/*
 *  linux/drivers/char/console.c
 *
 *  Copyright (C) 1991, 1992  Linus Torvalds
 */

/*
 * Hopefully this will be a rather complete VT102 implementation.
 *
 * Beeping thanks to John T Kohl.
 *
 * Virtual Consoles, Screen Blanking, Screen Dumping, Color, Graphics
 *   Chars, and VT100 enhancements by Peter MacDonald.
 *
 * Copy and paste function by Andrew Haylett,
 *   some enhancements by Alessandro Rubini.
 *
 * Code to check for different video-cards mostly by Galen Hunt,
 * <g-hunt@ee.utah.edu>
 *
 * Rudimentary ISO 10646/Unicode/UTF-8 character set support by
 * Markus Kuhn, <mskuhn@immd4.informatik.uni-erlangen.de>.
 *
 * Dynamic allocation of consoles, aeb@cwi.nl, May 1994
 * Resizing of consoles, aeb, 940926
 *
 * Code for xterm like mouse click reporting by Peter Orbaek 20-Jul-94
 * <poe@daimi.aau.dk>
 *
 * User-defined bell sound, new setterm control sequences and printk
 * redirection by Martin Mares <mj@k332.feld.cvut.cz> 19-Nov-95
 *
 * APM screenblank bug fixed Takashi Manabe <manabe@roy.dsl.tutics.tut.jp>
 *
 * Merge with the abstract console driver by Geert Uytterhoeven
 * <geert@linux-m68k.org>, Jan 1997.
 *
 *   Original m68k console driver modifications by
 *
 *     - Arno Griffioen <arno@usn.nl>
 *     - David Carter <carter@cs.bris.ac.uk>
 * 
 *   Note that the abstract console driver allows all consoles to be of
 *   potentially different sizes, so the following variables depend on the
 *   current console (currcons):
 *
 *     - video_num_columns
 *     - video_num_lines
 *     - video_size_row
 *     - can_do_color
 *
 *   The abstract console driver provides a generic interface for a text
 *   console. It supports VGA text mode, frame buffer based graphical consoles
 *   and special graphics processors that are only accessible through some
 *   registers (e.g. a TMS340x0 GSP).
 *
 *   The interface to the hardware is specified using a special structure
 *   (struct consw) which contains function pointers to console operations
 *   (see <linux/console.h> for more information).
 *
 * Support for changeable cursor shape
 * by Pavel Machek <pavel@atrey.karlin.mff.cuni.cz>, August 1997
 *
 * Ported to i386 and con_scrolldelta fixed
 * by Emmanuel Marty <core@ggi-project.org>, April 1998
 *
 * Resurrected character buffers in videoram plus lots of other trickery
 * by Martin Mares <mj@atrey.karlin.mff.cuni.cz>, July 1998
 *
 * Removed old-style timers, introduced console_timer, made timer
 * deletion SMP-safe.  17Jun00, Andrew Morton <andrewm@uow.edu.au>
 *
 * Removed console_lock, enabled interrupts across all console operations
 * 13 March 2001, Andrew Morton
 */

#include <linux/module.h>
#include <linux/sched.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/kd.h>
#include <linux/slab.h>
#include <linux/major.h>
#include <linux/mm.h>
#include <linux/console.h>
#include <linux/init.h>
#include <linux/devfs_fs_kernel.h>
#include <linux/vt_kern.h>
#include <linux/selection.h>
#include <linux/console_struct.h>
#include <linux/kbd_kern.h>
#include <linux/consolemap.h>
#include <linux/timer.h>
#include <linux/interrupt.h>
#include <linux/config.h>
#include <linux/version.h>
#include <linux/tqueue.h>
#include <linux/bootmem.h>
#include <linux/pm.h>
#include <linux/smp_lock.h>

#include <asm/io.h>
#include <asm/system.h>
#include <asm/uaccess.h>
#include <asm/bitops.h>

#include "console_macros.h"


const struct consw *conswitchp;

static void __console_callback(void);

/* A bitmap for codes <32. A bit of 1 indicates that the code
 * corresponding to that bit number invokes some special action
 * (such as cursor movement) and should not be displayed as a
 * glyph unless the disp_ctrl mode is explicitly enabled.
 */
#define CTRL_ACTION 0x0d00ff81
#define CTRL_ALWAYS 0x0800f501  /* Cannot be overridden by disp_ctrl */

/*
 * Here is the default bell parameters: 750HZ, 1/8th of a second
 */
#define DEFAULT_BELL_PITCH      750
#define DEFAULT_BELL_DURATION   (HZ/8)

extern void vcs_make_devfs (unsigned int index, int unregister);

#ifndef MIN
#define MIN(a,b)        ((a) < (b) ? (a) : (b))
#endif

static struct tty_struct *console_table[MAX_NR_CONSOLES];
static struct termios *console_termios[MAX_NR_CONSOLES];
static struct termios *console_termios_locked[MAX_NR_CONSOLES];
struct vc vc_cons [MAX_NR_CONSOLES];

#ifndef VT_SINGLE_DRIVER
static const struct consw *con_driver_map[MAX_NR_CONSOLES];
#endif

static int con_open(struct tty_struct *, struct file *);
static void vc_init(unsigned int console, unsigned int rows,
                    unsigned int cols, int do_clear);
static void blank_screen(unsigned long dummy);
static void gotoxy(int currcons, int new_x, int new_y);
static void save_cur(int currcons);
static void reset_terminal(int currcons, int do_clear);
static void con_flush_chars(struct tty_struct *tty);
static void set_vesa_blanking(unsigned long arg);
static void set_cursor(int currcons);
static void hide_cursor(int currcons);
static void unblank_screen_t(unsigned long dummy);
static void console_callback(void *ignored);

static int printable;           /* Is console ready for printing? */

int do_poke_blanked_console;
int console_blanked;

static int vesa_blank_mode; /* 0:none 1:suspendV 2:suspendH 3:powerdown */
static int blankinterval = 10*60*HZ;
static int vesa_off_interval;

static struct tq_struct console_callback_tq = {
        routine: console_callback,
};

/*
 * fg_console is the current virtual console,
 * last_console is the last used one,
 * want_console is the console we want to switch to,
 * kmsg_redirect is the console for kernel messages,
 */
int fg_console;
int last_console;
int want_console = -1;
int kmsg_redirect;

/*
 * For each existing display, we have a pointer to console currently visible
 * on that display, allowing consoles other than fg_console to be refreshed
 * appropriately. Unless the low-level driver supplies its own display_fg
 * variable, we use this one for the "master display".
 */
static struct vc_data *master_display_fg;

/*
 * Unfortunately, we need to delay tty echo when we're currently writing to the
 * console since the code is (and always was) not re-entrant, so we schedule
 * all flip requests to process context with schedule-task() and run it from
 * console_callback().
 */

/*
 * For the same reason, we defer scrollback to the console callback.
 */
static int scrollback_delta;

/*
 * Hook so that the power management routines can (un)blank
 * the console on our behalf.
 */
int (*console_blank_hook)(int);

static struct timer_list console_timer;

/*
 *      Low-Level Functions
 */

#define IS_FG (currcons == fg_console)
#define IS_VISIBLE CON_IS_VISIBLE(vc_cons[currcons].d)

#ifdef VT_BUF_VRAM_ONLY
#define DO_UPDATE 0
#else
#define DO_UPDATE IS_VISIBLE
#endif

static int pm_con_request(struct pm_dev *dev, pm_request_t rqst, void *data);
static struct pm_dev *pm_con;

static inline unsigned short *screenpos(int currcons, int offset, int viewed)
{
        unsigned short *p;
        
        if (!viewed)
                p = (unsigned short *)(origin + offset);
        else if (!sw->con_screen_pos)
                p = (unsigned short *)(visible_origin + offset);
        else
                p = sw->con_screen_pos(vc_cons[currcons].d, offset);
        return p;
}

static inline void scrolldelta(int lines)
{
        scrollback_delta += lines;
        schedule_console_callback();
}

extern int machine_paniced; 

void schedule_console_callback(void)
{
        /* Don't care about locking after panic - but I want to switch the console
           NOW */ 
        if (machine_paniced)
                __console_callback(); 
        else
                schedule_task(&console_callback_tq);
}

static void scrup(int currcons, unsigned int t, unsigned int b, int nr)
{
        unsigned short *d, *s;

        if (t+nr >= b)
                nr = b - t - 1;
        if (b > video_num_lines || t >= b || nr < 1)
                return;
        if (IS_VISIBLE && sw->con_scroll(vc_cons[currcons].d, t, b, SM_UP, nr))
                return;
        d = (unsigned short *) (origin+video_size_row*t);
        s = (unsigned short *) (origin+video_size_row*(t+nr));
        scr_memcpyw(d, s, (b-t-nr) * video_size_row);
        scr_memsetw(d + (b-t-nr) * video_num_columns, video_erase_char, video_size_row*nr);
}

static void
scrdown(int currcons, unsigned int t, unsigned int b, int nr)
{
        unsigned short *s;
        unsigned int step;

        if (t+nr >= b)
                nr = b - t - 1;
        if (b > video_num_lines || t >= b || nr < 1)
                return;
        if (IS_VISIBLE && sw->con_scroll(vc_cons[currcons].d, t, b, SM_DOWN, nr))
                return;
        s = (unsigned short *) (origin+video_size_row*t);
        step = video_num_columns * nr;
        scr_memmovew(s + step, s, (b-t-nr)*video_size_row);
        scr_memsetw(s, video_erase_char, 2*step);
}

static void do_update_region(int currcons, unsigned long start, int count)
{
#ifndef VT_BUF_VRAM_ONLY
        unsigned int xx, yy, offset;
        u16 *p;

        p = (u16 *) start;
        if (!sw->con_getxy) {
                offset = (start - origin) / 2;
                xx = offset % video_num_columns;
                yy = offset / video_num_columns;
        } else {
                int nxx, nyy;
                start = sw->con_getxy(vc_cons[currcons].d, start, &nxx, &nyy);
                xx = nxx; yy = nyy;
        }
        for(;;) {
                u16 attrib = scr_readw(p) & 0xff00;
                int startx = xx;
                u16 *q = p;
                while (xx < video_num_columns && count) {
                        if (attrib != (scr_readw(p) & 0xff00)) {
                                if (p > q)
                                        sw->con_putcs(vc_cons[currcons].d, q, p-q, yy, startx);
                                startx = xx;
                                q = p;
                                attrib = scr_readw(p) & 0xff00;
                        }
                        p++;
                        xx++;
                        count--;
                }
                if (p > q)
                        sw->con_putcs(vc_cons[currcons].d, q, p-q, yy, startx);
                if (!count)
                        break;
                xx = 0;
                yy++;
                if (sw->con_getxy) {
                        p = (u16 *)start;
                        start = sw->con_getxy(vc_cons[currcons].d, start, NULL, NULL);
                }
        }
#endif
}

void update_region(int currcons, unsigned long start, int count)
{
        if (DO_UPDATE) {
                hide_cursor(currcons);
                do_update_region(currcons, start, count);
                set_cursor(currcons);
        }
}

/* Structure of attributes is hardware-dependent */

static u8 build_attr(int currcons, u8 _color, u8 _intensity, u8 _blink, u8 _underline, u8 _reverse)
{
        if (sw->con_build_attr)
                return sw->con_build_attr(vc_cons[currcons].d, _color, _intensity, _blink, _underline, _reverse);

#ifndef VT_BUF_VRAM_ONLY
/*
 * ++roman: I completely changed the attribute format for monochrome
 * mode (!can_do_color). The formerly used MDA (monochrome display
 * adapter) format didn't allow the combination of certain effects.
 * Now the attribute is just a bit vector:
 *  Bit 0..1: intensity (0..2)
 *  Bit 2   : underline
 *  Bit 3   : reverse
 *  Bit 7   : blink
 */
        {
        u8 a = color;
        if (!can_do_color)
                return _intensity |
                       (_underline ? 4 : 0) |
                       (_reverse ? 8 : 0) |
                       (_blink ? 0x80 : 0);
        if (_underline)
                a = (a & 0xf0) | ulcolor;
        else if (_intensity == 0)
                a = (a & 0xf0) | halfcolor;
        if (_reverse)
                a = ((a) & 0x88) | ((((a) >> 4) | ((a) << 4)) & 0x77);
        if (_blink)
                a ^= 0x80;
        if (_intensity == 2)
                a ^= 0x08;
        if (hi_font_mask == 0x100)
                a <<= 1;
        return a;
        }
#else
        return 0;
#endif
}

static void update_attr(int currcons)
{
        attr = build_attr(currcons, color, intensity, blink, underline, reverse ^ decscnm);
        video_erase_char = (build_attr(currcons, color, 1, blink, 0, decscnm) << 8) | ' ';
}

/* Note: inverting the screen twice should revert to the original state */

void invert_screen(int currcons, int offset, int count, int viewed)
{
        unsigned short *p;

        count /= 2;
        p = screenpos(currcons, offset, viewed);
        if (sw->con_invert_region)
                sw->con_invert_region(vc_cons[currcons].d, p, count);
#ifndef VT_BUF_VRAM_ONLY
        else {
                u16 *q = p;
                int cnt = count;
                u16 a;

                if (!can_do_color) {
                        while (cnt--) {
                            a = scr_readw(q);
                            a ^= 0x0800;
                            scr_writew(a, q);
                            q++;
                        }
                } else if (hi_font_mask == 0x100) {
                        while (cnt--) {
                                a = scr_readw(q);
                                a = ((a) & 0x11ff) | (((a) & 0xe000) >> 4) | (((a) & 0x0e00) << 4);
                                scr_writew(a, q);
                                q++;
                        }
                } else {
                        while (cnt--) {
                                a = scr_readw(q);
                                a = ((a) & 0x88ff) | (((a) & 0x7000) >> 4) | (((a) & 0x0700) << 4);
                                scr_writew(a, q);
                                q++;
                        }
                }
        }
#endif
        if (DO_UPDATE)
                do_update_region(currcons, (unsigned long) p, count);
}

/* used by selection: complement pointer position */
void complement_pos(int currcons, int offset)
{
        static unsigned short *p;
        static unsigned short old;
        static unsigned short oldx, oldy;

        if (p) {
                scr_writew(old, p);
                if (DO_UPDATE)
                        sw->con_putc(vc_cons[currcons].d, old, oldy, oldx);
        }
        if (offset == -1)
                p = NULL;
        else {
                unsigned short new;
                p = screenpos(currcons, offset, 1);
                old = scr_readw(p);
                new = old ^ complement_mask;
                scr_writew(new, p);
                if (DO_UPDATE) {
                        oldx = (offset >> 1) % video_num_columns;
                        oldy = (offset >> 1) / video_num_columns;
                        sw->con_putc(vc_cons[currcons].d, new, oldy, oldx);
                }
        }
}

static void insert_char(int currcons, unsigned int nr)
{
        unsigned short *p, *q = (unsigned short *) pos;

        p = q + video_num_columns - nr - x;
        while (--p >= q)
                scr_writew(scr_readw(p), p + nr);
        scr_memsetw(q, video_erase_char, nr*2);
        need_wrap = 0;
        if (DO_UPDATE) {
                unsigned short oldattr = attr;
                sw->con_bmove(vc_cons[currcons].d,y,x,y,x+nr,1,
                              video_num_columns-x-nr);
                attr = video_erase_char >> 8;
                while (nr--)
                        sw->con_putc(vc_cons[currcons].d,
                                     video_erase_char,y,x+nr);
                attr = oldattr;
        }
}

static void delete_char(int currcons, unsigned int nr)
{
        unsigned int i = x;
        unsigned short *p = (unsigned short *) pos;

        while (++i <= video_num_columns - nr) {
                scr_writew(scr_readw(p+nr), p);
                p++;
        }
        scr_memsetw(p, video_erase_char, nr*2);
        need_wrap = 0;
        if (DO_UPDATE) {
                unsigned short oldattr = attr;
                sw->con_bmove(vc_cons[currcons].d, y, x+nr, y, x, 1,
                              video_num_columns-x-nr);
                attr = video_erase_char >> 8;
                while (nr--)
                        sw->con_putc(vc_cons[currcons].d,
                                     video_erase_char, y,
                                     video_num_columns-1-nr);
                attr = oldattr;
        }
}

static int softcursor_original;

static void add_softcursor(int currcons)
{
        int i = scr_readw((u16 *) pos);
        u32 type = cursor_type;

        if (! (type & 0x10)) return;
        if (softcursor_original != -1) return;
        softcursor_original = i;
        i |= ((type >> 8) & 0xff00 );
        i ^= ((type) & 0xff00 );
        if ((type & 0x20) && ((softcursor_original & 0x7000) == (i & 0x7000))) i ^= 0x7000;
        if ((type & 0x40) && ((i & 0x700) == ((i & 0x7000) >> 4))) i ^= 0x0700;
        scr_writew(i, (u16 *) pos);
        if (DO_UPDATE)
                sw->con_putc(vc_cons[currcons].d, i, y, x);
}

static void hide_cursor(int currcons)
{
        if (currcons == sel_cons)
                clear_selection();
        if (softcursor_original != -1) {
                scr_writew(softcursor_original,(u16 *) pos);
                if (DO_UPDATE)
                        sw->con_putc(vc_cons[currcons].d, softcursor_original, y, x);
                softcursor_original = -1;
        }
        sw->con_cursor(vc_cons[currcons].d,CM_ERASE);
}

static void set_cursor(int currcons)
{
    if (!IS_FG || console_blanked || vcmode == KD_GRAPHICS)
        return;
    if (deccm) {
        if (currcons == sel_cons)
                clear_selection();
        add_softcursor(currcons);
        if ((cursor_type & 0x0f) != 1)
            sw->con_cursor(vc_cons[currcons].d,CM_DRAW);
    } else
        hide_cursor(currcons);
}

static void set_origin(int currcons)
{
        if (!IS_VISIBLE ||
            !sw->con_set_origin ||
            !sw->con_set_origin(vc_cons[currcons].d))
                origin = (unsigned long) screenbuf;
        visible_origin = origin;
        scr_end = origin + screenbuf_size;
        pos = origin + video_size_row*y + 2*x;
}

static inline void save_screen(int currcons)
{
        if (sw->con_save_screen)
                sw->con_save_screen(vc_cons[currcons].d);
}

/*
 *      Redrawing of screen
 */

void redraw_screen(int new_console, int is_switch)
{
        int redraw = 1;
        int currcons, old_console;

        if (!vc_cons_allocated(new_console)) {
                /* strange ... */
                /* printk("redraw_screen: tty %d not allocated ??\n", new_console+1); */
                return;
        }

        if (is_switch) {
                currcons = fg_console;
                hide_cursor(currcons);
                if (fg_console != new_console) {
                        struct vc_data **display = vc_cons[new_console].d->vc_display_fg;
                        old_console = (*display) ? (*display)->vc_num : fg_console;
                        *display = vc_cons[new_console].d;
                        fg_console = new_console;
                        currcons = old_console;
                        if (!IS_VISIBLE) {
                                save_screen(currcons);
                                set_origin(currcons);
                        }
                        currcons = new_console;
                        if (old_console == new_console)
                                redraw = 0;
                }
        } else {
                currcons = new_console;
                hide_cursor(currcons);
        }

        if (redraw) {
                int update;
                set_origin(currcons);
                update = sw->con_switch(vc_cons[currcons].d);
                set_palette(currcons);
                if (update && vcmode != KD_GRAPHICS)
                        do_update_region(currcons, origin, screenbuf_size/2);
        }
        set_cursor(currcons);
        if (is_switch) {
                set_leds();
                compute_shiftstate();
        }
}

/*
 *      Allocation, freeing and resizing of VTs.
 */

int vc_cons_allocated(unsigned int i)
{
        return (i < MAX_NR_CONSOLES && vc_cons[i].d);
}

static void visual_init(int currcons, int init)
{
    /* ++Geert: sw->con_init determines console size */
    sw = conswitchp;
#ifndef VT_SINGLE_DRIVER
    if (con_driver_map[currcons])
        sw = con_driver_map[currcons];
#endif
    cons_num = currcons;
    display_fg = &master_display_fg;
    vc_cons[currcons].d->vc_uni_pagedir_loc = &vc_cons[currcons].d->vc_uni_pagedir;
    vc_cons[currcons].d->vc_uni_pagedir = 0;
    hi_font_mask = 0;
    complement_mask = 0;
    can_do_color = 0;
    sw->con_init(vc_cons[currcons].d, init);
    if (!complement_mask)
        complement_mask = can_do_color ? 0x7700 : 0x0800;
    s_complement_mask = complement_mask;
    video_size_row = video_num_columns<<1;
    screenbuf_size = video_num_lines*video_size_row;
}

int vc_allocate(unsigned int currcons)  /* return 0 on success */
{
        if (currcons >= MAX_NR_CONSOLES)
                return -ENXIO;
        if (!vc_cons[currcons].d) {
            long p, q;

            /* prevent users from taking too much memory */
            if (currcons >= MAX_NR_USER_CONSOLES && !capable(CAP_SYS_RESOURCE))
              return -EPERM;

            /* due to the granularity of kmalloc, we waste some memory here */
            /* the alloc is done in two steps, to optimize the common situation
               of a 25x80 console (structsize=216, screenbuf_size=4000) */
            /* although the numbers above are not valid since long ago, the
               point is still up-to-date and the comment still has its value
               even if only as a historical artifact.  --mj, July 1998 */
            p = (long) kmalloc(structsize, GFP_KERNEL);
            if (!p)
                return -ENOMEM;
            memset((void *)p, 0, structsize);
            vc_cons[currcons].d = (struct vc_data *)p;
            vt_cons[currcons] = (struct vt_struct *)(p+sizeof(struct vc_data));
            visual_init(currcons, 1);
            if (!*vc_cons[currcons].d->vc_uni_pagedir_loc)
                con_set_default_unimap(currcons);
            q = (long)kmalloc(screenbuf_size, GFP_KERNEL);
            if (!q) {
                kfree((char *) p);
                vc_cons[currcons].d = NULL;
                vt_cons[currcons] = NULL;
                return -ENOMEM;
            }
            screenbuf = (unsigned short *) q;
            kmalloced = 1;
            vc_init(currcons, video_num_lines, video_num_columns, 1);

            if (!pm_con) {
                    pm_con = pm_register(PM_SYS_DEV,
                                         PM_SYS_VGA,
                                         pm_con_request);
            }
        }
        return 0;
}

#define VC_RESIZE_MAXCOL (32767)
#define VC_RESIZE_MAXROW (32767)

/*
 * Change # of rows and columns (0 means unchanged/the size of fg_console)
 * [this is to be used together with some user program
 * like resize that changes the hardware videomode]
 */
int vc_resize(unsigned int lines, unsigned int cols,
              unsigned int first, unsigned int last)
{
        unsigned int cc, ll, ss, sr, todo = 0;
        unsigned int currcons = fg_console, i;
        unsigned short *newscreens[MAX_NR_CONSOLES];

        if (cols > VC_RESIZE_MAXCOL || lines > VC_RESIZE_MAXROW)
                return -EINVAL;

        cc = (cols ? cols : video_num_columns);
        ll = (lines ? lines : video_num_lines);
        sr = cc << 1;
        ss = sr * ll;

        for (currcons = first; currcons <= last; currcons++) {
                if (!vc_cons_allocated(currcons) ||
                    (cc == video_num_columns && ll == video_num_lines))
                        newscreens[currcons] = NULL;
                else {
                        unsigned short *p = (unsigned short *) kmalloc(ss, GFP_USER);
                        if (!p) {
                                for (i = first; i < currcons; i++)
                                        if (newscreens[i])
                                                kfree(newscreens[i]);
                                return -ENOMEM;
                        }
                        newscreens[currcons] = p;
                        todo++;
                }
        }
        if (!todo)
                return 0;

        for (currcons = first; currcons <= last; currcons++) {
                unsigned int occ, oll, oss, osr;
                unsigned long ol, nl, nlend, rlth, rrem;
                if (!newscreens[currcons] || !vc_cons_allocated(currcons))
                        continue;

                oll = video_num_lines;
                occ = video_num_columns;
                osr = video_size_row;
                oss = screenbuf_size;

                video_num_lines = ll;
                video_num_columns = cc;
                video_size_row = sr;
                screenbuf_size = ss;

                rlth = MIN(osr, sr);
                rrem = sr - rlth;
                ol = origin;
                nl = (long) newscreens[currcons];
                nlend = nl + ss;
                if (ll < oll)
                        ol += (oll - ll) * osr;

                update_attr(currcons);

                while (ol < scr_end) {
                        scr_memcpyw((unsigned short *) nl, (unsigned short *) ol, rlth);
                        if (rrem)
                                scr_memsetw((void *)(nl + rlth), video_erase_char, rrem);
                        ol += osr;
                        nl += sr;
                }
                if (nlend > nl)
                        scr_memsetw((void *) nl, video_erase_char, nlend - nl);
                if (kmalloced)
                        kfree(screenbuf);
                screenbuf = newscreens[currcons];
                kmalloced = 1;
                screenbuf_size = ss;
                set_origin(currcons);

                /* do part of a reset_terminal() */
                top = 0;
                bottom = video_num_lines;
                gotoxy(currcons, x, y);
                save_cur(currcons);

                if (console_table[currcons]) {
                        struct winsize ws, *cws = &console_table[currcons]->winsize;
                        memset(&ws, 0, sizeof(ws));
                        ws.ws_row = video_num_lines;
                        ws.ws_col = video_num_columns;
                        if ((ws.ws_row != cws->ws_row || ws.ws_col != cws->ws_col) &&
                            console_table[currcons]->pgrp > 0)
                                kill_pg(console_table[currcons]->pgrp, SIGWINCH, 1);
                        *cws = ws;
                }

                if (IS_VISIBLE)
                        update_screen(currcons);
        }

        return 0;
}


void vc_disallocate(unsigned int currcons)
{
        acquire_console_sem();
        if (vc_cons_allocated(currcons)) {
            sw->con_deinit(vc_cons[currcons].d);
            if (kmalloced)
                kfree(screenbuf);
            if (currcons >= MIN_NR_CONSOLES)
                kfree(vc_cons[currcons].d);
            vc_cons[currcons].d = NULL;
        }
        release_console_sem();
}

/*
 *      VT102 emulator
 */

#define set_kbd(x) set_vc_kbd_mode(kbd_table+currcons,x)
#define clr_kbd(x) clr_vc_kbd_mode(kbd_table+currcons,x)
#define is_kbd(x) vc_kbd_mode(kbd_table+currcons,x)

#define decarm          VC_REPEAT
#define decckm          VC_CKMODE
#define kbdapplic       VC_APPLIC
#define lnm             VC_CRLF

/*
 * this is what the terminal answers to a ESC-Z or csi0c query.
 */
#define VT100ID "\033[?1;2c"
#define VT102ID "\033[?6c"

unsigned char color_table[] = { 0, 4, 2, 6, 1, 5, 3, 7,
                                       8,12,10,14, 9,13,11,15 };

/* the default colour table, for VGA+ colour systems */
int default_red[] = {0x00,0xaa,0x00,0xaa,0x00,0xaa,0x00,0xaa,
    0x55,0xff,0x55,0xff,0x55,0xff,0x55,0xff};
int default_grn[] = {0x00,0x00,0xaa,0x55,0x00,0x00,0xaa,0xaa,
    0x55,0x55,0xff,0xff,0x55,0x55,0xff,0xff};
int default_blu[] = {0x00,0x00,0x00,0x00,0xaa,0xaa,0xaa,0xaa,
    0x55,0x55,0x55,0x55,0xff,0xff,0xff,0xff};

/*
 * gotoxy() must verify all boundaries, because the arguments
 * might also be negative. If the given position is out of
 * bounds, the cursor is placed at the nearest margin.
 */
static void gotoxy(int currcons, int new_x, int new_y)
{
        int min_y, max_y;

        if (new_x < 0)
                x = 0;
        else
                if (new_x >= video_num_columns)
                        x = video_num_columns - 1;
                else
                        x = new_x;
        if (decom) {
                min_y = top;
                max_y = bottom;
        } else {
                min_y = 0;
                max_y = video_num_lines;
        }
        if (new_y < min_y)
                y = min_y;
        else if (new_y >= max_y)
                y = max_y - 1;
        else
                y = new_y;
        pos = origin + y*video_size_row + (x<<1);
        need_wrap = 0;
}

/* for absolute user moves, when decom is set */
static void gotoxay(int currcons, int new_x, int new_y)
{
        gotoxy(currcons, new_x, decom ? (top+new_y) : new_y);
}

void scrollback(int lines)
{
        int currcons = fg_console;

        if (!lines)
                lines = video_num_lines/2;
        scrolldelta(-lines);
}

void scrollfront(int lines)
{
        int currcons = fg_console;

        if (!lines)
                lines = video_num_lines/2;
        scrolldelta(lines);
}

static void lf(int currcons)
{
        /* don't scroll if above bottom of scrolling region, or
         * if below scrolling region
         */
        if (y+1 == bottom)
                scrup(currcons,top,bottom,1);
        else if (y < video_num_lines-1) {
                y++;
                pos += video_size_row;
        }
        need_wrap = 0;
}

static void ri(int currcons)
{
        /* don't scroll if below top of scrolling region, or
         * if above scrolling region
         */
        if (y == top)
                scrdown(currcons,top,bottom,1);
        else if (y > 0) {
                y--;
                pos -= video_size_row;
        }
        need_wrap = 0;
}

static inline void cr(int currcons)
{
        pos -= x<<1;
        need_wrap = x = 0;
}

static inline void bs(int currcons)
{
        if (x) {
                pos -= 2;
                x--;
                need_wrap = 0;
        }
}

static inline void del(int currcons)
{
        /* ignored */
}

static void csi_J(int currcons, int vpar)
{
        unsigned int count;
        unsigned short * start;

        switch (vpar) {
                case 0: /* erase from cursor to end of display */
                        count = (scr_end-pos)>>1;
                        start = (unsigned short *) pos;
                        if (DO_UPDATE) {
                                /* do in two stages */
                                sw->con_clear(vc_cons[currcons].d, y, x, 1,
                                              video_num_columns-x);
                                sw->con_clear(vc_cons[currcons].d, y+1, 0,
                                              video_num_lines-y-1,
                                              video_num_columns);
                        }
                        break;
                case 1: /* erase from start to cursor */
                        count = ((pos-origin)>>1)+1;
                        start = (unsigned short *) origin;
                        if (DO_UPDATE) {
                                /* do in two stages */
                                sw->con_clear(vc_cons[currcons].d, 0, 0, y,
                                              video_num_columns);
                                sw->con_clear(vc_cons[currcons].d, y, 0, 1,
                                              x + 1);
                        }
                        break;
                case 2: /* erase whole display */
                        count = video_num_columns * video_num_lines;
                        start = (unsigned short *) origin;
                        if (DO_UPDATE)
                                sw->con_clear(vc_cons[currcons].d, 0, 0,
                                              video_num_lines,

                                              video_num_columns);
                        break;
                default:
                        return;
        }
        scr_memsetw(start, video_erase_char, 2*count);
        need_wrap = 0;
}

static void csi_K(int currcons, int vpar)
{
        unsigned int count;
        unsigned short * start;

        switch (vpar) {
                case 0: /* erase from cursor to end of line */
                        count = video_num_columns-x;
                        start = (unsigned short *) pos;
                        if (DO_UPDATE)
                                sw->con_clear(vc_cons[currcons].d, y, x, 1,
                                              video_num_columns-x);
                        break;
                case 1: /* erase from start of line to cursor */
                        start = (unsigned short *) (pos - (x<<1));
                        count = x+1;
                        if (DO_UPDATE)
                                sw->con_clear(vc_cons[currcons].d, y, 0, 1,
                                              x + 1);
                        break;
                case 2: /* erase whole line */
                        start = (unsigned short *) (pos - (x<<1));
                        count = video_num_columns;
                        if (DO_UPDATE)
                                sw->con_clear(vc_cons[currcons].d, y, 0, 1,
                                              video_num_columns);
                        break;
                default:
                        return;
        }
        scr_memsetw(start, video_erase_char, 2 * count);
        need_wrap = 0;
}

static void csi_X(int currcons, int vpar) /* erase the following vpar positions */
{                                         /* not vt100? */
        int count;

        if (!vpar)
                vpar++;
        count = (vpar > video_num_columns-x) ? (video_num_columns-x) : vpar;

        scr_memsetw((unsigned short *) pos, video_erase_char, 2 * count);
        if (DO_UPDATE)
                sw->con_clear(vc_cons[currcons].d, y, x, 1, count);
        need_wrap = 0;
}

static void default_attr(int currcons)
{
        intensity = 1;
        underline = 0;
        reverse = 0;
        blink = 0;
        color = def_color;
}

/* console_sem is held */
static void csi_m(int currcons)
{
        int i;

        for (i=0;i<=npar;i++)
                switch (par[i]) {
                        case 0: /* all attributes off */
                                default_attr(currcons);
                                break;
                        case 1:
                                intensity = 2;
                                break;
                        case 2:
                                intensity = 0;
                                break;
                        case 4:
                                underline = 1;
                                break;
                        case 5:
                                blink = 1;
                                break;
                        case 7:
                                reverse = 1;
                                break;
                        case 10: /* ANSI X3.64-1979 (SCO-ish?)
                                  * Select primary font, don't display
                                  * control chars if defined, don't set
                                  * bit 8 on output.
                                  */
                                translate = set_translate(charset == 0
                                                ? G0_charset
                                                : G1_charset,currcons);
                                disp_ctrl = 0;
                                toggle_meta = 0;
                                break;
                        case 11: /* ANSI X3.64-1979 (SCO-ish?)
                                  * Select first alternate font, lets
                                  * chars < 32 be displayed as ROM chars.
                                  */
                                translate = set_translate(IBMPC_MAP,currcons);
                                disp_ctrl = 1;
                                toggle_meta = 0;
                                break;
                        case 12: /* ANSI X3.64-1979 (SCO-ish?)
                                  * Select second alternate font, toggle
                                  * high bit before displaying as ROM char.
                                  */
                                translate = set_translate(IBMPC_MAP,currcons);
                                disp_ctrl = 1;
                                toggle_meta = 1;
                                break;
                        case 21:
                        case 22:
                                intensity = 1;
                                break;
                        case 24:
                                underline = 0;
                                break;
                        case 25:
                                blink = 0;
                                break;
                        case 27:
                                reverse = 0;
                                break;
                        case 38: /* ANSI X3.64-1979 (SCO-ish?)
                                  * Enables underscore, white foreground
                                  * with white underscore (Linux - use
                                  * default foreground).
                                  */
                                color = (def_color & 0x0f) | background;
                                underline = 1;
                                break;
                        case 39: /* ANSI X3.64-1979 (SCO-ish?)
                                  * Disable underline option.
                                  * Reset colour to default? It did this
                                  * before...
                                  */
                                color = (def_color & 0x0f) | background;
                                underline = 0;
                                break;
                        case 49:
                                color = (def_color & 0xf0) | foreground;
                                break;
                        default:
                                if (par[i] >= 30 && par[i] <= 37)
                                        color = color_table[par[i]-30]
                                                | background;
                                else if (par[i] >= 40 && par[i] <= 47)
                                        color = (color_table[par[i]-40]<<4)
                                                | foreground;
                                break;
                }
        update_attr(currcons);
}

static void respond_string(const char * p, struct tty_struct * tty)
{
        while (*p) {
                tty_insert_flip_char(tty, *p, 0);
                p++;
        }
        con_schedule_flip(tty);
}

static void cursor_report(int currcons, struct tty_struct * tty)
{
        char buf[40];

        sprintf(buf, "\033[%d;%dR", y + (decom ? top+1 : 1), x+1);
        respond_string(buf, tty);
}

static inline void status_report(struct tty_struct * tty)
{
        respond_string("\033[0n", tty); /* Terminal ok */
}

static inline void respond_ID(struct tty_struct * tty)
{
        respond_string(VT102ID, tty);
}

void mouse_report(struct tty_struct * tty, int butt, int mrx, int mry)
{
        char buf[8];

        sprintf(buf, "\033[M%c%c%c", (char)(' ' + butt), (char)('!' + mrx),
                (char)('!' + mry));
        respond_string(buf, tty);
}

/* invoked via ioctl(TIOCLINUX) and through set_selection */
int mouse_reporting(void)
{
        int currcons = fg_console;

        return report_mouse;
}

/* console_sem is held */
static void set_mode(int currcons, int on_off)
{
        int i;

        for (i=0; i<=npar; i++)
                if (ques) switch(par[i]) {      /* DEC private modes set/reset */
                        case 1:                 /* Cursor keys send ^[Ox/^[[x */
                                if (on_off)
                                        set_kbd(decckm);
                                else
                                        clr_kbd(decckm);
                                break;
                        case 3: /* 80/132 mode switch unimplemented */
                                deccolm = on_off;
#if 0
                                (void) vc_resize(video_num_lines, deccolm ? 132 : 80);
                                /* this alone does not suffice; some user mode
                                   utility has to change the hardware regs */
#endif
                                break;
                        case 5:                 /* Inverted screen on/off */
                                if (decscnm != on_off) {
                                        decscnm = on_off;
                                        invert_screen(currcons, 0, screenbuf_size, 0);
                                        update_attr(currcons);
                                }
                                break;
                        case 6:                 /* Origin relative/absolute */
                                decom = on_off;
                                gotoxay(currcons,0,0);
                                break;
                        case 7:                 /* Autowrap on/off */
                                decawm = on_off;
                                break;
                        case 8:                 /* Autorepeat on/off */
                                if (on_off)
                                        set_kbd(decarm);
                                else
                                        clr_kbd(decarm);
                                break;
                        case 9:
                                report_mouse = on_off ? 1 : 0;
                                break;
                        case 25:                /* Cursor on/off */
                                deccm = on_off;
                                break;
                        case 1000:
                                report_mouse = on_off ? 2 : 0;
                                break;
                } else switch(par[i]) {         /* ANSI modes set/reset */
                        case 3:                 /* Monitor (display ctrls) */
                                disp_ctrl = on_off;
                                break;
                        case 4:                 /* Insert Mode on/off */
                                decim = on_off;
                                break;
                        case 20:                /* Lf, Enter == CrLf/Lf */
                                if (on_off)
                                        set_kbd(lnm);
                                else
                                        clr_kbd(lnm);
                                break;
                }
}

/* console_sem is held */
static void setterm_command(int currcons)
{
        switch(par[0]) {
                case 1: /* set color for underline mode */
                        if (can_do_color && par[1] < 16) {
                                ulcolor = color_table[par[1]];
                                if (underline)
                                        update_attr(currcons);
                        }
                        break;
                case 2: /* set color for half intensity mode */
                        if (can_do_color && par[1] < 16) {
                                halfcolor = color_table[par[1]];
                                if (intensity == 0)
                                        update_attr(currcons);
                        }
                        break;
                case 8: /* store colors as defaults */
                        def_color = attr;
                        if (hi_font_mask == 0x100)
                                def_color >>= 1;
                        default_attr(currcons);
                        update_attr(currcons);
                        break;
                case 9: /* set blanking interval */
                        blankinterval = ((par[1] < 60) ? par[1] : 60) * 60 * HZ;
                        poke_blanked_console();
                        break;
                case 10: /* set bell frequency in Hz */
                        if (npar >= 1)
                                bell_pitch = par[1];
                        else
                                bell_pitch = DEFAULT_BELL_PITCH;
                        break;
                case 11: /* set bell duration in msec */
                        if (npar >= 1)
                                bell_duration = (par[1] < 2000) ?
                                        par[1]*HZ/1000 : 0;
                        else
                                bell_duration = DEFAULT_BELL_DURATION;
                        break;
                case 12: /* bring specified console to the front */
                        if (par[1] >= 1 && vc_cons_allocated(par[1]-1))
                                set_console(par[1] - 1);
                        break;
                case 13: /* unblank the screen */
                        poke_blanked_console();
                        break;
                case 14: /* set vesa powerdown interval */
                        vesa_off_interval = ((par[1] < 60) ? par[1] : 60) * 60 * HZ;
                        break;
        }
}

/* console_sem is held */
static void csi_at(int currcons, unsigned int nr)
{
        if (nr > video_num_columns - x)
                nr = video_num_columns - x;
        else if (!nr)
                nr = 1;
        insert_char(currcons, nr);
}

/* console_sem is held */
static void csi_L(int currcons, unsigned int nr)
{
        if (nr > video_num_lines - y)
                nr = video_num_lines - y;
        else if (!nr)
                nr = 1;
        scrdown(currcons,y,bottom,nr);
        need_wrap = 0;
}

/* console_sem is held */
static void csi_P(int currcons, unsigned int nr)
{
        if (nr > video_num_columns - x)
                nr = video_num_columns - x;
        else if (!nr)
                nr = 1;
        delete_char(currcons, nr);
}

/* console_sem is held */
static void csi_M(int currcons, unsigned int nr)
{
        if (nr > video_num_lines - y)
                nr = video_num_lines - y;
        else if (!nr)
                nr=1;
        scrup(currcons,y,bottom,nr);
        need_wrap = 0;
}

/* console_sem is held (except via vc_init->reset_terminal */
static void save_cur(int currcons)
{
        saved_x         = x;
        saved_y         = y;
        s_intensity     = intensity;
        s_underline     = underline;
        s_blink         = blink;
        s_reverse       = reverse;
        s_charset       = charset;
        s_color         = color;
        saved_G0        = G0_charset;
        saved_G1        = G1_charset;
}

/* console_sem is held */
static void restore_cur(int currcons)
{
        gotoxy(currcons,saved_x,saved_y);
        intensity       = s_intensity;
        underline       = s_underline;
        blink           = s_blink;
        reverse         = s_reverse;
        charset         = s_charset;
        color           = s_color;
        G0_charset      = saved_G0;
        G1_charset      = saved_G1;
        translate       = set_translate(charset ? G1_charset : G0_charset,currcons);
        update_attr(currcons);
        need_wrap = 0;
}

enum { ESnormal, ESesc, ESsquare, ESgetpars, ESgotpars, ESfunckey,
        EShash, ESsetG0, ESsetG1, ESpercent, ESignore, ESnonstd,
        ESpalette };

/* console_sem is held (except via vc_init()) */
static void reset_terminal(int currcons, int do_clear)
{
        top             = 0;
        bottom          = video_num_lines;
        vc_state        = ESnormal;
        ques            = 0;
        translate       = set_translate(LAT1_MAP,currcons);
        G0_charset      = LAT1_MAP;
        G1_charset      = GRAF_MAP;
        charset         = 0;
        need_wrap       = 0;
        report_mouse    = 0;
        utf             = 0;
        utf_count       = 0;

        disp_ctrl       = 0;
        toggle_meta     = 0;

        decscnm         = 0;
        decom           = 0;
        decawm          = 1;
        deccm           = 1;
        decim           = 0;

        set_kbd(decarm);
        clr_kbd(decckm);
        clr_kbd(kbdapplic);
        clr_kbd(lnm);
        kbd_table[currcons].lockstate = 0;
        kbd_table[currcons].slockstate = 0;
        kbd_table[currcons].ledmode = LED_SHOW_FLAGS;
        kbd_table[currcons].ledflagstate = kbd_table[currcons].default_ledflagstate;
        
        /* Only schedule the keyboard_tasklet if it is enabled. */
        if(!atomic_read(&keyboard_tasklet.count))
                set_leds();

        cursor_type = CUR_DEFAULT;
        complement_mask = s_complement_mask;

        default_attr(currcons);
        update_attr(currcons);

        tab_stop[0]     = 0x01010100;
        tab_stop[1]     =
        tab_stop[2]     =
        tab_stop[3]     =
        tab_stop[4]     = 0x01010101;

        bell_pitch = DEFAULT_BELL_PITCH;
        bell_duration = DEFAULT_BELL_DURATION;

        gotoxy(currcons,0,0);
        save_cur(currcons);
        if (do_clear)
            csi_J(currcons,2);
}

/* console_sem is held */
static void do_con_trol(struct tty_struct *tty, unsigned int currcons, int c)
{
        /*
         *  Control characters can be used in the _middle_
         *  of an escape sequence.
         */
        switch (c) {
        case 0:
                return;
        case 7:
                if (bell_duration)
                        kd_mksound(bell_pitch, bell_duration);
                return;
        case 8:
                bs(currcons);
                return;
        case 9:
                pos -= (x << 1);
                while (x < video_num_columns - 1) {
                        x++;
                        if (tab_stop[x >> 5] & (1 << (x & 31)))
                                break;
                }
                pos += (x << 1);
                return;
        case 10: case 11: case 12:
                lf(currcons);
                if (!is_kbd(lnm))
                        return;
        case 13:
                cr(currcons);
                return;
        case 14:
                charset = 1;
                translate = set_translate(G1_charset,currcons);
                disp_ctrl = 1;
                return;
        case 15:
                charset = 0;
                translate = set_translate(G0_charset,currcons);
                disp_ctrl = 0;
                return;
        case 24: case 26:
                vc_state = ESnormal;
                return;
        case 27:
                vc_state = ESesc;
                return;
        case 127:
                del(currcons);
                return;
        case 128+27:
                vc_state = ESsquare;
                return;
        }
        switch(vc_state) {
        case ESesc:
                vc_state = ESnormal;
                switch (c) {
                case '[':
                        vc_state = ESsquare;
                        return;
                case ']':
                        vc_state = ESnonstd;
                        return;
                case '%':
                        vc_state = ESpercent;
                        return;
                case 'E':
                        cr(currcons);
                        lf(currcons);
                        return;
                case 'M':
                        ri(currcons);
                        return;
                case 'D':
                        lf(currcons);
                        return;
                case 'H':
                        tab_stop[x >> 5] |= (1 << (x & 31));
                        return;
                case 'Z':
                        respond_ID(tty);
                        return;
                case '7':
                        save_cur(currcons);
                        return;
                case '8':
                        restore_cur(currcons);
                        return;
                case '(':
                        vc_state = ESsetG0;
                        return;
                case ')':
                        vc_state = ESsetG1;
                        return;
                case '#':
                        vc_state = EShash;
                        return;
                case 'c':
                        reset_terminal(currcons,1);
                        return;
                case '>':  /* Numeric keypad */
                        clr_kbd(kbdapplic);
                        return;
                case '=':  /* Appl. keypad */
                        set_kbd(kbdapplic);
                        return;
                }
                return;
        case ESnonstd:
                if (c=='P') {   /* palette escape sequence */
                        for (npar=0; npar<NPAR; npar++)
                                par[npar] = 0 ;
                        npar = 0 ;
                        vc_state = ESpalette;
                        return;
                } else if (c=='R') {   /* reset palette */
                        reset_palette(currcons);
                        vc_state = ESnormal;
                } else
                        vc_state = ESnormal;
                return;
        case ESpalette:
                if ( (c>='0'&&c<='9') || (c>='A'&&c<='F') || (c>='a'&&c<='f') ) {
                        par[npar++] = (c>'9' ? (c&0xDF)-'A'+10 : c-'0') ;
                        if (npar==7) {
                                int i = par[0]*3, j = 1;
                                palette[i] = 16*par[j++];
                                palette[i++] += par[j++];
                                palette[i] = 16*par[j++];
                                palette[i++] += par[j++];
                                palette[i] = 16*par[j++];
                                palette[i] += par[j];
                                set_palette(currcons);
                                vc_state = ESnormal;
                        }
                } else
                        vc_state = ESnormal;
                return;
        case ESsquare:
                for(npar = 0 ; npar < NPAR ; npar++)
                        par[npar] = 0;
                npar = 0;
                vc_state = ESgetpars;
                if (c == '[') { /* Function key */
                        vc_state=ESfunckey;
                        return;
                }
                ques = (c=='?');
                if (ques)
                        return;
        case ESgetpars:
                if (c==';' && npar<NPAR-1) {
                        npar++;
                        return;
                } else if (c>='0' && c<='9') {
                        par[npar] *= 10;
                        par[npar] += c-'0';
                        return;
                } else vc_state=ESgotpars;
        case ESgotpars:
                vc_state = ESnormal;
                switch(c) {
                case 'h':
                        set_mode(currcons,1);
                        return;
                case 'l':
                        set_mode(currcons,0);
                        return;
                case 'c':
                        if (ques) {
                                if (par[0])
                                        cursor_type = par[0] | (par[1]<<8) | (par[2]<<16);
                                else
                                        cursor_type = CUR_DEFAULT;
                                return;
                        }
                        break;
                case 'm':
                        if (ques) {
                                clear_selection();
                                if (par[0])
                                        complement_mask = par[0]<<8 | par[1];
                                else
                                        complement_mask = s_complement_mask;
                                return;
                        }
                        break;
                case 'n':
                        if (!ques) {
                                if (par[0] == 5)
                                        status_report(tty);
                                else if (par[0] == 6)
                                        cursor_report(currcons,tty);
                        }
                        return;
                }
                if (ques) {
                        ques = 0;
                        return;
                }
                switch(c) {
                case 'G': case '`':
                        if (par[0]) par[0]--;
                        gotoxy(currcons,par[0],y);
                        return;
                case 'A':
                        if (!par[0]) par[0]++;
                        gotoxy(currcons,x,y-par[0]);
                        return;
                case 'B': case 'e':
                        if (!par[0]) par[0]++;
                        gotoxy(currcons,x,y+par[0]);
                        return;
                case 'C': case 'a':
                        if (!par[0]) par[0]++;
                        gotoxy(currcons,x+par[0],y);
                        return;
                case 'D':
                        if (!par[0]) par[0]++;
                        gotoxy(currcons,x-par[0],y);
                        return;
                case 'E':
                        if (!par[0]) par[0]++;
                        gotoxy(currcons,0,y+par[0]);
                        return;
                case 'F':
                        if (!par[0]) par[0]++;
                        gotoxy(currcons,0,y-par[0]);
                        return;
                case 'd':
                        if (par[0]) par[0]--;
                        gotoxay(currcons,x,par[0]);
                        return;
                case 'H': case 'f':
                        if (par[0]) par[0]--;
                        if (par[1]) par[1]--;
                        gotoxay(currcons,par[1],par[0]);
                        return;
                case 'J':
                        csi_J(currcons,par[0]);
                        return;
                case 'K':
                        csi_K(currcons,par[0]);
                        return;
                case 'L':
                        csi_L(currcons,par[0]);
                        return;
                case 'M':
                        csi_M(currcons,par[0]);
                        return;
                case 'P':
                        csi_P(currcons,par[0]);
                        return;
                case 'c':
                        if (!par[0])
                                respond_ID(tty);
                        return;
                case 'g':
                        if (!par[0])
                                tab_stop[x >> 5] &= ~(1 << (x & 31));
                        else if (par[0] == 3) {
                                tab_stop[0] =
                                        tab_stop[1] =
                                        tab_stop[2] =
                                        tab_stop[3] =
                                        tab_stop[4] = 0;
                        }
                        return;
                case 'm':
                        csi_m(currcons);
                        return;
                case 'q': /* DECLL - but only 3 leds */
                        /* map 0,1,2,3 to 0,1,2,4 */
                        if (par[0] < 4)
                                setledstate(kbd_table + currcons,
                                            (par[0] < 3) ? par[0] : 4);
                        return;
                case 'r':
                        if (!par[0])
                                par[0]++;
                        if (!par[1])
                                par[1] = video_num_lines;
                        /* Minimum allowed region is 2 lines */
                        if (par[0] < par[1] &&
                            par[1] <= video_num_lines) {
                                top=par[0]-1;
                                bottom=par[1];
                                gotoxay(currcons,0,0);
                        }
                        return;
                case 's':
                        save_cur(currcons);
                        return;
                case 'u':
                        restore_cur(currcons);
                        return;
                case 'X':
                        csi_X(currcons, par[0]);
                        return;
                case '@':
                        csi_at(currcons,par[0]);
                        return;
                case ']': /* setterm functions */
                        setterm_command(currcons);
                        return;
                }
                return;
        case ESpercent:
                vc_state = ESnormal;
                switch (c) {
                case '@':  /* defined in ISO 2022 */
                        utf = 0;
                        return;
                case 'G':  /* prelim official escape code */
                case '8':  /* retained for compatibility */
                        utf = 1;
                        return;
                }
                return;
        case ESfunckey:
                vc_state = ESnormal;
                return;
        case EShash:
                vc_state = ESnormal;
                if (c == '8') {
                        /* DEC screen alignment test. kludge :-) */
                        video_erase_char =
                                (video_erase_char & 0xff00) | 'E';
                        csi_J(currcons, 2);
                        video_erase_char =
                                (video_erase_char & 0xff00) | ' ';
                        do_update_region(currcons, origin, screenbuf_size/2);
                }
                return;
        case ESsetG0:
                if (c == '0')
                        G0_charset = GRAF_MAP;
                else if (c == 'B')
                        G0_charset = LAT1_MAP;
                else if (c == 'U')
                        G0_charset = IBMPC_MAP;
                else if (c == 'K')
                        G0_charset = USER_MAP;
                if (charset == 0)
                        translate = set_translate(G0_charset,currcons);
                vc_state = ESnormal;
                return;
        case ESsetG1:
                if (c == '0')
                        G1_charset = GRAF_MAP;
                else if (c == 'B')
                        G1_charset = LAT1_MAP;
                else if (c == 'U')
                        G1_charset = IBMPC_MAP;
                else if (c == 'K')
                        G1_charset = USER_MAP;
                if (charset == 1)
                        translate = set_translate(G1_charset,currcons);
                vc_state = ESnormal;
                return;
        default:
                vc_state = ESnormal;
        }
}

/* This is a temporary buffer used to prepare a tty console write
 * so that we can easily avoid touching user space while holding the
 * console spinlock.  It is allocated in con_init and is shared by
 * this code and the vc_screen read/write tty calls.
 *
 * We have to allocate this statically in the kernel data section
 * since console_init (and thus con_init) are called before any
 * kernel memory allocation is available.
 */
char con_buf[PAGE_SIZE];
#define CON_BUF_SIZE    PAGE_SIZE
DECLARE_MUTEX(con_buf_sem);

/* acquires console_sem */
static int do_con_write(struct tty_struct * tty, int from_user,
                        const unsigned char *buf, int count)
{
#ifdef VT_BUF_VRAM_ONLY
#define FLUSH do { } while(0);
#else
#define FLUSH if (draw_x >= 0) { \
        sw->con_putcs(vc_cons[currcons].d, (u16 *)draw_from, (u16 *)draw_to-(u16 *)draw_from, y, draw_x); \
        draw_x = -1; \
        }
#endif

        int c, tc, ok, n = 0, draw_x = -1;
        unsigned int currcons;
        unsigned long draw_from = 0, draw_to = 0;
        struct vt_struct *vt = (struct vt_struct *)tty->driver_data;
        u16 himask, charmask;
        const unsigned char *orig_buf = NULL;
        int orig_count;

        if (in_interrupt())
                return count;
                
        currcons = vt->vc_num;
        if (!vc_cons_allocated(currcons)) {
            /* could this happen? */
            static int error = 0;
            if (!error) {
                error = 1;
                printk("con_write: tty %d not allocated\n", currcons+1);
            }
            return 0;
        }

        orig_buf = buf;
        orig_count = count;

        if (from_user) {
                down(&con_buf_sem);

again:
                if (count > CON_BUF_SIZE)
                        count = CON_BUF_SIZE;
                console_conditional_schedule();
                if (copy_from_user(con_buf, buf, count)) {
                        n = 0; /* ?? are error codes legal here ?? */
                        goto out;
                }

                buf = con_buf;
        }

        /* At this point 'buf' is guarenteed to be a kernel buffer
         * and therefore no access to userspace (and therefore sleeping)
         * will be needed.  The con_buf_sem serializes all tty based
         * console rendering and vcs write/read operations.  We hold
         * the console spinlock during the entire write.
         */

        acquire_console_sem();

        himask = hi_font_mask;
        charmask = himask ? 0x1ff : 0xff;

        /* undraw cursor first */
        if (IS_FG)
                hide_cursor(currcons);

        while (!tty->stopped && count) {
                c = *buf;
                buf++;
                n++;
                count--;

                if (utf) {
                    /* Combine UTF-8 into Unicode */
                    /* Incomplete characters silently ignored */
                    if(c > 0x7f) {
                        if (utf_count > 0 && (c & 0xc0) == 0x80) {
                                utf_char = (utf_char << 6) | (c & 0x3f);
                                utf_count--;
                                if (utf_count == 0)
                                    tc = c = utf_char;
                                else continue;
                        } else {
                                if ((c & 0xe0) == 0xc0) {
                                    utf_count = 1;
                                    utf_char = (c & 0x1f);
                                } else if ((c & 0xf0) == 0xe0) {
                                    utf_count = 2;
                                    utf_char = (c & 0x0f);
                                } else if ((c & 0xf8) == 0xf0) {
                                    utf_count = 3;
                                    utf_char = (c & 0x07);
                                } else if ((c & 0xfc) == 0xf8) {
                                    utf_count = 4;
                                    utf_char = (c & 0x03);
                                } else if ((c & 0xfe) == 0xfc) {
                                    utf_count = 5;
                                    utf_char = (c & 0x01);
                                } else
                                    utf_count = 0;
                                continue;
                              }
                    } else {
                      tc = c;
                      utf_count = 0;
                    }
                } else {        /* no utf */
                  tc = translate[toggle_meta ? (c|0x80) : c];
                }

                /* If the original code was a control character we
                 * only allow a glyph to be displayed if the code is
                 * not normally used (such as for cursor movement) or
                 * if the disp_ctrl mode has been explicitly enabled.
                 * Certain characters (as given by the CTRL_ALWAYS
                 * bitmap) are always displayed as control characters,
                 * as the console would be pretty useless without
                 * them; to display an arbitrary font position use the
                 * direct-to-font zone in UTF-8 mode.
                 */
                ok = tc && (c >= 32 ||
                            (!utf && !(((disp_ctrl ? CTRL_ALWAYS
                                         : CTRL_ACTION) >> c) & 1)))
                        && (c != 127 || disp_ctrl)
                        && (c != 128+27);

                if (vc_state == ESnormal && ok) {
                        /* Now try to find out how to display it */
                        tc = conv_uni_to_pc(vc_cons[currcons].d, tc);
                        if ( tc == -4 ) {
                                /* If we got -4 (not found) then see if we have
                                   defined a replacement character (U+FFFD) */
                                tc = conv_uni_to_pc(vc_cons[currcons].d, 0xfffd);

                                /* One reason for the -4 can be that we just
                                   did a clear_unimap();
                                   try at least to show something. */
                                if (tc == -4)
                                     tc = c;
                        } else if ( tc == -3 ) {
                                /* Bad hash table -- hope for the best */
                                tc = c;
                        }
                        if (tc & ~charmask)
                                continue; /* Conversion failed */

                        if (need_wrap || decim)
                                FLUSH
                        if (need_wrap) {
                                cr(currcons);
                                lf(currcons);
                        }

                        if (decim)
                                insert_char(currcons, 1);
                        scr_writew(himask ?
                                     ((attr << 8) & ~himask) + ((tc & 0x100) ? himask : 0) + (tc & 0xff) :
                                     (attr << 8) + tc,
                                   (u16 *) pos);
                        if (DO_UPDATE && draw_x < 0) {
                                draw_x = x;
                                draw_from = pos;
                        }
                        if (x == video_num_columns - 1) {
                                need_wrap = decawm;
                                draw_to = pos+2;
                        } else {
                                x++;
                                draw_to = (pos+=2);
                        }
                        continue;
                }
                FLUSH
                do_con_trol(tty, currcons, c);
        }
        FLUSH
        console_conditional_schedule();
        release_console_sem();

out:
        if (from_user) {
                /* If the user requested something larger than
                 * the CON_BUF_SIZE, and the tty is not stopped,
                 * keep going.
                 */
                if ((orig_count > CON_BUF_SIZE) && !tty->stopped) {
                        orig_count -= CON_BUF_SIZE;
                        orig_buf += CON_BUF_SIZE;
                        count = orig_count;
                        buf = orig_buf;
                        goto again;
                }

                up(&con_buf_sem);
        }

        return n;
#undef FLUSH
}

/*
 * This is the console switching callback.
 *
 * Doing console switching in a process context allows
 * us to do the switches asynchronously (needed when we want
 * to switch due to a keyboard interrupt).  Synchronization
 * with other console code and prevention of re-entrancy is
 * ensured with console_sem.
 */
static void console_callback(void *unused) 
{
        acquire_console_sem();
        __console_callback(); 
        release_console_sem();  
} 

static void __console_callback(void)
{
        if (want_console >= 0) {
                if (want_console != fg_console && vc_cons_allocated(want_console)) {
                        hide_cursor(fg_console);
                        change_console(want_console);
                        /* we only changed when the console had already
                           been allocated - a new console is not created
                           in an interrupt routine */
                }
                want_console = -1;
        }
        if (do_poke_blanked_console) { /* do not unblank for a LED change */
                do_poke_blanked_console = 0;
                poke_blanked_console();
        }
        if (scrollback_delta) {
                int currcons = fg_console;
                clear_selection();
                if (vcmode == KD_TEXT)
                        sw->con_scrolldelta(vc_cons[currcons].d, scrollback_delta);
                scrollback_delta = 0;
        }
}

void set_console(int nr)
{
        want_console = nr;
        schedule_console_callback();
}

#ifdef CONFIG_VT_CONSOLE

/*
 *      Console on virtual terminal
 *
 * The console must be locked when we get here.
 */

void vt_console_print(struct console *co, const char * b, unsigned count)
{
        int currcons = fg_console;
        unsigned char c;
        static unsigned long printing;
        const ushort *start;
        ushort cnt = 0;
        ushort myx;

        /* console busy or not yet initialized */
        if (!printable || test_and_set_bit(0, &printing))
                return;

        pm_access(pm_con);

        if (kmsg_redirect && vc_cons_allocated(kmsg_redirect - 1))
                currcons = kmsg_redirect - 1;

        /* read `x' only after setting currecons properly (otherwise
           the `x' macro will read the x of the foreground console). */
        myx = x;

        if (!vc_cons_allocated(currcons)) {
                /* impossible */
                /* printk("vt_console_print: tty %d not allocated ??\n", currcons+1); */
                goto quit;
        }

        if (vcmode != KD_TEXT)
                goto quit;

        /* undraw cursor first */
        if (IS_FG)
                hide_cursor(currcons);

        start = (ushort *)pos;

        /* Contrived structure to try to emulate original need_wrap behaviour
         * Problems caused when we have need_wrap set on '\n' character */
        while (count--) {
                c = *b++;
                if (c == 10 || c == 13 || c == 8 || need_wrap) {
                        if (cnt > 0) {
                                if (IS_VISIBLE)
                                        sw->con_putcs(vc_cons[currcons].d, start, cnt, y, x);
                                x += cnt;
                                if (need_wrap)
                                        x--;
                                cnt = 0;
                        }
                        if (c == 8) {           /* backspace */
                                bs(currcons);
                                start = (ushort *)pos;
                                myx = x;
                                continue;
                        }
                        if (c != 13)
                                lf(currcons);
                        cr(currcons);
                        start = (ushort *)pos;
                        myx = x;
                        if (c == 10 || c == 13)
                                continue;
                }
                scr_writew((attr << 8) + c, (unsigned short *) pos);
                cnt++;
                if (myx == video_num_columns - 1) {
                        need_wrap = 1;
                        continue;
                }
                pos+=2;
                myx++;
        }
        if (cnt > 0) {
                if (IS_VISIBLE)
                        sw->con_putcs(vc_cons[currcons].d, start, cnt, y, x);
                x += cnt;
                if (x == video_num_columns) {
                        x--;
                        need_wrap = 1;
                }
        }
        set_cursor(currcons);

        if (!oops_in_progress)
                poke_blanked_console();

quit:
        clear_bit(0, &printing);
}

static kdev_t vt_console_device(struct console *c)
{
        return MKDEV(TTY_MAJOR, c->index ? c->index : fg_console + 1);
}

struct console vt_console_driver = {
        name:           "tty",
        write:          vt_console_print,
        device:         vt_console_device,
        unblank:        unblank_screen,
        flags:          CON_PRINTBUFFER,
        index:          -1,
};
#endif

/*
 *      Handling of Linux-specific VC ioctls
 */

/*
 * Generally a bit racy with respect to console_sem().
 *
 * There are some functions which don't need it.
 *
 * There are some functions which can sleep for arbitrary periods (paste_selection)
 * but we don't need the lock there anyway.
 *
 * set_selection has locking, and definitely needs it
 */

int tioclinux(struct tty_struct *tty, unsigned long arg)
{
        char type, data;
        int ret;

        if (tty->driver.type != TTY_DRIVER_TYPE_CONSOLE)
                return -EINVAL;
        if (current->tty != tty && !capable(CAP_SYS_ADMIN))
                return -EPERM;
        if (get_user(type, (char *)arg))
                return -EFAULT;
        ret = 0;
        switch (type)
        {
                case 2:
                        acquire_console_sem();
                        ret = set_selection(arg, tty, 1);
                        release_console_sem();
                        break;
                case 3:
                        ret = paste_selection(tty);
                        break;
                case 4:
                        unblank_screen();
                        break;
                case 5:
                        ret = sel_loadlut(arg);
                        break;
                case 6:
                        
        /*
         * Make it possible to react to Shift+Mousebutton.
         * Note that 'shift_state' is an undocumented
         * kernel-internal variable; programs not closely
         * related to the kernel should not use this.
         */
                        data = shift_state;
                        ret = __put_user(data, (char *) arg);
                        break;
                case 7:
                        data = mouse_reporting();
                        ret = __put_user(data, (char *) arg);
                        break;
                case 10:
                        set_vesa_blanking(arg);
                        break;;
                case 11:        /* set kmsg redirect */
                        if (!capable(CAP_SYS_ADMIN)) {
                                ret = -EPERM;
                        } else {
                                if (get_user(data, (char *)arg+1))
                                        ret = -EFAULT;
                                else
                                        kmsg_redirect = data;
                        }
                        break;
                case 12:        /* get fg_console */
                        ret = fg_console;
                        break;
                default:
                        ret = -EINVAL;
                        break;
        }
        return ret;
}

/*
 *      /dev/ttyN handling
 */

static int con_write(struct tty_struct * tty, int from_user,
                     const unsigned char *buf, int count)
{
        int     retval;

        pm_access(pm_con);
        retval = do_con_write(tty, from_user, buf, count);
        con_flush_chars(tty);

        return retval;
}

static void con_put_char(struct tty_struct *tty, unsigned char ch)
{
        if (in_interrupt())
                return;         /* n_r3964 calls put_char() from interrupt context */
        pm_access(pm_con);
        do_con_write(tty, 0, &ch, 1);
}

static int con_write_room(struct tty_struct *tty)
{
        if (tty->stopped)
                return 0;
        return 4096;            /* No limit, really; we're not buffering */
}

static int con_chars_in_buffer(struct tty_struct *tty)
{
        return 0;               /* we're not buffering */
}

/*
 * con_throttle and con_unthrottle are only used for
 * paste_selection(), which has to stuff in a large number of
 * characters...
 */
static void con_throttle(struct tty_struct *tty)
{
}

static void con_unthrottle(struct tty_struct *tty)
{
        struct vt_struct *vt = (struct vt_struct *) tty->driver_data;

        wake_up_interruptible(&vt->paste_wait);
}

/*
 * Turn the Scroll-Lock LED on when the tty is stopped
 */
static void con_stop(struct tty_struct *tty)
{
        int console_num;
        if (!tty)
                return;
        console_num = MINOR(tty->device) - (tty->driver.minor_start);
        if (!vc_cons_allocated(console_num))
                return;
        set_vc_kbd_led(kbd_table + console_num, VC_SCROLLOCK);
        set_leds();
}

/*
 * Turn the Scroll-Lock LED off when the console is started
 */
static void con_start(struct tty_struct *tty)
{
        int console_num;
        if (!tty)
                return;
        console_num = MINOR(tty->device) - (tty->driver.minor_start);
        if (!vc_cons_allocated(console_num))
                return;
        clr_vc_kbd_led(kbd_table + console_num, VC_SCROLLOCK);
        set_leds();
}

/*
 * we can race here against con_close, so we grab the bkl
 * and check the pointer before calling set_cursor
 */
static void con_flush_chars(struct tty_struct *tty)
{
        struct vt_struct *vt;

        if (in_interrupt())     /* from flush_to_ldisc */
                return;

        pm_access(pm_con);
        lock_kernel();
        acquire_console_sem();
        vt = (struct vt_struct *)tty->driver_data;
        if (vt)
                set_cursor(vt->vc_num);
        release_console_sem();
        unlock_kernel();
}

/*
 * Allocate the console screen memory.
 */
static int con_open(struct tty_struct *tty, struct file * filp)
{
        unsigned int    currcons;
        int i;

        currcons = MINOR(tty->device) - tty->driver.minor_start;

        i = vc_allocate(currcons);
        if (i)
                return i;

        vt_cons[currcons]->vc_num = currcons;
        tty->driver_data = vt_cons[currcons];

        if (!tty->winsize.ws_row && !tty->winsize.ws_col) {
                tty->winsize.ws_row = video_num_lines;
                tty->winsize.ws_col = video_num_columns;
        }
        if (tty->count == 1)
                vcs_make_devfs (currcons, 0);
        return 0;
}

static void con_close(struct tty_struct *tty, struct file * filp)
{
        if (!tty)
                return;
        if (tty->count != 1) return;
        vcs_make_devfs (MINOR (tty->device) - tty->driver.minor_start, 1);
        tty->driver_data = 0;
}

static void vc_init(unsigned int currcons, unsigned int rows, unsigned int cols, int do_clear)
{
        int j, k ;

        video_num_columns = cols;
        video_num_lines = rows;
        video_size_row = cols<<1;
        screenbuf_size = video_num_lines * video_size_row;

        set_origin(currcons);
        pos = origin;
        reset_vc(currcons);
        for (j=k=0; j<16; j++) {
                vc_cons[currcons].d->vc_palette[k++] = default_red[j] ;
                vc_cons[currcons].d->vc_palette[k++] = default_grn[j] ;
                vc_cons[currcons].d->vc_palette[k++] = default_blu[j] ;
        }
        def_color       = 0x07;   /* white */
        ulcolor         = 0x0f;   /* bold white */
        halfcolor       = 0x08;   /* grey */
        init_waitqueue_head(&vt_cons[currcons]->paste_wait);
        reset_terminal(currcons, do_clear);
}

/*
 * This routine initializes console interrupts, and does nothing
 * else. If you want the screen to clear, call tty_write with
 * the appropriate escape-sequence.
 */

struct tty_driver console_driver;
static int console_refcount;

void __init con_init(void)
{
        const char *display_desc = NULL;
        unsigned int currcons = 0;

        if (conswitchp)
                display_desc = conswitchp->con_startup();
        if (!display_desc) {
                fg_console = 0;
                return;
        }

        memset(&console_driver, 0, sizeof(struct tty_driver));
        console_driver.magic = TTY_DRIVER_MAGIC;
        console_driver.name = "vc/%d";
        console_driver.name_base = 1;
        console_driver.major = TTY_MAJOR;
        console_driver.minor_start = 1;
        console_driver.num = MAX_NR_CONSOLES;
        console_driver.type = TTY_DRIVER_TYPE_CONSOLE;
        console_driver.init_termios = tty_std_termios;
        console_driver.flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_RESET_TERMIOS;
        /* Tell tty_register_driver() to skip consoles because they are
         * registered before kmalloc() is ready. We'll patch them in later. 
         * See comments at console_init(); see also con_init_devfs(). 
         */
        console_driver.flags |= TTY_DRIVER_NO_DEVFS;
        console_driver.refcount = &console_refcount;
        console_driver.table = console_table;
        console_driver.termios = console_termios;
        console_driver.termios_locked = console_termios_locked;

        console_driver.open = con_open;
        console_driver.close = con_close;
        console_driver.write = con_write;
        console_driver.write_room = con_write_room;
        console_driver.put_char = con_put_char;
        console_driver.flush_chars = con_flush_chars;
        console_driver.chars_in_buffer = con_chars_in_buffer;
        console_driver.ioctl = vt_ioctl;
        console_driver.stop = con_stop;
        console_driver.start = con_start;
        console_driver.throttle = con_throttle;
        console_driver.unthrottle = con_unthrottle;

        if (tty_register_driver(&console_driver))
                panic("Couldn't register console driver\n");

        init_timer(&console_timer);
        console_timer.function = blank_screen;
        if (blankinterval) {
                mod_timer(&console_timer, jiffies + blankinterval);
        }

        /*
         * kmalloc is not running yet - we use the bootmem allocator.
         */
        for (currcons = 0; currcons < MIN_NR_CONSOLES; currcons++) {
                vc_cons[currcons].d = (struct vc_data *)
                                alloc_bootmem(sizeof(struct vc_data));
                vt_cons[currcons] = (struct vt_struct *)
                                alloc_bootmem(sizeof(struct vt_struct));
                visual_init(currcons, 1);
                screenbuf = (unsigned short *) alloc_bootmem(screenbuf_size);
                kmalloced = 0;
                vc_init(currcons, video_num_lines, video_num_columns, 
                        currcons || !sw->con_save_screen);
        }
        currcons = fg_console = 0;
        master_display_fg = vc_cons[currcons].d;
        set_origin(currcons);
        save_screen(currcons);
        gotoxy(currcons,x,y);
        csi_J(currcons, 0);
        update_screen(fg_console);
        printk("Console: %s %s %dx%d",
                can_do_color ? "colour" : "mono",
                display_desc, video_num_columns, video_num_lines);
        printable = 1;
        printk("\n");

#ifdef CONFIG_VT_CONSOLE
        register_console(&vt_console_driver);
#endif
}

#ifndef VT_SINGLE_DRIVER

static void clear_buffer_attributes(int currcons)
{
        unsigned short *p = (unsigned short *) origin;
        int count = screenbuf_size/2;
        int mask = hi_font_mask | 0xff;

        for (; count > 0; count--, p++) {
                scr_writew((scr_readw(p)&mask) | (video_erase_char&~mask), p);
        }
}

/*
 *      If we support more console drivers, this function is used
 *      when a driver wants to take over some existing consoles
 *      and become default driver for newly opened ones.
 */

void take_over_console(const struct consw *csw, int first, int last, int deflt)
{
        int i, j = -1;
        const char *desc;

        desc = csw->con_startup();
        if (!desc) return;
        if (deflt)
                conswitchp = csw;

        for (i = first; i <= last; i++) {
                int old_was_color;
                int currcons = i;

                con_driver_map[i] = csw;

                if (!vc_cons[i].d || !vc_cons[i].d->vc_sw)
                        continue;

                j = i;
                if (IS_VISIBLE)
                        save_screen(i);
                old_was_color = vc_cons[i].d->vc_can_do_color;
                vc_cons[i].d->vc_sw->con_deinit(vc_cons[i].d);
                visual_init(i, 0);
                update_attr(i);

                /* If the console changed between mono <-> color, then
                 * the attributes in the screenbuf will be wrong.  The
                 * following resets all attributes to something sane.
                 */
                if (old_was_color != vc_cons[i].d->vc_can_do_color)
                        clear_buffer_attributes(i);

                if (IS_VISIBLE)
                        update_screen(i);
        }
        printk("Console: switching ");
        if (!deflt)
                printk("consoles %d-%d ", first+1, last+1);
        if (j >= 0)
                printk("to %s %s %dx%d\n",
                       vc_cons[j].d->vc_can_do_color ? "colour" : "mono",
                       desc, vc_cons[j].d->vc_cols, vc_cons[j].d->vc_rows);
        else
                printk("to %s\n", desc);
}

void give_up_console(const struct consw *csw)
{
        int i;

        for(i = 0; i < MAX_NR_CONSOLES; i++)
                if (con_driver_map[i] == csw)
                        con_driver_map[i] = NULL;
}

#endif

/*
 *      Screen blanking
 */

static void set_vesa_blanking(unsigned long arg)
{
        char *argp = (char *)arg + 1;
        unsigned int mode;
        if (get_user(mode, argp) == 0)
                vesa_blank_mode = (mode < 4) ? mode : 0;
}

/* We can't register the console with devfs during con_init(), because it
 * is called before kmalloc() works.  This function is called later to
 * do the registration.
 */
void __init con_init_devfs (void)
{
        int i;

        for (i = 0; i < console_driver.num; i++)
                tty_register_devfs (&console_driver, DEVFS_FL_AOPEN_NOTIFY,
                                    console_driver.minor_start + i);
}

/*
 * This is called by a timer handler
 */
static void vesa_powerdown(void)
{
    struct vc_data *c = vc_cons[fg_console].d;
    /*
     *  Power down if currently suspended (1 or 2),
     *  suspend if currently blanked (0),
     *  else do nothing (i.e. already powered down (3)).
     *  Called only if powerdown features are allowed.
     */
    switch (vesa_blank_mode) {
        case VESA_NO_BLANKING:
            c->vc_sw->con_blank(c, VESA_VSYNC_SUSPEND+1);
            break;
        case VESA_VSYNC_SUSPEND:
        case VESA_HSYNC_SUSPEND:
            c->vc_sw->con_blank(c, VESA_POWERDOWN+1);
            break;
    }
}

/*
 * This is a timer handler
 */
static void vesa_powerdown_screen(unsigned long dummy)
{
        console_timer.function = unblank_screen_t;

        vesa_powerdown();
}

static void timer_do_blank_screen(int entering_gfx, int from_timer_handler)
{
        int currcons = fg_console;
        int i;

        if (console_blanked)
                return;

        /* entering graphics mode? */
        if (entering_gfx) {
                hide_cursor(currcons);
                save_screen(currcons);
                sw->con_blank(vc_cons[currcons].d, -1);
                console_blanked = fg_console + 1;
                set_origin(currcons);
                return;
        }

        /* don't blank graphics */
        if (vcmode != KD_TEXT) {
                console_blanked = fg_console + 1;
                return;
        }

        hide_cursor(currcons);
        if (!from_timer_handler)
                del_timer_sync(&console_timer);
        if (vesa_off_interval) {
                console_timer.function = vesa_powerdown_screen;
                mod_timer(&console_timer, jiffies + vesa_off_interval);
        } else {
                if (!from_timer_handler)
                        del_timer_sync(&console_timer);
                console_timer.function = unblank_screen_t;
        }

        save_screen(currcons);
        /* In case we need to reset origin, blanking hook returns 1 */
        i = sw->con_blank(vc_cons[currcons].d, 1);
        console_blanked = fg_console + 1;
        if (i)
                set_origin(currcons);

        if (console_blank_hook && console_blank_hook(1))
                return;
        if (vesa_blank_mode)
                sw->con_blank(vc_cons[currcons].d, vesa_blank_mode + 1);
}

void do_blank_screen(int entering_gfx)
{
        timer_do_blank_screen(entering_gfx, 0);
}

/*
 * This is a timer handler
 */
static void unblank_screen_t(unsigned long dummy)
{
        unblank_screen();
}

/*
 * Called by timer as well as from vt_console_driver
 */
void unblank_screen(void)
{
        int currcons;

        if (!console_blanked)
                return;
        if (!vc_cons_allocated(fg_console)) {
                /* impossible */
                printk("unblank_screen: tty %d not allocated ??\n", fg_console+1);
                return;
        }
        currcons = fg_console;
        if (vcmode != KD_TEXT)
                return; /* but leave console_blanked != 0 */

        console_timer.function = blank_screen;
        if (blankinterval) {
                mod_timer(&console_timer, jiffies + blankinterval);
        }

        console_blanked = 0;
        if (console_blank_hook)
                console_blank_hook(0);
        set_palette(currcons);
        if (sw->con_blank(vc_cons[currcons].d, 0))
                /* Low-level driver cannot restore -> do it ourselves */
                update_screen(fg_console);
        set_cursor(fg_console);
}

/*
 * This is both a user-level callable and a timer handler
 */
static void blank_screen(unsigned long dummy)
{
        timer_do_blank_screen(0, 1);
}

void disable_console_blank(void)
{
        del_timer_sync(&console_timer);
        blankinterval = 0;
}

void poke_blanked_console(void)
{
        del_timer(&console_timer);
        if (!vt_cons[fg_console] || vt_cons[fg_console]->vc_mode == KD_GRAPHICS)
                return;
        if (console_blanked) {
                console_timer.function = unblank_screen_t;
                mod_timer(&console_timer, jiffies);     /* Now */
        } else if (blankinterval) {
                mod_timer(&console_timer, jiffies + blankinterval);
        }
}

/*
 *      Palettes
 */

void set_palette(int currcons)
{
        if (vcmode != KD_GRAPHICS)
                sw->con_set_palette(vc_cons[currcons].d, color_table);
}

static int set_get_cmap(unsigned char *arg, int set)
{
    int i, j, k;

    for (i = 0; i < 16; i++)
        if (set) {
            get_user(default_red[i], arg++);
            get_user(default_grn[i], arg++);
            get_user(default_blu[i], arg++);
        } else {
            put_user(default_red[i], arg++);
            put_user(default_grn[i], arg++);
            put_user(default_blu[i], arg++);
        }
    if (set) {
        for (i = 0; i < MAX_NR_CONSOLES; i++)
            if (vc_cons_allocated(i)) {
                for (j = k = 0; j < 16; j++) {
                    vc_cons[i].d->vc_palette[k++] = default_red[j];
                    vc_cons[i].d->vc_palette[k++] = default_grn[j];
                    vc_cons[i].d->vc_palette[k++] = default_blu[j];
                }
                set_palette(i);
            }
    }
    return 0;
}

/*
 * Load palette into the DAC registers. arg points to a colour
 * map, 3 bytes per colour, 16 colours, range from 0 to 255.
 */

int con_set_cmap(unsigned char *arg)
{
        return set_get_cmap (arg,1);
}

int con_get_cmap(unsigned char *arg)
{
        return set_get_cmap (arg,0);
}

void reset_palette(int currcons)
{
        int j, k;
        for (j=k=0; j<16; j++) {
                palette[k++] = default_red[j];
                palette[k++] = default_grn[j];
                palette[k++] = default_blu[j];
        }
        set_palette(currcons);
}

/*
 *  Font switching
 *
 *  Currently we only support fonts up to 32 pixels wide, at a maximum height
 *  of 32 pixels. Userspace fontdata is stored with 32 bytes (shorts/ints, 
 *  depending on width) reserved for each character which is kinda wasty, but 
 *  this is done in order to maintain compatibility with the EGA/VGA fonts. It 
 *  is upto the actual low-level console-driver convert data into its favorite
 *  format (maybe we should add a `fontoffset' field to the `display'
 *  structure so we wont have to convert the fontdata all the time.
 *  /Jes
 */

#define max_font_size 65536

int con_font_op(int currcons, struct console_font_op *op)
{
        int rc = -EINVAL;
        int size = max_font_size, set;
        u8 *temp = NULL;
        struct console_font_op old_op;

        if (vt_cons[currcons]->vc_mode != KD_TEXT)
                goto quit;
        memcpy(&old_op, op, sizeof(old_op));
        if (op->op == KD_FONT_OP_SET) {
                if (!op->data)
                        return -EINVAL;
                if (op->charcount > 512)
                        goto quit;
                if (!op->height) {              /* Need to guess font height [compat] */
                        int h, i;
                        u8 *charmap = op->data, tmp;
                        
                        /* If from KDFONTOP ioctl, don't allow things which can be done in userland,
                           so that we can get rid of this soon */
                        if (!(op->flags & KD_FONT_FLAG_OLD))
                                goto quit;
                        rc = -EFAULT;
                        for (h = 32; h > 0; h--)
                                for (i = 0; i < op->charcount; i++) {
                                        if (get_user(tmp, &charmap[32*i+h-1]))
                                                goto quit;
                                        if (tmp)
                                                goto nonzero;
                                }
                        rc = -EINVAL;
                        goto quit;
                nonzero:
                        rc = -EINVAL;
                        op->height = h;
                }
                if (op->width > 32 || op->height > 32)
                        goto quit;
                size = (op->width+7)/8 * 32 * op->charcount;
                if (size > max_font_size)
                        return -ENOSPC;
                set = 1;
        } else if (op->op == KD_FONT_OP_GET)
                set = 0;
        else
                return sw->con_font_op(vc_cons[currcons].d, op);
        if (op->data) {
                temp = kmalloc(size, GFP_KERNEL);
                if (!temp)
                        return -ENOMEM;
                if (set && copy_from_user(temp, op->data, size)) {
                        rc = -EFAULT;
                        goto quit;
                }
                op->data = temp;
        }

        acquire_console_sem();
        rc = sw->con_font_op(vc_cons[currcons].d, op);
        release_console_sem();

        op->data = old_op.data;
        if (!rc && !set) {
                int c = (op->width+7)/8 * 32 * op->charcount;
                
                if (op->data && op->charcount > old_op.charcount)
                        rc = -ENOSPC;
                if (!(op->flags & KD_FONT_FLAG_OLD)) {
                        if (op->width > old_op.width || 
                            op->height > old_op.height)
                                rc = -ENOSPC;
                } else {
                        if (op->width != 8)
                                rc = -EIO;
                        else if ((old_op.height && op->height > old_op.height) ||
                                 op->height > 32)
                                rc = -ENOSPC;
                }
                if (!rc && op->data && copy_to_user(op->data, temp, c))
                        rc = -EFAULT;
        }
quit:   if (temp)
                kfree(temp);
        return rc;
}

/*
 *      Interface exported to selection and vcs.
 */

/* used by selection */
u16 screen_glyph(int currcons, int offset)
{
        u16 w = scr_readw(screenpos(currcons, offset, 1));
        u16 c = w & 0xff;

        if (w & hi_font_mask)
                c |= 0x100;
        return c;
}

/* used by vcs - note the word offset */
unsigned short *screen_pos(int currcons, int w_offset, int viewed)
{
        return screenpos(currcons, 2 * w_offset, viewed);
}

void getconsxy(int currcons, char *p)
{
        p[0] = x;
        p[1] = y;
}

void putconsxy(int currcons, char *p)
{
        gotoxy(currcons, p[0], p[1]);