/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2009, 2013 The FreeBSD Foundation
 *
 * This software was developed by Ed Schouten under sponsorship from the
 * FreeBSD Foundation.
 *
 * Portions of this software were developed by Oleksandr Rybalko
 * under sponsorship from the FreeBSD Foundation.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/param.h>
#include <sys/consio.h>
#include <sys/devctl.h>
#include <sys/eventhandler.h>
#include <sys/fbio.h>
#include <sys/font.h>
#include <sys/kbio.h>
#include <sys/kdb.h>
#include <sys/kernel.h>
#include <sys/linker.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mutex.h>
#include <sys/splash.h>
#include <sys/power.h>
#include <sys/priv.h>
#include <sys/proc.h>
#include <sys/random.h>
#include <sys/reboot.h>
#include <sys/sbuf.h>
#include <sys/systm.h>
#include <sys/terminal.h>

#include <dev/kbd/kbdreg.h>
#include <dev/vt/vt.h>

#if defined(__i386__) || defined(__amd64__)
#include <machine/psl.h>
#include <machine/frame.h>
#endif

static int vtterm_cngrab_noswitch(struct vt_device *, struct vt_window *);
static int vtterm_cnungrab_noswitch(struct vt_device *, struct vt_window *);

static tc_bell_t        vtterm_bell;
static tc_cursor_t      vtterm_cursor;
static tc_putchar_t     vtterm_putchar;
static tc_fill_t        vtterm_fill;
static tc_copy_t        vtterm_copy;
static tc_pre_input_t   vtterm_pre_input;
static tc_post_input_t  vtterm_post_input;
static tc_param_t       vtterm_param;
static tc_done_t        vtterm_done;

static tc_cnprobe_t     vtterm_cnprobe;
static tc_cngetc_t      vtterm_cngetc;

static tc_cngrab_t      vtterm_cngrab;
static tc_cnungrab_t    vtterm_cnungrab;

static tc_opened_t      vtterm_opened;
static tc_ioctl_t       vtterm_ioctl;
static tc_mmap_t        vtterm_mmap;

static const struct terminal_class vt_termclass = {
        .tc_bell        = vtterm_bell,
        .tc_cursor      = vtterm_cursor,
        .tc_putchar     = vtterm_putchar,
        .tc_fill        = vtterm_fill,
        .tc_copy        = vtterm_copy,
        .tc_pre_input   = vtterm_pre_input,
        .tc_post_input  = vtterm_post_input,
        .tc_param       = vtterm_param,
        .tc_done        = vtterm_done,

        .tc_cnprobe     = vtterm_cnprobe,
        .tc_cngetc      = vtterm_cngetc,

        .tc_cngrab      = vtterm_cngrab,
        .tc_cnungrab    = vtterm_cnungrab,

        .tc_opened      = vtterm_opened,
        .tc_ioctl       = vtterm_ioctl,
        .tc_mmap        = vtterm_mmap,
};

/*
 * Use a constant timer of 25 Hz to redraw the screen.
 *
 * XXX: In theory we should only fire up the timer when there is really
 * activity. Unfortunately we cannot always start timers. We really
 * don't want to process kernel messages synchronously, because it
 * really slows down the system.
 */
#define VT_TIMERFREQ    25

/* Bell pitch/duration. */
#define VT_BELLDURATION (SBT_1S / 20)
#define VT_BELLPITCH    800

#define VT_UNIT(vw)     ((vw)->vw_device->vd_unit * VT_MAXWINDOWS + \
                        (vw)->vw_number)

static SYSCTL_NODE(_kern, OID_AUTO, vt, CTLFLAG_RD | CTLFLAG_MPSAFE, 0,
    "vt(4) parameters");
static VT_SYSCTL_INT(enable_altgr, 1, "Enable AltGr key (Do not assume R.Alt as Alt)");
static VT_SYSCTL_INT(enable_bell, 0, "Enable bell");
static VT_SYSCTL_INT(debug, 0, "vt(4) debug level");
static VT_SYSCTL_INT(deadtimer, 15, "Time to wait busy process in VT_PROCESS mode");
static VT_SYSCTL_INT(suspendswitch, 1, "Switch to VT0 before suspend");

/* Slow down and dont rely on timers and interrupts */
static VT_SYSCTL_INT(slow_down, 0, "Non-zero make console slower and synchronous.");

/* Allow to disable some keyboard combinations. */
static VT_SYSCTL_INT(kbd_halt, 1, "Enable halt keyboard combination.  "
    "See kbdmap(5) to configure.");
static VT_SYSCTL_INT(kbd_poweroff, 1, "Enable Power Off keyboard combination.  "
    "See kbdmap(5) to configure.");
static VT_SYSCTL_INT(kbd_reboot, 1, "Enable reboot keyboard combination.  "
    "See kbdmap(5) to configure (typically Ctrl-Alt-Delete).");
static VT_SYSCTL_INT(kbd_debug, 1, "Enable key combination to enter debugger.  "
    "See kbdmap(5) to configure (typically Ctrl-Alt-Esc).");
static VT_SYSCTL_INT(kbd_panic, 0, "Enable request to panic.  "
    "See kbdmap(5) to configure.");

/* Used internally, not a tunable. */
int vt_draw_logo_cpus;
VT_SYSCTL_INT(splash_cpu, 0, "Show logo CPUs during boot");
VT_SYSCTL_INT(splash_ncpu, 0, "Override number of logos displayed "
    "(0 = do not override)");
VT_SYSCTL_INT(splash_cpu_style, 2, "Draw logo style "
    "(0 = Alternate beastie, 1 = Beastie, 2 = Orb)");
VT_SYSCTL_INT(splash_cpu_duration, 10, "Hide logos after (seconds)");

static unsigned int vt_unit = 0;
static MALLOC_DEFINE(M_VT, "vt", "vt device");
struct vt_device *main_vd = &vt_consdev;

/* Boot logo. */
extern unsigned int vt_logo_width;
extern unsigned int vt_logo_height;
extern unsigned int vt_logo_depth;
extern unsigned char vt_logo_image[];
#ifndef DEV_SPLASH
#define vtterm_draw_cpu_logos(...)      do {} while (0)
const unsigned int vt_logo_sprite_height;
#endif

/*
 * Console font. vt_font_loader will be filled with font data passed
 * by loader. If there is no font passed by boot loader, we use built in
 * default.
 */
extern struct vt_font vt_font_default;
static struct vt_font vt_font_loader;
static struct vt_font *vt_font_assigned = &vt_font_default;

#ifndef SC_NO_CUTPASTE
extern struct vt_mouse_cursor vt_default_mouse_pointer;
#endif

static int signal_vt_rel(struct vt_window *);
static int signal_vt_acq(struct vt_window *);
static int finish_vt_rel(struct vt_window *, int, int *);
static int finish_vt_acq(struct vt_window *);
static int vt_window_switch(struct vt_window *);
static int vt_late_window_switch(struct vt_window *);
static int vt_proc_alive(struct vt_window *);
static void vt_resize(struct vt_device *);
static void vt_update_static(void *);
#ifndef SC_NO_CUTPASTE
static void vt_mouse_paste(void);
#endif
static void vt_suspend_handler(void *priv, enum power_stype stype);
static void vt_resume_handler(void *priv, enum power_stype stype);

SET_DECLARE(vt_drv_set, struct vt_driver);

#define _VTDEFH MAX(100, PIXEL_HEIGHT(VT_FB_MAX_HEIGHT))
#define _VTDEFW MAX(200, PIXEL_WIDTH(VT_FB_MAX_WIDTH))

static struct terminal  vt_consterm;
static struct vt_window vt_conswindow;
static term_char_t vt_consdrawn[PIXEL_HEIGHT(VT_FB_MAX_HEIGHT) * PIXEL_WIDTH(VT_FB_MAX_WIDTH)];
static term_color_t vt_consdrawnfg[PIXEL_HEIGHT(VT_FB_MAX_HEIGHT) * PIXEL_WIDTH(VT_FB_MAX_WIDTH)];
static term_color_t vt_consdrawnbg[PIXEL_HEIGHT(VT_FB_MAX_HEIGHT) * PIXEL_WIDTH(VT_FB_MAX_WIDTH)];
static bool vt_cons_pos_to_flush[PIXEL_HEIGHT(VT_FB_MAX_HEIGHT) * PIXEL_WIDTH(VT_FB_MAX_WIDTH)];
struct vt_device        vt_consdev = {
        .vd_driver = NULL,
        .vd_softc = NULL,
        .vd_prev_driver = NULL,
        .vd_prev_softc = NULL,
        .vd_flags = VDF_INVALID,
        .vd_windows = { [VT_CONSWINDOW] =  &vt_conswindow, },
        .vd_curwindow = &vt_conswindow,
        .vd_kbstate = 0,

#ifndef SC_NO_CUTPASTE
        .vd_pastebuf = {
                .vpb_buf = NULL,
                .vpb_bufsz = 0,
                .vpb_len = 0
        },
        .vd_mcursor = &vt_default_mouse_pointer,
        .vd_mcursor_fg = TC_WHITE,
        .vd_mcursor_bg = TC_BLACK,
#endif

        .vd_drawn = vt_consdrawn,
        .vd_drawnfg = vt_consdrawnfg,
        .vd_drawnbg = vt_consdrawnbg,

        .vd_pos_to_flush = vt_cons_pos_to_flush,
};
static term_char_t vt_constextbuf[(_VTDEFW) * (VBF_DEFAULT_HISTORY_SIZE)];
static term_char_t *vt_constextbufrows[VBF_DEFAULT_HISTORY_SIZE];
static struct vt_window vt_conswindow = {
        .vw_number = VT_CONSWINDOW,
        .vw_flags = VWF_CONSOLE,
        .vw_buf = {
                .vb_buffer = &vt_constextbuf[0],
                .vb_rows = &vt_constextbufrows[0],
                .vb_history_size = VBF_DEFAULT_HISTORY_SIZE,
                .vb_curroffset = 0,
                .vb_roffset = 0,
                .vb_flags = VBF_STATIC,
                .vb_mark_start = {.tp_row = 0, .tp_col = 0,},
                .vb_mark_end = {.tp_row = 0, .tp_col = 0,},
                .vb_scr_size = {
                        .tp_row = _VTDEFH,
                        .tp_col = _VTDEFW,
                },
        },
        .vw_device = &vt_consdev,
        .vw_terminal = &vt_consterm,
        .vw_kbdmode = K_XLATE,
        .vw_grabbed = 0,
        .vw_bell_pitch = VT_BELLPITCH,
        .vw_bell_duration = VT_BELLDURATION,
};

/* Add to set of consoles. */
TERMINAL_DECLARE_EARLY(vt_consterm, vt_termclass, &vt_conswindow);

/*
 * Right after kmem is done to allow early drivers to use locking and allocate
 * memory.
 */
SYSINIT(vt_update_static, SI_SUB_KMEM, SI_ORDER_ANY, vt_update_static,
    &vt_consdev);
/* Delay until all devices attached, to not waste time. */
SYSINIT(vt_early_cons, SI_SUB_INT_CONFIG_HOOKS, SI_ORDER_ANY, vt_upgrade,
    &vt_consdev);

static bool inside_vt_flush = false;
static bool inside_vt_window_switch = false;

/* Initialize locks/mem depended members. */
static void
vt_update_static(void *dummy)
{

        if (!vty_enabled(VTY_VT))
                return;
        if (main_vd->vd_driver != NULL)
                printf("VT(%s): %s %ux%u\n", main_vd->vd_driver->vd_name,
                    (main_vd->vd_flags & VDF_TEXTMODE) ? "text" : "resolution",
                    main_vd->vd_width, main_vd->vd_height);
        else
                printf("VT: init without driver.\n");

        mtx_init(&main_vd->vd_lock, "vtdev", NULL, MTX_DEF);
        mtx_init(&main_vd->vd_flush_lock, "vtdev flush", NULL, MTX_DEF);
        cv_init(&main_vd->vd_winswitch, "vtwswt");
}

static void
vt_schedule_flush(struct vt_device *vd, int ms)
{

        if (ms <= 0)
                /* Default to initial value. */
                ms = 1000 / VT_TIMERFREQ;

        callout_schedule(&vd->vd_timer, hz / (1000 / ms));
}

void
vt_resume_flush_timer(struct vt_window *vw, int ms)
{
        struct vt_device *vd = vw->vw_device;

        if (vd->vd_curwindow != vw)
                return;

        if (!(vd->vd_flags & VDF_ASYNC) ||
            !atomic_cmpset_int(&vd->vd_timer_armed, 0, 1))
                return;

        vt_schedule_flush(vd, ms);
}

static void
vt_suspend_flush_timer(struct vt_device *vd)
{
        /*
         * As long as this function is called locked, callout_stop()
         * has the same effect like callout_drain() with regard to
         * preventing the callback function from executing.
         */
        VT_LOCK_ASSERT(vd, MA_OWNED);

        if (!(vd->vd_flags & VDF_ASYNC) ||
            !atomic_cmpset_int(&vd->vd_timer_armed, 1, 0))
                return;

        callout_stop(&vd->vd_timer);
}

static void
vt_switch_timer(void *arg, int pending)
{

        (void)vt_late_window_switch((struct vt_window *)arg);
}

static int
vt_save_kbd_mode(struct vt_window *vw, keyboard_t *kbd)
{
        int mode, ret;

        mode = 0;
        ret = kbdd_ioctl(kbd, KDGKBMODE, (caddr_t)&mode);
        if (ret == ENOIOCTL)
                ret = ENODEV;
        if (ret != 0)
                return (ret);

        vw->vw_kbdmode = mode;

        return (0);
}

static int
vt_update_kbd_mode(struct vt_window *vw, keyboard_t *kbd)
{
        int ret;

        ret = kbdd_ioctl(kbd, KDSKBMODE, (caddr_t)&vw->vw_kbdmode);
        if (ret == ENOIOCTL)
                ret = ENODEV;

        return (ret);
}

static int
vt_save_kbd_state(struct vt_window *vw, keyboard_t *kbd)
{
        int state, ret;

        state = 0;
        ret = kbdd_ioctl(kbd, KDGKBSTATE, (caddr_t)&state);
        if (ret == ENOIOCTL)
                ret = ENODEV;
        if (ret != 0)
                return (ret);

        vw->vw_kbdstate &= ~LOCK_MASK;
        vw->vw_kbdstate |= state & LOCK_MASK;

        return (0);
}

static int
vt_update_kbd_state(struct vt_window *vw, keyboard_t *kbd)
{
        int state, ret;

        state = vw->vw_kbdstate & LOCK_MASK;
        ret = kbdd_ioctl(kbd, KDSKBSTATE, (caddr_t)&state);
        if (ret == ENOIOCTL)
                ret = ENODEV;

        return (ret);
}

static int
vt_save_kbd_leds(struct vt_window *vw, keyboard_t *kbd)
{
        int leds, ret;

        leds = 0;
        ret = kbdd_ioctl(kbd, KDGETLED, (caddr_t)&leds);
        if (ret == ENOIOCTL)
                ret = ENODEV;
        if (ret != 0)
                return (ret);

        vw->vw_kbdstate &= ~LED_MASK;
        vw->vw_kbdstate |= leds & LED_MASK;

        return (0);
}

static int
vt_update_kbd_leds(struct vt_window *vw, keyboard_t *kbd)
{
        int leds, ret;

        leds = vw->vw_kbdstate & LED_MASK;
        ret = kbdd_ioctl(kbd, KDSETLED, (caddr_t)&leds);
        if (ret == ENOIOCTL)
                ret = ENODEV;

        return (ret);
}

static int
vt_window_preswitch(struct vt_window *vw, struct vt_window *curvw)
{

        DPRINTF(40, "%s\n", __func__);
        curvw->vw_switch_to = vw;
        /* Set timer to allow switch in case when process hang. */
        taskqueue_enqueue_timeout(taskqueue_thread, &vw->vw_timeout_task_dead, hz * vt_deadtimer);
        /* Notify process about vt switch attempt. */
        DPRINTF(30, "%s: Notify process.\n", __func__);
        signal_vt_rel(curvw);

        return (0);
}

static int
vt_window_postswitch(struct vt_window *vw)
{

        signal_vt_acq(vw);
        return (0);
}

/* vt_late_window_switch will do VT switching for regular case. */
static int
vt_late_window_switch(struct vt_window *vw)
{
        struct vt_window *curvw;
        int ret;

        taskqueue_cancel_timeout(taskqueue_thread, &vw->vw_timeout_task_dead, NULL);

        ret = vt_window_switch(vw);
        if (ret != 0) {
                /*
                 * If the switch hasn't happened, then return the VT
                 * to the current owner, if any.
                 */
                curvw = vw->vw_device->vd_curwindow;
                if (curvw->vw_smode.mode == VT_PROCESS)
                        (void)vt_window_postswitch(curvw);
                return (ret);
        }

        /* Notify owner process about terminal availability. */
        if (vw->vw_smode.mode == VT_PROCESS) {
                ret = vt_window_postswitch(vw);
        }
        return (ret);
}

/* Switch window. */
static int
vt_proc_window_switch(struct vt_window *vw)
{
        struct vt_window *curvw;
        struct vt_device *vd;
        int ret;

        /* Prevent switching to NULL */
        if (vw == NULL) {
                DPRINTF(30, "%s: Cannot switch: vw is NULL.", __func__);
                return (EINVAL);
        }
        vd = vw->vw_device;
        curvw = vd->vd_curwindow;

        /* Check if virtual terminal is locked */
        if (curvw->vw_flags & VWF_VTYLOCK)
                return (EBUSY);

        /* Check if switch already in progress */
        if (curvw->vw_flags & VWF_SWWAIT_REL) {
                /* Check if switching to same window */
                if (curvw->vw_switch_to == vw) {
                        DPRINTF(30, "%s: Switch in progress to same vw.", __func__);
                        return (0);     /* success */
                }
                DPRINTF(30, "%s: Switch in progress to different vw.", __func__);
                return (EBUSY);
        }

        /* Avoid switching to already selected window */
        if (vw == curvw) {
                DPRINTF(30, "%s: Cannot switch: vw == curvw.", __func__);
                return (0);     /* success */
        }

        /*
         * Early check for an attempt to switch to a non-functional VT.
         * The same check is done in vt_window_switch(), but it's better
         * to fail as early as possible to avoid needless pre-switch
         * actions.
         */
        VT_LOCK(vd);
        if ((vw->vw_flags & (VWF_OPENED|VWF_CONSOLE)) == 0) {
                VT_UNLOCK(vd);
                return (EINVAL);
        }
        VT_UNLOCK(vd);

        /* Ask current process permission to switch away. */
        if (curvw->vw_smode.mode == VT_PROCESS) {
                DPRINTF(30, "%s: VT_PROCESS ", __func__);
                if (vt_proc_alive(curvw) == FALSE) {
                        DPRINTF(30, "Dead. Cleaning.");
                        /* Dead */
                } else {
                        DPRINTF(30, "%s: Signaling process.\n", __func__);
                        /* Alive, try to ask him. */
                        ret = vt_window_preswitch(vw, curvw);
                        /* Wait for process answer or timeout. */
                        return (ret);
                }
                DPRINTF(30, "\n");
        }

        ret = vt_late_window_switch(vw);
        return (ret);
}

/* Switch window ignoring process locking. */
static int
vt_window_switch(struct vt_window *vw)
{
        struct vt_device *vd = vw->vw_device;
        struct vt_window *curvw = vd->vd_curwindow;
        keyboard_t *kbd;

        if (inside_vt_window_switch && KERNEL_PANICKED())
                return (0);

        inside_vt_window_switch = true;

        if (kdb_active) {
                /*
                 * When grabbing the console for the debugger, avoid
                 * locks as that can result in deadlock.  While this
                 * could use try locks, that wouldn't really make a
                 * difference as there are sufficient barriers in
                 * debugger entry/exit to be equivalent to
                 * successfully try-locking here.
                 */
                if (!(vw->vw_flags & (VWF_OPENED|VWF_CONSOLE))) {
                        inside_vt_window_switch = false;
                        return (EINVAL);
                }

                vd->vd_curwindow = vw;
                vd->vd_flags |= VDF_INVALID;
                if (vd->vd_driver->vd_postswitch)
                        vd->vd_driver->vd_postswitch(vd);
                inside_vt_window_switch = false;
                return (0);
        }

        VT_LOCK(vd);
        if (curvw == vw) {
                /*
                 * Nothing to do, except ensure the driver has the opportunity to
                 * switch to console mode when panicking, making sure the panic
                 * is readable (even when a GUI was using ttyv0).
                 */
                if ((kdb_active || KERNEL_PANICKED()) &&
                    vd->vd_driver->vd_postswitch)
                        vd->vd_driver->vd_postswitch(vd);
                inside_vt_window_switch = false;
                VT_UNLOCK(vd);
                return (0);
        }
        if (!(vw->vw_flags & (VWF_OPENED|VWF_CONSOLE))) {
                inside_vt_window_switch = false;
                VT_UNLOCK(vd);
                return (EINVAL);
        }

        vt_suspend_flush_timer(vd);

        vd->vd_curwindow = vw;
        vd->vd_flags |= VDF_INVALID;
        cv_broadcast(&vd->vd_winswitch);
        VT_UNLOCK(vd);

        if (vd->vd_driver->vd_postswitch)
                vd->vd_driver->vd_postswitch(vd);

        vt_resume_flush_timer(vw, 0);

        /* Restore per-window keyboard mode. */
        mtx_lock(&Giant);
        if ((kbd = vd->vd_keyboard) != NULL) {
                if (curvw->vw_kbdmode == K_XLATE)
                        vt_save_kbd_state(curvw, kbd);

                vt_update_kbd_mode(vw, kbd);
                vt_update_kbd_state(vw, kbd);
        }
        mtx_unlock(&Giant);
        DPRINTF(10, "%s(ttyv%d) done\n", __func__, vw->vw_number);

        inside_vt_window_switch = false;
        return (0);
}

void
vt_termsize(struct vt_device *vd, struct vt_font *vf, term_pos_t *size)
{

        size->tp_row = vd->vd_height;
        if (vt_draw_logo_cpus)
                size->tp_row -= vt_logo_sprite_height;
        size->tp_col = vd->vd_width;
        if (vf != NULL) {
                size->tp_row = MIN(size->tp_row / vf->vf_height,
                    PIXEL_HEIGHT(VT_FB_MAX_HEIGHT));
                size->tp_col = MIN(size->tp_col / vf->vf_width,
                    PIXEL_WIDTH(VT_FB_MAX_WIDTH));
        }
}

static inline void
vt_termrect(struct vt_device *vd, struct vt_font *vf, term_rect_t *rect)
{

        rect->tr_begin.tp_row = rect->tr_begin.tp_col = 0;
        if (vt_draw_logo_cpus)
                rect->tr_begin.tp_row = vt_logo_sprite_height;

        rect->tr_end.tp_row = vd->vd_height;
        rect->tr_end.tp_col = vd->vd_width;

        if (vf != NULL) {
                rect->tr_begin.tp_row =
                    howmany(rect->tr_begin.tp_row, vf->vf_height);

                rect->tr_end.tp_row = MIN(rect->tr_end.tp_row / vf->vf_height,
                    PIXEL_HEIGHT(VT_FB_MAX_HEIGHT));
                rect->tr_end.tp_col = MIN(rect->tr_end.tp_col / vf->vf_width,
                    PIXEL_WIDTH(VT_FB_MAX_WIDTH));
        }
}

void
vt_winsize(struct vt_device *vd, struct vt_font *vf, struct winsize *size)
{

        size->ws_ypixel = vd->vd_height;
        if (vt_draw_logo_cpus)
                size->ws_ypixel -= vt_logo_sprite_height;
        size->ws_row = size->ws_ypixel;
        size->ws_col = size->ws_xpixel = vd->vd_width;
        if (vf != NULL) {
                size->ws_row = MIN(size->ws_row / vf->vf_height,
                    PIXEL_HEIGHT(VT_FB_MAX_HEIGHT));
                size->ws_col = MIN(size->ws_col / vf->vf_width,
                    PIXEL_WIDTH(VT_FB_MAX_WIDTH));
        }
}

void
vt_compute_drawable_area(struct vt_window *vw)
{
        struct vt_device *vd;
        struct vt_font *vf;
        vt_axis_t height;

        vd = vw->vw_device;

        if (vw->vw_font == NULL) {
                vw->vw_draw_area.tr_begin.tp_col = 0;
                vw->vw_draw_area.tr_begin.tp_row = 0;
                if (vt_draw_logo_cpus)
                        vw->vw_draw_area.tr_begin.tp_row = vt_logo_sprite_height;
                vw->vw_draw_area.tr_end.tp_col = vd->vd_width;
                vw->vw_draw_area.tr_end.tp_row = vd->vd_height;
                return;
        }

        vf = vw->vw_font;

        /*
         * Compute the drawable area, so that the text is centered on
         * the screen.
         */

        height = vd->vd_height;
        if (vt_draw_logo_cpus)
                height -= vt_logo_sprite_height;
        vw->vw_draw_area.tr_begin.tp_col = (vd->vd_width % vf->vf_width) / 2;
        vw->vw_draw_area.tr_begin.tp_row = (height % vf->vf_height) / 2;
        if (vt_draw_logo_cpus)
                vw->vw_draw_area.tr_begin.tp_row += vt_logo_sprite_height;
        vw->vw_draw_area.tr_end.tp_col = vw->vw_draw_area.tr_begin.tp_col +
            rounddown(vd->vd_width, vf->vf_width);
        vw->vw_draw_area.tr_end.tp_row = vw->vw_draw_area.tr_begin.tp_row +
            rounddown(height, vf->vf_height);
}

static void
vt_scroll(struct vt_window *vw, int offset, int whence)
{
        int diff;
        term_pos_t size;

        if ((vw->vw_flags & VWF_SCROLL) == 0)
                return;

        vt_termsize(vw->vw_device, vw->vw_font, &size);

        diff = vthistory_seek(&vw->vw_buf, offset, whence);
        if (diff)
                vw->vw_device->vd_flags |= VDF_INVALID;
        vt_resume_flush_timer(vw, 0);
}

static int
vt_machine_kbdevent(struct vt_device *vd, int c)
{

        switch (c) {
        case SPCLKEY | DBG: /* kbdmap(5) keyword `debug`. */
                if (vt_kbd_debug) {
                        kdb_enter(KDB_WHY_BREAK, "manual escape to debugger");
#if VT_ALT_TO_ESC_HACK
                        /*
                         * There's an unfortunate conflict between SPCLKEY|DBG
                         * and VT_ALT_TO_ESC_HACK.  Just assume they didn't mean
                         * it if we got to here.
                         */
                        vd->vd_kbstate &= ~ALKED;
#endif
                }
                return (1);
        case SPCLKEY | HALT: /* kbdmap(5) keyword `halt`. */
                if (vt_kbd_halt)
                        shutdown_nice(RB_HALT);
                return (1);
        case SPCLKEY | PASTE: /* kbdmap(5) keyword `paste`. */
#ifndef SC_NO_CUTPASTE
                /* Insert text from cut-paste buffer. */
                vt_mouse_paste();
#endif
                break;
        case SPCLKEY | PDWN: /* kbdmap(5) keyword `pdwn`. */
                if (vt_kbd_poweroff)
                        shutdown_nice(RB_HALT|RB_POWEROFF);
                return (1);
        case SPCLKEY | PNC: /* kbdmap(5) keyword `panic`. */
                /*
                 * Request to immediate panic if sysctl
                 * kern.vt.enable_panic_key allow it.
                 */
                if (vt_kbd_panic)
                        panic("Forced by the panic key");
                return (1);
        case SPCLKEY | RBT: /* kbdmap(5) keyword `boot`. */
                if (vt_kbd_reboot)
                        shutdown_nice(RB_AUTOBOOT);
                return (1);
        case SPCLKEY | SPSC: /* kbdmap(5) keyword `spsc`. */
                /* Force activatation/deactivation of the screen saver. */
                /* TODO */
                return (1);
        case SPCLKEY | STBY: /* XXX Not present in kbdcontrol parser. */
                /* Put machine into Stand-By mode. */
                power_pm_suspend(POWER_SSTATE_TRANSITION_STANDBY);
                return (1);
        case SPCLKEY | SUSP: /* kbdmap(5) keyword `susp`. */
                /* Suspend machine. */
                power_pm_suspend(POWER_SSTATE_TRANSITION_SUSPEND);
                return (1);
        }

        return (0);
}

static void
vt_scrollmode_kbdevent(struct vt_window *vw, int c, int console)
{
        struct vt_device *vd;
        term_pos_t size;

        vd = vw->vw_device;
        /* Only special keys handled in ScrollLock mode */
        if ((c & SPCLKEY) == 0)
                return;

        c &= ~SPCLKEY;

        if (console == 0) {
                if (c >= F_SCR && c <= MIN(L_SCR, F_SCR + VT_MAXWINDOWS - 1)) {
                        vw = vd->vd_windows[c - F_SCR];
                        vt_proc_window_switch(vw);
                        return;
                }
                VT_LOCK(vd);
        }

        switch (c) {
        case SLK: {
                /* Turn scrolling off. */
                vt_scroll(vw, 0, VHS_END);
                VTBUF_SLCK_DISABLE(&vw->vw_buf);
                vw->vw_flags &= ~VWF_SCROLL;
                break;
        }
        case FKEY | F(49): /* Home key. */
                vt_scroll(vw, 0, VHS_SET);
                break;
        case FKEY | F(50): /* Arrow up. */
                vt_scroll(vw, -1, VHS_CUR);
                break;
        case FKEY | F(51): /* Page up. */
                vt_termsize(vd, vw->vw_font, &size);
                vt_scroll(vw, -size.tp_row, VHS_CUR);
                break;
        case FKEY | F(57): /* End key. */
                vt_scroll(vw, 0, VHS_END);
                break;
        case FKEY | F(58): /* Arrow down. */
                vt_scroll(vw, 1, VHS_CUR);
                break;
        case FKEY | F(59): /* Page down. */
                vt_termsize(vd, vw->vw_font, &size);
                vt_scroll(vw, size.tp_row, VHS_CUR);
                break;
        }

        if (console == 0)
                VT_UNLOCK(vd);
}

static int
vt_processkey(keyboard_t *kbd, struct vt_device *vd, int c)
{
        struct vt_window *vw = vd->vd_curwindow;

#ifdef RANDOM_ENABLE_KBD
        random_harvest_queue(&c, sizeof(c), RANDOM_KEYBOARD);
#endif
#if VT_ALT_TO_ESC_HACK
        if (c & RELKEY) {
                switch (c & ~RELKEY) {
                case (SPCLKEY | RALT):
                        if (vt_enable_altgr != 0)
                                break;
                case (SPCLKEY | LALT):
                        vd->vd_kbstate &= ~ALKED;
                }
                /* Other keys ignored for RELKEY event. */
                return (0);
        } else {
                switch (c & ~RELKEY) {
                case (SPCLKEY | RALT):
                        if (vt_enable_altgr != 0)
                                break;
                case (SPCLKEY | LALT):
                        vd->vd_kbstate |= ALKED;
                }
        }
#else
        if (c & RELKEY)
                /* Other keys ignored for RELKEY event. */
                return (0);
#endif

        if (vt_machine_kbdevent(vd, c))
                return (0);

        if (vw->vw_flags & VWF_SCROLL) {
                vt_scrollmode_kbdevent(vw, c, 0/* Not a console */);
                /* Scroll mode keys handled, nothing to do more. */
                return (0);
        }

        if (c & SPCLKEY) {
                c &= ~SPCLKEY;

                if (c >= F_SCR && c <= MIN(L_SCR, F_SCR + VT_MAXWINDOWS - 1)) {
                        vw = vd->vd_windows[c - F_SCR];
                        vt_proc_window_switch(vw);
                        return (0);
                }

                switch (c) {
                case NEXT:
                        /* Switch to next VT. */
                        c = (vw->vw_number + 1) % VT_MAXWINDOWS;
                        vw = vd->vd_windows[c];
                        vt_proc_window_switch(vw);
                        return (0);
                case PREV:
                        /* Switch to previous VT. */
                        c = (vw->vw_number + VT_MAXWINDOWS - 1) % VT_MAXWINDOWS;
                        vw = vd->vd_windows[c];
                        vt_proc_window_switch(vw);
                        return (0);
                case SLK: {
                        vt_save_kbd_state(vw, kbd);
                        VT_LOCK(vd);
                        if (vw->vw_kbdstate & SLKED) {
                                /* Turn scrolling on. */
                                vw->vw_flags |= VWF_SCROLL;
                                VTBUF_SLCK_ENABLE(&vw->vw_buf);
                        } else {
                                /* Turn scrolling off. */
                                vw->vw_flags &= ~VWF_SCROLL;
                                VTBUF_SLCK_DISABLE(&vw->vw_buf);
                                vt_scroll(vw, 0, VHS_END);
                        }
                        VT_UNLOCK(vd);
                        break;
                }
                case BKEY | BTAB: /* Back tab (usually, shift+tab). */
                        terminal_input_special(vw->vw_terminal, TKEY_BTAB);
                        break;
                case FKEY | F(1):  case FKEY | F(2):  case FKEY | F(3):
                case FKEY | F(4):  case FKEY | F(5):  case FKEY | F(6):
                case FKEY | F(7):  case FKEY | F(8):  case FKEY | F(9):
                case FKEY | F(10): case FKEY | F(11): case FKEY | F(12):
                        /* F1 through F12 keys. */
                        terminal_input_special(vw->vw_terminal,
                            TKEY_F1 + c - (FKEY | F(1)));
                        break;
                case FKEY | F(49): /* Home key. */
                        terminal_input_special(vw->vw_terminal, TKEY_HOME);
                        break;
                case FKEY | F(50): /* Arrow up. */
                        terminal_input_special(vw->vw_terminal, TKEY_UP);
                        break;
                case FKEY | F(51): /* Page up. */
                        terminal_input_special(vw->vw_terminal, TKEY_PAGE_UP);
                        break;
                case FKEY | F(53): /* Arrow left. */
                        terminal_input_special(vw->vw_terminal, TKEY_LEFT);
                        break;
                case FKEY | F(55): /* Arrow right. */
                        terminal_input_special(vw->vw_terminal, TKEY_RIGHT);
                        break;
                case FKEY | F(57): /* End key. */
                        terminal_input_special(vw->vw_terminal, TKEY_END);
                        break;
                case FKEY | F(58): /* Arrow down. */
                        terminal_input_special(vw->vw_terminal, TKEY_DOWN);
                        break;
                case FKEY | F(59): /* Page down. */
                        terminal_input_special(vw->vw_terminal, TKEY_PAGE_DOWN);
                        break;
                case FKEY | F(60): /* Insert key. */
                        terminal_input_special(vw->vw_terminal, TKEY_INSERT);
                        break;
                case FKEY | F(61): /* Delete key. */
                        terminal_input_special(vw->vw_terminal, TKEY_DELETE);
                        break;
                }
        } else if (KEYFLAGS(c) == 0) {
                /* Don't do UTF-8 conversion when doing raw mode. */
                if (vw->vw_kbdmode == K_XLATE) {
#if VT_ALT_TO_ESC_HACK
                        if (vd->vd_kbstate & ALKED) {
                                /*
                                 * Prepend ESC sequence if one of ALT keys down.
                                 */
                                terminal_input_char(vw->vw_terminal, 0x1b);
                        }
#endif
#if defined(KDB)
                        kdb_alt_break(c, &vd->vd_altbrk);
#endif
                        terminal_input_char(vw->vw_terminal, KEYCHAR(c));
                } else
                        terminal_input_raw(vw->vw_terminal, c);
        }
        return (0);
}

static int
vt_kbdevent(keyboard_t *kbd, int event, void *arg)
{
        struct vt_device *vd = arg;
        int c;

        switch (event) {
        case KBDIO_KEYINPUT:
                break;
        case KBDIO_UNLOADING:
                mtx_lock(&Giant);
                vd->vd_keyboard = NULL;
                kbd_release(kbd, (void *)vd);
                mtx_unlock(&Giant);
                return (0);
        default:
                return (EINVAL);
        }

        while ((c = kbdd_read_char(kbd, 0)) != NOKEY)
                vt_processkey(kbd, vd, c);

        return (0);
}

static int
vt_allocate_keyboard(struct vt_device *vd)
{
        int              grabbed, i, idx0, idx;
        keyboard_t      *k0, *k;
        keyboard_info_t  ki;

        /*
         * If vt_upgrade() happens while the console is grabbed, we are
         * potentially going to switch keyboard devices while the keyboard is in
         * use. Unwind the grabbing of the current keyboard first, then we will
         * re-grab the new keyboard below, before we return.
         */
        if (vd->vd_curwindow == &vt_conswindow) {
                grabbed = vd->vd_curwindow->vw_grabbed;
                for (i = 0; i < grabbed; ++i)
                        vtterm_cnungrab_noswitch(vd, vd->vd_curwindow);
        }

        idx0 = kbd_allocate("kbdmux", -1, vd, vt_kbdevent, vd);
        if (idx0 >= 0) {
                DPRINTF(20, "%s: kbdmux allocated, idx = %d\n", __func__, idx0);
                k0 = kbd_get_keyboard(idx0);

                for (idx = kbd_find_keyboard2("*", -1, 0);
                     idx != -1;
                     idx = kbd_find_keyboard2("*", -1, idx + 1)) {
                        k = kbd_get_keyboard(idx);

                        if (idx == idx0 || KBD_IS_BUSY(k))
                                continue;

                        bzero(&ki, sizeof(ki));
                        strncpy(ki.kb_name, k->kb_name, sizeof(ki.kb_name));
                        ki.kb_name[sizeof(ki.kb_name) - 1] = '\0';
                        ki.kb_unit = k->kb_unit;

                        kbdd_ioctl(k0, KBADDKBD, (caddr_t) &ki);
                }
        } else {
                DPRINTF(20, "%s: no kbdmux allocated\n", __func__);
                idx0 = kbd_allocate("*", -1, vd, vt_kbdevent, vd);
                if (idx0 < 0) {
                        DPRINTF(10, "%s: No keyboard found.\n", __func__);
                        return (-1);
                }
                k0 = kbd_get_keyboard(idx0);
        }
        vd->vd_keyboard = k0;
        DPRINTF(20, "%s: vd_keyboard = %d\n", __func__,
            vd->vd_keyboard->kb_index);

        if (vd->vd_curwindow == &vt_conswindow) {
                for (i = 0; i < grabbed; ++i)
                        vtterm_cngrab_noswitch(vd, vd->vd_curwindow);
        }

        return (idx0);
}

#define DEVCTL_LEN 64
static void
vtterm_devctl(bool enabled, bool hushed, int hz, sbintime_t duration)
{
        struct sbuf sb;
        char *buf;

        buf = malloc(DEVCTL_LEN, M_VT, M_NOWAIT);
        if (buf == NULL)
                return;
        sbuf_new(&sb, buf, DEVCTL_LEN, SBUF_FIXEDLEN);
        sbuf_printf(&sb, "enabled=%s hushed=%s hz=%d duration_ms=%d",
            enabled ? "true" : "false", hushed ? "true" : "false",
            hz, (int)(duration / SBT_1MS));
        sbuf_finish(&sb);
        if (sbuf_error(&sb) == 0)
                devctl_notify("VT", "BELL", "RING", sbuf_data(&sb));
        sbuf_delete(&sb);
        free(buf, M_VT);
}

static void
vtterm_bell(struct terminal *tm)
{
        struct vt_window *vw = tm->tm_softc;
        struct vt_device *vd = vw->vw_device;

        vtterm_devctl(vt_enable_bell, vd->vd_flags & VDF_QUIET_BELL,
            vw->vw_bell_pitch, vw->vw_bell_duration);

        if (!vt_enable_bell)
                return;

        if (vd->vd_flags & VDF_QUIET_BELL)
                return;

        if (vw->vw_bell_pitch == 0 ||
            vw->vw_bell_duration == 0)
                return;

        sysbeep(vw->vw_bell_pitch, vw->vw_bell_duration);
}

/*
 * Beep with user-provided frequency and duration as specified by a KDMKTONE
 * ioctl (compatible with Linux).  The frequency is specified as a 8254 PIT
 * divisor for a 1.19MHz clock.
 *
 * See https://tldp.org/LDP/lpg/node83.html.
 */
static void
vtterm_beep(struct terminal *tm, u_int param)
{
        u_int freq;
        sbintime_t period;
        struct vt_window *vw = tm->tm_softc;
        struct vt_device *vd = vw->vw_device;

        if ((param == 0) || ((param & 0xffff) == 0)) {
                vtterm_bell(tm);
                return;
        }

        /* XXX period unit is supposed to be "timer ticks." */
        period = ((param >> 16) & 0xffff) * SBT_1MS;
        freq = 1193182 / (param & 0xffff);

        vtterm_devctl(vt_enable_bell, vd->vd_flags & VDF_QUIET_BELL,
            freq, period);

        if (!vt_enable_bell)
                return;

        sysbeep(freq, period);
}

static void
vtterm_cursor(struct terminal *tm, const term_pos_t *p)
{
        struct vt_window *vw = tm->tm_softc;

        vtbuf_cursor_position(&vw->vw_buf, p);
}

static void
vtterm_putchar(struct terminal *tm, const term_pos_t *p, term_char_t c)
{
        struct vt_window *vw = tm->tm_softc;

        vtbuf_putchar(&vw->vw_buf, p, c);
}

static void
vtterm_fill(struct terminal *tm, const term_rect_t *r, term_char_t c)
{
        struct vt_window *vw = tm->tm_softc;

        vtbuf_fill(&vw->vw_buf, r, c);
}

static void
vtterm_copy(struct terminal *tm, const term_rect_t *r,
    const term_pos_t *p)
{
        struct vt_window *vw = tm->tm_softc;

        vtbuf_copy(&vw->vw_buf, r, p);
}

static void
vtterm_param(struct terminal *tm, int cmd, unsigned int arg)
{
        struct vt_window *vw = tm->tm_softc;

        switch (cmd) {
        case TP_SETLOCALCURSOR:
                /*
                 * 0 means normal (usually block), 1 means hidden, and
                 * 2 means blinking (always block) for compatibility with
                 * syscons.  We don't support any changes except hiding,
                 * so must map 2 to 0.
                 */
                arg = (arg == 1) ? 0 : 1;
                /* FALLTHROUGH */
        case TP_SHOWCURSOR:
                vtbuf_cursor_visibility(&vw->vw_buf, arg);
                vt_resume_flush_timer(vw, 0);
                break;
        case TP_MOUSE:
                vw->vw_mouse_level = arg;
                break;
        case TP_SETBELLPD:
                vw->vw_bell_pitch = TP_SETBELLPD_PITCH(arg);
                vw->vw_bell_duration =
                    TICKS_2_MSEC(TP_SETBELLPD_DURATION(arg)) * SBT_1MS;
                break;
        }
}

void
vt_determine_colors(term_char_t c, int cursor,
    term_color_t *fg, term_color_t *bg)
{
        term_color_t tmp;
        int invert;

        invert = 0;

        *fg = TCHAR_FGCOLOR(c);
        if (TCHAR_FORMAT(c) & TF_BOLD)
                *fg = TCOLOR_LIGHT(*fg);
        *bg = TCHAR_BGCOLOR(c);
        if (TCHAR_FORMAT(c) & TF_BLINK)
                *bg = TCOLOR_LIGHT(*bg);

        if (TCHAR_FORMAT(c) & TF_REVERSE)
                invert ^= 1;
        if (cursor)
                invert ^= 1;

        if (invert) {
                tmp = *fg;
                *fg = *bg;
                *bg = tmp;
        }
}

#ifndef SC_NO_CUTPASTE
int
vt_is_cursor_in_area(const struct vt_device *vd, const term_rect_t *area)
{
        unsigned int mx, my;

        /*
         * We use the cursor position saved during the current refresh,
         * in case the cursor moved since.
         */
        mx = vd->vd_mx_drawn + vd->vd_curwindow->vw_draw_area.tr_begin.tp_col;
        my = vd->vd_my_drawn + vd->vd_curwindow->vw_draw_area.tr_begin.tp_row;

        if (mx >= area->tr_end.tp_col ||
            mx + vd->vd_mcursor->width <= area->tr_begin.tp_col ||
            my >= area->tr_end.tp_row ||
            my + vd->vd_mcursor->height <= area->tr_begin.tp_row)
                return (0);
        return (1);
}

static void
vt_mark_mouse_position_as_dirty(struct vt_device *vd, int locked)
{
        term_rect_t area;
        struct vt_window *vw;
        struct vt_font *vf;
        int x, y;

        vw = vd->vd_curwindow;
        vf = vw->vw_font;

        x = vd->vd_mx_drawn;
        y = vd->vd_my_drawn;

        if (vf != NULL) {
                area.tr_begin.tp_col = x / vf->vf_width;
                area.tr_begin.tp_row = y / vf->vf_height;
                area.tr_end.tp_col =
                    ((x + vd->vd_mcursor->width) / vf->vf_width) + 1;
                area.tr_end.tp_row =
                    ((y + vd->vd_mcursor->height) / vf->vf_height) + 1;
        } else {
                /*
                 * No font loaded (ie. vt_vga operating in textmode).
                 *
                 * FIXME: This fake area needs to be revisited once the
                 * mouse cursor is supported in vt_vga's textmode.
                 */
                area.tr_begin.tp_col = x;
                area.tr_begin.tp_row = y;
                area.tr_end.tp_col = x + 2;
                area.tr_end.tp_row = y + 2;
        }

        if (!locked)
                vtbuf_lock(&vw->vw_buf);
        if (vd->vd_driver->vd_invalidate_text)
                vd->vd_driver->vd_invalidate_text(vd, &area);
        vtbuf_dirty(&vw->vw_buf, &area);
        if (!locked)
                vtbuf_unlock(&vw->vw_buf);
}
#endif

static void
vt_set_border(struct vt_device *vd, const term_rect_t *area,
    term_color_t c)
{
        vd_drawrect_t *drawrect = vd->vd_driver->vd_drawrect;

        if (drawrect == NULL)
                return;

        /* Top bar */
        if (area->tr_begin.tp_row > 0)
                drawrect(vd, 0, 0, vd->vd_width - 1,
                    area->tr_begin.tp_row - 1, 1, c);

        /* Left bar */
        if (area->tr_begin.tp_col > 0)
                drawrect(vd, 0, area->tr_begin.tp_row,
                    area->tr_begin.tp_col - 1, area->tr_end.tp_row - 1, 1, c);

        /* Right bar */
        if (area->tr_end.tp_col < vd->vd_width)
                drawrect(vd, area->tr_end.tp_col, area->tr_begin.tp_row,
                    vd->vd_width - 1, area->tr_end.tp_row - 1, 1, c);

        /* Bottom bar */
        if (area->tr_end.tp_row < vd->vd_height)
                drawrect(vd, 0, area->tr_end.tp_row, vd->vd_width - 1,
                    vd->vd_height - 1, 1, c);
}

static void
vt_flush_to_buffer(struct vt_device *vd,
    const struct vt_window *vw, const term_rect_t *area)
{
        unsigned int col, row;
        term_char_t c;
        term_color_t fg, bg;
        size_t z;

        for (row = area->tr_begin.tp_row; row < area->tr_end.tp_row; ++row) {
                for (col = area->tr_begin.tp_col; col < area->tr_end.tp_col;
                    ++col) {
                        z = row * PIXEL_WIDTH(VT_FB_MAX_WIDTH) + col;
                        if (z >= PIXEL_HEIGHT(VT_FB_MAX_HEIGHT) *
                            PIXEL_WIDTH(VT_FB_MAX_WIDTH))
                                continue;

                        c = VTBUF_GET_FIELD(&vw->vw_buf, row, col);
                        vt_determine_colors(c,
                            VTBUF_ISCURSOR(&vw->vw_buf, row, col), &fg, &bg);

                        if (vd->vd_drawn && (vd->vd_drawn[z] == c) &&
                            vd->vd_drawnfg && (vd->vd_drawnfg[z] == fg) &&
                            vd->vd_drawnbg && (vd->vd_drawnbg[z] == bg)) {
                                vd->vd_pos_to_flush[z] = false;
                                continue;
                        }

                        vd->vd_pos_to_flush[z] = true;

                        if (vd->vd_drawn)
                                vd->vd_drawn[z] = c;
                        if (vd->vd_drawnfg)
                                vd->vd_drawnfg[z] = fg;
                        if (vd->vd_drawnbg)
                                vd->vd_drawnbg[z] = bg;
                }
        }
}

static void
vt_bitblt_buffer(struct vt_device *vd, const struct vt_window *vw,
    const term_rect_t *area)
{
        unsigned int col, row, x, y;
        struct vt_font *vf;
        term_char_t c;
        term_color_t fg, bg;
        const uint8_t *pattern;
        size_t z;

        vf = vw->vw_font;

        for (row = area->tr_begin.tp_row; row < area->tr_end.tp_row; ++row) {
                for (col = area->tr_begin.tp_col; col < area->tr_end.tp_col;
                    ++col) {
                        x = col * vf->vf_width +
                            vw->vw_draw_area.tr_begin.tp_col;
                        y = row * vf->vf_height +
                            vw->vw_draw_area.tr_begin.tp_row;

                        z = row * PIXEL_WIDTH(VT_FB_MAX_WIDTH) + col;
                        if (z >= PIXEL_HEIGHT(VT_FB_MAX_HEIGHT) *
                            PIXEL_WIDTH(VT_FB_MAX_WIDTH))
                                continue;
                        if (!vd->vd_pos_to_flush[z])
                                continue;

                        c = vd->vd_drawn[z];
                        fg = vd->vd_drawnfg[z];
                        bg = vd->vd_drawnbg[z];

                        pattern = vtfont_lookup(vf, c);
                        vd->vd_driver->vd_bitblt_bmp(vd, vw,
                            pattern, NULL, vf->vf_width, vf->vf_height,
                            x, y, fg, bg);
                }
        }

#ifndef SC_NO_CUTPASTE
        if (!vd->vd_mshown)
                return;

        term_rect_t drawn_area;

        drawn_area.tr_begin.tp_col = area->tr_begin.tp_col * vf->vf_width;
        drawn_area.tr_begin.tp_row = area->tr_begin.tp_row * vf->vf_height;
        drawn_area.tr_end.tp_col = area->tr_end.tp_col * vf->vf_width;
        drawn_area.tr_end.tp_row = area->tr_end.tp_row * vf->vf_height;

        if (vt_is_cursor_in_area(vd, &drawn_area)) {
                vd->vd_driver->vd_bitblt_bmp(vd, vw,
                    vd->vd_mcursor->map, vd->vd_mcursor->mask,
                    vd->vd_mcursor->width, vd->vd_mcursor->height,
                    vd->vd_mx_drawn + vw->vw_draw_area.tr_begin.tp_col,
                    vd->vd_my_drawn + vw->vw_draw_area.tr_begin.tp_row,
                    vd->vd_mcursor_fg, vd->vd_mcursor_bg);
        }
#endif
}

static void
vt_draw_decorations(struct vt_device *vd)
{
        struct vt_window *vw;
        const teken_attr_t *a;

        vw = vd->vd_curwindow;

        a = teken_get_curattr(&vw->vw_terminal->tm_emulator);
        vt_set_border(vd, &vw->vw_draw_area, a->ta_bgcolor);

        if (vt_draw_logo_cpus)
                vtterm_draw_cpu_logos(vd);
}

static int
vt_flush(struct vt_device *vd)
{
        struct vt_window *vw;
        struct vt_font *vf;
        term_rect_t tarea;
#ifndef SC_NO_CUTPASTE
        int cursor_was_shown, cursor_moved;
#endif
        bool needs_refresh;

        if (inside_vt_flush && KERNEL_PANICKED())
                return (0);

        vw = vd->vd_curwindow;
        if (vw == NULL)
                return (0);

        if (vd->vd_flags & VDF_SPLASH || vw->vw_flags & VWF_BUSY)
                return (0);

        vf = vw->vw_font;
        if (((vd->vd_flags & VDF_TEXTMODE) == 0) && (vf == NULL))
                return (0);

        VT_FLUSH_LOCK(vd);

        vtbuf_lock(&vw->vw_buf);
        inside_vt_flush = true;

#ifndef SC_NO_CUTPASTE
        cursor_was_shown = vd->vd_mshown;
        cursor_moved = (vd->vd_mx != vd->vd_mx_drawn ||
            vd->vd_my != vd->vd_my_drawn);

        /* Check if the cursor should be displayed or not. */
        if ((vd->vd_flags & VDF_MOUSECURSOR) && /* Mouse support enabled. */
            !(vw->vw_flags & VWF_MOUSE_HIDE) && /* Cursor displayed.      */
            !kdb_active && !KERNEL_PANICKED()) {  /* DDB inactive.          */
                vd->vd_mshown = 1;
        } else {
                vd->vd_mshown = 0;
        }

        /*
         * If the cursor changed display state or moved, we must mark
         * the old position as dirty, so that it's erased.
         */
        if (cursor_was_shown != vd->vd_mshown ||
            (vd->vd_mshown && cursor_moved))
                vt_mark_mouse_position_as_dirty(vd, true);

        /*
         * Save position of the mouse cursor. It's used by backends to
         * know where to draw the cursor and during the next refresh to
         * erase the previous position.
         */
        vd->vd_mx_drawn = vd->vd_mx;
        vd->vd_my_drawn = vd->vd_my;

        /*
         * If the cursor is displayed and has moved since last refresh,
         * mark the new position as dirty.
         */
        if (vd->vd_mshown && cursor_moved)
                vt_mark_mouse_position_as_dirty(vd, true);
#endif

        vtbuf_undirty(&vw->vw_buf, &tarea);

        /* Force a full redraw when the screen contents might be invalid. */
        needs_refresh = false;
        if (vd->vd_flags & (VDF_INVALID | VDF_SUSPENDED)) {
                needs_refresh = true;
                vd->vd_flags &= ~VDF_INVALID;

                vt_termrect(vd, vf, &tarea);
                if (vd->vd_driver->vd_invalidate_text)
                        vd->vd_driver->vd_invalidate_text(vd, &tarea);
        }

        if (tarea.tr_begin.tp_col < tarea.tr_end.tp_col) {
                if (vd->vd_driver->vd_bitblt_after_vtbuf_unlock) {
                        /*
                         * When `vd_bitblt_after_vtbuf_unlock` is set to true,
                         * we first remember the characters to redraw. They are
                         * already copied to the `vd_drawn` arrays.
                         *
                         * We then unlock vt_buf and proceed with the actual
                         * drawing using the backend driver.
                         */
                        vt_flush_to_buffer(vd, vw, &tarea);
                        vtbuf_unlock(&vw->vw_buf);
                        vt_bitblt_buffer(vd, vw, &tarea);

                        if (needs_refresh)
                                vt_draw_decorations(vd);

                        /*
                         * We can reset `inside_vt_flush` after unlocking vtbuf
                         * here because we also hold vt_flush_lock in this code
                         * path.
                         */
                        inside_vt_flush = false;
                } else {
                        /*
                         * When `vd_bitblt_after_vtbuf_unlock` is false, we use
                         * the backend's `vd_bitblt_text` callback directly.
                         */
                        vd->vd_driver->vd_bitblt_text(vd, vw, &tarea);

                        if (needs_refresh)
                                vt_draw_decorations(vd);

                        inside_vt_flush = false;
                        vtbuf_unlock(&vw->vw_buf);
                }

                VT_FLUSH_UNLOCK(vd);

                return (1);
        }

        inside_vt_flush = false;
        vtbuf_unlock(&vw->vw_buf);

        VT_FLUSH_UNLOCK(vd);

        return (0);
}

static void
vt_timer(void *arg)
{
        struct vt_device *vd;
        int changed;

        vd = arg;
        /* Update screen if required. */
        changed = vt_flush(vd);

        /* Schedule for next update. */
        if (changed)
                vt_schedule_flush(vd, 0);
        else
                vd->vd_timer_armed = 0;
}

static void
vtterm_pre_input(struct terminal *tm)
{
        struct vt_window *vw = tm->tm_softc;

        if (inside_vt_flush && KERNEL_PANICKED())
                return;

        vtbuf_lock(&vw->vw_buf);
}

static void
vtterm_post_input(struct terminal *tm)
{
        struct vt_window *vw = tm->tm_softc;

        if (inside_vt_flush && KERNEL_PANICKED())
                return;

        vtbuf_unlock(&vw->vw_buf);
        vt_resume_flush_timer(vw, 0);
}

static void
vtterm_done(struct terminal *tm)
{
        struct vt_window *vw = tm->tm_softc;
        struct vt_device *vd = vw->vw_device;

        if (kdb_active || KERNEL_PANICKED()) {
                /* Switch to the debugger. */
                if (vd->vd_curwindow != vw) {
                        vd->vd_curwindow = vw;
                        vd->vd_flags |= VDF_INVALID;
                        if (vd->vd_driver->vd_postswitch)
                                vd->vd_driver->vd_postswitch(vd);
                }
                vd->vd_flags &= ~VDF_SPLASH;
                vt_flush(vd);
        } else if (vt_slow_down > 0) {
                int i, j;
                for (i = 0; i < vt_slow_down; i++) {
                        for (j = 0; j < 1000; j++)
                                vt_flush(vd);
                }
        } else if (!(vd->vd_flags & VDF_ASYNC)) {
                vt_flush(vd);
        }
}

#ifdef DEV_SPLASH
static void
vtterm_splash(struct vt_device *vd)
{
        struct splash_info *si;
        uintptr_t image;
        vt_axis_t top, left;

        if (!(vd->vd_flags & VDF_TEXTMODE) && (boothowto & RB_MUTE)) {
                if (rebooting == 1) {
                        si = MD_FETCH(preload_kmdp, MODINFOMD_SHTDWNSPLASH, struct splash_info *);
                        vd->vd_driver->vd_blank(vd, TC_BLACK);
                } else {
                        si = MD_FETCH(preload_kmdp, MODINFOMD_SPLASH, struct splash_info *);
                }
                if (si == NULL) {
                        top = (vd->vd_height - vt_logo_height) / 2;
                        left = (vd->vd_width - vt_logo_width) / 2;
                        vd->vd_driver->vd_bitblt_bmp(vd, vd->vd_curwindow,
                            vt_logo_image, NULL, vt_logo_width, vt_logo_height,
                            left, top, TC_WHITE, TC_BLACK);
                } else {
                        if (si->si_depth != 4)
                                return;
                        image = (uintptr_t)si + sizeof(struct splash_info);
                        image = roundup2(image, 8);
                        top = (vd->vd_height - si->si_height) / 2;
                        left = (vd->vd_width - si->si_width) / 2;
                        vd->vd_driver->vd_bitblt_argb(vd, vd->vd_curwindow,
                            (unsigned char *)image, si->si_width, si->si_height,
                            left, top);
                }
                vd->vd_flags |= VDF_SPLASH;
        }
}
#endif

static struct vt_font *
parse_font_info_static(struct font_info *fi)
{
        struct vt_font *vfp;
        uintptr_t ptr;
        uint32_t checksum;

        if (fi == NULL)
                return (NULL);

        ptr = (uintptr_t)fi;
        /*
         * Compute and verify checksum. The total sum of all the fields
         * must be 0.
         */
        checksum = fi->fi_width;
        checksum += fi->fi_height;
        checksum += fi->fi_bitmap_size;
        for (unsigned i = 0; i < VFNT_MAPS; i++)
                checksum += fi->fi_map_count[i];

        if (checksum + fi->fi_checksum != 0)
                return (NULL);

        ptr += sizeof(struct font_info);
        ptr = roundup2(ptr, 8);

        vfp = &vt_font_loader;
        vfp->vf_height = fi->fi_height;
        vfp->vf_width = fi->fi_width;
        /* This is default font, set refcount 1 to disable removal. */
        vfp->vf_refcount = 1;
        for (unsigned i = 0; i < VFNT_MAPS; i++) {
                if (fi->fi_map_count[i] == 0)
                        continue;
                vfp->vf_map_count[i] = fi->fi_map_count[i];
                vfp->vf_map[i] = (vfnt_map_t *)ptr;
                ptr += (fi->fi_map_count[i] * sizeof(vfnt_map_t));
                ptr = roundup2(ptr, 8);
        }
        vfp->vf_bytes = (uint8_t *)ptr;
        return (vfp);
}

/*
 * Set up default font with allocated data structures.
 * However, we can not set refcount here, because it is already set and
 * incremented in vtterm_cnprobe() to avoid being released by font load from
 * userland.
 */
static struct vt_font *
parse_font_info(struct font_info *fi)
{
        struct vt_font *vfp;
        uintptr_t ptr;
        uint32_t checksum;
        size_t size;

        if (fi == NULL)
                return (NULL);

        ptr = (uintptr_t)fi;
        /*
         * Compute and verify checksum. The total sum of all the fields
         * must be 0.
         */
        checksum = fi->fi_width;
        checksum += fi->fi_height;
        checksum += fi->fi_bitmap_size;
        for (unsigned i = 0; i < VFNT_MAPS; i++)
                checksum += fi->fi_map_count[i];

        if (checksum + fi->fi_checksum != 0)
                return (NULL);

        ptr += sizeof(struct font_info);
        ptr = roundup2(ptr, 8);

        vfp = &vt_font_loader;
        vfp->vf_height = fi->fi_height;
        vfp->vf_width = fi->fi_width;
        for (unsigned i = 0; i < VFNT_MAPS; i++) {
                if (fi->fi_map_count[i] == 0)
                        continue;
                vfp->vf_map_count[i] = fi->fi_map_count[i];
                size = fi->fi_map_count[i] * sizeof(vfnt_map_t);
                vfp->vf_map[i] = malloc(size, M_VT, M_WAITOK | M_ZERO);
                bcopy((vfnt_map_t *)ptr, vfp->vf_map[i], size);
                ptr += size;
                ptr = roundup2(ptr, 8);
        }
        vfp->vf_bytes = malloc(fi->fi_bitmap_size, M_VT, M_WAITOK | M_ZERO);
        bcopy((uint8_t *)ptr, vfp->vf_bytes, fi->fi_bitmap_size);
        return (vfp);
}

static void
vt_init_font(void *arg)
{
        struct font_info *fi;
        struct vt_font *font;

        fi = MD_FETCH(preload_kmdp, MODINFOMD_FONT, struct font_info *);

        font = parse_font_info(fi);
        if (font != NULL)
                vt_font_assigned = font;
}

SYSINIT(vt_init_font, SI_SUB_KMEM, SI_ORDER_ANY, vt_init_font, &vt_consdev);

static void
vt_init_font_static(void)
{
        struct font_info *fi;
        struct vt_font *font;

        fi = MD_FETCH(preload_kmdp, MODINFOMD_FONT, struct font_info *);

        font = parse_font_info_static(fi);
        if (font != NULL)
                vt_font_assigned = font;
}

#ifdef DEV_SPLASH
static int
vt_shutdown_splash(struct vt_window *vw)
{
        vtterm_splash(vw->vw_device);
        return (0);
}
#endif

static void
vtterm_cnprobe(struct terminal *tm, struct consdev *cp)
{
        struct vt_driver *vtd, **vtdlist, *vtdbest = NULL;
        struct vt_window *vw = tm->tm_softc;
        struct vt_device *vd = vw->vw_device;
        struct winsize wsz;
        const term_attr_t *a;

        if (!vty_enabled(VTY_VT))
                return;

        if (vd->vd_flags & VDF_INITIALIZED)
                /* Initialization already done. */
                return;

        SET_FOREACH(vtdlist, vt_drv_set) {
                vtd = *vtdlist;
                if (vtd->vd_probe == NULL)
                        continue;
                if (vtd->vd_probe(vd) == CN_DEAD)
                        continue;
                if ((vtdbest == NULL) ||
                    (vtd->vd_priority > vtdbest->vd_priority))
                        vtdbest = vtd;
        }
        if (vtdbest == NULL) {
                cp->cn_pri = CN_DEAD;
                vd->vd_flags |= VDF_DEAD;
        } else {
                vd->vd_driver = vtdbest;
                cp->cn_pri = vd->vd_driver->vd_init(vd);
        }

        /* Check if driver's vt_init return CN_DEAD. */
        if (cp->cn_pri == CN_DEAD) {
                vd->vd_flags |= VDF_DEAD;
        }

        /* Initialize any early-boot keyboard drivers */
        kbd_configure(KB_CONF_PROBE_ONLY);

        vd->vd_unit = atomic_fetchadd_int(&vt_unit, 1);
        vd->vd_windows[VT_CONSWINDOW] = vw;
        sprintf(cp->cn_name, "ttyv%r", VT_UNIT(vw));

        vt_init_font_static();

        /* Attach default font if not in TEXTMODE. */
        if ((vd->vd_flags & VDF_TEXTMODE) == 0) {
                vw->vw_font = vtfont_ref(vt_font_assigned);
                vt_compute_drawable_area(vw);
        }

        /*
         * The original screen size was faked (_VTDEFW x _VTDEFH). Now
         * that we have the real viewable size, fix it in the static
         * buffer.
         */
        if (vd->vd_width != 0 && vd->vd_height != 0)
                vt_termsize(vd, vw->vw_font, &vw->vw_buf.vb_scr_size);

        /* We need to access terminal attributes from vtbuf */
        vw->vw_buf.vb_terminal = tm;
        vtbuf_init_early(&vw->vw_buf);
        vt_winsize(vd, vw->vw_font, &wsz);
        a = teken_get_curattr(&tm->tm_emulator);
        terminal_set_winsize_blank(tm, &wsz, 1, a);

        if (vtdbest != NULL) {
#ifdef DEV_SPLASH
                if (!vt_splash_cpu)
                        vtterm_splash(vd);
#endif
                vd->vd_flags |= VDF_INITIALIZED;
        }
}

static int
vtterm_cngetc(struct terminal *tm)
{
        struct vt_window *vw = tm->tm_softc;
        struct vt_device *vd = vw->vw_device;
        keyboard_t *kbd;
        u_int c;

        if (vw->vw_kbdsq && *vw->vw_kbdsq)
                return (*vw->vw_kbdsq++);

        /* Make sure the splash screen is not there. */
        if (vd->vd_flags & VDF_SPLASH) {
                /* Remove splash */
                vd->vd_flags &= ~VDF_SPLASH;
                /* Mark screen as invalid to force update */
                vd->vd_flags |= VDF_INVALID;
                vt_flush(vd);
        }

        /* Stripped down keyboard handler. */
        if ((kbd = vd->vd_keyboard) == NULL)
                return (-1);

        /* Force keyboard input mode to K_XLATE */
        vw->vw_kbdmode = K_XLATE;
        vt_update_kbd_mode(vw, kbd);

        /* Switch the keyboard to polling to make it work here. */
        kbdd_poll(kbd, TRUE);
        c = kbdd_read_char(kbd, 0);
        kbdd_poll(kbd, FALSE);
        if (c & RELKEY)
                return (-1);

        if (vw->vw_flags & VWF_SCROLL) {
                vt_scrollmode_kbdevent(vw, c, 1/* Console mode */);
                vt_flush(vd);
                return (-1);
        }

        /* Stripped down handling of vt_kbdevent(), without locking, etc. */
        if (c & SPCLKEY) {
                switch (c) {
                case SPCLKEY | SLK:
                        vt_save_kbd_state(vw, kbd);
                        if (vw->vw_kbdstate & SLKED) {
                                /* Turn scrolling on. */
                                vw->vw_flags |= VWF_SCROLL;
                                VTBUF_SLCK_ENABLE(&vw->vw_buf);
                        } else {
                                /* Turn scrolling off. */
                                vt_scroll(vw, 0, VHS_END);
                                vw->vw_flags &= ~VWF_SCROLL;
                                VTBUF_SLCK_DISABLE(&vw->vw_buf);
                        }
                        break;
                case SPCLKEY | BTAB: /* Back tab (usually, shift+tab). */
                        vw->vw_kbdsq = "\x1b[Z";
                        break;
                /* XXX: KDB can handle history. */
                case SPCLKEY | FKEY | F(50): /* Arrow up. */
                        vw->vw_kbdsq = "\x1b[A";
                        break;
                case SPCLKEY | FKEY | F(58): /* Arrow down. */
                        vw->vw_kbdsq = "\x1b[B";
                        break;
                case SPCLKEY | FKEY | F(55): /* Arrow right. */
                        vw->vw_kbdsq = "\x1b[C";
                        break;
                case SPCLKEY | FKEY | F(53): /* Arrow left. */
                        vw->vw_kbdsq = "\x1b[D";
                        break;
                }

                /* Force refresh to make scrollback work. */
                vt_flush(vd);
        } else if (KEYFLAGS(c) == 0) {
                return (KEYCHAR(c));
        }

        if (vw->vw_kbdsq && *vw->vw_kbdsq)
                return (*vw->vw_kbdsq++);

        return (-1);
}

/*
 * These two do most of what we want to do in vtterm_cnungrab, but without
 * actually switching windows.  This is necessary for, e.g.,
 * vt_allocate_keyboard() to get the current keyboard into the state it needs to
 * be in without damaging the device's window state.
 *
 * Both return the current grab count, though it's only used in vtterm_cnungrab.
 */
static int
vtterm_cngrab_noswitch(struct vt_device *vd, struct vt_window *vw)
{
        keyboard_t *kbd;

        if (vw->vw_grabbed++ > 0)
                return (vw->vw_grabbed);

        if ((kbd = vd->vd_keyboard) == NULL)
                return (1);

        /*
         * Make sure the keyboard is accessible even when the kbd device
         * driver is disabled.
         */
        kbdd_enable(kbd);

        /* We shall always use the keyboard in the XLATE mode here. */
        vw->vw_prev_kbdmode = vw->vw_kbdmode;
        vw->vw_kbdmode = K_XLATE;
        vt_update_kbd_mode(vw, kbd);

        kbdd_poll(kbd, TRUE);
        return (1);
}

static int
vtterm_cnungrab_noswitch(struct vt_device *vd, struct vt_window *vw)
{
        keyboard_t *kbd;

        if (--vw->vw_grabbed > 0)
                return (vw->vw_grabbed);

        if ((kbd = vd->vd_keyboard) == NULL)
                return (0);

        kbdd_poll(kbd, FALSE);

        vw->vw_kbdmode = vw->vw_prev_kbdmode;
        vt_update_kbd_mode(vw, kbd);
        kbdd_disable(kbd);
        return (0);
}

static void
vtterm_cngrab(struct terminal *tm)
{
        struct vt_device *vd;
        struct vt_window *vw;

        vw = tm->tm_softc;
        vd = vw->vw_device;

        /* To be restored after we ungrab. */
        if (vd->vd_grabwindow == NULL)
                vd->vd_grabwindow = vd->vd_curwindow;

        if (!cold)
                vt_window_switch(vw);

        vtterm_cngrab_noswitch(vd, vw);
}

static void
vtterm_cnungrab(struct terminal *tm)
{
        struct vt_device *vd;
        struct vt_window *vw, *grabwindow;

        vw = tm->tm_softc;
        vd = vw->vw_device;

        MPASS(vd->vd_grabwindow != NULL);
        if (vtterm_cnungrab_noswitch(vd, vw) != 0)
                return;

        /*
         * We set `vd_grabwindow` to NULL before calling vt_window_switch()
         * because it allows the underlying vt(4) backend to distinguish a
         * "grab" from an "ungrab" of the console.
         *
         * This is used by `vt_drmfb` in drm-kmod to call either
         * fb_debug_enter() or fb_debug_leave() appropriately.
         */
        grabwindow = vd->vd_grabwindow;
        vd->vd_grabwindow = NULL;

        if (!cold)
                vt_window_switch(grabwindow);
}

static void
vtterm_opened(struct terminal *tm, int opened)
{
        struct vt_window *vw = tm->tm_softc;
        struct vt_device *vd = vw->vw_device;

        VT_LOCK(vd);
        vd->vd_flags &= ~VDF_SPLASH;
        if (opened)
                vw->vw_flags |= VWF_OPENED;
        else {
                vw->vw_flags &= ~VWF_OPENED;
                /* TODO: finish ACQ/REL */
        }
        VT_UNLOCK(vd);
}

static int
vt_change_font(struct vt_window *vw, struct vt_font *vf)
{
        struct vt_device *vd = vw->vw_device;
        struct terminal *tm = vw->vw_terminal;
        term_pos_t size;
        struct winsize wsz;

        /*
         * Changing fonts.
         *
         * Changing fonts is a little tricky.  We must prevent
         * simultaneous access to the device, so we must stop
         * the display timer and the terminal from accessing.
         * We need to switch fonts and grow our screen buffer.
         *
         * XXX: Right now the code uses terminal_mute() to
         * prevent data from reaching the console driver while
         * resizing the screen buffer.  This isn't elegant...
         */

        VT_LOCK(vd);
        if (vw->vw_flags & VWF_BUSY) {
                /* Another process is changing the font. */
                VT_UNLOCK(vd);
                return (EBUSY);
        }
        vw->vw_flags |= VWF_BUSY;
        VT_UNLOCK(vd);

        vt_termsize(vd, vf, &size);
        vt_winsize(vd, vf, &wsz);

        /* Grow the screen buffer and terminal. */
        terminal_mute(tm, 1);
        vtbuf_grow(&vw->vw_buf, &size, vw->vw_buf.vb_history_size);
        terminal_set_winsize_blank(tm, &wsz, 0, NULL);
        terminal_set_cursor(tm, &vw->vw_buf.vb_cursor);
        terminal_mute(tm, 0);

        /* Actually apply the font to the current window. */
        VT_LOCK(vd);
        if (vw->vw_font != vf && vw->vw_font != NULL && vf != NULL) {
                /*
                 * In case vt_change_font called to update size we don't need
                 * to update font link.
                 */
                vtfont_unref(vw->vw_font);
                vw->vw_font = vtfont_ref(vf);
        }

        /*
         * Compute the drawable area and move the mouse cursor inside
         * it, in case the new area is smaller than the previous one.
         */
        vt_compute_drawable_area(vw);
        vd->vd_mx = min(vd->vd_mx,
            vw->vw_draw_area.tr_end.tp_col -
            vw->vw_draw_area.tr_begin.tp_col - 1);
        vd->vd_my = min(vd->vd_my,
            vw->vw_draw_area.tr_end.tp_row -
            vw->vw_draw_area.tr_begin.tp_row - 1);

        /* Force a full redraw the next timer tick. */
        if (vd->vd_curwindow == vw) {
                vd->vd_flags |= VDF_INVALID;
                vt_resume_flush_timer(vw, 0);
        }
        vw->vw_flags &= ~VWF_BUSY;
        VT_UNLOCK(vd);
        return (0);
}

static int
vt_proc_alive(struct vt_window *vw)
{
        struct proc *p;

        if (vw->vw_smode.mode != VT_PROCESS)
                return (FALSE);

        if (vw->vw_proc) {
                if ((p = pfind(vw->vw_pid)) != NULL)
                        PROC_UNLOCK(p);
                if (vw->vw_proc == p)
                        return (TRUE);
                vw->vw_proc = NULL;
                vw->vw_smode.mode = VT_AUTO;
                DPRINTF(1, "vt controlling process %d died\n", vw->vw_pid);
                vw->vw_pid = 0;
        }
        return (FALSE);
}

static int
signal_vt_rel(struct vt_window *vw)
{

        if (vw->vw_smode.mode != VT_PROCESS)
                return (FALSE);
        if (vw->vw_proc == NULL || vt_proc_alive(vw) == FALSE) {
                vw->vw_proc = NULL;
                vw->vw_pid = 0;
                return (TRUE);
        }
        vw->vw_flags |= VWF_SWWAIT_REL;
        PROC_LOCK(vw->vw_proc);
        kern_psignal(vw->vw_proc, vw->vw_smode.relsig);
        PROC_UNLOCK(vw->vw_proc);
        DPRINTF(1, "sending relsig to %d\n", vw->vw_pid);
        return (TRUE);
}

static int
signal_vt_acq(struct vt_window *vw)
{

        if (vw->vw_smode.mode != VT_PROCESS)
                return (FALSE);
        if (vw == vw->vw_device->vd_windows[VT_CONSWINDOW])
                cnavailable(vw->vw_terminal->consdev, FALSE);
        if (vw->vw_proc == NULL || vt_proc_alive(vw) == FALSE) {
                vw->vw_proc = NULL;
                vw->vw_pid = 0;
                return (TRUE);
        }
        vw->vw_flags |= VWF_SWWAIT_ACQ;
        PROC_LOCK(vw->vw_proc);
        kern_psignal(vw->vw_proc, vw->vw_smode.acqsig);
        PROC_UNLOCK(vw->vw_proc);
        DPRINTF(1, "sending acqsig to %d\n", vw->vw_pid);
        return (TRUE);
}

static int
finish_vt_rel(struct vt_window *vw, int release, int *s)
{

        if (vw->vw_flags & VWF_SWWAIT_REL) {
                vw->vw_flags &= ~VWF_SWWAIT_REL;
                if (release) {
                        taskqueue_drain_timeout(taskqueue_thread, &vw->vw_timeout_task_dead);
                        (void)vt_late_window_switch(vw->vw_switch_to);
                }
                return (0);
        }
        return (EINVAL);
}

static int
finish_vt_acq(struct vt_window *vw)
{

        if (vw->vw_flags & VWF_SWWAIT_ACQ) {
                vw->vw_flags &= ~VWF_SWWAIT_ACQ;
                return (0);
        }
        return (EINVAL);
}

#ifndef SC_NO_CUTPASTE
static void
vt_mouse_terminput_button(struct vt_device *vd, int button)
{
        struct vt_window *vw;
        struct vt_font *vf;
        char mouseb[6] = "\x1B[M";
        int i, x, y;

        vw = vd->vd_curwindow;
        vf = vw->vw_font;

        /* Translate to char position. */
        x = vd->vd_mx / vf->vf_width;
        y = vd->vd_my / vf->vf_height;
        /* Avoid overflow. */
        x = MIN(x, 255 - '!');
        y = MIN(y, 255 - '!');

        mouseb[3] = ' ' + button;
        mouseb[4] = '!' + x;
        mouseb[5] = '!' + y;

        for (i = 0; i < sizeof(mouseb); i++)
                terminal_input_char(vw->vw_terminal, mouseb[i]);
}

static void
vt_mouse_terminput(struct vt_device *vd, int type, int x, int y, int event,
    int cnt)
{

        switch (type) {
        case MOUSE_BUTTON_EVENT:
                if (cnt > 0) {
                        /* Mouse button pressed. */
                        if (event & MOUSE_BUTTON1DOWN)
                                vt_mouse_terminput_button(vd, 0);
                        if (event & MOUSE_BUTTON2DOWN)
                                vt_mouse_terminput_button(vd, 1);
                        if (event & MOUSE_BUTTON3DOWN)
                                vt_mouse_terminput_button(vd, 2);
                } else {
                        /* Mouse button released. */
                        vt_mouse_terminput_button(vd, 3);
                }
                break;
#ifdef notyet
        case MOUSE_MOTION_EVENT:
                if (mouse->u.data.z < 0) {
                        /* Scroll up. */
                        sc_mouse_input_button(vd, 64);
                } else if (mouse->u.data.z > 0) {
                        /* Scroll down. */
                        sc_mouse_input_button(vd, 65);
                }
                break;
#endif
        }
}

static void
vt_mouse_paste(void)
{
        term_char_t *buf;
        int i, len;

        len = VD_PASTEBUFLEN(main_vd);
        buf = VD_PASTEBUF(main_vd);
        len /= sizeof(term_char_t);
        for (i = 0; i < len; i++) {
                if (TCHAR_CHARACTER(buf[i]) == '\0')
                        continue;
                terminal_input_char(main_vd->vd_curwindow->vw_terminal,
                    buf[i]);
        }
}

void
vt_mouse_event(int type, int x, int y, int event, int cnt, int mlevel)
{
        struct vt_device *vd;
        struct vt_window *vw;
        struct vt_font *vf;
        term_pos_t size;
        int len, mark;

        vd = main_vd;
        vw = vd->vd_curwindow;
        vf = vw->vw_font;

        if (vw->vw_flags & (VWF_MOUSE_HIDE | VWF_GRAPHICS))
                /*
                 * Either the mouse is disabled, or the window is in
                 * "graphics mode". The graphics mode is usually set by
                 * an X server, using the KDSETMODE ioctl.
                 */
                return;

        if (vf == NULL) /* Text mode. */
                return;

        /*
         * TODO: add flag about pointer position changed, to not redraw chars
         * under mouse pointer when nothing changed.
         */

        if (vw->vw_mouse_level > 0)
                vt_mouse_terminput(vd, type, x, y, event, cnt);

        switch (type) {
        case MOUSE_ACTION:
        case MOUSE_MOTION_EVENT:
                /* Movement */
                x += vd->vd_mx;
                y += vd->vd_my;

                vt_termsize(vd, vf, &size);

                /* Apply limits. */
                x = MAX(x, 0);
                y = MAX(y, 0);
                x = MIN(x, (size.tp_col * vf->vf_width) - 1);
                y = MIN(y, (size.tp_row * vf->vf_height) - 1);

                vd->vd_mx = x;
                vd->vd_my = y;
                if (vd->vd_mstate & (MOUSE_BUTTON1DOWN | VT_MOUSE_EXTENDBUTTON))
                        vtbuf_set_mark(&vw->vw_buf, VTB_MARK_MOVE,
                            vd->vd_mx / vf->vf_width,
                            vd->vd_my / vf->vf_height);

                vt_resume_flush_timer(vw, 0);
                return; /* Done */
        case MOUSE_BUTTON_EVENT:
                /* Buttons */
                break;
        default:
                return; /* Done */
        }

        switch (event) {
        case MOUSE_BUTTON1DOWN:
                switch (cnt % 4) {
                case 0: /* up */
                        mark = VTB_MARK_END;
                        break;
                case 1: /* single click: start cut operation */
                        mark = VTB_MARK_START;
                        break;
                case 2: /* double click: cut a word */
                        mark = VTB_MARK_WORD;
                        break;
                default:        /* triple click: cut a line */
                        mark = VTB_MARK_ROW;
                        break;
                }
                break;
        case VT_MOUSE_PASTEBUTTON:
                switch (cnt) {
                case 0: /* up */
                        break;
                default:
                        vt_mouse_paste();
                        /* clear paste buffer selection after paste */
                        vtbuf_set_mark(&vw->vw_buf, VTB_MARK_START,
                            vd->vd_mx / vf->vf_width,
                            vd->vd_my / vf->vf_height);
                        break;
                }
                return; /* Done */
        case VT_MOUSE_EXTENDBUTTON:
                switch (cnt) {
                case 0: /* up */
                        if (!(vd->vd_mstate & MOUSE_BUTTON1DOWN))
                                mark = VTB_MARK_EXTEND;
                        else
                                mark = VTB_MARK_NONE;
                        break;
                default:
                        mark = VTB_MARK_EXTEND;
                        break;
                }
                break;
        default:
                return; /* Done */
        }

        /* Save buttons state. */
        if (cnt > 0)
                vd->vd_mstate |= event;
        else
                vd->vd_mstate &= ~event;

        if (vtbuf_set_mark(&vw->vw_buf, mark, vd->vd_mx / vf->vf_width,
            vd->vd_my / vf->vf_height) == 1) {
                /*
                 * We have something marked to copy, so update pointer to
                 * window with selection.
                 */
                vt_resume_flush_timer(vw, 0);

                switch (mark) {
                case VTB_MARK_END:
                case VTB_MARK_WORD:
                case VTB_MARK_ROW:
                case VTB_MARK_EXTEND:
                        break;
                default:
                        /* Other types of mark do not require to copy data. */
                        return;
                }

                /* Get current selection size in bytes. */
                len = vtbuf_get_marked_len(&vw->vw_buf);
                if (len <= 0)
                        return;

                /* Reallocate buffer only if old one is too small. */
                if (len > VD_PASTEBUFSZ(vd)) {
                        VD_PASTEBUF(vd) = realloc(VD_PASTEBUF(vd), len, M_VT,
                            M_WAITOK | M_ZERO);
                        /* Update buffer size. */
                        VD_PASTEBUFSZ(vd) = len;
                }
                /* Request copy/paste buffer data, no more than `len' */
                vtbuf_extract_marked(&vw->vw_buf, VD_PASTEBUF(vd), len, mark);

                VD_PASTEBUFLEN(vd) = len;

                /* XXX VD_PASTEBUF(vd) have to be freed on shutdown/unload. */
        }
}

void
vt_mouse_state(int show)
{
        struct vt_device *vd;
        struct vt_window *vw;

        vd = main_vd;
        vw = vd->vd_curwindow;

        switch (show) {
        case VT_MOUSE_HIDE:
                vw->vw_flags |= VWF_MOUSE_HIDE;
                break;
        case VT_MOUSE_SHOW:
                vw->vw_flags &= ~VWF_MOUSE_HIDE;
                break;
        }

        /* Mark mouse position as dirty. */
        vt_mark_mouse_position_as_dirty(vd, false);
        vt_resume_flush_timer(vw, 0);
}
#endif

static int
vtterm_mmap(struct terminal *tm, vm_ooffset_t offset, vm_paddr_t * paddr,
    int nprot, vm_memattr_t *memattr)
{
        struct vt_window *vw = tm->tm_softc;
        struct vt_device *vd = vw->vw_device;

        if (vd->vd_driver->vd_fb_mmap)
                return (vd->vd_driver->vd_fb_mmap(vd, offset, paddr, nprot,
                    memattr));

        return (ENXIO);
}

static int
vtterm_ioctl(struct terminal *tm, u_long cmd, caddr_t data,
    struct thread *td)
{
        struct vt_window *vw = tm->tm_softc;
        struct vt_device *vd = vw->vw_device;
        keyboard_t *kbd;
        int error, i, s;
#if defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD5) || \
    defined(COMPAT_FREEBSD4) || defined(COMPAT_43)
        int ival;

        switch (cmd) {
        case _IO('v', 4):
                cmd = VT_RELDISP;
                break;
        case _IO('v', 5):
                cmd = VT_ACTIVATE;
                break;
        case _IO('v', 6):
                cmd = VT_WAITACTIVE;
                break;
        case _IO('K', 20):
                cmd = KDSKBSTATE;
                break;
        case _IO('K', 67):
                cmd = KDSETRAD;
                break;
        case _IO('K', 7):
                cmd = KDSKBMODE;
                break;
        case _IO('K', 8):
                cmd = KDMKTONE;
                break;
        case _IO('K', 10):
                cmd = KDSETMODE;
                break;
        case _IO('K', 13):
                cmd = KDSBORDER;
                break;
        case _IO('K', 63):
                cmd = KIOCSOUND;
                break;
        case _IO('K', 66):
                cmd = KDSETLED;
                break;
        case _IO('c', 104):
                cmd = CONS_SETWINORG;
                break;
        case _IO('c', 110):
                cmd = CONS_SETKBD;
                break;
        default:
                goto skip_thunk;
        }
        ival = IOCPARM_IVAL(data);
        data = (caddr_t)&ival;
skip_thunk:
#endif

        switch (cmd) {
        case KDSETRAD:          /* set keyboard repeat & delay rates (old) */
                if (*(int *)data & ~0x7f)
                        return (EINVAL);
                /* FALLTHROUGH */
        case GIO_KEYMAP:
        case PIO_KEYMAP:
        case GIO_DEADKEYMAP:
        case PIO_DEADKEYMAP:
#ifdef COMPAT_FREEBSD13
        case OGIO_DEADKEYMAP:
        case OPIO_DEADKEYMAP:
#endif /* COMPAT_FREEBSD13 */
        case GETFKEY:
        case SETFKEY:
        case KDGKBINFO:
        case KDGKBTYPE:
        case KDGETREPEAT:       /* get keyboard repeat & delay rates */
        case KDSETREPEAT:       /* set keyboard repeat & delay rates (new) */
        case KBADDKBD:          /* add keyboard to mux */
        case KBRELKBD: {        /* release keyboard from mux */
                error = 0;

                mtx_lock(&Giant);
                if ((kbd = vd->vd_keyboard) != NULL)
                        error = kbdd_ioctl(kbd, cmd, data);
                mtx_unlock(&Giant);
                if (error == ENOIOCTL) {
                        if (cmd == KDGKBTYPE) {
                                /* always return something? XXX */
                                *(int *)data = 0;
                        } else {
                                return (ENODEV);
                        }
                }
                return (error);
        }
        case KDGKBSTATE: {      /* get keyboard state (locks) */
                error = 0;

                if (vw == vd->vd_curwindow) {
                        mtx_lock(&Giant);
                        if ((kbd = vd->vd_keyboard) != NULL)
                                error = vt_save_kbd_state(vw, kbd);
                        mtx_unlock(&Giant);

                        if (error != 0)
                                return (error);
                }

                *(int *)data = vw->vw_kbdstate & LOCK_MASK;

                return (error);
        }
        case KDSKBSTATE: {      /* set keyboard state (locks) */
                int state;

                state = *(int *)data;
                if (state & ~LOCK_MASK)
                        return (EINVAL);

                vw->vw_kbdstate &= ~LOCK_MASK;
                vw->vw_kbdstate |= state;

                error = 0;
                if (vw == vd->vd_curwindow) {
                        mtx_lock(&Giant);
                        if ((kbd = vd->vd_keyboard) != NULL)
                                error = vt_update_kbd_state(vw, kbd);
                        mtx_unlock(&Giant);
                }

                return (error);
        }
        case KDGETLED: {        /* get keyboard LED status */
                error = 0;

                if (vw == vd->vd_curwindow) {
                        mtx_lock(&Giant);
                        if ((kbd = vd->vd_keyboard) != NULL)
                                error = vt_save_kbd_leds(vw, kbd);
                        mtx_unlock(&Giant);

                        if (error != 0)
                                return (error);
                }

                *(int *)data = vw->vw_kbdstate & LED_MASK;

                return (error);
        }
        case KDSETLED: {        /* set keyboard LED status */
                int leds;

                leds = *(int *)data;
                if (leds & ~LED_MASK)
                        return (EINVAL);

                vw->vw_kbdstate &= ~LED_MASK;
                vw->vw_kbdstate |= leds;

                error = 0;
                if (vw == vd->vd_curwindow) {
                        mtx_lock(&Giant);
                        if ((kbd = vd->vd_keyboard) != NULL)
                                error = vt_update_kbd_leds(vw, kbd);
                        mtx_unlock(&Giant);
                }

                return (error);
        }
        case KDGETMODE:
                *(int *)data = (vw->vw_flags & VWF_GRAPHICS) ?
                    KD_GRAPHICS : KD_TEXT;
                return (0);
        case KDGKBMODE: {
                error = 0;

                if (vw == vd->vd_curwindow) {
                        mtx_lock(&Giant);
                        if ((kbd = vd->vd_keyboard) != NULL)
                                error = vt_save_kbd_mode(vw, kbd);
                        mtx_unlock(&Giant);

                        if (error != 0)
                                return (error);
                }

                *(int *)data = vw->vw_kbdmode;

                return (error);
        }
        case KDSKBMODE: {
                int mode;

                mode = *(int *)data;
                switch (mode) {
                case K_XLATE:
                case K_RAW:
                case K_CODE:
                        vw->vw_kbdmode = mode;

                        error = 0;
                        if (vw == vd->vd_curwindow) {
                                mtx_lock(&Giant);
                                if ((kbd = vd->vd_keyboard) != NULL)
                                        error = vt_update_kbd_mode(vw, kbd);
                                mtx_unlock(&Giant);
                        }

                        return (error);
                default:
                        return (EINVAL);
                }
        }
        case FBIOGTYPE:
        case FBIO_GETWINORG:    /* get frame buffer window origin */
        case FBIO_GETDISPSTART: /* get display start address */
        case FBIO_GETLINEWIDTH: /* get scan line width in bytes */
        case FBIO_BLANK:        /* blank display */
        case FBIO_GETRGBOFFS:   /* get RGB offsets */
                if (vd->vd_driver->vd_fb_ioctl)
                        return (vd->vd_driver->vd_fb_ioctl(vd, cmd, data, td));
                break;
        case CONS_BLANKTIME:
                /* XXX */
                return (0);
        case CONS_HISTORY:
                if (*(int *)data < 0)
                        return EINVAL;
                if (*(int *)data != vw->vw_buf.vb_history_size)
                        vtbuf_sethistory_size(&vw->vw_buf, *(int *)data);
                return (0);
        case CONS_CLRHIST:
                vtbuf_clearhistory(&vw->vw_buf);
                /*
                 * Invalidate the entire visible window; it is not guaranteed
                 * that this operation will be immediately followed by a scroll
                 * event, so it would otherwise be possible for prior artifacts
                 * to remain visible.
                 */
                VT_LOCK(vd);
                if (vw == vd->vd_curwindow) {
                        vd->vd_flags |= VDF_INVALID;
                        vt_resume_flush_timer(vw, 0);
                }
                VT_UNLOCK(vd);
                return (0);
        case CONS_GET:
                /* XXX */
                *(int *)data = M_CG640x480;
                return (0);
        case CONS_BELLTYPE:     /* set bell type sound */
                if ((*(int *)data) & CONS_QUIET_BELL)
                        vd->vd_flags |= VDF_QUIET_BELL;
                else
                        vd->vd_flags &= ~VDF_QUIET_BELL;
                return (0);
        case CONS_GETINFO: {
                vid_info_t *vi = (vid_info_t *)data;
                if (vi->size != sizeof(struct vid_info))
                        return (EINVAL);

                if (vw == vd->vd_curwindow) {
                        mtx_lock(&Giant);
                        if ((kbd = vd->vd_keyboard) != NULL)
                                vt_save_kbd_state(vw, kbd);
                        mtx_unlock(&Giant);
                }

                vi->m_num = vd->vd_curwindow->vw_number + 1;
                vi->mk_keylock = vw->vw_kbdstate & LOCK_MASK;
                /* XXX: other fields! */
                return (0);
        }
        case CONS_GETVERS:
                *(int *)data = 0x200;
                return (0);
        case CONS_MODEINFO:
                /* XXX */
                return (0);
        case CONS_MOUSECTL: {
                mouse_info_t *mouse = (mouse_info_t*)data;

                /*
                 * All the commands except MOUSE_SHOW nd MOUSE_HIDE
                 * should not be applied to individual TTYs, but only to
                 * consolectl.
                 */
                switch (mouse->operation) {
                case MOUSE_HIDE:
                        if (vd->vd_flags & VDF_MOUSECURSOR) {
                                vd->vd_flags &= ~VDF_MOUSECURSOR;
#ifndef SC_NO_CUTPASTE
                                vt_mouse_state(VT_MOUSE_HIDE);
#endif
                        }
                        return (0);
                case MOUSE_SHOW:
                        if (!(vd->vd_flags & VDF_MOUSECURSOR)) {
                                vd->vd_flags |= VDF_MOUSECURSOR;
                                vd->vd_mx = vd->vd_width / 2;
                                vd->vd_my = vd->vd_height / 2;
#ifndef SC_NO_CUTPASTE
                                vt_mouse_state(VT_MOUSE_SHOW);
#endif
                        }
                        return (0);
                default:
                        return (EINVAL);
                }
        }
        case PIO_VFONT: {
                struct vt_font *vf;

                if (vd->vd_flags & VDF_TEXTMODE)
                        return (ENOTSUP);

                error = vtfont_load((void *)data, &vf);
                if (error != 0)
                        return (error);

                error = vt_change_font(vw, vf);
                vtfont_unref(vf);
                return (error);
        }
        case PIO_VFONT_DEFAULT: {
                /* Reset to default font. */
                error = vt_change_font(vw, vt_font_assigned);
                return (error);
        }
        case GIO_SCRNMAP: {
                scrmap_t *sm = (scrmap_t *)data;

                /* We don't have screen maps, so return a handcrafted one. */
                for (i = 0; i < 256; i++)
                        sm->scrmap[i] = i;
                return (0);
        }
        case KDSETMODE:
                /*
                 * FIXME: This implementation is incomplete compared to
                 * syscons.
                 */
                switch (*(int *)data) {
                case KD_TEXT:
                case KD_TEXT1:
                case KD_PIXEL:
                        vw->vw_flags &= ~VWF_GRAPHICS;
                        break;
                case KD_GRAPHICS:
                        vw->vw_flags |= VWF_GRAPHICS;
                        break;
                }
                return (0);
        case KDENABIO:          /* allow io operations */
                error = priv_check(td, PRIV_IO);
                if (error != 0)
                        return (error);
                error = securelevel_gt(td->td_ucred, 0);
                if (error != 0)
                        return (error);
#if defined(__i386__)
                td->td_frame->tf_eflags |= PSL_IOPL;
#elif defined(__amd64__)
                td->td_frame->tf_rflags |= PSL_IOPL;
#endif
                return (0);
        case KDDISABIO:         /* disallow io operations (default) */
#if defined(__i386__)
                td->td_frame->tf_eflags &= ~PSL_IOPL;
#elif defined(__amd64__)
                td->td_frame->tf_rflags &= ~PSL_IOPL;
#endif
                return (0);
        case KDMKTONE:          /* sound the bell */
                vtterm_beep(tm, *(u_int *)data);
                return (0);
        case KIOCSOUND:         /* make tone (*data) hz */
                /* TODO */
                return (0);
        case CONS_SETKBD:       /* set the new keyboard */
                mtx_lock(&Giant);
                error = 0;
                if (vd->vd_keyboard == NULL ||
                    vd->vd_keyboard->kb_index != *(int *)data) {
                        kbd = kbd_get_keyboard(*(int *)data);
                        if (kbd == NULL) {
                                mtx_unlock(&Giant);
                                return (EINVAL);
                        }
                        i = kbd_allocate(kbd->kb_name, kbd->kb_unit,
                            (void *)vd, vt_kbdevent, vd);
                        if (i >= 0) {
                                if ((kbd = vd->vd_keyboard) != NULL) {
                                        vt_save_kbd_state(vd->vd_curwindow, kbd);
                                        kbd_release(kbd, (void *)vd);
                                }
                                kbd = vd->vd_keyboard = kbd_get_keyboard(i);

                                vt_update_kbd_mode(vd->vd_curwindow, kbd);
                                vt_update_kbd_state(vd->vd_curwindow, kbd);
                        } else {
                                error = EPERM;  /* XXX */
                        }
                }
                mtx_unlock(&Giant);
                return (error);
        case CONS_RELKBD:       /* release the current keyboard */
                mtx_lock(&Giant);
                error = 0;
                if ((kbd = vd->vd_keyboard) != NULL) {
                        vt_save_kbd_state(vd->vd_curwindow, kbd);
                        error = kbd_release(kbd, (void *)vd);
                        if (error == 0) {
                                vd->vd_keyboard = NULL;
                        }
                }
                mtx_unlock(&Giant);
                return (error);
        case VT_ACTIVATE: {
                int win;
                win = *(int *)data - 1;
                DPRINTF(5, "%s%d: VT_ACTIVATE ttyv%d ", SC_DRIVER_NAME,
                    VT_UNIT(vw), win);
                if ((win >= VT_MAXWINDOWS) || (win < 0))
                        return (EINVAL);
                return (vt_proc_window_switch(vd->vd_windows[win]));
        }
        case VT_GETACTIVE:
                *(int *)data = vd->vd_curwindow->vw_number + 1;
                return (0);
        case VT_GETINDEX:
                *(int *)data = vw->vw_number + 1;
                return (0);
        case VT_LOCKSWITCH:
                /* TODO: Check current state, switching can be in progress. */
                if ((*(int *)data) == 0x01)
                        vw->vw_flags |= VWF_VTYLOCK;
                else if ((*(int *)data) == 0x02)
                        vw->vw_flags &= ~VWF_VTYLOCK;
                else
                        return (EINVAL);
                return (0);
        case VT_OPENQRY:
                VT_LOCK(vd);
                for (i = 0; i < VT_MAXWINDOWS; i++) {
                        vw = vd->vd_windows[i];
                        if (vw == NULL)
                                continue;
                        if (!(vw->vw_flags & VWF_OPENED)) {
                                *(int *)data = vw->vw_number + 1;
                                VT_UNLOCK(vd);
                                return (0);
                        }
                }
                VT_UNLOCK(vd);
                return (EINVAL);
        case VT_WAITACTIVE: {
                unsigned int idx;

                error = 0;

                idx = *(unsigned int *)data;
                if (idx > VT_MAXWINDOWS)
                        return (EINVAL);
                if (idx > 0)
                        vw = vd->vd_windows[idx - 1];

                VT_LOCK(vd);
                while (vd->vd_curwindow != vw && error == 0)
                        error = cv_wait_sig(&vd->vd_winswitch, &vd->vd_lock);
                VT_UNLOCK(vd);
                return (error);
        }
        case VT_SETMODE: {      /* set screen switcher mode */
                struct vt_mode *mode;
                struct proc *p1;

                mode = (struct vt_mode *)data;
                DPRINTF(5, "%s%d: VT_SETMODE ", SC_DRIVER_NAME, VT_UNIT(vw));
                if (vw->vw_smode.mode == VT_PROCESS) {
                        p1 = pfind(vw->vw_pid);
                        if (vw->vw_proc == p1 && vw->vw_proc != td->td_proc) {
                                if (p1)
                                        PROC_UNLOCK(p1);
                                DPRINTF(5, "error EPERM\n");
                                return (EPERM);
                        }
                        if (p1)
                                PROC_UNLOCK(p1);
                }
                if (mode->mode == VT_AUTO) {
                        vw->vw_smode.mode = VT_AUTO;
                        vw->vw_proc = NULL;
                        vw->vw_pid = 0;
                        DPRINTF(5, "VT_AUTO, ");
                        if (vw == vw->vw_device->vd_windows[VT_CONSWINDOW])
                                cnavailable(vw->vw_terminal->consdev, TRUE);
                        /* were we in the middle of the vty switching process? */
                        if (finish_vt_rel(vw, TRUE, &s) == 0)
                                DPRINTF(5, "reset WAIT_REL, ");
                        if (finish_vt_acq(vw) == 0)
                                DPRINTF(5, "reset WAIT_ACQ, ");
                        return (0);
                } else if (mode->mode == VT_PROCESS) {
                        if (!(_SIG_VALID(mode->relsig) &&
                            _SIG_VALID(mode->acqsig) &&
                            (mode->frsig == 0 || _SIG_VALID(mode->frsig)))) {
                                DPRINTF(5, "error EINVAL\n");
                                return (EINVAL);
                        }
                        DPRINTF(5, "VT_PROCESS %d, ", td->td_proc->p_pid);
                        bcopy(data, &vw->vw_smode, sizeof(struct vt_mode));
                        vw->vw_proc = td->td_proc;
                        vw->vw_pid = vw->vw_proc->p_pid;
                        if (vw == vw->vw_device->vd_windows[VT_CONSWINDOW])
                                cnavailable(vw->vw_terminal->consdev, FALSE);
                } else {
                        DPRINTF(5, "VT_SETMODE failed, unknown mode %d\n",
                            mode->mode);
                        return (EINVAL);
                }
                DPRINTF(5, "\n");
                return (0);
        }
        case VT_GETMODE:        /* get screen switcher mode */
                bcopy(&vw->vw_smode, data, sizeof(struct vt_mode));
                return (0);

        case VT_RELDISP:        /* screen switcher ioctl */
                /*
                 * This must be the current vty which is in the VT_PROCESS
                 * switching mode...
                 */
                if ((vw != vd->vd_curwindow) || (vw->vw_smode.mode !=
                    VT_PROCESS)) {
                        return (EINVAL);
                }
                /* ...and this process is controlling it. */
                if (vw->vw_proc != td->td_proc) {
                        return (EPERM);
                }
                error = EINVAL;
                switch(*(int *)data) {
                case VT_FALSE:  /* user refuses to release screen, abort */
                        if ((error = finish_vt_rel(vw, FALSE, &s)) == 0)
                                DPRINTF(5, "%s%d: VT_RELDISP: VT_FALSE\n",
                                    SC_DRIVER_NAME, VT_UNIT(vw));
                        break;
                case VT_TRUE:   /* user has released screen, go on */
                        /* finish_vt_rel(..., TRUE, ...) should not be locked */
                        if (vw->vw_flags & VWF_SWWAIT_REL) {
                                if ((error = finish_vt_rel(vw, TRUE, &s)) == 0)
                                        DPRINTF(5, "%s%d: VT_RELDISP: VT_TRUE\n",
                                            SC_DRIVER_NAME, VT_UNIT(vw));
                        } else {
                                error = EINVAL;
                        }
                        return (error);
                case VT_ACKACQ: /* acquire acknowledged, switch completed */
                        if ((error = finish_vt_acq(vw)) == 0)
                                DPRINTF(5, "%s%d: VT_RELDISP: VT_ACKACQ\n",
                                    SC_DRIVER_NAME, VT_UNIT(vw));
                        break;
                default:
                        break;
                }
                return (error);
        }

        return (ENOIOCTL);
}

static struct vt_window *
vt_allocate_window(struct vt_device *vd, unsigned int window)
{
        struct vt_window *vw;
        struct terminal *tm;
        term_pos_t size;
        struct winsize wsz;

        vw = malloc(sizeof *vw, M_VT, M_WAITOK|M_ZERO);
        vw->vw_device = vd;
        vw->vw_number = window;
        vw->vw_kbdmode = K_XLATE;

        if ((vd->vd_flags & VDF_TEXTMODE) == 0) {
                vw->vw_font = vtfont_ref(vt_font_assigned);
                vt_compute_drawable_area(vw);
        }

        vt_termsize(vd, vw->vw_font, &size);
        vt_winsize(vd, vw->vw_font, &wsz);
        tm = vw->vw_terminal = terminal_alloc(&vt_termclass, vw);
        vw->vw_buf.vb_terminal = tm;    /* must be set before vtbuf_init() */
        vtbuf_init(&vw->vw_buf, &size);

        terminal_set_winsize(tm, &wsz);
        vd->vd_windows[window] = vw;
        TIMEOUT_TASK_INIT(taskqueue_thread, &vw->vw_timeout_task_dead, 0, &vt_switch_timer, vw);

        return (vw);
}

void
vt_upgrade(struct vt_device *vd)
{
        struct vt_window *vw;
        unsigned int i;
        int register_handlers;

        if (!vty_enabled(VTY_VT))
                return;
        if (main_vd->vd_driver == NULL)
                return;

        for (i = 0; i < VT_MAXWINDOWS; i++) {
                vw = vd->vd_windows[i];
                if (vw == NULL) {
                        /* New window. */
                        vw = vt_allocate_window(vd, i);
                }
                if (!(vw->vw_flags & VWF_READY)) {
                        TIMEOUT_TASK_INIT(taskqueue_thread, &vw->vw_timeout_task_dead, 0, &vt_switch_timer, vw);
                        terminal_maketty(vw->vw_terminal, "v%r", VT_UNIT(vw));
                        vw->vw_flags |= VWF_READY;
                        if (vw->vw_flags & VWF_CONSOLE) {
                                /* For existing console window. */
                                EVENTHANDLER_REGISTER(shutdown_pre_sync,
                                    vt_window_switch, vw, SHUTDOWN_PRI_DEFAULT);
#ifdef DEV_SPLASH
                                EVENTHANDLER_REGISTER(shutdown_pre_sync,
                                    vt_shutdown_splash, vw, SHUTDOWN_PRI_DEFAULT);
#endif
                        }
                }
        }
        VT_LOCK(vd);
        if (vd->vd_curwindow == NULL)
                vd->vd_curwindow = vd->vd_windows[VT_CONSWINDOW];

        register_handlers = 0;
        if (!(vd->vd_flags & VDF_ASYNC)) {
                /* Attach keyboard. */
                vt_allocate_keyboard(vd);

                /* Init 25 Hz timer. */
                callout_init_mtx(&vd->vd_timer, &vd->vd_lock, 0);

                /*
                 * Start timer when everything ready.
                 * Note that the operations here are purposefully ordered.
                 * We need to ensure vd_timer_armed is non-zero before we set
                 * the VDF_ASYNC flag. That prevents this function from
                 * racing with vt_resume_flush_timer() to update the
                 * callout structure.
                 */
                atomic_add_acq_int(&vd->vd_timer_armed, 1);
                vd->vd_flags |= VDF_ASYNC;
                callout_reset(&vd->vd_timer, hz / VT_TIMERFREQ, vt_timer, vd);
                register_handlers = 1;
        }

        VT_UNLOCK(vd);

        /* Refill settings with new sizes. */
        vt_resize(vd);

        if (register_handlers) {
                /* Register suspend/resume handlers. */
                EVENTHANDLER_REGISTER(power_suspend_early, vt_suspend_handler,
                    vd, EVENTHANDLER_PRI_ANY);
                EVENTHANDLER_REGISTER(power_resume, vt_resume_handler, vd,
                    EVENTHANDLER_PRI_ANY);
        }
}

static void
vt_resize(struct vt_device *vd)
{
        struct vt_window *vw;
        int i;

        for (i = 0; i < VT_MAXWINDOWS; i++) {
                vw = vd->vd_windows[i];
                VT_LOCK(vd);
                /* Assign default font to window, if not textmode. */
                if (!(vd->vd_flags & VDF_TEXTMODE) && vw->vw_font == NULL)
                        vw->vw_font = vtfont_ref(vt_font_assigned);
                VT_UNLOCK(vd);

                /* Resize terminal windows */
                while (vt_change_font(vw, vw->vw_font) == EBUSY) {
                        DPRINTF(100, "%s: vt_change_font() is busy, "
                            "window %d\n", __func__, i);
                }
        }
}

static void
vt_replace_backend(const struct vt_driver *drv, void *softc)
{
        struct vt_device *vd;

        vd = main_vd;

        if (vd->vd_flags & VDF_ASYNC) {
                /* Stop vt_flush periodic task. */
                VT_LOCK(vd);
                vt_suspend_flush_timer(vd);
                VT_UNLOCK(vd);
                /*
                 * Mute current terminal until we done. vt_change_font (called
                 * from vt_resize) will unmute it.
                 */
                terminal_mute(vd->vd_curwindow->vw_terminal, 1);
        }

        /*
         * Reset VDF_TEXTMODE flag, driver who require that flag (vt_vga) will
         * set it.
         */
        VT_LOCK(vd);
        vd->vd_flags &= ~VDF_TEXTMODE;

        if (drv != NULL) {
                /*
                 * We want to upgrade from the current driver to the
                 * given driver.
                 */

                vd->vd_prev_driver = vd->vd_driver;
                vd->vd_prev_softc = vd->vd_softc;
                vd->vd_driver = drv;
                vd->vd_softc = softc;

                vd->vd_driver->vd_init(vd);
        } else if (vd->vd_prev_driver != NULL && vd->vd_prev_softc != NULL) {
                /*
                 * No driver given: we want to downgrade to the previous
                 * driver.
                 */
                const struct vt_driver *old_drv;
                void *old_softc;

                old_drv = vd->vd_driver;
                old_softc = vd->vd_softc;

                vd->vd_driver = vd->vd_prev_driver;
                vd->vd_softc = vd->vd_prev_softc;
                vd->vd_prev_driver = NULL;
                vd->vd_prev_softc = NULL;

                vd->vd_flags |= VDF_DOWNGRADE;

                vd->vd_driver->vd_init(vd);

                if (old_drv->vd_fini)
                        old_drv->vd_fini(vd, old_softc);

                vd->vd_flags &= ~VDF_DOWNGRADE;
        }

        VT_UNLOCK(vd);

        /* Update windows sizes and initialize last items. */
        vt_upgrade(vd);

        /*
         * Give a chance to the new backend to run the post-switch code, for
         * instance to refresh the screen.
         */
        if (vd->vd_driver->vd_postswitch)
                vd->vd_driver->vd_postswitch(vd);

#ifdef DEV_SPLASH
        if (vd->vd_flags & VDF_SPLASH)
                vtterm_splash(vd);
#endif

        if (vd->vd_flags & VDF_ASYNC) {
                /* Allow to put chars now. */
                terminal_mute(vd->vd_curwindow->vw_terminal, 0);
                /* Rerun timer for screen updates. */
                vt_resume_flush_timer(vd->vd_curwindow, 0);
        }

        /*
         * Register as console. If it already registered, cnadd() will ignore
         * it.
         */
        termcn_cnregister(vd->vd_windows[VT_CONSWINDOW]->vw_terminal);
}

static void
vt_suspend_handler(void *priv, enum power_stype stype)
{
        struct vt_device *vd;

        vd = priv;
        vd->vd_flags |= VDF_SUSPENDED;
        if (vd->vd_driver != NULL && vd->vd_driver->vd_suspend != NULL)
                vd->vd_driver->vd_suspend(vd);
}

static void
vt_resume_handler(void *priv, enum power_stype stype)
{
        struct vt_device *vd;

        vd = priv;
        if (vd->vd_driver != NULL && vd->vd_driver->vd_resume != NULL)
                vd->vd_driver->vd_resume(vd);
        vd->vd_flags &= ~VDF_SUSPENDED;
}

int
vt_allocate(const struct vt_driver *drv, void *softc)
{

        if (!vty_enabled(VTY_VT))
                return (EINVAL);

        if (main_vd->vd_driver == NULL) {
                main_vd->vd_driver = drv;
                printf("VT: initialize with new VT driver \"%s\".\n",
                    drv->vd_name);
        } else {
                /*
                 * Check if have rights to replace current driver. For example:
                 * it is bad idea to replace KMS driver with generic VGA one.
                 */
                if (drv->vd_priority <= main_vd->vd_driver->vd_priority) {
                        printf("VT: Driver priority %d too low. Current %d\n ",
                            drv->vd_priority, main_vd->vd_driver->vd_priority);
                        return (EEXIST);
                }
                printf("VT: Replacing driver \"%s\" with new \"%s\".\n",
                    main_vd->vd_driver->vd_name, drv->vd_name);
        }

        vt_replace_backend(drv, softc);

        return (0);
}

int
vt_deallocate(const struct vt_driver *drv, void *softc)
{

        if (!vty_enabled(VTY_VT))
                return (EINVAL);

        if (main_vd->vd_prev_driver == NULL ||
            main_vd->vd_driver != drv ||
            main_vd->vd_softc != softc)
                return (EPERM);

        printf("VT: Switching back from \"%s\" to \"%s\".\n",
            main_vd->vd_driver->vd_name, main_vd->vd_prev_driver->vd_name);

        vt_replace_backend(NULL, NULL);

        return (0);
}

void
vt_suspend(struct vt_device *vd)
{
        int error;

        if (vt_suspendswitch == 0)
                return;
        /* Save current window. */
        vd->vd_savedwindow = vd->vd_curwindow;
        /* Ask holding process to free window and switch to console window */
        vt_proc_window_switch(vd->vd_windows[VT_CONSWINDOW]);

        /* Wait for the window switch to complete. */
        error = 0;
        VT_LOCK(vd);
        while (vd->vd_curwindow != vd->vd_windows[VT_CONSWINDOW] && error == 0)
                error = cv_wait_sig(&vd->vd_winswitch, &vd->vd_lock);
        VT_UNLOCK(vd);
}

void
vt_resume(struct vt_device *vd)
{

        if (vt_suspendswitch == 0)
                return;
        /* Switch back to saved window, if any */
        vt_proc_window_switch(vd->vd_savedwindow);
        vd->vd_savedwindow = NULL;
}