev = malloc(sizeof(dev_t)*sc->vtys, M_DEVBUF, M_WAITOK|M_ZERO);
              sc->dev[0] = makedev(CDEV_MAJOR, unit*MAXCONS);
              sc->dev[0]->si_tty = ttymalloc(sc->dev[0]->si_tty);
              scp = alloc_scp(sc, sc->first_vty);
          }
          SC_STAT(sc->dev[0]) = scp;
          sc->cur_scp = scp;
  
          /* copy screen to temporary buffer */
          sc_vtb_init(&scp->scr, VTB_FRAMEBUFFER, scp->xsize, scp->ysize,
                      (void *)scp->sc->adp->va_window, FALSE);
          if (ISTEXTSC(scp))
              sc_vtb_copy(&scp->scr, 0, &scp->vtb, 0, scp->xsize*scp->ysize);
  
          /* move cursors to the initial positions */
          scp->mouse_pos = scp->mouse_oldpos = 0;
          if (col >= scp->xsize)
              col = 0;
          if (row >= scp->ysize)
              row = scp->ysize - 1;
          scp->xpos = col;
          scp->ypos = row;
          scp->cursor_pos = scp->cursor_oldpos = row*scp->xsize + col;
  
          if (bios_value.cursor_end < scp->font_size)
              sc->dflt_curs_attr.base = scp->font_size - 
                                            bios_value.cursor_end - 1;
          else
              sc->dflt_curs_attr.base = 0;
          i = bios_value.cursor_end - bios_value.cursor_start + 1;
          sc->dflt_curs_attr.height = imin(i, scp->font_size);
          sc->dflt_curs_attr.flags = 0;
          sc->curs_attr = sc->dflt_curs_attr;
          scp->curr_curs_attr = scp->dflt_curs_attr = sc->curs_attr;
  
          if (!ISGRAPHSC(scp)) {
              sc_set_cursor_image(scp);
              sc_draw_cursor_image(scp);
          }
  
          /* save font and palette */
  #ifndef SC_NO_FONT_LOADING
          sc->fonts_loaded = 0;
          if (ISFONTAVAIL(sc->adp->va_flags)) {
  #ifdef SC_DFLT_FONT
              bcopy(dflt_font_8, sc->font_8, sizeof(dflt_font_8));
              bcopy(dflt_font_14, sc->font_14, sizeof(dflt_font_14));
              bcopy(dflt_font_16, sc->font_16, sizeof(dflt_font_16));
              sc->fonts_loaded = FONT_16 | FONT_14 | FONT_8;
              if (scp->font_size < 14) {
                  sc_load_font(scp, 0, 8, sc->font_8, 0, 256);
              } else if (scp->font_size >= 16) {
                  sc_load_font(scp, 0, 16, sc->font_16, 0, 256);
              } else {
                  sc_load_font(scp, 0, 14, sc->font_14, 0, 256);
              }
  #else /* !SC_DFLT_FONT */
              if (scp->font_size < 14) {
                  sc_save_font(scp, 0, 8, sc->font_8, 0, 256);
                  sc->fonts_loaded = FONT_8;
              } else if (scp->font_size >= 16) {
                  sc_save_font(scp, 0, 16, sc->font_16, 0, 256);
                  sc->fonts_loaded = FONT_16;
              } else {
                  sc_save_font(scp, 0, 14, sc->font_14, 0, 256);
                  sc->fonts_loaded = FONT_14;
              }
  #endif /* SC_DFLT_FONT */
              /* FONT KLUDGE: always use the font page #0. XXX */
              sc_show_font(scp, 0);
          }
  #endif /* !SC_NO_FONT_LOADING */
  
  #ifndef SC_NO_PALETTE_LOADING
          save_palette(sc->adp, sc->palette);
  #endif
  
  #ifdef DEV_SPLASH
          if (!(sc->flags & SC_SPLASH_SCRN) && (flags & SC_KERNEL_CONSOLE)) {
              /* we are ready to put up the splash image! */
              splash_init(sc->adp, scsplash_callback, sc);
              sc->flags |= SC_SPLASH_SCRN;
          }
  #endif
      }
  
      /* the rest is not necessary, if we have done it once */
      if (sc->flags & SC_INIT_DONE)
          return;
  
      /* initialize mapscrn arrays to a one to one map */
      for (i = 0; i < sizeof(sc->scr_map); i++)
          sc->scr_map[i] = sc->scr_rmap[i] = i;
  #ifdef PC98
      sc->scr_map[0x5c] = (u_char)0xfc;   /* for backslash */
  #endif
  
      sc->flags |= SC_INIT_DONE;
  }
  
  #if __i386__
  static void
  scterm(int unit, int flags)
  {
      sc_softc_t *sc;
      scr_stat *scp;
  
      sc = sc_get_softc(unit, flags & SC_KERNEL_CONSOLE);
      if (sc == NULL)
          return;                 /* shouldn't happen */
  
  #ifdef DEV_SPLASH
      /* this console is no longer available for the splash screen */
      if (sc->flags & SC_SPLASH_SCRN) {
          splash_term(sc->adp);
          sc->flags &= ~SC_SPLASH_SCRN;
      }
  #endif
  
      /* release the keyboard and the video card */
      if (sc->keyboard >= 0)
          kbd_release(sc->kbd, &sc->keyboard);
      if (sc->adapter >= 0)
          vid_release(sc->adp, &sc->adapter);
  
      /* stop the terminal emulator, if any */
      scp = SC_STAT(sc->dev[0]);
      if (scp->tsw)
          (*scp->tsw->te_term)(scp, &scp->ts);
      if (scp->ts != NULL)
          free(scp->ts, M_DEVBUF);
  
      /* clear the structure */
      if (!(flags & SC_KERNEL_CONSOLE)) {
          /* XXX: We need delete_dev() for this */
          free(sc->dev, M_DEVBUF);
  #if 0
          /* XXX: We need a ttyunregister for this */
          free(sc->tty, M_DEVBUF);
  #endif
  #ifndef SC_NO_FONT_LOADING
          free(sc->font_8, M_DEVBUF);
          free(sc->font_14, M_DEVBUF);
          free(sc->font_16, M_DEVBUF);
  #endif
          /* XXX vtb, history */
      }
      bzero(sc, sizeof(*sc));
      sc->keyboard = -1;
      sc->adapter = -1;
  }
  #endif
  
  static void
  scshutdown(void *arg, int howto)
  {
      /* assert(sc_console != NULL) */
  
      sc_touch_scrn_saver();
      if (!cold && sc_console
          && sc_console->sc->cur_scp->smode.mode == VT_AUTO 
          && sc_console->smode.mode == VT_AUTO)
          sc_switch_scr(sc_console->sc, sc_console->index);
      shutdown_in_progress = TRUE;
  }
  
  int
  sc_clean_up(scr_stat *scp)
  {
  #ifdef DEV_SPLASH
      int error;
  #endif
  
      if (scp->sc->flags & SC_SCRN_BLANKED) {
          sc_touch_scrn_saver();
  #ifdef DEV_SPLASH
          if ((error = wait_scrn_saver_stop(scp->sc)))
              return error;
  #endif
      }
      scp->status &= ~MOUSE_VISIBLE;
      sc_remove_cutmarking(scp);
      return 0;
  }
  
  void
  sc_alloc_scr_buffer(scr_stat *scp, int wait, int discard)
  {
      sc_vtb_t new;
      sc_vtb_t old;
  
      old = scp->vtb;
      sc_vtb_init(&new, VTB_MEMORY, scp->xsize, scp->ysize, NULL, wait);
      if (!discard && (old.vtb_flags & VTB_VALID)) {
          /* retain the current cursor position and buffer contants */
          scp->cursor_oldpos = scp->cursor_pos;
          /* 
           * This works only if the old buffer has the same size as or larger 
           * than the new one. XXX
           */
          sc_vtb_copy(&old, 0, &new, 0, scp->xsize*scp->ysize);
          scp->vtb = new;
      } else {
          scp->vtb = new;
          sc_vtb_destroy(&old);
      }
  
  #ifndef SC_NO_SYSMOUSE
      /* move the mouse cursor at the center of the screen */
      sc_mouse_move(scp, scp->xpixel / 2, scp->ypixel / 2);
  #endif
  }
  
  static scr_stat
  *alloc_scp(sc_softc_t *sc, int vty)
  {
      scr_stat *scp;
  
      /* assert(sc_malloc) */
  
      scp = (scr_stat *)malloc(sizeof(scr_stat), M_DEVBUF, M_WAITOK);
      init_scp(sc, vty, scp);
  
      sc_alloc_scr_buffer(scp, TRUE, TRUE);
      if (sc_init_emulator(scp, SC_DFLT_TERM))
          sc_init_emulator(scp, "*");
  
  #ifndef SC_NO_CUTPASTE
      sc_alloc_cut_buffer(scp, TRUE);
  #endif
  
  #ifndef SC_NO_HISTORY
      sc_alloc_history_buffer(scp, 0, 0, TRUE);
  #endif
  
      return scp;
  }
  
  static void
  init_scp(sc_softc_t *sc, int vty, scr_stat *scp)
  {
      video_info_t info;
  
      bzero(scp, sizeof(*scp));
  
      scp->index = vty;
      scp->sc = sc;
      scp->status = 0;
      scp->mode = sc->initial_mode;
      (*vidsw[sc->adapter]->get_info)(sc->adp, scp->mode, &info);
      if (info.vi_flags & V_INFO_GRAPHICS) {
          scp->status |= GRAPHICS_MODE;
          scp->xpixel = info.vi_width;
          scp->ypixel = info.vi_height;
          scp->xsize = info.vi_width/info.vi_cwidth;
          scp->ysize = info.vi_height/info.vi_cheight;
          scp->font_size = 0;
          scp->font = NULL;
      } else {
          scp->xsize = info.vi_width;
          scp->ysize = info.vi_height;
          scp->xpixel = scp->xsize*info.vi_cwidth;
          scp->ypixel = scp->ysize*info.vi_cheight;
          if (info.vi_cheight < 14) {
              scp->font_size = 8;
  #ifndef SC_NO_FONT_LOADING
              scp->font = sc->font_8;
  #else
              scp->font = NULL;
  #endif
          } else if (info.vi_cheight >= 16) {
              scp->font_size = 16;
  #ifndef SC_NO_FONT_LOADING
              scp->font = sc->font_16;
  #else
              scp->font = NULL;
  #endif
          } else {
              scp->font_size = 14;
  #ifndef SC_NO_FONT_LOADING
              scp->font = sc->font_14;
  #else
              scp->font = NULL;
  #endif
          }
      }
      sc_vtb_init(&scp->vtb, VTB_MEMORY, 0, 0, NULL, FALSE);
      sc_vtb_init(&scp->scr, VTB_FRAMEBUFFER, 0, 0, NULL, FALSE);
      scp->xoff = scp->yoff = 0;
      scp->xpos = scp->ypos = 0;
      scp->start = scp->xsize * scp->ysize - 1;
      scp->end = 0;
      scp->tsw = NULL;
      scp->ts = NULL;
      scp->rndr = NULL;
      scp->border = BG_BLACK;
      scp->curr_curs_attr = scp->dflt_curs_attr = sc->curs_attr;
      scp->mouse_xpos = scp->xoff*8 + scp->xsize*8/2;
      scp->mouse_ypos = (scp->ysize + scp->yoff)*scp->font_size/2;
      scp->mouse_cut_start = scp->xsize*scp->ysize;
      scp->mouse_cut_end = -1;
      scp->mouse_signal = 0;
      scp->mouse_pid = 0;
      scp->mouse_proc = NULL;
      scp->kbd_mode = K_XLATE;
      scp->bell_pitch = bios_value.bell_pitch;
      scp->bell_duration = BELL_DURATION;
      scp->status |= (bios_value.shift_state & NLKED);
      scp->status |= CURSOR_ENABLED;
      scp->pid = 0;
      scp->proc = NULL;
      scp->smode.mode = VT_AUTO;
      scp->history = NULL;
      scp->history_pos = 0;
      scp->history_size = 0;
  }
  
  int
  sc_init_emulator(scr_stat *scp, char *name)
  {
      sc_term_sw_t *sw;
      sc_rndr_sw_t *rndr;
      void *p;
      int error;
  
      if (name == NULL)   /* if no name is given, use the current emulator */
          sw = scp->tsw;
      else                /* ...otherwise find the named emulator */
          sw = sc_term_match(name);
      if (sw == NULL)
          return EINVAL;
  
      rndr = NULL;
      if (strcmp(sw->te_renderer, "*") != 0) {
          rndr = sc_render_match(scp, sw->te_renderer,
                                 scp->status & (GRAPHICS_MODE | PIXEL_MODE));
      }
      if (rndr == NULL) {
          rndr = sc_render_match(scp, scp->sc->adp->va_name,
                                 scp->status & (GRAPHICS_MODE | PIXEL_MODE));
          if (rndr == NULL)
              return ENODEV;
      }
  
      if (sw == scp->tsw) {
          error = (*sw->te_init)(scp, &scp->ts, SC_TE_WARM_INIT);
          scp->rndr = rndr;
          sc_clear_screen(scp);
          /* assert(error == 0); */
          return error;
      }
  
      if (sc_malloc && (sw->te_size > 0))
          p = malloc(sw->te_size, M_DEVBUF, M_NOWAIT);
      else
          p = NULL;
      error = (*sw->te_init)(scp, &p, SC_TE_COLD_INIT);
      if (error)
          return error;
  
      if (scp->tsw)
          (*scp->tsw->te_term)(scp, &scp->ts);
      if (scp->ts != NULL)
          free(scp->ts, M_DEVBUF);
      scp->tsw = sw;
      scp->ts = p;
      scp->rndr = rndr;
  
      /* XXX */
      (*sw->te_default_attr)(scp, user_default.std_color, user_default.rev_color);
      sc_clear_screen(scp);
  
      return 0;
  }
  
  /*
   * scgetc(flags) - get character from keyboard.
   * If flags & SCGETC_CN, then avoid harmful side effects.
   * If flags & SCGETC_NONBLOCK, then wait until a key is pressed, else
   * return NOKEY if there is nothing there.
   */
  static u_int
  scgetc(sc_softc_t *sc, u_int flags)
  {
      scr_stat *scp;
  #ifndef SC_NO_HISTORY
      struct tty *tp;
  #endif
      u_int c;
      int this_scr;
      int f;
      int i;
  
      if (sc->kbd == NULL)
          return NOKEY;
  
  next_code:
  #if 1
      /* I don't like this, but... XXX */
      if (flags & SCGETC_CN)
          sccnupdate(sc->cur_scp);
  #endif
      scp = sc->cur_scp;
      /* first see if there is something in the keyboard port */
      for (;;) {
          c = kbd_read_char(sc->kbd, !(flags & SCGETC_NONBLOCK));
          if (c == ERRKEY) {
              if (!(flags & SCGETC_CN))
                  sc_bell(scp, bios_value.bell_pitch, BELL_DURATION);
          } else if (c == NOKEY)
              return c;
          else
              break;
      }
  
      /* make screensaver happy */
      if (!(c & RELKEY))
          sc_touch_scrn_saver();
  
      if (!(flags & SCGETC_CN))
          random_harvest(&c, sizeof(c), 1, 0, RANDOM_KEYBOARD);
  
      if (scp->kbd_mode != K_XLATE)
          return KEYCHAR(c);
  
      /* if scroll-lock pressed allow history browsing */
      if (!ISGRAPHSC(scp) && scp->history && scp->status & SLKED) {
  
          scp->status &= ~CURSOR_ENABLED;
          sc_remove_cursor_image(scp);
  
  #ifndef SC_NO_HISTORY
          if (!(scp->status & BUFFER_SAVED)) {
              scp->status |= BUFFER_SAVED;
              sc_hist_save(scp);
          }
          switch (c) {
          /* FIXME: key codes */
          case SPCLKEY | FKEY | F(49):  /* home key */
              sc_remove_cutmarking(scp);
              sc_hist_home(scp);
              goto next_code;
  
          case SPCLKEY | FKEY | F(57):  /* end key */
              sc_remove_cutmarking(scp);
              sc_hist_end(scp);
              goto next_code;
  
          case SPCLKEY | FKEY | F(50):  /* up arrow key */
              sc_remove_cutmarking(scp);
              if (sc_hist_up_line(scp))
                  if (!(flags & SCGETC_CN))
                      sc_bell(scp, bios_value.bell_pitch, BELL_DURATION);
              goto next_code;
  
          case SPCLKEY | FKEY | F(58):  /* down arrow key */
              sc_remove_cutmarking(scp);
              if (sc_hist_down_line(scp))
                  if (!(flags & SCGETC_CN))
                      sc_bell(scp, bios_value.bell_pitch, BELL_DURATION);
              goto next_code;
  
          case SPCLKEY | FKEY | F(51):  /* page up key */
              sc_remove_cutmarking(scp);
              for (i=0; i<scp->ysize; i++)
              if (sc_hist_up_line(scp)) {
                  if (!(flags & SCGETC_CN))
                      sc_bell(scp, bios_value.bell_pitch, BELL_DURATION);
                  break;
              }
              goto next_code;
  
          case SPCLKEY | FKEY | F(59):  /* page down key */
              sc_remove_cutmarking(scp);
              for (i=0; i<scp->ysize; i++)
              if (sc_hist_down_line(scp)) {
                  if (!(flags & SCGETC_CN))
                      sc_bell(scp, bios_value.bell_pitch, BELL_DURATION);
                  break;
              }
              goto next_code;
          }
  #endif /* SC_NO_HISTORY */
      }
  
      /* 
       * Process and consume special keys here.  Return a plain char code
       * or a char code with the META flag or a function key code.
       */
      if (c & RELKEY) {
          /* key released */
          /* goto next_code */
      } else {
          /* key pressed */
          if (c & SPCLKEY) {
              c &= ~SPCLKEY;
              switch (KEYCHAR(c)) {
              /* LOCKING KEYS */
              case NLK: case CLK: case ALK:
                  break;
              case SLK:
                  kbd_ioctl(sc->kbd, KDGKBSTATE, (caddr_t)&f);
                  if (f & SLKED) {
                      scp->status |= SLKED;
                  } else {
                      if (scp->status & SLKED) {
                          scp->status &= ~SLKED;
  #ifndef SC_NO_HISTORY
                          if (scp->status & BUFFER_SAVED) {
                              if (!sc_hist_restore(scp))
                                  sc_remove_cutmarking(scp);
                              scp->status &= ~BUFFER_SAVED;
                              scp->status |= CURSOR_ENABLED;
                              sc_draw_cursor_image(scp);
                          }
                          tp = VIRTUAL_TTY(sc, scp->index);
                          if (ISTTYOPEN(tp))
                              scstart(tp);
  #endif
                      }
                  }
                  break;
  
              case PASTE:
  #ifndef SC_NO_CUTPASTE
                  sc_mouse_paste(scp);
  #endif
                  break;
  
              /* NON-LOCKING KEYS */
              case NOP:
              case LSH:  case RSH:  case LCTR: case RCTR:
              case LALT: case RALT: case ASH:  case META:
                  break;
  
              case BTAB:
                  if (!(sc->flags & SC_SCRN_BLANKED))
                      return c;
                  break;
  
              case SPSC:
  #ifdef DEV_SPLASH
                  /* force activatation/deactivation of the screen saver */
                  if (!(sc->flags & SC_SCRN_BLANKED)) {
                      run_scrn_saver = TRUE;
                      sc->scrn_time_stamp -= scrn_blank_time;
                  }
                  if (cold) {
                      /*
                       * While devices are being probed, the screen saver need
                       * to be invoked explictly. XXX
                       */
                      if (sc->flags & SC_SCRN_BLANKED) {
                          scsplash_stick(FALSE);
                          stop_scrn_saver(sc, current_saver);
                      } else {
                          if (!ISGRAPHSC(scp)) {
                              scsplash_stick(TRUE);
                              (*current_saver)(sc, TRUE);
                          }
                      }
                  }
  #endif /* DEV_SPLASH */
                  break;
  
              case RBT:
  #ifndef SC_DISABLE_REBOOT
                  shutdown_nice(0);
  #endif
                  break;
  
              case HALT:
  #ifndef SC_DISABLE_REBOOT
                  shutdown_nice(RB_HALT);
  #endif
                  break;
  
              case PDWN:
  #ifndef SC_DISABLE_REBOOT
                  shutdown_nice(RB_HALT|RB_POWEROFF);
  #endif
                  break;
  
              case SUSP:
                  power_pm_suspend(POWER_SLEEP_STATE_SUSPEND);
                  break;
              case STBY:
                  power_pm_suspend(POWER_SLEEP_STATE_STANDBY);
                  break;
  
              case DBG:
  #ifndef SC_DISABLE_DDBKEY
  #ifdef DDB
                  Debugger("manual escape to debugger");
  #else
                  printf("No debugger in kernel\n");
  #endif
  #else /* SC_DISABLE_DDBKEY */
                  /* do nothing */
  #endif /* SC_DISABLE_DDBKEY */
                  break;
  
              case PNC:
                  if (enable_panic_key)
                          panic("Forced by the panic key");
                  break;
  
              case NEXT:
                  this_scr = scp->index;
                  for (i = (this_scr - sc->first_vty + 1)%sc->vtys;
                          sc->first_vty + i != this_scr; 
                          i = (i + 1)%sc->vtys) {
                      struct tty *tp = VIRTUAL_TTY(sc, sc->first_vty + i);
                      if (ISTTYOPEN(tp)) {
                          sc_switch_scr(scp->sc, sc->first_vty + i);
                          break;
                      }
                  }
                  break;
  
              case PREV:
                  this_scr = scp->index;
                  for (i = (this_scr - sc->first_vty + sc->vtys - 1)%sc->vtys;
                          sc->first_vty + i != this_scr;
                          i = (i + sc->vtys - 1)%sc->vtys) {
                      struct tty *tp = VIRTUAL_TTY(sc, sc->first_vty + i);
                      if (ISTTYOPEN(tp)) {
                          sc_switch_scr(scp->sc, sc->first_vty + i);
                          break;
                      }
                  }
                  break;
  
              default:
                  if (KEYCHAR(c) >= F_SCR && KEYCHAR(c) <= L_SCR) {
                      sc_switch_scr(scp->sc, sc->first_vty + KEYCHAR(c) - F_SCR);
                      break;
                  }
                  /* assert(c & FKEY) */
                  if (!(sc->flags & SC_SCRN_BLANKED))
                      return c;
                  break;
              }
              /* goto next_code */
          } else {
              /* regular keys (maybe MKEY is set) */
              if (!(sc->flags & SC_SCRN_BLANKED))
                  return c;
          }
      }
  
      goto next_code;
  }
  
  static int
  scmmap(dev_t dev, vm_offset_t offset, int nprot)
  {
      scr_stat *scp;
  
      scp = SC_STAT(dev);
      if (scp != scp->sc->cur_scp)
          return -1;
      return (*vidsw[scp->sc->adapter]->mmap)(scp->sc->adp, offset, nprot);
  }
  
  static int
  save_kbd_state(scr_stat *scp)
  {
      int state;
      int error;
  
      error = kbd_ioctl(scp->sc->kbd, KDGKBSTATE, (caddr_t)&state);
      if (error == ENOIOCTL)
          error = ENODEV;
      if (error == 0) {
          scp->status &= ~LOCK_MASK;
          scp->status |= state;
      }
      return error;
  }
  
  static int
  update_kbd_state(scr_stat *scp, int new_bits, int mask)
  {
      int state;
      int error;
  
      if (mask != LOCK_MASK) {
          error = kbd_ioctl(scp->sc->kbd, KDGKBSTATE, (caddr_t)&state);
          if (error == ENOIOCTL)
              error = ENODEV;
          if (error)
              return error;
          state &= ~mask;
          state |= new_bits & mask;
      } else {
          state = new_bits & LOCK_MASK;
      }
      error = kbd_ioctl(scp->sc->kbd, KDSKBSTATE, (caddr_t)&state);
      if (error == ENOIOCTL)
          error = ENODEV;
      return error;
  }
  
  static int
  update_kbd_leds(scr_stat *scp, int which)
  {
      int error;
  
      which &= LOCK_MASK;
      error = kbd_ioctl(scp->sc->kbd, KDSETLED, (caddr_t)&which);
      if (error == ENOIOCTL)
          error = ENODEV;
      return error;
  }
  
  int
  set_mode(scr_stat *scp)
  {
      video_info_t info;
  
      /* reject unsupported mode */
      if ((*vidsw[scp->sc->adapter]->get_info)(scp->sc->adp, scp->mode, &info))
          return 1;
  
      /* if this vty is not currently showing, do nothing */
      if (scp != scp->sc->cur_scp)
          return 0;
  
      /* setup video hardware for the given mode */
      (*vidsw[scp->sc->adapter]->set_mode)(scp->sc->adp, scp->mode);
      sc_vtb_init(&scp->scr, VTB_FRAMEBUFFER, scp->xsize, scp->ysize,
                  (void *)scp->sc->adp->va_window, FALSE);
  
  #ifndef SC_NO_FONT_LOADING
      /* load appropriate font */
      if (!(scp->status & GRAPHICS_MODE)) {
          if (!(scp->status & PIXEL_MODE) && ISFONTAVAIL(scp->sc->adp->va_flags)) {
              if (scp->font_size < 14) {
                  if (scp->sc->fonts_loaded & FONT_8)
                      sc_load_font(scp, 0, 8, scp->sc->font_8, 0, 256);
              } else if (scp->font_size >= 16) {
                  if (scp->sc->fonts_loaded & FONT_16)
                      sc_load_font(scp, 0, 16, scp->sc->font_16, 0, 256);
              } else {
                  if (scp->sc->fonts_loaded & FONT_14)
                      sc_load_font(scp, 0, 14, scp->sc->font_14, 0, 256);
              }
              /*
               * FONT KLUDGE:
               * This is an interim kludge to display correct font.
               * Always use the font page #0 on the video plane 2.
               * Somehow we cannot show the font in other font pages on
               * some video cards... XXX
               */ 
              sc_show_font(scp, 0);
          }
          mark_all(scp);
      }
  #endif /* !SC_NO_FONT_LOADING */
  
      sc_set_border(scp, scp->border);
      sc_set_cursor_image(scp);
  
      return 0;
  }
  
  void
  sc_set_border(scr_stat *scp, int color)
  {
      ++scp->sc->videoio_in_progress;
      (*scp->rndr->draw_border)(scp, color);
      --scp->sc->videoio_in_progress;
  }
  
  #ifndef SC_NO_FONT_LOADING
  void
  sc_load_font(scr_stat *scp, int page, int size, u_char *buf,
               int base, int count)
  {
      sc_softc_t *sc;
  
      sc = scp->sc;
      sc->font_loading_in_progress = TRUE;
      (*vidsw[sc->adapter]->load_font)(sc->adp, page, size, buf, base, count);
      sc->font_loading_in_progress = FALSE;
  }
  
  void
  sc_save_font(scr_stat *scp, int page, int size, u_char *buf,
               int base, int count)
  {
      sc_softc_t *sc;
  
      sc = scp->sc;
      sc->font_loading_in_progress = TRUE;
      (*vidsw[sc->adapter]->save_font)(sc->adp, page, size, buf, base, count);
      sc->font_loading_in_progress = FALSE;
  }
  
  void
  sc_show_font(scr_stat *scp, int page)
  {
      (*vidsw[scp->sc->adapter]->show_font)(scp->sc->adp, page);
  }
  #endif /* !SC_NO_FONT_LOADING */
  
  void
  sc_paste(scr_stat *scp, u_char *p, int count) 
  {
      struct tty *tp;
      u_char *rmap;
  
      if (scp->status & MOUSE_VISIBLE) {
          tp = VIRTUAL_TTY(scp->sc, scp->sc->cur_scp->index);
          if (!ISTTYOPEN(tp))
              return;
          rmap = scp->sc->scr_rmap;
          for (; count > 0; --count)
              (*linesw[tp->t_line].l_rint)(rmap[*p++], tp);
      }
  }
  
  void
  sc_bell(scr_stat *scp, int pitch, int duration)
  {
      if (cold || shutdown_in_progress)
          return;
  
      if (scp != scp->sc->cur_scp && (scp->sc->flags & SC_QUIET_BELL))
          return;
  
      if (scp->sc->flags & SC_VISUAL_BELL) {
          if (scp->sc->blink_in_progress)
              return;
          scp->sc->blink_in_progress = 3;
          if (scp != scp->sc->cur_scp)
              scp->sc->blink_in_progress += 2;
          blink_screen(scp->sc->cur_scp);
      } else {
          if (scp != scp->sc->cur_scp)
              pitch *= 2;
          sysbeep(pitch, duration);
      }
  }
  
  static void
  blink_screen(void *arg)
  {
      scr_stat *scp = arg;
      struct tty *tp;
  
      if (ISGRAPHSC(scp) || (scp->sc->blink_in_progress <= 1)) {
          scp->sc->blink_in_progress = 0;
          mark_all(scp);
          tp = VIRTUAL_TTY(scp->sc, scp->index);
          if (ISTTYOPEN(tp))
              scstart(tp);
          if (scp->sc->delayed_next_scr)
              sc_switch_scr(scp->sc, scp->sc->delayed_next_scr - 1);
      }
      else {
          (*scp->rndr->draw)(scp, 0, scp->xsize*scp->ysize, 
                             scp->sc->blink_in_progress & 1);
          scp->sc->blink_in_progress--;
          timeout(blink_screen, scp, hz / 10);
      }
  }