/*
   *  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>
   * 
   *   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
   *
   * Removed console_lock, enabled interrupts across all console operations
   * 13 March 2001, Andrew Morton
   *
   * Fixed UTF-8 mode so alternate charset modes always work according
   * to control sequences interpreted in do_con_trol function
   * preserving backward VT100 semigraphics compatibility,
   * malformed UTF sequences represented as sequences of replacement glyphs,
   * original codes or '?' as a last resort if replacement glyph is undefined
   * by Adam Tla/lka <atlka@pg.gda.pl>, Aug 2006
   */
  
  #include <linux/module.h>
  #include <linux/types.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/mutex.h>
  #include <linux/vt_kern.h>
  #include <linux/selection.h>
  #include <linux/tiocl.h>
  #include <linux/kbd_kern.h>
  #include <linux/consolemap.h>
  #include <linux/timer.h>
  #include <linux/interrupt.h>
  #include <linux/workqueue.h>
  #include <linux/pm.h>
  #include <linux/font.h>
  #include <linux/bitops.h>
  #include <linux/notifier.h>
  #include <linux/device.h>
  #include <linux/io.h>
  #include <linux/uaccess.h>
  #include <linux/kdb.h>
  #include <linux/ctype.h>
  
  #define MAX_NR_CON_DRIVER 16
  
  #define CON_DRIVER_FLAG_MODULE 1
  #define CON_DRIVER_FLAG_INIT   2
  #define CON_DRIVER_FLAG_ATTR   4
  
  struct con_driver {
  	const struct consw *con;
  	const char *desc;
  	struct device *dev;
  	int node;
  	int first;
  	int last;
  	int flag;
  };
  
  static struct con_driver registered_con_driver[MAX_NR_CON_DRIVER];
  const struct consw *conswitchp;
  
  /* 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)
  
  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(struct vc_data *vc, unsigned int rows,
  		    unsigned int cols, int do_clear);
  static void gotoxy(struct vc_data *vc, int new_x, int new_y);
  static void save_cur(struct vc_data *vc);
  static void reset_terminal(struct vc_data *vc, int do_clear);
  static void con_flush_chars(struct tty_struct *tty);
  static int set_vesa_blanking(char __user *p);
  static void set_cursor(struct vc_data *vc);
  static void hide_cursor(struct vc_data *vc);
  static void console_callback(struct work_struct *ignored);
  static void blank_screen_t(unsigned long dummy);
  static void set_palette(struct vc_data *vc);
  
  static int printable;		/* Is console ready for printing? */
  int default_utf8 = true;
  module_param(default_utf8, int, S_IRUGO | S_IWUSR);
  int global_cursor_default = -1;
  module_param(global_cursor_default, int, S_IRUGO | S_IWUSR);
  
  static int cur_default = CUR_DEFAULT;
  module_param(cur_default, int, S_IRUGO | S_IWUSR);
  
  /*
   * ignore_poke: don't unblank the screen when things are typed.  This is
   * mainly for the privacy of braille terminal users.
   */
  static int ignore_poke;
  
  int do_poke_blanked_console;
  int console_blanked;
  
  static int vesa_blank_mode; /* 0:none 1:suspendV 2:suspendH 3:powerdown */
  static int vesa_off_interval;
  static int blankinterval = 0;		// 10*60;
  core_param(consoleblank, blankinterval, int, 0444);
  
  static DECLARE_WORK(console_work, 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,
   * saved_* variants are for save/restore around kernel debugger enter/leave
   */
  int fg_console;
  int last_console;
  int want_console = -1;
  static int saved_fg_console;
  static int saved_last_console;
  static int saved_want_console;
  static int saved_vc_mode;
  static int saved_console_blanked;
  
  /*
   * 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 DEFINE_TIMER(console_timer, blank_screen_t, 0, 0);
  static int blank_state;
  static int blank_timer_expired;
  enum {
  	blank_off = 0,
  	blank_normal_wait,
  	blank_vesa_wait,
  };
  
  /*
   * /sys/class/tty/tty0/
   *
   * the attribute 'active' contains the name of the current vc
   * console and it supports poll() to detect vc switches
   */
  static struct device *tty0dev;
  
  /*
   * Notifier list for console events.
   */
  static ATOMIC_NOTIFIER_HEAD(vt_notifier_list);
  
  int register_vt_notifier(struct notifier_block *nb)
  {
  	return atomic_notifier_chain_register(&vt_notifier_list, nb);
  }
  EXPORT_SYMBOL_GPL(register_vt_notifier);
  
  int unregister_vt_notifier(struct notifier_block *nb)
  {
  	return atomic_notifier_chain_unregister(&vt_notifier_list, nb);
  }
  EXPORT_SYMBOL_GPL(unregister_vt_notifier);
  
  static void notify_write(struct vc_data *vc, unsigned int unicode)
  {
  	struct vt_notifier_param param = { .vc = vc, .c = unicode };
  	atomic_notifier_call_chain(&vt_notifier_list, VT_WRITE, &param);
  }
  
  static void notify_update(struct vc_data *vc)
  {
  	struct vt_notifier_param param = { .vc = vc };
  	atomic_notifier_call_chain(&vt_notifier_list, VT_UPDATE, &param);
  }
  /*
   *	Low-Level Functions
   */
  
  #define IS_FG(vc)	((vc)->vc_num == fg_console)
  
  #ifdef VT_BUF_VRAM_ONLY
  #define DO_UPDATE(vc)	0
  #else
  #define DO_UPDATE(vc)	(CON_IS_VISIBLE(vc) && !console_blanked)
  #endif
  
  static inline unsigned short *screenpos(struct vc_data *vc, int offset, int viewed)
  {
  	unsigned short *p;
  	
  	if (!viewed)
  		p = (unsigned short *)(vc->vc_origin + offset);
  	else if (!vc->vc_sw->con_screen_pos)
  		p = (unsigned short *)(vc->vc_visible_origin + offset);
  	else
  		p = vc->vc_sw->con_screen_pos(vc, offset);
  	return p;
  }
  
  /* Called  from the keyboard irq path.. */
  static inline void scrolldelta(int lines)
  {
  	/* FIXME */
  	/* scrolldelta needs some kind of consistency lock, but the BKL was
  	   and still is not protecting versus the scheduled back end */
  	scrollback_delta += lines;
  	schedule_console_callback();
  }
  
  void schedule_console_callback(void)
  {
  	schedule_work(&console_work);
  }
  
  static void scrup(struct vc_data *vc, unsigned int t, unsigned int b, int nr)
  {
  	unsigned short *d, *s;
  
  	if (t+nr >= b)
  		nr = b - t - 1;
  	if (b > vc->vc_rows || t >= b || nr < 1)
  		return;
  	if (CON_IS_VISIBLE(vc) && vc->vc_sw->con_scroll(vc, t, b, SM_UP, nr))
  		return;
  	d = (unsigned short *)(vc->vc_origin + vc->vc_size_row * t);
  	s = (unsigned short *)(vc->vc_origin + vc->vc_size_row * (t + nr));
  	scr_memmovew(d, s, (b - t - nr) * vc->vc_size_row);
  	scr_memsetw(d + (b - t - nr) * vc->vc_cols, vc->vc_video_erase_char,
  		    vc->vc_size_row * nr);
  }
  
  static void scrdown(struct vc_data *vc, unsigned int t, unsigned int b, int nr)
  {
  	unsigned short *s;
  	unsigned int step;
  
  	if (t+nr >= b)
  		nr = b - t - 1;
  	if (b > vc->vc_rows || t >= b || nr < 1)
  		return;
  	if (CON_IS_VISIBLE(vc) && vc->vc_sw->con_scroll(vc, t, b, SM_DOWN, nr))
  		return;
  	s = (unsigned short *)(vc->vc_origin + vc->vc_size_row * t);
  	step = vc->vc_cols * nr;
  	scr_memmovew(s + step, s, (b - t - nr) * vc->vc_size_row);
  	scr_memsetw(s, vc->vc_video_erase_char, 2 * step);
  }
  
  static void do_update_region(struct vc_data *vc, unsigned long start, int count)
  {
  #ifndef VT_BUF_VRAM_ONLY
  	unsigned int xx, yy, offset;
  	u16 *p;
  
  	p = (u16 *) start;
  	if (!vc->vc_sw->con_getxy) {
  		offset = (start - vc->vc_origin) / 2;
  		xx = offset % vc->vc_cols;
  		yy = offset / vc->vc_cols;
  	} else {
  		int nxx, nyy;
  		start = vc->vc_sw->con_getxy(vc, start, &nxx, &nyy);
  		xx = nxx; yy = nyy;
  	}
  	for(;;) {
  		u16 attrib = scr_readw(p) & 0xff00;
  		int startx = xx;
  		u16 *q = p;
  		while (xx < vc->vc_cols && count) {
  			if (attrib != (scr_readw(p) & 0xff00)) {
  				if (p > q)
  					vc->vc_sw->con_putcs(vc, q, p-q, yy, startx);
  				startx = xx;
  				q = p;
  				attrib = scr_readw(p) & 0xff00;
  			}
  			p++;
  			xx++;
  			count--;
  		}
  		if (p > q)
  			vc->vc_sw->con_putcs(vc, q, p-q, yy, startx);
  		if (!count)
  			break;
  		xx = 0;
  		yy++;
  		if (vc->vc_sw->con_getxy) {
  			p = (u16 *)start;
  			start = vc->vc_sw->con_getxy(vc, start, NULL, NULL);
  		}
  	}
  #endif
  }
  
  void update_region(struct vc_data *vc, unsigned long start, int count)
  {
  	WARN_CONSOLE_UNLOCKED();
  
  	if (DO_UPDATE(vc)) {
  		hide_cursor(vc);
  		do_update_region(vc, start, count);
  		set_cursor(vc);
  	}
  }
  
  /* Structure of attributes is hardware-dependent */
  
  static u8 build_attr(struct vc_data *vc, u8 _color, u8 _intensity, u8 _blink,
      u8 _underline, u8 _reverse, u8 _italic)
  {
  	if (vc->vc_sw->con_build_attr)
  		return vc->vc_sw->con_build_attr(vc, _color, _intensity,
  		       _blink, _underline, _reverse, _italic);
  
  #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 (!vc->vc_can_do_color)
  		return _intensity |
  		       (_italic ? 2 : 0) |
  		       (_underline ? 4 : 0) |
  		       (_reverse ? 8 : 0) |
  		       (_blink ? 0x80 : 0);
  	if (_italic)
  		a = (a & 0xF0) | vc->vc_itcolor;
  	else if (_underline)
  		a = (a & 0xf0) | vc->vc_ulcolor;
  	else if (_intensity == 0)
  		a = (a & 0xf0) | vc->vc_ulcolor;
  	if (_reverse)
  		a = ((a) & 0x88) | ((((a) >> 4) | ((a) << 4)) & 0x77);
  	if (_blink)
  		a ^= 0x80;
  	if (_intensity == 2)
  		a ^= 0x08;
  	if (vc->vc_hi_font_mask == 0x100)
  		a <<= 1;
  	return a;
  	}
  #else
  	return 0;
  #endif
  }
  
  static void update_attr(struct vc_data *vc)
  {
  	vc->vc_attr = build_attr(vc, vc->vc_color, vc->vc_intensity,
  	              vc->vc_blink, vc->vc_underline,
  	              vc->vc_reverse ^ vc->vc_decscnm, vc->vc_italic);
  	vc->vc_video_erase_char = (build_attr(vc, vc->vc_color, 1, vc->vc_blink, 0, vc->vc_decscnm, 0) << 8) | ' ';
  }
  
  /* Note: inverting the screen twice should revert to the original state */
  void invert_screen(struct vc_data *vc, int offset, int count, int viewed)
  {
  	unsigned short *p;
  
  	WARN_CONSOLE_UNLOCKED();
  
  	count /= 2;
  	p = screenpos(vc, offset, viewed);
  	if (vc->vc_sw->con_invert_region)
  		vc->vc_sw->con_invert_region(vc, p, count);
  #ifndef VT_BUF_VRAM_ONLY
  	else {
  		u16 *q = p;
  		int cnt = count;
  		u16 a;
  
  		if (!vc->vc_can_do_color) {
  			while (cnt--) {
  			    a = scr_readw(q);
  			    a ^= 0x0800;
  			    scr_writew(a, q);
  			    q++;
  			}
  		} else if (vc->vc_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(vc))
  		do_update_region(vc, (unsigned long) p, count);
  }
  
  /* used by selection: complement pointer position */
  void complement_pos(struct vc_data *vc, int offset)
  {
  	static int old_offset = -1;
  	static unsigned short old;
  	static unsigned short oldx, oldy;
  
  	WARN_CONSOLE_UNLOCKED();
  
  	if (old_offset != -1 && old_offset >= 0 &&
  	    old_offset < vc->vc_screenbuf_size) {
  		scr_writew(old, screenpos(vc, old_offset, 1));
  		if (DO_UPDATE(vc))
  			vc->vc_sw->con_putc(vc, old, oldy, oldx);
  	}
  
  	old_offset = offset;
  
  	if (offset != -1 && offset >= 0 &&
  	    offset < vc->vc_screenbuf_size) {
  		unsigned short new;
  		unsigned short *p;
  		p = screenpos(vc, offset, 1);
  		old = scr_readw(p);
  		new = old ^ vc->vc_complement_mask;
  		scr_writew(new, p);
  		if (DO_UPDATE(vc)) {
  			oldx = (offset >> 1) % vc->vc_cols;
  			oldy = (offset >> 1) / vc->vc_cols;
  			vc->vc_sw->con_putc(vc, new, oldy, oldx);
  		}
  	}
  
  }
  
  static void insert_char(struct vc_data *vc, unsigned int nr)
  {
  	unsigned short *p = (unsigned short *) vc->vc_pos;
  
  	scr_memmovew(p + nr, p, (vc->vc_cols - vc->vc_x - nr) * 2);
  	scr_memsetw(p, vc->vc_video_erase_char, nr * 2);
  	vc->vc_need_wrap = 0;
  	if (DO_UPDATE(vc))
  		do_update_region(vc, (unsigned long) p,
  			vc->vc_cols - vc->vc_x);
  }
  
  static void delete_char(struct vc_data *vc, unsigned int nr)
  {
  	unsigned short *p = (unsigned short *) vc->vc_pos;
  
  	scr_memcpyw(p, p + nr, (vc->vc_cols - vc->vc_x - nr) * 2);
  	scr_memsetw(p + vc->vc_cols - vc->vc_x - nr, vc->vc_video_erase_char,
  			nr * 2);
  	vc->vc_need_wrap = 0;
  	if (DO_UPDATE(vc))
  		do_update_region(vc, (unsigned long) p,
  			vc->vc_cols - vc->vc_x);
  }
  
  static int softcursor_original;
  
  static void add_softcursor(struct vc_data *vc)
  {
  	int i = scr_readw((u16 *) vc->vc_pos);
  	u32 type = vc->vc_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 *) vc->vc_pos);
  	if (DO_UPDATE(vc))
  		vc->vc_sw->con_putc(vc, i, vc->vc_y, vc->vc_x);
  }
  
  static void hide_softcursor(struct vc_data *vc)
  {
  	if (softcursor_original != -1) {
  		scr_writew(softcursor_original, (u16 *)vc->vc_pos);
  		if (DO_UPDATE(vc))
  			vc->vc_sw->con_putc(vc, softcursor_original,
  					vc->vc_y, vc->vc_x);
  		softcursor_original = -1;
  	}
  }
  
  static void hide_cursor(struct vc_data *vc)
  {
  	if (vc == sel_cons)
  		clear_selection();
  	vc->vc_sw->con_cursor(vc, CM_ERASE);
  	hide_softcursor(vc);
  }
  
  static void set_cursor(struct vc_data *vc)
  {
  	if (!IS_FG(vc) || console_blanked ||
  	    vc->vc_mode == KD_GRAPHICS)
  		return;
  	if (vc->vc_deccm) {
  		if (vc == sel_cons)
  			clear_selection();
  		add_softcursor(vc);
  		if ((vc->vc_cursor_type & 0x0f) != 1)
  			vc->vc_sw->con_cursor(vc, CM_DRAW);
  	} else
  		hide_cursor(vc);
  }
  
  static void set_origin(struct vc_data *vc)
  {
  	WARN_CONSOLE_UNLOCKED();
  
  	if (!CON_IS_VISIBLE(vc) ||
  	    !vc->vc_sw->con_set_origin ||
  	    !vc->vc_sw->con_set_origin(vc))
  		vc->vc_origin = (unsigned long)vc->vc_screenbuf;
  	vc->vc_visible_origin = vc->vc_origin;
  	vc->vc_scr_end = vc->vc_origin + vc->vc_screenbuf_size;
  	vc->vc_pos = vc->vc_origin + vc->vc_size_row * vc->vc_y + 2 * vc->vc_x;
  }
  
  static inline void save_screen(struct vc_data *vc)
  {
  	WARN_CONSOLE_UNLOCKED();
  
  	if (vc->vc_sw->con_save_screen)
  		vc->vc_sw->con_save_screen(vc);
  }
  
  /*
   *	Redrawing of screen
   */
  
  void clear_buffer_attributes(struct vc_data *vc)
  {
  	unsigned short *p = (unsigned short *)vc->vc_origin;
  	int count = vc->vc_screenbuf_size / 2;
  	int mask = vc->vc_hi_font_mask | 0xff;
  
  	for (; count > 0; count--, p++) {
  		scr_writew((scr_readw(p)&mask) | (vc->vc_video_erase_char & ~mask), p);
  	}
  }
  
  void redraw_screen(struct vc_data *vc, int is_switch)
  {
  	int redraw = 0;
  
  	WARN_CONSOLE_UNLOCKED();
  
  	if (!vc) {
  		/* strange ... */
  		/* printk("redraw_screen: tty %d not allocated ??
  ", new_console+1); */
  		return;
  	}
  
  	if (is_switch) {
  		struct vc_data *old_vc = vc_cons[fg_console].d;
  		if (old_vc == vc)
  			return;
  		if (!CON_IS_VISIBLE(vc))
  			redraw = 1;
  		*vc->vc_display_fg = vc;
  		fg_console = vc->vc_num;
  		hide_cursor(old_vc);
  		if (!CON_IS_VISIBLE(old_vc)) {
  			save_screen(old_vc);
  			set_origin(old_vc);
  		}
  		if (tty0dev)
  			sysfs_notify(&tty0dev->kobj, NULL, "active");
  	} else {
  		hide_cursor(vc);
  		redraw = 1;
  	}
  
  	if (redraw) {
  		int update;
  		int old_was_color = vc->vc_can_do_color;
  
  		set_origin(vc);
  		update = vc->vc_sw->con_switch(vc);
  		set_palette(vc);
  		/*
  		 * If console changed from mono<->color, the best we can do
  		 * is to clear the buffer attributes. As it currently stands,
  		 * rebuilding new attributes from the old buffer is not doable
  		 * without overly complex code.
  		 */
  		if (old_was_color != vc->vc_can_do_color) {
  			update_attr(vc);
  			clear_buffer_attributes(vc);
  		}
  
  		/* Forcibly update if we're panicing */
  		if ((update && vc->vc_mode != KD_GRAPHICS) ||
  		    vt_force_oops_output(vc))
  			do_update_region(vc, vc->vc_origin, vc->vc_screenbuf_size / 2);
  	}
  	set_cursor(vc);
  	if (is_switch) {
  		set_leds();
  		compute_shiftstate();
  		notify_update(vc);
  	}
  }
  
  /*
   *	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(struct vc_data *vc, int num, int init)
  {
  	/* ++Geert: vc->vc_sw->con_init determines console size */
  	if (vc->vc_sw)
  		module_put(vc->vc_sw->owner);
  	vc->vc_sw = conswitchp;
  #ifndef VT_SINGLE_DRIVER
  	if (con_driver_map[num])
  		vc->vc_sw = con_driver_map[num];
  #endif
  	__module_get(vc->vc_sw->owner);
  	vc->vc_num = num;
  	vc->vc_display_fg = &master_display_fg;
  	vc->vc_uni_pagedir_loc = &vc->vc_uni_pagedir;
  	vc->vc_uni_pagedir = 0;
  	vc->vc_hi_font_mask = 0;
  	vc->vc_complement_mask = 0;
  	vc->vc_can_do_color = 0;
  	vc->vc_panic_force_write = false;
  	vc->vc_sw->con_init(vc, init);
  	if (!vc->vc_complement_mask)
  		vc->vc_complement_mask = vc->vc_can_do_color ? 0x7700 : 0x0800;
  	vc->vc_s_complement_mask = vc->vc_complement_mask;
  	vc->vc_size_row = vc->vc_cols << 1;
  	vc->vc_screenbuf_size = vc->vc_rows * vc->vc_size_row;
  }
  
  int vc_allocate(unsigned int currcons)	/* return 0 on success */
  {
  	WARN_CONSOLE_UNLOCKED();
  
  	if (currcons >= MAX_NR_CONSOLES)
  		return -ENXIO;
  	if (!vc_cons[currcons].d) {
  	    struct vc_data *vc;
  	    struct vt_notifier_param param;
  
  	    /* 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 */
  	    param.vc = vc = kzalloc(sizeof(struct vc_data), GFP_KERNEL);
  	    if (!vc)
  		return -ENOMEM;
  	    vc_cons[currcons].d = vc;
  	    tty_port_init(&vc->port);
  	    INIT_WORK(&vc_cons[currcons].SAK_work, vc_SAK);
  	    visual_init(vc, currcons, 1);
  	    if (!*vc->vc_uni_pagedir_loc)
  		con_set_default_unimap(vc);
  	    vc->vc_screenbuf = kmalloc(vc->vc_screenbuf_size, GFP_KERNEL);
  	    if (!vc->vc_screenbuf) {
  		kfree(vc);
  		vc_cons[currcons].d = NULL;
  		return -ENOMEM;
  	    }
  
  	    /* If no drivers have overridden us and the user didn't pass a
  	       boot option, default to displaying the cursor */
  	    if (global_cursor_default == -1)
  		    global_cursor_default = 1;
  
  	    vc_init(vc, vc->vc_rows, vc->vc_cols, 1);
  	    vcs_make_sysfs(currcons);
  	    atomic_notifier_call_chain(&vt_notifier_list, VT_ALLOCATE, &param);
  	}
  	return 0;
  }
  
  static inline int resize_screen(struct vc_data *vc, int width, int height,
  				int user)
  {
  	/* Resizes the resolution of the display adapater */
  	int err = 0;
  
  	if (vc->vc_mode != KD_GRAPHICS && vc->vc_sw->con_resize)
  		err = vc->vc_sw->con_resize(vc, width, height, user);
  
  	return err;
  }
  
  /*
   * 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]
   */
  #define VC_RESIZE_MAXCOL (32767)
  #define VC_RESIZE_MAXROW (32767)
  
  /**
   *	vc_do_resize	-	resizing method for the tty
   *	@tty: tty being resized
   *	@real_tty: real tty (different to tty if a pty/tty pair)
   *	@vc: virtual console private data
   *	@cols: columns
   *	@lines: lines
   *
   *	Resize a virtual console, clipping according to the actual constraints.
   *	If the caller passes a tty structure then update the termios winsize
   *	information and perform any necessary signal handling.
   *
   *	Caller must hold the console semaphore. Takes the termios rwsem and
   *	ctrl_lock of the tty IFF a tty is passed.
   */
  
  static int vc_do_resize(struct tty_struct *tty, struct vc_data *vc,
  				unsigned int cols, unsigned int lines)
  {
  	unsigned long old_origin, new_origin, new_scr_end, rlth, rrem, err = 0;
  	unsigned long end;
  	unsigned int old_rows, old_row_size;
  	unsigned int new_cols, new_rows, new_row_size, new_screen_size;
  	unsigned int user;
  	unsigned short *newscreen;
  
  	WARN_CONSOLE_UNLOCKED();
  
  	if (!vc)
  		return -ENXIO;
  
  	user = vc->vc_resize_user;
  	vc->vc_resize_user = 0;
  
  	if (cols > VC_RESIZE_MAXCOL || lines > VC_RESIZE_MAXROW)
  		return -EINVAL;
  
  	new_cols = (cols ? cols : vc->vc_cols);
  	new_rows = (lines ? lines : vc->vc_rows);
  	new_row_size = new_cols << 1;
  	new_screen_size = new_row_size * new_rows;
  
  	if (new_cols == vc->vc_cols && new_rows == vc->vc_rows)
  		return 0;
  
  	newscreen = kmalloc(new_screen_size, GFP_USER);
  	if (!newscreen)
  		return -ENOMEM;
  
  	old_rows = vc->vc_rows;
  	old_row_size = vc->vc_size_row;
  
  	err = resize_screen(vc, new_cols, new_rows, user);
  	if (err) {
  		kfree(newscreen);
  		return err;
  	}
  
  	vc->vc_rows = new_rows;
  	vc->vc_cols = new_cols;
  	vc->vc_size_row = new_row_size;
  	vc->vc_screenbuf_size = new_screen_size;
  
  	rlth = min(old_row_size, new_row_size);
  	rrem = new_row_size - rlth;
  	old_origin = vc->vc_origin;
  	new_origin = (long) newscreen;
  	new_scr_end = new_origin + new_screen_size;
  
  	if (vc->vc_y > new_rows) {
  		if (old_rows - vc->vc_y < new_rows) {
  			/*
  			 * Cursor near the bottom, copy contents from the
  			 * bottom of buffer
  			 */
  			old_origin += (old_rows - new_rows) * old_row_size;
  		} else {
  			/*
  			 * Cursor is in no man's land, copy 1/2 screenful
  			 * from the top and bottom of cursor position
  			 */
  			old_origin += (vc->vc_y - new_rows/2) * old_row_size;
  		}
  	}
  
  	end = old_origin + old_row_size * min(old_rows, new_rows);
  
  	update_attr(vc);
  
  	while (old_origin < end) {
  		scr_memcpyw((unsigned short *) new_origin,
  			    (unsigned short *) old_origin, rlth);
  		if (rrem)
  			scr_memsetw((void *)(new_origin + rlth),
  				    vc->vc_video_erase_char, rrem);
  		old_origin += old_row_size;
  		new_origin += new_row_size;
  	}
  	if (new_scr_end > new_origin)
  		scr_memsetw((void *)new_origin, vc->vc_video_erase_char,
  			    new_scr_end - new_origin);
  	kfree(vc->vc_screenbuf);
  	vc->vc_screenbuf = newscreen;
  	vc->vc_screenbuf_size = new_screen_size;
  	set_origin(vc);
  
  	/* do part of a reset_terminal() */
  	vc->vc_top = 0;
  	vc->vc_bottom = vc->vc_rows;
  	gotoxy(vc, vc->vc_x, vc->vc_y);
  	save_cur(vc);
  
  	if (tty) {
  		/* Rewrite the requested winsize data with the actual
  		   resulting sizes */
  		struct winsize ws;
  		memset(&ws, 0, sizeof(ws));
  		ws.ws_row = vc->vc_rows;
  		ws.ws_col = vc->vc_cols;
  		ws.ws_ypixel = vc->vc_scan_lines;
  		tty_do_resize(tty, &ws);
  	}
  
  	if (CON_IS_VISIBLE(vc))
  		update_screen(vc);
  	vt_event_post(VT_EVENT_RESIZE, vc->vc_num, vc->vc_num);
  	return err;
  }
  
  /**
   *	vc_resize		-	resize a VT
   *	@vc: virtual console
   *	@cols: columns
   *	@rows: rows
   *
   *	Resize a virtual console as seen from the console end of things. We
   *	use the common vc_do_resize methods to update the structures. The
   *	caller must hold the console sem to protect console internals and
   *	vc->port.tty
   */
  
  int vc_resize(struct vc_data *vc, unsigned int cols, unsigned int rows)
  {
  	return vc_do_resize(vc->port.tty, vc, cols, rows);
  }
  
  /**
   *	vt_resize		-	resize a VT
   *	@tty: tty to resize
   *	@ws: winsize attributes
   *
   *	Resize a virtual terminal. This is called by the tty layer as we
   *	register our own handler for resizing. The mutual helper does all
   *	the actual work.
   *
   *	Takes the console sem and the called methods then take the tty
   *	termios_rwsem and the tty ctrl_lock in that order.
   */
  static int vt_resize(struct tty_struct *tty, struct winsize *ws)
  {
  	struct vc_data *vc = tty->driver_data;
  	int ret;
  
  	console_lock();
  	ret = vc_do_resize(tty, vc, ws->ws_col, ws->ws_row);
  	console_unlock();
  	return ret;
  }
  
  struct vc_data *vc_deallocate(unsigned int currcons)
  {
  	struct vc_data *vc = NULL;
  
  	WARN_CONSOLE_UNLOCKED();
  
  	if (vc_cons_allocated(currcons)) {
  		struct vt_notifier_param param;
  
  		param.vc = vc = vc_cons[currcons].d;
  		atomic_notifier_call_chain(&vt_notifier_list, VT_DEALLOCATE, &param);
  		vcs_remove_sysfs(currcons);
  		vc->vc_sw->con_deinit(vc);
  		put_pid(vc->vt_pid);
  		module_put(vc->vc_sw->owner);
  		kfree(vc->vc_screenbuf);
  		vc_cons[currcons].d = NULL;
  	}
  	return vc;
  }
  
  /*
   *	VT102 emulator
   */
  
  #define set_kbd(vc, x)	vt_set_kbd_mode_bit((vc)->vc_num, (x))
  #define clr_kbd(vc, x)	vt_clr_kbd_mode_bit((vc)->vc_num, (x))
  #define is_kbd(vc, x)	vt_get_kbd_mode_bit((vc)->vc_num, (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};
  
  module_param_array(default_red, int, NULL, S_IRUGO | S_IWUSR);
  module_param_array(default_grn, int, NULL, S_IRUGO | S_IWUSR);
  module_param_array(default_blu, int, NULL, S_IRUGO | S_IWUSR);
  
  /*
   * 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(struct vc_data *vc, int new_x, int new_y)
  {
  	int min_y, max_y;
  
  	if (new_x < 0)
  		vc->vc_x = 0;
  	else {
  		if (new_x >= vc->vc_cols)
  			vc->vc_x = vc->vc_cols - 1;
  		else
  			vc->vc_x = new_x;
  	}
  
   	if (vc->vc_decom) {
  		min_y = vc->vc_top;
  		max_y = vc->vc_bottom;
  	} else {
  		min_y = 0;
  		max_y = vc->vc_rows;
  	}
  	if (new_y < min_y)
  		vc->vc_y = min_y;
  	else if (new_y >= max_y)
  		vc->vc_y = max_y - 1;
  	else
  		vc->vc_y = new_y;
  	vc->vc_pos = vc->vc_origin + vc->vc_y * vc->vc_size_row + (vc->vc_x<<1);
  	vc->vc_need_wrap = 0;
  }
  
  /* for absolute user moves, when decom is set */
  static void gotoxay(struct vc_data *vc, int new_x, int new_y)
  {
  	gotoxy(vc, new_x, vc->vc_decom ? (vc->vc_top + new_y) : new_y);
  }
  
  void scrollback(struct vc_data *vc, int lines)
  {
  	if (!lines)
  		lines = vc->vc_rows / 2;
  	scrolldelta(-lines);
  }
  
  void scrollfront(struct vc_data *vc, int lines)
  {
  	if (!lines)
  		lines = vc->vc_rows / 2;
  	scrolldelta(lines);
  }
  
  static void lf(struct vc_data *vc)
  {
      	/* don't scroll if above bottom of scrolling region, or
  	 * if below scrolling region
  	 */
      	if (vc->vc_y + 1 == vc->vc_bottom)
  		scrup(vc, vc->vc_top, vc->vc_bottom, 1);
  	else if (vc->vc_y < vc->vc_rows - 1) {
  	    	vc->vc_y++;
  		vc->vc_pos += vc->vc_size_row;
  	}
  	vc->vc_need_wrap = 0;
  	notify_write(vc, '
  ');
  }
  
  static void ri(struct vc_data *vc)
  {
      	/* don't scroll if below top of scrolling region, or
  	 * if above scrolling region
  	 */
  	if (vc->vc_y == vc->vc_top)
  		scrdown(vc, vc->vc_top, vc->vc_bottom, 1);
  	else if (vc->vc_y > 0) {
  		vc->vc_y--;
  		vc->vc_pos -= vc->vc_size_row;
  	}
  	vc->vc_need_wrap = 0;
  }
  
  static inline void cr(struct vc_data *vc)
  {
  	vc->vc_pos -= vc->vc_x << 1;
  	vc->vc_need_wrap = vc->vc_x = 0;
  	notify_write(vc, '\r');
  }
  
  static inline void bs(struct vc_data *vc)
  {
  	if (vc->vc_x) {
  		vc->vc_pos -= 2;
  		vc->vc_x--;
  		vc->vc_need_wrap = 0;
  		notify_write(vc, '\b');
  	}
  }
  
  static inline void del(struct vc_data *vc)
  {
  	/* ignored */
  }
  
  static void csi_J(struct vc_data *vc, int vpar)
  {
  	unsigned int count;
  	unsigned short * start;
  
  	switch (vpar) {
  		case 0:	/* erase from cursor to end of display */
  			count = (vc->vc_scr_end - vc->vc_pos) >> 1;
  			start = (unsigned short *)vc->vc_pos;
  			break;
  		case 1:	/* erase from start to cursor */
  			count = ((vc->vc_pos - vc->vc_origin) >> 1) + 1;
  			start = (unsigned short *)vc->vc_origin;
  			break;
  		case 3: /* erase scroll-back buffer (and whole display) */
  			scr_memsetw(vc->vc_screenbuf, vc->vc_video_erase_char,
  				    vc->vc_screenbuf_size >> 1);
  			set_origin(vc);
  			if (CON_IS_VISIBLE(vc))
  				update_screen(vc);
  			/* fall through */
  		case 2: /* erase whole display */
  			count = vc->vc_cols * vc->vc_rows;
  			start = (unsigned short *)vc->vc_origin;
  			break;
  		default:
  			return;
  	}
  	scr_memsetw(start, vc->vc_video_erase_char, 2 * count);
  	if (DO_UPDATE(vc))
  		do_update_region(vc, (unsigned long) start, count);
  	vc->vc_need_wrap = 0;
  }
  
  static void csi_K(struct vc_data *vc, int vpar)
  {
  	unsigned int count;
  	unsigned short * start;
  
  	switch (vpar) {
  		case 0:	/* erase from cursor to end of line */
  			count = vc->vc_cols - vc->vc_x;
  			start = (unsigned short *)vc->vc_pos;
  			break;
  		case 1:	/* erase from start of line to cursor */
  			start = (unsigned short *)(vc->vc_pos - (vc->vc_x << 1));
  			count = vc->vc_x + 1;
  			break;
  		case 2: /* erase whole line */
  			start = (unsigned short *)(vc->vc_pos - (vc->vc_x << 1));
  			count = vc->vc_cols;
  			break;
  		default:
  			return;
  	}
  	scr_memsetw(start, vc->vc_video_erase_char, 2 * count);
  	vc->vc_need_wrap = 0;
  	if (DO_UPDATE(vc))
  		do_update_region(vc, (unsigned long) start, count);
  }
  
  static void csi_X(struct vc_data *vc, int vpar) /* erase the following vpar positions */
  {					  /* not vt100? */
  	int count;
  
  	if (!vpar)
  		vpar++;
  	count = (vpar > vc->vc_cols - vc->vc_x) ? (vc->vc_cols - vc->vc_x) : vpar;
  
  	scr_memsetw((unsigned short *)vc->vc_pos, vc->vc_video_erase_char, 2 * count);
  	if (DO_UPDATE(vc))
  		vc->vc_sw->con_clear(vc, vc->vc_y, vc->vc_x, 1, count);
  	vc->vc_need_wrap = 0;
  }
  
  static void default_attr(struct vc_data *vc)
  {
  	vc->vc_intensity = 1;
  	vc->vc_italic = 0;
  	vc->vc_underline = 0;
  	vc->vc_reverse = 0;
  	vc->vc_blink = 0;
  	vc->vc_color = vc->vc_def_color;
  }
  
  /* console_lock is held */
  static void csi_m(struct vc_data *vc)
  {
  	int i;
  
  	for (i = 0; i <= vc->vc_npar; i++)
  		switch (vc->vc_par[i]) {
  			case 0:	/* all attributes off */
  				default_attr(vc);
  				break;
  			case 1:
  				vc->vc_intensity = 2;
  				break;
  			case 2:
  				vc->vc_intensity = 0;
  				break;
  			case 3:
  				vc->vc_italic = 1;
  				break;
  			case 4:
  				vc->vc_underline = 1;
  				break;
  			case 5:
  				vc->vc_blink = 1;
  				break;
  			case 7:
  				vc->vc_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.
  				  */
  				vc->vc_translate = set_translate(vc->vc_charset == 0
  						? vc->vc_G0_charset
  						: vc->vc_G1_charset, vc);
  				vc->vc_disp_ctrl = 0;
  				vc->vc_toggle_meta = 0;
  				break;
  			case 11: /* ANSI X3.64-1979 (SCO-ish?)
  				  * Select first alternate font, lets
  				  * chars < 32 be displayed as ROM chars.
  				  */
  				vc->vc_translate = set_translate(IBMPC_MAP, vc);
  				vc->vc_disp_ctrl = 1;
  				vc->vc_toggle_meta = 0;
  				break;
  			case 12: /* ANSI X3.64-1979 (SCO-ish?)
  				  * Select second alternate font, toggle
  				  * high bit before displaying as ROM char.
  				  */
  				vc->vc_translate = set_translate(IBMPC_MAP, vc);
  				vc->vc_disp_ctrl = 1;
  				vc->vc_toggle_meta = 1;
  				break;
  			case 21:
  			case 22:
  				vc->vc_intensity = 1;
  				break;
  			case 23:
  				vc->vc_italic = 0;
  				break;
  			case 24:
  				vc->vc_underline = 0;
  				break;
  			case 25:
  				vc->vc_blink = 0;
  				break;
  			case 27:
  				vc->vc_reverse = 0;
  				break;
  			case 38:
  			case 48: /* ITU T.416
  				  * Higher colour modes.
  				  * They break the usual properties of SGR codes
  				  * and thus need to be detected and ignored by
  				  * hand.  Strictly speaking, that standard also
  				  * wants : rather than ; as separators, contrary
  				  * to ECMA-48, but no one produces such codes
  				  * and almost no one accepts them.
  				  */
  				i++;
  				if (i > vc->vc_npar)
  					break;
  				if (vc->vc_par[i] == 5)      /* 256 colours */
  					i++;                 /* ubiquitous */
  				else if (vc->vc_par[i] == 2) /* 24 bit colours */
  					i += 3;              /* extremely rare */
  				/* Subcommands 3 (CMY) and 4 (CMYK) are so insane
  				 * that detecting them is not worth the few extra
  				 * bytes of kernel's size.
  				 */
  				break;
  			case 39:
  				vc->vc_color = (vc->vc_def_color & 0x0f) | (vc->vc_color & 0xf0);
  				break;
  			case 49:
  				vc->vc_color = (vc->vc_def_color & 0xf0) | (vc->vc_color & 0x0f);
  				break;
  			default:
  				if (vc->vc_par[i] >= 30 && vc->vc_par[i] <= 37)
  					vc->vc_color = color_table[vc->vc_par[i] - 30]
  						| (vc->vc_color & 0xf0);
  				else if (vc->vc_par[i] >= 40 && vc->vc_par[i] <= 47)
  					vc->vc_color = (color_table[vc->vc_par[i] - 40] << 4)
  						| (vc->vc_color & 0x0f);
  				break;
  		}
  	update_attr(vc);
  }
  
  static void respond_string(const char *p, struct tty_port *port)
  {
  	while (*p) {
  		tty_insert_flip_char(port, *p, 0);
  		p++;
  	}
  	tty_schedule_flip(port);
  }
  
  static void cursor_report(struct vc_data *vc, struct tty_struct *tty)
  {
  	char buf[40];
  
  	sprintf(buf, "\033[%d;%dR", vc->vc_y + (vc->vc_decom ? vc->vc_top + 1 : 1), vc->vc_x + 1);
  	respond_string(buf, tty->port);
  }
  
  static inline void status_report(struct tty_struct *tty)
  {
  	respond_string("\033[0n", tty->port);	/* Terminal ok */
  }
  
  static inline void respond_ID(struct tty_struct *tty)
  {
  	respond_string(VT102ID, tty->port);
  }
  
  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->port);
  }
  
  /* invoked via ioctl(TIOCLINUX) and through set_selection */
  int mouse_reporting(void)
  {
  	return vc_cons[fg_console].d->vc_report_mouse;
  }
  
  /* console_lock is held */
  static void set_mode(struct vc_data *vc, int on_off)
  {
  	int i;
  
  	for (i = 0; i <= vc->vc_npar; i++)
  		if (vc->vc_ques) {
  			switch(vc->vc_par[i]) {	/* DEC private modes set/reset */
  			case 1:			/* Cursor keys send ^[Ox/^[[x */
  				if (on_off)
  					set_kbd(vc, decckm);
  				else
  					clr_kbd(vc, decckm);
  				break;
  			case 3:	/* 80/132 mode switch unimplemented */
  				vc->vc_deccolm = on_off;
  #if 0
  				vc_resize(deccolm ? 132 : 80, vc->vc_rows);
  				/* this alone does not suffice; some user mode
  				   utility has to change the hardware regs */
  #endif
  				break;
  			case 5:			/* Inverted screen on/off */
  				if (vc->vc_decscnm != on_off) {
  					vc->vc_decscnm = on_off;
  					invert_screen(vc, 0, vc->vc_screenbuf_size, 0);
  					update_attr(vc);
  				}
  				break;
  			case 6:			/* Origin relative/absolute */
  				vc->vc_decom = on_off;
  				gotoxay(vc, 0, 0);
  				break;
  			case 7:			/* Autowrap on/off */
  				vc->vc_decawm = on_off;
  				break;
  			case 8:			/* Autorepeat on/off */
  				if (on_off)
  					set_kbd(vc, decarm);
  				else
  					clr_kbd(vc, decarm);
  				break;
  			case 9:
  				vc->vc_report_mouse = on_off ? 1 : 0;
  				break;
  			case 25:		/* Cursor on/off */
  				vc->vc_deccm = on_off;
  				break;
  			case 1000:
  				vc->vc_report_mouse = on_off ? 2 : 0;
  				break;
  			}
  		} else {
  			switch(vc->vc_par[i]) {	/* ANSI modes set/reset */
  			case 3:			/* Monitor (display ctrls) */
  				vc->vc_disp_ctrl = on_off;
  				break;
  			case 4:			/* Insert Mode on/off */
  				vc->vc_decim = on_off;
  				break;
  			case 20:		/* Lf, Enter == CrLf/Lf */
  				if (on_off)
  					set_kbd(vc, lnm);
  				else
  					clr_kbd(vc, lnm);
  				break;
  			}
  		}
  }
  
  /* console_lock is held */
  static void setterm_command(struct vc_data *vc)
  {
  	switch(vc->vc_par[0]) {
  		case 1:	/* set color for underline mode */
  			if (vc->vc_can_do_color &&
  					vc->vc_par[1] < 16) {
  				vc->vc_ulcolor = color_table[vc->vc_par[1]];
  				if (vc->vc_underline)
  					update_attr(vc);
  			}
  			break;
  		case 2:	/* set color for half intensity mode */
  			if (vc->vc_can_do_color &&
  					vc->vc_par[1] < 16) {
  				vc->vc_halfcolor = color_table[vc->vc_par[1]];
  				if (vc->vc_intensity == 0)
  					update_attr(vc);
  			}
  			break;
  		case 8:	/* store colors as defaults */
  			vc->vc_def_color = vc->vc_attr;
  			if (vc->vc_hi_font_mask == 0x100)
  				vc->vc_def_color >>= 1;
  			default_attr(vc);
  			update_attr(vc);
  			break;
  		case 9:	/* set blanking interval */
  			blankinterval = ((vc->vc_par[1] < 60) ? vc->vc_par[1] : 60) * 60;
  			poke_blanked_console();
  			break;
  		case 10: /* set bell frequency in Hz */
  			if (vc->vc_npar >= 1)
  				vc->vc_bell_pitch = vc->vc_par[1];
  			else
  				vc->vc_bell_pitch = DEFAULT_BELL_PITCH;
  			break;
  		case 11: /* set bell duration in msec */
  			if (vc->vc_npar >= 1)
  				vc->vc_bell_duration = (vc->vc_par[1] < 2000) ?
  					vc->vc_par[1] * HZ / 1000 : 0;
  			else
  				vc->vc_bell_duration = DEFAULT_BELL_DURATION;
  			break;
  		case 12: /* bring specified console to the front */
  			if (vc->vc_par[1] >= 1 && vc_cons_allocated(vc->vc_par[1] - 1))
  				set_console(vc->vc_par[1] - 1);
  			break;
  		case 13: /* unblank the screen */
  			poke_blanked_console();
  			break;
  		case 14: /* set vesa powerdown interval */
  			vesa_off_interval = ((vc->vc_par[1] < 60) ? vc->vc_par[1] : 60) * 60 * HZ;
  			break;
  		case 15: /* activate the previous console */
  			set_console(last_console);
  			break;
  	}
  }
  
  /* console_lock is held */
  static void csi_at(struct vc_data *vc, unsigned int nr)
  {
  	if (nr > vc->vc_cols - vc->vc_x)
  		nr = vc->vc_cols - vc->vc_x;
  	else if (!nr)
  		nr = 1;
  	insert_char(vc, nr);
  }
  
  /* console_lock is held */
  static void csi_L(struct vc_data *vc, unsigned int nr)
  {
  	if (nr > vc->vc_rows - vc->vc_y)
  		nr = vc->vc_rows - vc->vc_y;
  	else if (!nr)
  		nr = 1;
  	scrdown(vc, vc->vc_y, vc->vc_bottom, nr);
  	vc->vc_need_wrap = 0;
  }
  
  /* console_lock is held */
  static void csi_P(struct vc_data *vc, unsigned int nr)
  {
  	if (nr > vc->vc_cols - vc->vc_x)
  		nr = vc->vc_cols - vc->vc_x;
  	else if (!nr)
  		nr = 1;
  	delete_char(vc, nr);
  }
  
  /* console_lock is held */
  static void csi_M(struct vc_data *vc, unsigned int nr)
  {
  	if (nr > vc->vc_rows - vc->vc_y)
  		nr = vc->vc_rows - vc->vc_y;
  	else if (!nr)
  		nr=1;
  	scrup(vc, vc->vc_y, vc->vc_bottom, nr);
  	vc->vc_need_wrap = 0;
  }
  
  /* console_lock is held (except via vc_init->reset_terminal */
  static void save_cur(struct vc_data *vc)
  {
  	vc->vc_saved_x		= vc->vc_x;
  	vc->vc_saved_y		= vc->vc_y;
  	vc->vc_s_intensity	= vc->vc_intensity;
  	vc->vc_s_italic         = vc->vc_italic;
  	vc->vc_s_underline	= vc->vc_underline;
  	vc->vc_s_blink		= vc->vc_blink;
  	vc->vc_s_reverse	= vc->vc_reverse;
  	vc->vc_s_charset	= vc->vc_charset;
  	vc->vc_s_color		= vc->vc_color;
  	vc->vc_saved_G0		= vc->vc_G0_charset;
  	vc->vc_saved_G1		= vc->vc_G1_charset;
  }
  
  /* console_lock is held */
  static void restore_cur(struct vc_data *vc)
  {
  	gotoxy(vc, vc->vc_saved_x, vc->vc_saved_y);
  	vc->vc_intensity	= vc->vc_s_intensity;
  	vc->vc_italic		= vc->vc_s_italic;
  	vc->vc_underline	= vc->vc_s_underline;
  	vc->vc_blink		= vc->vc_s_blink;
  	vc->vc_reverse		= vc->vc_s_reverse;
  	vc->vc_charset		= vc->vc_s_charset;
  	vc->vc_color		= vc->vc_s_color;
  	vc->vc_G0_charset	= vc->vc_saved_G0;
  	vc->vc_G1_charset	= vc->vc_saved_G1;
  	vc->vc_translate	= set_translate(vc->vc_charset ? vc->vc_G1_charset : vc->vc_G0_charset, vc);
  	update_attr(vc);
  	vc->vc_need_wrap = 0;
  }
  
  enum { ESnormal, ESesc, ESsquare, ESgetpars, ESgotpars, ESfunckey,
  	EShash, ESsetG0, ESsetG1, ESpercent, ESignore, ESnonstd,
  	ESpalette };
  
  /* console_lock is held (except via vc_init()) */
  static void reset_terminal(struct vc_data *vc, int do_clear)
  {
  	vc->vc_top		= 0;
  	vc->vc_bottom		= vc->vc_rows;
  	vc->vc_state		= ESnormal;
  	vc->vc_ques		= 0;
  	vc->vc_translate	= set_translate(LAT1_MAP, vc);
  	vc->vc_G0_charset	= LAT1_MAP;
  	vc->vc_G1_charset	= GRAF_MAP;
  	vc->vc_charset		= 0;
  	vc->vc_need_wrap	= 0;
  	vc->vc_report_mouse	= 0;
  	vc->vc_utf              = default_utf8;
  	vc->vc_utf_count	= 0;
  
  	vc->vc_disp_ctrl	= 0;
  	vc->vc_toggle_meta	= 0;
  
  	vc->vc_decscnm		= 0;
  	vc->vc_decom		= 0;
  	vc->vc_decawm		= 1;
  	vc->vc_deccm		= global_cursor_default;
  	vc->vc_decim		= 0;
  
  	vt_reset_keyboard(vc->vc_num);
  
  	vc->vc_cursor_type = cur_default;
  	vc->vc_complement_mask = vc->vc_s_complement_mask;
  
  	default_attr(vc);
  	update_attr(vc);
  
  	vc->vc_tab_stop[0]	= 0x01010100;
  	vc->vc_tab_stop[1]	=
  	vc->vc_tab_stop[2]	=
  	vc->vc_tab_stop[3]	=
  	vc->vc_tab_stop[4]	=
  	vc->vc_tab_stop[5]	=
  	vc->vc_tab_stop[6]	=
  	vc->vc_tab_stop[7]	= 0x01010101;
  
  	vc->vc_bell_pitch = DEFAULT_BELL_PITCH;
  	vc->vc_bell_duration = DEFAULT_BELL_DURATION;
  
  	gotoxy(vc, 0, 0);
  	save_cur(vc);
  	if (do_clear)
  	    csi_J(vc, 2);
  }
  
  /* console_lock is held */
  static void do_con_trol(struct tty_struct *tty, struct vc_data *vc, int c)
  {
  	/*
  	 *  Control characters can be used in the _middle_
  	 *  of an escape sequence.
  	 */
  	switch (c) {
  	case 0:
  		return;
  	case 7:
  		if (vc->vc_bell_duration)
  			kd_mksound(vc->vc_bell_pitch, vc->vc_bell_duration);
  		return;
  	case 8:
  		bs(vc);
  		return;
  	case 9:
  		vc->vc_pos -= (vc->vc_x << 1);
  		while (vc->vc_x < vc->vc_cols - 1) {
  			vc->vc_x++;
  			if (vc->vc_tab_stop[vc->vc_x >> 5] & (1 << (vc->vc_x & 31)))
  				break;
  		}
  		vc->vc_pos += (vc->vc_x << 1);
  		notify_write(vc, '\t');
  		return;
  	case 10: case 11: case 12:
  		lf(vc);
  		if (!is_kbd(vc, lnm))
  			return;
  	case 13:
  		cr(vc);
  		return;
  	case 14:
  		vc->vc_charset = 1;
  		vc->vc_translate = set_translate(vc->vc_G1_charset, vc);
  		vc->vc_disp_ctrl = 1;
  		return;
  	case 15:
  		vc->vc_charset = 0;
  		vc->vc_translate = set_translate(vc->vc_G0_charset, vc);
  		vc->vc_disp_ctrl = 0;
  		return;
  	case 24: case 26:
  		vc->vc_state = ESnormal;
  		return;
  	case 27:
  		vc->vc_state = ESesc;
  		return;
  	case 127:
  		del(vc);
  		return;
  	case 128+27:
  		vc->vc_state = ESsquare;
  		return;
  	}
  	switch(vc->vc_state) {
  	case ESesc:
  		vc->vc_state = ESnormal;
  		switch (c) {
  		case '[':
  			vc->vc_state = ESsquare;
  			return;
  		case ']':
  			vc->vc_state = ESnonstd;
  			return;
  		case '%':
  			vc->vc_state = ESpercent;
  			return;
  		case 'E':
  			cr(vc);
  			lf(vc);
  			return;
  		case 'M':
  			ri(vc);
  			return;
  		case 'D':
  			lf(vc);
  			return;
  		case 'H':
  			vc->vc_tab_stop[vc->vc_x >> 5] |= (1 << (vc->vc_x & 31));
  			return;
  		case 'Z':
  			respond_ID(tty);
  			return;
  		case '7':
  			save_cur(vc);
  			return;
  		case '8':
  			restore_cur(vc);
  			return;
  		case '(':
  			vc->vc_state = ESsetG0;
  			return;
  		case ')':
  			vc->vc_state = ESsetG1;
  			return;
  		case '#':
  			vc->vc_state = EShash;
  			return;
  		case 'c':
  			reset_terminal(vc, 1);
  			return;
  		case '>':  /* Numeric keypad */
  			clr_kbd(vc, kbdapplic);
  			return;
  		case '=':  /* Appl. keypad */
  			set_kbd(vc, kbdapplic);
  			return;
  		}
  		return;
  	case ESnonstd:
  		if (c=='P') {   /* palette escape sequence */
  			for (vc->vc_npar = 0; vc->vc_npar < NPAR; vc->vc_npar++)
  				vc->vc_par[vc->vc_npar] = 0;
  			vc->vc_npar = 0;
  			vc->vc_state = ESpalette;
  			return;
  		} else if (c=='R') {   /* reset palette */
  			reset_palette(vc);
  			vc->vc_state = ESnormal;
  		} else
  			vc->vc_state = ESnormal;
  		return;
  	case ESpalette:
  		if (isxdigit(c)) {
  			vc->vc_par[vc->vc_npar++] = hex_to_bin(c);
  			if (vc->vc_npar == 7) {
  				int i = vc->vc_par[0] * 3, j = 1;
  				vc->vc_palette[i] = 16 * vc->vc_par[j++];
  				vc->vc_palette[i++] += vc->vc_par[j++];
  				vc->vc_palette[i] = 16 * vc->vc_par[j++];
  				vc->vc_palette[i++] += vc->vc_par[j++];
  				vc->vc_palette[i] = 16 * vc->vc_par[j++];
  				vc->vc_palette[i] += vc->vc_par[j];
  				set_palette(vc);
  				vc->vc_state = ESnormal;
  			}
  		} else
  			vc->vc_state = ESnormal;
  		return;
  	case ESsquare:
  		for (vc->vc_npar = 0; vc->vc_npar < NPAR; vc->vc_npar++)
  			vc->vc_par[vc->vc_npar] = 0;
  		vc->vc_npar = 0;
  		vc->vc_state = ESgetpars;
  		if (c == '[') { /* Function key */
  			vc->vc_state=ESfunckey;
  			return;
  		}
  		vc->vc_ques = (c == '?');
  		if (vc->vc_ques)
  			return;
  	case ESgetpars:
  		if (c == ';' && vc->vc_npar < NPAR - 1) {
  			vc->vc_npar++;
  			return;
  		} else if (c>='0' && c<='9') {
  			vc->vc_par[vc->vc_npar] *= 10;
  			vc->vc_par[vc->vc_npar] += c - '0';
  			return;
  		} else
  			vc->vc_state = ESgotpars;
  	case ESgotpars:
  		vc->vc_state = ESnormal;
  		switch(c) {
  		case 'h':
  			set_mode(vc, 1);
  			return;
  		case 'l':
  			set_mode(vc, 0);
  			return;
  		case 'c':
  			if (vc->vc_ques) {
  				if (vc->vc_par[0])
  					vc->vc_cursor_type = vc->vc_par[0] | (vc->vc_par[1] << 8) | (vc->vc_par[2] << 16);
  				else
  					vc->vc_cursor_type = cur_default;
  				return;
  			}
  			break;
  		case 'm':
  			if (vc->vc_ques) {
  				clear_selection();
  				if (vc->vc_par[0])
  					vc->vc_complement_mask = vc->vc_par[0] << 8 | vc->vc_par[1];
  				else
  					vc->vc_complement_mask = vc->vc_s_complement_mask;
  				return;
  			}
  			break;
  		case 'n':
  			if (!vc->vc_ques) {
  				if (vc->vc_par[0] == 5)
  					status_report(tty);
  				else if (vc->vc_par[0] == 6)
  					cursor_report(vc, tty);
  			}
  			return;
  		}
  		if (vc->vc_ques) {
  			vc->vc_ques = 0;
  			return;
  		}
  		switch(c) {
  		case 'G': case '`':
  			if (vc->vc_par[0])
  				vc->vc_par[0]--;
  			gotoxy(vc, vc->vc_par[0], vc->vc_y);
  			return;
  		case 'A':
  			if (!vc->vc_par[0])
  				vc->vc_par[0]++;
  			gotoxy(vc, vc->vc_x, vc->vc_y - vc->vc_par[0]);
  			return;
  		case 'B': case 'e':
  			if (!vc->vc_par[0])
  				vc->vc_par[0]++;
  			gotoxy(vc, vc->vc_x, vc->vc_y + vc->vc_par[0]);
  			return;
  		case 'C': case 'a':
  			if (!vc->vc_par[0])
  				vc->vc_par[0]++;
  			gotoxy(vc, vc->vc_x + vc->vc_par[0], vc->vc_y);
  			return;
  		case 'D':
  			if (!vc->vc_par[0])
  				vc->vc_par[0]++;
  			gotoxy(vc, vc->vc_x - vc->vc_par[0], vc->vc_y);
  			return;
  		case 'E':
  			if (!vc->vc_par[0])
  				vc->vc_par[0]++;
  			gotoxy(vc, 0, vc->vc_y + vc->vc_par[0]);
  			return;
  		case 'F':
  			if (!vc->vc_par[0])
  				vc->vc_par[0]++;
  			gotoxy(vc, 0, vc->vc_y - vc->vc_par[0]);
  			return;
  		case 'd':
  			if (vc->vc_par[0])
  				vc->vc_par[0]--;
  			gotoxay(vc, vc->vc_x ,vc->vc_par[0]);
  			return;
  		case 'H': case 'f':
  			if (vc->vc_par[0])
  				vc->vc_par[0]--;
  			if (vc->vc_par[1])
  				vc->vc_par[1]--;
  			gotoxay(vc, vc->vc_par[1], vc->vc_par[0]);
  			return;
  		case 'J':
  			csi_J(vc, vc->vc_par[0]);
  			return;
  		case 'K':
  			csi_K(vc, vc->vc_par[0]);
  			return;
  		case 'L':
  			csi_L(vc, vc->vc_par[0]);
  			return;
  		case 'M':
  			csi_M(vc, vc->vc_par[0]);
  			return;
  		case 'P':
  			csi_P(vc, vc->vc_par[0]);
  			return;
  		case 'c':
  			if (!vc->vc_par[0])
  				respond_ID(tty);
  			return;
  		case 'g':
  			if (!vc->vc_par[0])
  				vc->vc_tab_stop[vc->vc_x >> 5] &= ~(1 << (vc->vc_x & 31));
  			else if (vc->vc_par[0] == 3) {
  				vc->vc_tab_stop[0] =
  					vc->vc_tab_stop[1] =
  					vc->vc_tab_stop[2] =
  					vc->vc_tab_stop[3] =
  					vc->vc_tab_stop[4] =
  					vc->vc_tab_stop[5] =
  					vc->vc_tab_stop[6] =
  					vc->vc_tab_stop[7] = 0;
  			}
  			return;
  		case 'm':
  			csi_m(vc);
  			return;
  		case 'q': /* DECLL - but only 3 leds */
  			/* map 0,1,2,3 to 0,1,2,4 */
  			if (vc->vc_par[0] < 4)
  				vt_set_led_state(vc->vc_num,
  					    (vc->vc_par[0] < 3) ? vc->vc_par[0] : 4);
  			return;
  		case 'r':
  			if (!vc->vc_par[0])
  				vc->vc_par[0]++;
  			if (!vc->vc_par[1])
  				vc->vc_par[1] = vc->vc_rows;
  			/* Minimum allowed region is 2 lines */
  			if (vc->vc_par[0] < vc->vc_par[1] &&
  			    vc->vc_par[1] <= vc->vc_rows) {
  				vc->vc_top = vc->vc_par[0] - 1;
  				vc->vc_bottom = vc->vc_par[1];
  				gotoxay(vc, 0, 0);
  			}
  			return;
  		case 's':
  			save_cur(vc);
  			return;
  		case 'u':
  			restore_cur(vc);
  			return;
  		case 'X':
  			csi_X(vc, vc->vc_par[0]);
  			return;
  		case '@':
  			csi_at(vc, vc->vc_par[0]);
  			return;
  		case ']': /* setterm functions */
  			setterm_command(vc);
  			return;
  		}
  		return;
  	case ESpercent:
  		vc->vc_state = ESnormal;
  		switch (c) {
  		case '@':  /* defined in ISO 2022 */
  			vc->vc_utf = 0;
  			return;
  		case 'G':  /* prelim official escape code */
  		case '8':  /* retained for compatibility */
  			vc->vc_utf = 1;
  			return;
  		}
  		return;
  	case ESfunckey:
  		vc->vc_state = ESnormal;
  		return;
  	case EShash:
  		vc->vc_state = ESnormal;
  		if (c == '8') {
  			/* DEC screen alignment test. kludge :-) */
  			vc->vc_video_erase_char =
  				(vc->vc_video_erase_char & 0xff00) | 'E';
  			csi_J(vc, 2);
  			vc->vc_video_erase_char =
  				(vc->vc_video_erase_char & 0xff00) | ' ';
  			do_update_region(vc, vc->vc_origin, vc->vc_screenbuf_size / 2);
  		}
  		return;
  	case ESsetG0:
  		if (c == '0')
  			vc->vc_G0_charset = GRAF_MAP;
  		else if (c == 'B')
  			vc->vc_G0_charset = LAT1_MAP;
  		else if (c == 'U')
  			vc->vc_G0_charset = IBMPC_MAP;
  		else if (c == 'K')
  			vc->vc_G0_charset = USER_MAP;
  		if (vc->vc_charset == 0)
  			vc->vc_translate = set_translate(vc->vc_G0_charset, vc);
  		vc->vc_state = ESnormal;
  		return;
  	case ESsetG1:
  		if (c == '0')
  			vc->vc_G1_charset = GRAF_MAP;
  		else if (c == 'B')
  			vc->vc_G1_charset = LAT1_MAP;
  		else if (c == 'U')
  			vc->vc_G1_charset = IBMPC_MAP;
  		else if (c == 'K')
  			vc->vc_G1_charset = USER_MAP;
  		if (vc->vc_charset == 1)
  			vc->vc_translate = set_translate(vc->vc_G1_charset, vc);
  		vc->vc_state = ESnormal;
  		return;
  	default:
  		vc->vc_state = ESnormal;
  	}
  }
  
  /* is_double_width() is based on the wcwidth() implementation by
   * Markus Kuhn -- 2007-05-26 (Unicode 5.0)
   * Latest version: http://www.cl.cam.ac.uk/~mgk25/ucs/wcwidth.c
   */
  struct interval {
  	uint32_t first;
  	uint32_t last;
  };
  
  static int bisearch(uint32_t ucs, const struct interval *table, int max)
  {
  	int min = 0;
  	int mid;
  
  	if (ucs < table[0].first || ucs > table[max].last)
  		return 0;
  	while (max >= min) {
  		mid = (min + max) / 2;
  		if (ucs > table[mid].last)
  			min = mid + 1;
  		else if (ucs < table[mid].first)
  			max = mid - 1;
  		else
  			return 1;
  	}
  	return 0;
  }
  
  static int is_double_width(uint32_t ucs)
  {
  	static const struct interval double_width[] = {
  		{ 0x1100, 0x115F }, { 0x2329, 0x232A }, { 0x2E80, 0x303E },
  		{ 0x3040, 0xA4CF }, { 0xAC00, 0xD7A3 }, { 0xF900, 0xFAFF },
  		{ 0xFE10, 0xFE19 }, { 0xFE30, 0xFE6F }, { 0xFF00, 0xFF60 },
  		{ 0xFFE0, 0xFFE6 }, { 0x20000, 0x2FFFD }, { 0x30000, 0x3FFFD }
  	};
  	return bisearch(ucs, double_width, ARRAY_SIZE(double_width) - 1);
  }
  
  /* acquires console_lock */
  static int do_con_write(struct tty_struct *tty, const unsigned char *buf, int count)
  {
  #ifdef VT_BUF_VRAM_ONLY
  #define FLUSH do { } while(0);
  #else
  #define FLUSH if (draw_x >= 0) { \
  	vc->vc_sw->con_putcs(vc, (u16 *)draw_from, (u16 *)draw_to - (u16 *)draw_from, vc->vc_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 vc_data *vc;
  	unsigned char vc_attr;
  	struct vt_notifier_param param;
  	uint8_t rescan;
  	uint8_t inverse;
  	uint8_t width;
  	u16 himask, charmask;
  
  	if (in_interrupt())
  		return count;
  
  	might_sleep();
  
  	console_lock();
  	vc = tty->driver_data;
  	if (vc == NULL) {
  		printk(KERN_ERR "vt: argh, driver_data is NULL !
  ");
  		console_unlock();
  		return 0;
  	}
  
  	currcons = vc->vc_num;
  	if (!vc_cons_allocated(currcons)) {
  		/* could this happen? */
  		pr_warn_once("con_write: tty %d not allocated
  ", currcons+1);
  		console_unlock();
  		return 0;
  	}
  
  	himask = vc->vc_hi_font_mask;
  	charmask = himask ? 0x1ff : 0xff;
  
  	/* undraw cursor first */
  	if (IS_FG(vc))
  		hide_cursor(vc);
  
  	param.vc = vc;
  
  	while (!tty->stopped && count) {
  		int orig = *buf;
  		c = orig;
  		buf++;
  		n++;
  		count--;
  		rescan = 0;
  		inverse = 0;
  		width = 1;
  
  		/* Do no translation at all in control states */
  		if (vc->vc_state != ESnormal) {
  			tc = c;
  		} else if (vc->vc_utf && !vc->vc_disp_ctrl) {
  		    /* Combine UTF-8 into Unicode in vc_utf_char.
  		     * vc_utf_count is the number of continuation bytes still
  		     * expected to arrive.
  		     * vc_npar is the number of continuation bytes arrived so
  		     * far
  		     */
  rescan_last_byte:
  		    if ((c & 0xc0) == 0x80) {
  			/* Continuation byte received */
  			static const uint32_t utf8_length_changes[] = { 0x0000007f, 0x000007ff, 0x0000ffff, 0x001fffff, 0x03ffffff, 0x7fffffff };
  			if (vc->vc_utf_count) {
  			    vc->vc_utf_char = (vc->vc_utf_char << 6) | (c & 0x3f);
  			    vc->vc_npar++;
  			    if (--vc->vc_utf_count) {
  				/* Still need some bytes */
  				continue;
  			    }
  			    /* Got a whole character */
  			    c = vc->vc_utf_char;
  			    /* Reject overlong sequences */
  			    if (c <= utf8_length_changes[vc->vc_npar - 1] ||
  					c > utf8_length_changes[vc->vc_npar])
  				c = 0xfffd;
  			} else {
  			    /* Unexpected continuation byte */
  			    vc->vc_utf_count = 0;
  			    c = 0xfffd;
  			}
  		    } else {
  			/* Single ASCII byte or first byte of a sequence received */
  			if (vc->vc_utf_count) {
  			    /* Continuation byte expected */
  			    rescan = 1;
  			    vc->vc_utf_count = 0;
  			    c = 0xfffd;
  			} else if (c > 0x7f) {
  			    /* First byte of a multibyte sequence received */
  			    vc->vc_npar = 0;
  			    if ((c & 0xe0) == 0xc0) {
  				vc->vc_utf_count = 1;
  				vc->vc_utf_char = (c & 0x1f);
  			    } else if ((c & 0xf0) == 0xe0) {
  				vc->vc_utf_count = 2;
  				vc->vc_utf_char = (c & 0x0f);
  			    } else if ((c & 0xf8) == 0xf0) {
  				vc->vc_utf_count = 3;
  				vc->vc_utf_char = (c & 0x07);
  			    } else if ((c & 0xfc) == 0xf8) {
  				vc->vc_utf_count = 4;
  				vc->vc_utf_char = (c & 0x03);
  			    } else if ((c & 0xfe) == 0xfc) {
  				vc->vc_utf_count = 5;
  				vc->vc_utf_char = (c & 0x01);
  			    } else {
  				/* 254 and 255 are invalid */
  				c = 0xfffd;
  			    }
  			    if (vc->vc_utf_count) {
  				/* Still need some bytes */
  				continue;
  			    }
  			}
  			/* Nothing to do if an ASCII byte was received */
  		    }
  		    /* End of UTF-8 decoding. */
  		    /* c is the received character, or U+FFFD for invalid sequences. */
  		    /* Replace invalid Unicode code points with U+FFFD too */
  		    if ((c >= 0xd800 && c <= 0xdfff) || c == 0xfffe || c == 0xffff)
  			c = 0xfffd;
  		    tc = c;
  		} else {	/* no utf or alternate charset mode */
  		    tc = vc_translate(vc, c);
  		}
  
  		param.c = tc;
  		if (atomic_notifier_call_chain(&vt_notifier_list, VT_PREWRITE,
  					&param) == NOTIFY_STOP)
  			continue;
  
                  /* 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 ||
  			    !(vc->vc_disp_ctrl ? (CTRL_ALWAYS >> c) & 1 :
  				  vc->vc_utf || ((CTRL_ACTION >> c) & 1)))
  			&& (c != 127 || vc->vc_disp_ctrl)
  			&& (c != 128+27);
  
  		if (vc->vc_state == ESnormal && ok) {
  			if (vc->vc_utf && !vc->vc_disp_ctrl) {
  				if (is_double_width(c))
  					width = 2;
  			}
  			/* Now try to find out how to display it */
  			tc = conv_uni_to_pc(vc, tc);
  			if (tc & ~charmask) {
  				if (tc == -1 || tc == -2) {
  				    continue; /* nothing to display */
  				}
  				/* Glyph not found */
  				if ((!(vc->vc_utf && !vc->vc_disp_ctrl) || c < 128) && !(c & ~charmask)) {
  				    /* In legacy mode use the glyph we get by a 1:1 mapping.
  				       This would make absolutely no sense with Unicode in mind,
  				       but do this for ASCII characters since a font may lack
  				       Unicode mapping info and we don't want to end up with
  				       having question marks only. */
  				    tc = c;
  				} else {
  				    /* Display U+FFFD. If it's not found, display an inverse question mark. */
  				    tc = conv_uni_to_pc(vc, 0xfffd);
  				    if (tc < 0) {
  					inverse = 1;
  					tc = conv_uni_to_pc(vc, '?');
  					if (tc < 0) tc = '?';
  				    }
  				}
  			}
  
  			if (!inverse) {
  				vc_attr = vc->vc_attr;
  			} else {
  				/* invert vc_attr */
  				if (!vc->vc_can_do_color) {
  					vc_attr = (vc->vc_attr) ^ 0x08;
  				} else if (vc->vc_hi_font_mask == 0x100) {
  					vc_attr = ((vc->vc_attr) & 0x11) | (((vc->vc_attr) & 0xe0) >> 4) | (((vc->vc_attr) & 0x0e) << 4);
  				} else {
  					vc_attr = ((vc->vc_attr) & 0x88) | (((vc->vc_attr) & 0x70) >> 4) | (((vc->vc_attr) & 0x07) << 4);
  				}
  				FLUSH
  			}
  
  			while (1) {
  				if (vc->vc_need_wrap || vc->vc_decim)
  					FLUSH
  				if (vc->vc_need_wrap) {
  					cr(vc);
  					lf(vc);
  				}
  				if (vc->vc_decim)
  					insert_char(vc, 1);
  				scr_writew(himask ?
  					     ((vc_attr << 8) & ~himask) + ((tc & 0x100) ? himask : 0) + (tc & 0xff) :
  					     (vc_attr << 8) + tc,
  					   (u16 *) vc->vc_pos);
  				if (DO_UPDATE(vc) && draw_x < 0) {
  					draw_x = vc->vc_x;
  					draw_from = vc->vc_pos;
  				}
  				if (vc->vc_x == vc->vc_cols - 1) {
  					vc->vc_need_wrap = vc->vc_decawm;
  					draw_to = vc->vc_pos + 2;
  				} else {
  					vc->vc_x++;
  					draw_to = (vc->vc_pos += 2);
  				}
  
  				if (!--width) break;
  
  				tc = conv_uni_to_pc(vc, ' '); /* A space is printed in the second column */
  				if (tc < 0) tc = ' ';
  			}
  			notify_write(vc, c);
  
  			if (inverse) {
  				FLUSH
  			}
  
  			if (rescan) {
  				rescan = 0;
  				inverse = 0;
  				width = 1;
  				c = orig;
  				goto rescan_last_byte;
  			}
  			continue;
  		}
  		FLUSH
  		do_con_trol(tty, vc, orig);
  	}
  	FLUSH
  	console_conditional_schedule();
  	console_unlock();
  	notify_update(vc);
  	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_lock.
   */
  static void console_callback(struct work_struct *ignored)
  {
  	console_lock();
  
  	if (want_console >= 0) {
  		if (want_console != fg_console &&
  		    vc_cons_allocated(want_console)) {
  			hide_cursor(vc_cons[fg_console].d);
  			change_console(vc_cons[want_console].d);
  			/* 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) {
  		struct vc_data *vc = vc_cons[fg_console].d;
  		clear_selection();
  		if (vc->vc_mode == KD_TEXT)
  			vc->vc_sw->con_scrolldelta(vc, scrollback_delta);
  		scrollback_delta = 0;
  	}
  	if (blank_timer_expired) {
  		do_blank_screen(0);
  		blank_timer_expired = 0;
  	}
  	notify_update(vc_cons[fg_console].d);
  
  	console_unlock();
  }
  
  int set_console(int nr)
  {
  	struct vc_data *vc = vc_cons[fg_console].d;
  
  	if (!vc_cons_allocated(nr) || vt_dont_switch ||
  		(vc->vt_mode.mode == VT_AUTO && vc->vc_mode == KD_GRAPHICS)) {
  
  		/*
  		 * Console switch will fail in console_callback() or
  		 * change_console() so there is no point scheduling
  		 * the callback
  		 *
  		 * Existing set_console() users don't check the return
  		 * value so this shouldn't break anything
  		 */
  		return -EINVAL;
  	}
  
  	want_console = nr;
  	schedule_console_callback();
  
  	return 0;
  }
  
  struct tty_driver *console_driver;
  
  #ifdef CONFIG_VT_CONSOLE
  
  /**
   * vt_kmsg_redirect() - Sets/gets the kernel message console
   * @new:	The new virtual terminal number or -1 if the console should stay
   * 		unchanged
   *
   * By default, the kernel messages are always printed on the current virtual
   * console. However, the user may modify that default with the
   * TIOCL_SETKMSGREDIRECT ioctl call.
   *
   * This function sets the kernel message console to be @new. It returns the old
   * virtual console number. The virtual terminal number 0 (both as parameter and
   * return value) means no redirection (i.e. always printed on the currently
   * active console).
   *
   * The parameter -1 means that only the current console is returned, but the
   * value is not modified. You may use the macro vt_get_kmsg_redirect() in that
   * case to make the code more understandable.
   *
   * When the kernel is compiled without CONFIG_VT_CONSOLE, this function ignores
   * the parameter and always returns 0.
   */
  int vt_kmsg_redirect(int new)
  {
  	static int kmsg_con;
  
  	if (new != -1)
  		return xchg(&kmsg_con, new);
  	else
  		return kmsg_con;
  }
  
  /*
   *	Console on virtual terminal
   *
   * The console must be locked when we get here.
   */
  
  static void vt_console_print(struct console *co, const char *b, unsigned count)
  {
  	struct vc_data *vc = vc_cons[fg_console].d;
  	unsigned char c;
  	static DEFINE_SPINLOCK(printing_lock);
  	const ushort *start;
  	ushort cnt = 0;
  	ushort myx;
  	int kmsg_console;
  
  	/* console busy or not yet initialized */
  	if (!printable)
  		return;
  	if (!spin_trylock(&printing_lock))
  		return;
  
  	kmsg_console = vt_get_kmsg_redirect();
  	if (kmsg_console && vc_cons_allocated(kmsg_console - 1))
  		vc = vc_cons[kmsg_console - 1].d;
  
  	/* read `x' only after setting currcons properly (otherwise
  	   the `x' macro will read the x of the foreground console). */
  	myx = vc->vc_x;
  
  	if (!vc_cons_allocated(fg_console)) {
  		/* impossible */
  		/* printk("vt_console_print: tty %d not allocated ??
  ", currcons+1); */
  		goto quit;
  	}
  
  	if (vc->vc_mode != KD_TEXT && !vt_force_oops_output(vc))
  		goto quit;
  
  	/* undraw cursor first */
  	if (IS_FG(vc))
  		hide_cursor(vc);
  
  	start = (ushort *)vc->vc_pos;
  
  	/* Contrived structure to try to emulate original need_wrap behaviour
  	 * Problems caused when we have need_wrap set on '
  ' character */
  	while (count--) {
  		c = *b++;
  		if (c == 10 || c == 13 || c == 8 || vc->vc_need_wrap) {
  			if (cnt > 0) {
  				if (CON_IS_VISIBLE(vc))
  					vc->vc_sw->con_putcs(vc, start, cnt, vc->vc_y, vc->vc_x);
  				vc->vc_x += cnt;
  				if (vc->vc_need_wrap)
  					vc->vc_x--;
  				cnt = 0;
  			}
  			if (c == 8) {		/* backspace */
  				bs(vc);
  				start = (ushort *)vc->vc_pos;
  				myx = vc->vc_x;
  				continue;
  			}
  			if (c != 13)
  				lf(vc);
  			cr(vc);
  			start = (ushort *)vc->vc_pos;
  			myx = vc->vc_x;
  			if (c == 10 || c == 13)
  				continue;
  		}
  		scr_writew((vc->vc_attr << 8) + c, (unsigned short *)vc->vc_pos);
  		notify_write(vc, c);
  		cnt++;
  		if (myx == vc->vc_cols - 1) {
  			vc->vc_need_wrap = 1;
  			continue;
  		}
  		vc->vc_pos += 2;
  		myx++;
  	}
  	if (cnt > 0) {
  		if (CON_IS_VISIBLE(vc))
  			vc->vc_sw->con_putcs(vc, start, cnt, vc->vc_y, vc->vc_x);
  		vc->vc_x += cnt;
  		if (vc->vc_x == vc->vc_cols) {
  			vc->vc_x--;
  			vc->vc_need_wrap = 1;
  		}
  	}
  	set_cursor(vc);
  	notify_update(vc);
  
  quit:
  	spin_unlock(&printing_lock);
  }
  
  static struct tty_driver *vt_console_device(struct console *c, int *index)
  {
  	*index = c->index ? c->index-1 : fg_console;
  	return console_driver;
  }
  
  static 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_lock();.
   *
   * 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;
  	char __user *p = (char __user *)arg;
  	int lines;
  	int ret;
  
  	if (current->signal->tty != tty && !capable(CAP_SYS_ADMIN))
  		return -EPERM;
  	if (get_user(type, p))
  		return -EFAULT;
  	ret = 0;
  
  	switch (type)
  	{
  		case TIOCL_SETSEL:
  			console_lock();
  			ret = set_selection((struct tiocl_selection __user *)(p+1), tty);
  			console_unlock();
  			break;
  		case TIOCL_PASTESEL:
  			ret = paste_selection(tty);
  			break;
  		case TIOCL_UNBLANKSCREEN:
  			console_lock();
  			unblank_screen();
  			console_unlock();
  			break;
  		case TIOCL_SELLOADLUT:
  			console_lock();
  			ret = sel_loadlut(p);
  			console_unlock();
  			break;
  		case TIOCL_GETSHIFTSTATE:
  
  	/*
  	 * 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 = vt_get_shift_state();
  			ret = __put_user(data, p);
  			break;
  		case TIOCL_GETMOUSEREPORTING:
  			console_lock();	/* May be overkill */
  			data = mouse_reporting();
  			console_unlock();
  			ret = __put_user(data, p);
  			break;
  		case TIOCL_SETVESABLANK:
  			console_lock();
  			ret = set_vesa_blanking(p);
  			console_unlock();
  			break;
  		case TIOCL_GETKMSGREDIRECT:
  			data = vt_get_kmsg_redirect();
  			ret = __put_user(data, p);
  			break;
  		case TIOCL_SETKMSGREDIRECT:
  			if (!capable(CAP_SYS_ADMIN)) {
  				ret = -EPERM;
  			} else {
  				if (get_user(data, p+1))
  					ret = -EFAULT;
  				else
  					vt_kmsg_redirect(data);
  			}
  			break;
  		case TIOCL_GETFGCONSOLE:
  			/* No locking needed as this is a transiently
  			   correct return anyway if the caller hasn't
  			   disabled switching */
  			ret = fg_console;
  			break;
  		case TIOCL_SCROLLCONSOLE:
  			if (get_user(lines, (s32 __user *)(p+4))) {
  				ret = -EFAULT;
  			} else {
  				/* Need the console lock here. Note that lots
  				   of other calls need fixing before the lock
  				   is actually useful ! */
  				console_lock();
  				scrollfront(vc_cons[fg_console].d, lines);
  				console_unlock();
  				ret = 0;
  			}
  			break;
  		case TIOCL_BLANKSCREEN:	/* until explicitly unblanked, not only poked */
  			console_lock();
  			ignore_poke = 1;
  			do_blank_screen(0);
  			console_unlock();
  			break;
  		case TIOCL_BLANKEDSCREEN:
  			ret = console_blanked;
  			break;
  		default:
  			ret = -EINVAL;
  			break;
  	}
  	return ret;
  }
  
  /*
   * /dev/ttyN handling
   */
  
  static int con_write(struct tty_struct *tty, const unsigned char *buf, int count)
  {
  	int	retval;
  
  	retval = do_con_write(tty, buf, count);
  	con_flush_chars(tty);
  
  	return retval;
  }
  
  static int con_put_char(struct tty_struct *tty, unsigned char ch)
  {
  	if (in_interrupt())
  		return 0;	/* n_r3964 calls put_char() from interrupt context */
  	return do_con_write(tty, &ch, 1);
  }
  
  static int con_write_room(struct tty_struct *tty)
  {
  	if (tty->stopped)
  		return 0;
  	return 32768;		/* 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 vc_data *vc = tty->driver_data;
  
  	wake_up_interruptible(&vc->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 = tty->index;
  	if (!vc_cons_allocated(console_num))
  		return;
  	vt_kbd_con_stop(console_num);
  }
  
  /*
   * 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 = tty->index;
  	if (!vc_cons_allocated(console_num))
  		return;
  	vt_kbd_con_start(console_num);
  }
  
  static void con_flush_chars(struct tty_struct *tty)
  {
  	struct vc_data *vc;
  
  	if (in_interrupt())	/* from flush_to_ldisc */
  		return;
  
  	/* if we race with con_close(), vt may be null */
  	console_lock();
  	vc = tty->driver_data;
  	if (vc)
  		set_cursor(vc);
  	console_unlock();
  }
  
  /*
   * Allocate the console screen memory.
   */
  static int con_install(struct tty_driver *driver, struct tty_struct *tty)
  {
  	unsigned int currcons = tty->index;
  	struct vc_data *vc;
  	int ret;
  
  	console_lock();
  	ret = vc_allocate(currcons);
  	if (ret)
  		goto unlock;
  
  	vc = vc_cons[currcons].d;
  
  	/* Still being freed */
  	if (vc->port.tty) {
  		ret = -ERESTARTSYS;
  		goto unlock;
  	}
  
  	ret = tty_port_install(&vc->port, driver, tty);
  	if (ret)
  		goto unlock;
  
  	tty->driver_data = vc;
  	vc->port.tty = tty;
  
  	if (!tty->winsize.ws_row && !tty->winsize.ws_col) {
  		tty->winsize.ws_row = vc_cons[currcons].d->vc_rows;
  		tty->winsize.ws_col = vc_cons[currcons].d->vc_cols;
  	}
  	if (vc->vc_utf)
  		tty->termios.c_iflag |= IUTF8;
  	else
  		tty->termios.c_iflag &= ~IUTF8;
  unlock:
  	console_unlock();
  	return ret;
  }
  
  static int con_open(struct tty_struct *tty, struct file *filp)
  {
  	/* everything done in install */
  	return 0;
  }
  
  
  static void con_close(struct tty_struct *tty, struct file *filp)
  {
  	/* Nothing to do - we defer to shutdown */
  }
  
  static void con_shutdown(struct tty_struct *tty)
  {
  	struct vc_data *vc = tty->driver_data;
  	BUG_ON(vc == NULL);
  	console_lock();
  	vc->port.tty = NULL;
  	console_unlock();
  }
  
  static int default_color           = 7; /* white */
  static int default_italic_color    = 2; // green (ASCII)
  static int default_underline_color = 3; // cyan (ASCII)
  module_param_named(color, default_color, int, S_IRUGO | S_IWUSR);
  module_param_named(italic, default_italic_color, int, S_IRUGO | S_IWUSR);
  module_param_named(underline, default_underline_color, int, S_IRUGO | S_IWUSR);
  
  static void vc_init(struct vc_data *vc, unsigned int rows,
  		    unsigned int cols, int do_clear)
  {
  	int j, k ;
  
  	vc->vc_cols = cols;
  	vc->vc_rows = rows;
  	vc->vc_size_row = cols << 1;
  	vc->vc_screenbuf_size = vc->vc_rows * vc->vc_size_row;
  
  	set_origin(vc);
  	vc->vc_pos = vc->vc_origin;
  	reset_vc(vc);
  	for (j=k=0; j<16; j++) {
  		vc->vc_palette[k++] = default_red[j] ;
  		vc->vc_palette[k++] = default_grn[j] ;
  		vc->vc_palette[k++] = default_blu[j] ;
  	}
  	vc->vc_def_color       = default_color;
  	vc->vc_ulcolor         = default_underline_color;
  	vc->vc_itcolor         = default_italic_color;
  	vc->vc_halfcolor       = 0x08;   /* grey */
  	init_waitqueue_head(&vc->paste_wait);
  	reset_terminal(vc, 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.
   */
  
  static int __init con_init(void)
  {
  	const char *display_desc = NULL;
  	struct vc_data *vc;
  	unsigned int currcons = 0, i;
  
  	console_lock();
  
  	if (conswitchp)
  		display_desc = conswitchp->con_startup();
  	if (!display_desc) {
  		fg_console = 0;
  		console_unlock();
  		return 0;
  	}
  
  	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
  		struct con_driver *con_driver = &registered_con_driver[i];
  
  		if (con_driver->con == NULL) {
  			con_driver->con = conswitchp;
  			con_driver->desc = display_desc;
  			con_driver->flag = CON_DRIVER_FLAG_INIT;
  			con_driver->first = 0;
  			con_driver->last = MAX_NR_CONSOLES - 1;
  			break;
  		}
  	}
  
  	for (i = 0; i < MAX_NR_CONSOLES; i++)
  		con_driver_map[i] = conswitchp;
  
  	if (blankinterval) {
  		blank_state = blank_normal_wait;
  		mod_timer(&console_timer, jiffies + (blankinterval * HZ));
  	}
  
  	for (currcons = 0; currcons < MIN_NR_CONSOLES; currcons++) {
  		vc_cons[currcons].d = vc = kzalloc(sizeof(struct vc_data), GFP_NOWAIT);
  		INIT_WORK(&vc_cons[currcons].SAK_work, vc_SAK);
  		tty_port_init(&vc->port);
  		visual_init(vc, currcons, 1);
  		vc->vc_screenbuf = kzalloc(vc->vc_screenbuf_size, GFP_NOWAIT);
  		vc_init(vc, vc->vc_rows, vc->vc_cols,
  			currcons || !vc->vc_sw->con_save_screen);
  	}
  	currcons = fg_console = 0;
  	master_display_fg = vc = vc_cons[currcons].d;
  	set_origin(vc);
  	save_screen(vc);
  	gotoxy(vc, vc->vc_x, vc->vc_y);
  	csi_J(vc, 0);
  	update_screen(vc);
  	pr_info("Console: %s %s %dx%d
  ",
  		vc->vc_can_do_color ? "colour" : "mono",
  		display_desc, vc->vc_cols, vc->vc_rows);
  	printable = 1;
  
  	console_unlock();
  
  #ifdef CONFIG_VT_CONSOLE
  	register_console(&vt_console_driver);
  #endif
  	return 0;
  }
  console_initcall(con_init);
  
  static const struct tty_operations con_ops = {
  	.install = con_install,
  	.open = con_open,
  	.close = con_close,
  	.write = con_write,
  	.write_room = con_write_room,
  	.put_char = con_put_char,
  	.flush_chars = con_flush_chars,
  	.chars_in_buffer = con_chars_in_buffer,
  	.ioctl = vt_ioctl,
  #ifdef CONFIG_COMPAT
  	.compat_ioctl = vt_compat_ioctl,
  #endif
  	.stop = con_stop,
  	.start = con_start,
  	.throttle = con_throttle,
  	.unthrottle = con_unthrottle,
  	.resize = vt_resize,
  	.shutdown = con_shutdown
  };
  
  static struct cdev vc0_cdev;
  
  static ssize_t show_tty_active(struct device *dev,
  				struct device_attribute *attr, char *buf)
  {
  	return sprintf(buf, "tty%d
  ", fg_console + 1);
  }
  static DEVICE_ATTR(active, S_IRUGO, show_tty_active, NULL);
  
  int __init vty_init(const struct file_operations *console_fops)
  {
  	cdev_init(&vc0_cdev, console_fops);
  	if (cdev_add(&vc0_cdev, MKDEV(TTY_MAJOR, 0), 1) ||
  	    register_chrdev_region(MKDEV(TTY_MAJOR, 0), 1, "/dev/vc/0") < 0)
  		panic("Couldn't register /dev/tty0 driver
  ");
  	tty0dev = device_create(tty_class, NULL, MKDEV(TTY_MAJOR, 0), NULL, "tty0");
  	if (IS_ERR(tty0dev))
  		tty0dev = NULL;
  	else
  		WARN_ON(device_create_file(tty0dev, &dev_attr_active) < 0);
  
  	vcs_init();
  
  	console_driver = alloc_tty_driver(MAX_NR_CONSOLES);
  	if (!console_driver)
  		panic("Couldn't allocate console driver
  ");
  
  	console_driver->name = "tty";
  	console_driver->name_base = 1;
  	console_driver->major = TTY_MAJOR;
  	console_driver->minor_start = 1;
  	console_driver->type = TTY_DRIVER_TYPE_CONSOLE;
  	console_driver->init_termios = tty_std_termios;
  	if (default_utf8)
  		console_driver->init_termios.c_iflag |= IUTF8;
  	console_driver->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_RESET_TERMIOS;
  	tty_set_operations(console_driver, &con_ops);
  	if (tty_register_driver(console_driver))
  		panic("Couldn't register console driver
  ");
  	kbd_init();
  	console_map_init();
  #ifdef CONFIG_MDA_CONSOLE
  	mda_console_init();
  #endif
  	return 0;
  }
  
  #ifndef VT_SINGLE_DRIVER
  
  static struct class *vtconsole_class;
  
  static int do_bind_con_driver(const struct consw *csw, int first, int last,
  			   int deflt)
  {
  	struct module *owner = csw->owner;
  	const char *desc = NULL;
  	struct con_driver *con_driver;
  	int i, j = -1, k = -1, retval = -ENODEV;
  
  	if (!try_module_get(owner))
  		return -ENODEV;
  
  	WARN_CONSOLE_UNLOCKED();
  
  	/* check if driver is registered */
  	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
  		con_driver = &registered_con_driver[i];
  
  		if (con_driver->con == csw) {
  			desc = con_driver->desc;
  			retval = 0;
  			break;
  		}
  	}
  
  	if (retval)
  		goto err;
  
  	if (!(con_driver->flag & CON_DRIVER_FLAG_INIT)) {
  		csw->con_startup();
  		con_driver->flag |= CON_DRIVER_FLAG_INIT;
  	}
  
  	if (deflt) {
  		if (conswitchp)
  			module_put(conswitchp->owner);
  
  		__module_get(owner);
  		conswitchp = csw;
  	}
  
  	first = max(first, con_driver->first);
  	last = min(last, con_driver->last);
  
  	for (i = first; i <= last; i++) {
  		int old_was_color;
  		struct vc_data *vc = vc_cons[i].d;
  
  		if (con_driver_map[i])
  			module_put(con_driver_map[i]->owner);
  		__module_get(owner);
  		con_driver_map[i] = csw;
  
  		if (!vc || !vc->vc_sw)
  			continue;
  
  		j = i;
  
  		if (CON_IS_VISIBLE(vc)) {
  			k = i;
  			save_screen(vc);
  		}
  
  		old_was_color = vc->vc_can_do_color;
  		vc->vc_sw->con_deinit(vc);
  		vc->vc_origin = (unsigned long)vc->vc_screenbuf;
  		visual_init(vc, i, 0);
  		set_origin(vc);
  		update_attr(vc);
  
  		/* 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->vc_can_do_color)
  			clear_buffer_attributes(vc);
  	}
  
  	pr_info("Console: switching ");
  	if (!deflt)
  		printk("consoles %d-%d ", first+1, last+1);
  	if (j >= 0) {
  		struct vc_data *vc = vc_cons[j].d;
  
  		printk("to %s %s %dx%d
  ",
  		       vc->vc_can_do_color ? "colour" : "mono",
  		       desc, vc->vc_cols, vc->vc_rows);
  
  		if (k >= 0) {
  			vc = vc_cons[k].d;
  			update_screen(vc);
  		}
  	} else
  		printk("to %s
  ", desc);
  
  	retval = 0;
  err:
  	module_put(owner);
  	return retval;
  };
  
  
  #ifdef CONFIG_VT_HW_CONSOLE_BINDING
  static int con_is_graphics(const struct consw *csw, int first, int last)
  {
  	int i, retval = 0;
  
  	for (i = first; i <= last; i++) {
  		struct vc_data *vc = vc_cons[i].d;
  
  		if (vc && vc->vc_mode == KD_GRAPHICS) {
  			retval = 1;
  			break;
  		}
  	}
  
  	return retval;
  }
  
  /* unlocked version of unbind_con_driver() */
  int do_unbind_con_driver(const struct consw *csw, int first, int last, int deflt)
  {
  	struct module *owner = csw->owner;
  	const struct consw *defcsw = NULL;
  	struct con_driver *con_driver = NULL, *con_back = NULL;
  	int i, retval = -ENODEV;
  
  	if (!try_module_get(owner))
  		return -ENODEV;
  
  	WARN_CONSOLE_UNLOCKED();
  
  	/* check if driver is registered and if it is unbindable */
  	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
  		con_driver = &registered_con_driver[i];
  
  		if (con_driver->con == csw &&
  		    con_driver->flag & CON_DRIVER_FLAG_MODULE) {
  			retval = 0;
  			break;
  		}
  	}
  
  	if (retval)
  		goto err;
  
  	retval = -ENODEV;
  
  	/* check if backup driver exists */
  	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
  		con_back = &registered_con_driver[i];
  
  		if (con_back->con &&
  		    !(con_back->flag & CON_DRIVER_FLAG_MODULE)) {
  			defcsw = con_back->con;
  			retval = 0;
  			break;
  		}
  	}
  
  	if (retval)
  		goto err;
  
  	if (!con_is_bound(csw))
  		goto err;
  
  	first = max(first, con_driver->first);
  	last = min(last, con_driver->last);
  
  	for (i = first; i <= last; i++) {
  		if (con_driver_map[i] == csw) {
  			module_put(csw->owner);
  			con_driver_map[i] = NULL;
  		}
  	}
  
  	if (!con_is_bound(defcsw)) {
  		const struct consw *defconsw = conswitchp;
  
  		defcsw->con_startup();
  		con_back->flag |= CON_DRIVER_FLAG_INIT;
  		/*
  		 * vgacon may change the default driver to point
  		 * to dummycon, we restore it here...
  		 */
  		conswitchp = defconsw;
  	}
  
  	if (!con_is_bound(csw))
  		con_driver->flag &= ~CON_DRIVER_FLAG_INIT;
  
  	/* ignore return value, binding should not fail */
  	do_bind_con_driver(defcsw, first, last, deflt);
  err:
  	module_put(owner);
  	return retval;
  
  }
  EXPORT_SYMBOL_GPL(do_unbind_con_driver);
  
  static int vt_bind(struct con_driver *con)
  {
  	const struct consw *defcsw = NULL, *csw = NULL;
  	int i, more = 1, first = -1, last = -1, deflt = 0;
  
   	if (!con->con || !(con->flag & CON_DRIVER_FLAG_MODULE) ||
  	    con_is_graphics(con->con, con->first, con->last))
  		goto err;
  
  	csw = con->con;
  
  	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
  		struct con_driver *con = &registered_con_driver[i];
  
  		if (con->con && !(con->flag & CON_DRIVER_FLAG_MODULE)) {
  			defcsw = con->con;
  			break;
  		}
  	}
  
  	if (!defcsw)
  		goto err;
  
  	while (more) {
  		more = 0;
  
  		for (i = con->first; i <= con->last; i++) {
  			if (con_driver_map[i] == defcsw) {
  				if (first == -1)
  					first = i;
  				last = i;
  				more = 1;
  			} else if (first != -1)
  				break;
  		}
  
  		if (first == 0 && last == MAX_NR_CONSOLES -1)
  			deflt = 1;
  
  		if (first != -1) {
  			console_lock();
  			do_bind_con_driver(csw, first, last, deflt);
  			console_unlock();
  		}
  
  		first = -1;
  		last = -1;
  		deflt = 0;
  	}
  
  err:
  	return 0;
  }
  
  static int vt_unbind(struct con_driver *con)
  {
  	const struct consw *csw = NULL;
  	int i, more = 1, first = -1, last = -1, deflt = 0;
  
   	if (!con->con || !(con->flag & CON_DRIVER_FLAG_MODULE) ||
  	    con_is_graphics(con->con, con->first, con->last))
  		goto err;
  
  	csw = con->con;
  
  	while (more) {
  		more = 0;
  
  		for (i = con->first; i <= con->last; i++) {
  			if (con_driver_map[i] == csw) {
  				if (first == -1)
  					first = i;
  				last = i;
  				more = 1;
  			} else if (first != -1)
  				break;
  		}
  
  		if (first == 0 && last == MAX_NR_CONSOLES -1)
  			deflt = 1;
  
  		if (first != -1) {
  			console_lock();
  			do_unbind_con_driver(csw, first, last, deflt);
  			console_unlock();
  		}
  
  		first = -1;
  		last = -1;
  		deflt = 0;
  	}
  
  err:
  	return 0;
  }
  #else
  static inline int vt_bind(struct con_driver *con)
  {
  	return 0;
  }
  static inline int vt_unbind(struct con_driver *con)
  {
  	return 0;
  }
  #endif /* CONFIG_VT_HW_CONSOLE_BINDING */
  
  static ssize_t store_bind(struct device *dev, struct device_attribute *attr,
  			  const char *buf, size_t count)
  {
  	struct con_driver *con = dev_get_drvdata(dev);
  	int bind = simple_strtoul(buf, NULL, 0);
  
  	if (bind)
  		vt_bind(con);
  	else
  		vt_unbind(con);
  
  	return count;
  }
  
  static ssize_t show_bind(struct device *dev, struct device_attribute *attr,
  			 char *buf)
  {
  	struct con_driver *con = dev_get_drvdata(dev);
  	int bind = con_is_bound(con->con);
  
  	return snprintf(buf, PAGE_SIZE, "%i
  ", bind);
  }
  
  static ssize_t show_name(struct device *dev, struct device_attribute *attr,
  			 char *buf)
  {
  	struct con_driver *con = dev_get_drvdata(dev);
  
  	return snprintf(buf, PAGE_SIZE, "%s %s
  ",
  			(con->flag & CON_DRIVER_FLAG_MODULE) ? "(M)" : "(S)",
  			 con->desc);
  
  }
  
  static struct device_attribute device_attrs[] = {
  	__ATTR(bind, S_IRUGO|S_IWUSR, show_bind, store_bind),
  	__ATTR(name, S_IRUGO, show_name, NULL),
  };
  
  static int vtconsole_init_device(struct con_driver *con)
  {
  	int i;
  	int error = 0;
  
  	con->flag |= CON_DRIVER_FLAG_ATTR;
  	dev_set_drvdata(con->dev, con);
  	for (i = 0; i < ARRAY_SIZE(device_attrs); i++) {
  		error = device_create_file(con->dev, &device_attrs[i]);
  		if (error)
  			break;
  	}
  
  	if (error) {
  		while (--i >= 0)
  			device_remove_file(con->dev, &device_attrs[i]);
  		con->flag &= ~CON_DRIVER_FLAG_ATTR;
  	}
  
  	return error;
  }
  
  static void vtconsole_deinit_device(struct con_driver *con)
  {
  	int i;
  
  	if (con->flag & CON_DRIVER_FLAG_ATTR) {
  		for (i = 0; i < ARRAY_SIZE(device_attrs); i++)
  			device_remove_file(con->dev, &device_attrs[i]);
  		con->flag &= ~CON_DRIVER_FLAG_ATTR;
  	}
  }
  
  /**
   * con_is_bound - checks if driver is bound to the console
   * @csw: console driver
   *
   * RETURNS: zero if unbound, nonzero if bound
   *
   * Drivers can call this and if zero, they should release
   * all resources allocated on con_startup()
   */
  int con_is_bound(const struct consw *csw)
  {
  	int i, bound = 0;
  
  	for (i = 0; i < MAX_NR_CONSOLES; i++) {
  		if (con_driver_map[i] == csw) {
  			bound = 1;
  			break;
  		}
  	}
  
  	return bound;
  }
  EXPORT_SYMBOL(con_is_bound);
  
  /**
   * con_debug_enter - prepare the console for the kernel debugger
   * @sw: console driver
   *
   * Called when the console is taken over by the kernel debugger, this
   * function needs to save the current console state, then put the console
   * into a state suitable for the kernel debugger.
   *
   * RETURNS:
   * Zero on success, nonzero if a failure occurred when trying to prepare
   * the console for the debugger.
   */
  int con_debug_enter(struct vc_data *vc)
  {
  	int ret = 0;
  
  	saved_fg_console = fg_console;
  	saved_last_console = last_console;
  	saved_want_console = want_console;
  	saved_vc_mode = vc->vc_mode;
  	saved_console_blanked = console_blanked;
  	vc->vc_mode = KD_TEXT;
  	console_blanked = 0;
  	if (vc->vc_sw->con_debug_enter)
  		ret = vc->vc_sw->con_debug_enter(vc);
  #ifdef CONFIG_KGDB_KDB
  	/* Set the initial LINES variable if it is not already set */
  	if (vc->vc_rows < 999) {
  		int linecount;
  		char lns[4];
  		const char *setargs[3] = {
  			"set",
  			"LINES",
  			lns,
  		};
  		if (kdbgetintenv(setargs[0], &linecount)) {
  			snprintf(lns, 4, "%i", vc->vc_rows);
  			kdb_set(2, setargs);
  		}
  	}
  	if (vc->vc_cols < 999) {
  		int colcount;
  		char cols[4];
  		const char *setargs[3] = {
  			"set",
  			"COLUMNS",
  			cols,
  		};
  		if (kdbgetintenv(setargs[0], &colcount)) {
  			snprintf(cols, 4, "%i", vc->vc_cols);
  			kdb_set(2, setargs);
  		}
  	}
  #endif /* CONFIG_KGDB_KDB */
  	return ret;
  }
  EXPORT_SYMBOL_GPL(con_debug_enter);
  
  /**
   * con_debug_leave - restore console state
   * @sw: console driver
   *
   * Restore the console state to what it was before the kernel debugger
   * was invoked.
   *
   * RETURNS:
   * Zero on success, nonzero if a failure occurred when trying to restore
   * the console.
   */
  int con_debug_leave(void)
  {
  	struct vc_data *vc;
  	int ret = 0;
  
  	fg_console = saved_fg_console;
  	last_console = saved_last_console;
  	want_console = saved_want_console;
  	console_blanked = saved_console_blanked;
  	vc_cons[fg_console].d->vc_mode = saved_vc_mode;
  
  	vc = vc_cons[fg_console].d;
  	if (vc->vc_sw->con_debug_leave)
  		ret = vc->vc_sw->con_debug_leave(vc);
  	return ret;
  }
  EXPORT_SYMBOL_GPL(con_debug_leave);
  
  static int do_register_con_driver(const struct consw *csw, int first, int last)
  {
  	struct module *owner = csw->owner;
  	struct con_driver *con_driver;
  	const char *desc;
  	int i, retval = 0;
  
  	WARN_CONSOLE_UNLOCKED();
  
  	if (!try_module_get(owner))
  		return -ENODEV;
  
  	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
  		con_driver = &registered_con_driver[i];
  
  		/* already registered */
  		if (con_driver->con == csw)
  			retval = -EBUSY;
  	}
  
  	if (retval)
  		goto err;
  
  	desc = csw->con_startup();
  
  	if (!desc)
  		goto err;
  
  	retval = -EINVAL;
  
  	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
  		con_driver = &registered_con_driver[i];
  
  		if (con_driver->con == NULL) {
  			con_driver->con = csw;
  			con_driver->desc = desc;
  			con_driver->node = i;
  			con_driver->flag = CON_DRIVER_FLAG_MODULE |
  			                   CON_DRIVER_FLAG_INIT;
  			con_driver->first = first;
  			con_driver->last = last;
  			retval = 0;
  			break;
  		}
  	}
  
  	if (retval)
  		goto err;
  
  	con_driver->dev = device_create(vtconsole_class, NULL,
  						MKDEV(0, con_driver->node),
  						NULL, "vtcon%i",
  						con_driver->node);
  
  	if (IS_ERR(con_driver->dev)) {
  		printk(KERN_WARNING "Unable to create device for %s; "
  		       "errno = %ld
  ", con_driver->desc,
  		       PTR_ERR(con_driver->dev));
  		con_driver->dev = NULL;
  	} else {
  		vtconsole_init_device(con_driver);
  	}
  
  err:
  	module_put(owner);
  	return retval;
  }
  
  
  /**
   * do_unregister_con_driver - unregister console driver from console layer
   * @csw: console driver
   *
   * DESCRIPTION: All drivers that registers to the console layer must
   * call this function upon exit, or if the console driver is in a state
   * where it won't be able to handle console services, such as the
   * framebuffer console without loaded framebuffer drivers.
   *
   * The driver must unbind first prior to unregistration.
   */
  int do_unregister_con_driver(const struct consw *csw)
  {
  	int i, retval = -ENODEV;
  
  	/* cannot unregister a bound driver */
  	if (con_is_bound(csw))
  		goto err;
  
  	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
  		struct con_driver *con_driver = &registered_con_driver[i];
  
  		if (con_driver->con == csw &&
  		    con_driver->flag & CON_DRIVER_FLAG_MODULE) {
  			vtconsole_deinit_device(con_driver);
  			device_destroy(vtconsole_class,
  				       MKDEV(0, con_driver->node));
  			con_driver->con = NULL;
  			con_driver->desc = NULL;
  			con_driver->dev = NULL;
  			con_driver->node = 0;
  			con_driver->flag = 0;
  			con_driver->first = 0;
  			con_driver->last = 0;
  			retval = 0;
  			break;
  		}
  	}
  err:
  	return retval;
  }
  EXPORT_SYMBOL_GPL(do_unregister_con_driver);
  
  /*
   *	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.
   *
   *	do_take_over_console is basically a register followed by unbind
   */
  int do_take_over_console(const struct consw *csw, int first, int last, int deflt)
  {
  	int err;
  
  	err = do_register_con_driver(csw, first, last);
  	/*
  	 * If we get an busy error we still want to bind the console driver
  	 * and return success, as we may have unbound the console driver
  	 * but not unregistered it.
  	 */
  	if (err == -EBUSY)
  		err = 0;
  	if (!err)
  		do_bind_con_driver(csw, first, last, deflt);
  
  	return err;
  }
  EXPORT_SYMBOL_GPL(do_take_over_console);
  
  
  /*
   * give_up_console is a wrapper to unregister_con_driver. It will only
   * work if driver is fully unbound.
   */
  void give_up_console(const struct consw *csw)
  {
  	console_lock();
  	do_unregister_con_driver(csw);
  	console_unlock();
  }
  
  static int __init vtconsole_class_init(void)
  {
  	int i;
  
  	vtconsole_class = class_create(THIS_MODULE, "vtconsole");
  	if (IS_ERR(vtconsole_class)) {
  		printk(KERN_WARNING "Unable to create vt console class; "
  		       "errno = %ld
  ", PTR_ERR(vtconsole_class));
  		vtconsole_class = NULL;
  	}
  
  	/* Add system drivers to sysfs */
  	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
  		struct con_driver *con = &registered_con_driver[i];
  
  		if (con->con && !con->dev) {
  			con->dev = device_create(vtconsole_class, NULL,
  							 MKDEV(0, con->node),
  							 NULL, "vtcon%i",
  							 con->node);
  
  			if (IS_ERR(con->dev)) {
  				printk(KERN_WARNING "Unable to create "
  				       "device for %s; errno = %ld
  ",
  				       con->desc, PTR_ERR(con->dev));
  				con->dev = NULL;
  			} else {
  				vtconsole_init_device(con);
  			}
  		}
  	}
  
  	return 0;
  }
  postcore_initcall(vtconsole_class_init);
  
  #endif
  
  /*
   *	Screen blanking
   */
  
  static int set_vesa_blanking(char __user *p)
  {
  	unsigned int mode;
  
  	if (get_user(mode, p + 1))
  		return -EFAULT;
  
  	vesa_blank_mode = (mode < 4) ? mode : 0;
  	return 0;
  }
  
  void do_blank_screen(int entering_gfx)
  {
  	struct vc_data *vc = vc_cons[fg_console].d;
  	int i;
  
  	WARN_CONSOLE_UNLOCKED();
  
  	if (console_blanked) {
  		if (blank_state == blank_vesa_wait) {
  			blank_state = blank_off;
  			vc->vc_sw->con_blank(vc, vesa_blank_mode + 1, 0);
  		}
  		return;
  	}
  
  	/* entering graphics mode? */
  	if (entering_gfx) {
  		hide_cursor(vc);
  		save_screen(vc);
  		vc->vc_sw->con_blank(vc, -1, 1);
  		console_blanked = fg_console + 1;
  		blank_state = blank_off;
  		set_origin(vc);
  		return;
  	}
  
  	if (blank_state != blank_normal_wait)
  		return;
  	blank_state = blank_off;
  
  	/* don't blank graphics */
  	if (vc->vc_mode != KD_TEXT) {
  		console_blanked = fg_console + 1;
  		return;
  	}
  
  	hide_cursor(vc);
  	del_timer_sync(&console_timer);
  	blank_timer_expired = 0;
  
  	save_screen(vc);
  	/* In case we need to reset origin, blanking hook returns 1 */
  	i = vc->vc_sw->con_blank(vc, vesa_off_interval ? 1 : (vesa_blank_mode + 1), 0);
  	console_blanked = fg_console + 1;
  	if (i)
  		set_origin(vc);
  
  	if (console_blank_hook && console_blank_hook(1))
  		return;
  
  	if (vesa_off_interval && vesa_blank_mode) {
  		blank_state = blank_vesa_wait;
  		mod_timer(&console_timer, jiffies + vesa_off_interval);
  	}
  	vt_event_post(VT_EVENT_BLANK, vc->vc_num, vc->vc_num);
  }
  EXPORT_SYMBOL(do_blank_screen);
  
  /*
   * Called by timer as well as from vt_console_driver
   */
  void do_unblank_screen(int leaving_gfx)
  {
  	struct vc_data *vc;
  
  	/* This should now always be called from a "sane" (read: can schedule)
  	 * context for the sake of the low level drivers, except in the special
  	 * case of oops_in_progress
  	 */
  	if (!oops_in_progress)
  		might_sleep();
  
  	WARN_CONSOLE_UNLOCKED();
  
  	ignore_poke = 0;
  	if (!console_blanked)
  		return;
  	if (!vc_cons_allocated(fg_console)) {
  		/* impossible */
  		pr_warning("unblank_screen: tty %d not allocated ??
  ",
  			   fg_console+1);
  		return;
  	}
  	vc = vc_cons[fg_console].d;
  	/* Try to unblank in oops case too */
  	if (vc->vc_mode != KD_TEXT && !vt_force_oops_output(vc))
  		return; /* but leave console_blanked != 0 */
  
  	if (blankinterval) {
  		mod_timer(&console_timer, jiffies + (blankinterval * HZ));
  		blank_state = blank_normal_wait;
  	}
  
  	console_blanked = 0;
  	if (vc->vc_sw->con_blank(vc, 0, leaving_gfx) || vt_force_oops_output(vc))
  		/* Low-level driver cannot restore -> do it ourselves */
  		update_screen(vc);
  	if (console_blank_hook)
  		console_blank_hook(0);
  	set_palette(vc);
  	set_cursor(vc);
  	vt_event_post(VT_EVENT_UNBLANK, vc->vc_num, vc->vc_num);
  }
  EXPORT_SYMBOL(do_unblank_screen);
  
  /*
   * This is called by the outside world to cause a forced unblank, mostly for
   * oopses. Currently, I just call do_unblank_screen(0), but we could eventually
   * call it with 1 as an argument and so force a mode restore... that may kill
   * X or at least garbage the screen but would also make the Oops visible...
   */
  void unblank_screen(void)
  {
  	do_unblank_screen(0);
  }
  
  /*
   * We defer the timer blanking to work queue so it can take the console mutex
   * (console operations can still happen at irq time, but only from printk which
   * has the console mutex. Not perfect yet, but better than no locking
   */
  static void blank_screen_t(unsigned long dummy)
  {
  	if (unlikely(!keventd_up())) {
  		mod_timer(&console_timer, jiffies + (blankinterval * HZ));
  		return;
  	}
  	blank_timer_expired = 1;
  	schedule_work(&console_work);
  }
  
  void poke_blanked_console(void)
  {
  	WARN_CONSOLE_UNLOCKED();
  
  	/* Add this so we quickly catch whoever might call us in a non
  	 * safe context. Nowadays, unblank_screen() isn't to be called in
  	 * atomic contexts and is allowed to schedule (with the special case
  	 * of oops_in_progress, but that isn't of any concern for this
  	 * function. --BenH.
  	 */
  	might_sleep();
  
  	/* This isn't perfectly race free, but a race here would be mostly harmless,
  	 * at worse, we'll do a spurrious blank and it's unlikely
  	 */
  	del_timer(&console_timer);
  	blank_timer_expired = 0;
  
  	if (ignore_poke || !vc_cons[fg_console].d || vc_cons[fg_console].d->vc_mode == KD_GRAPHICS)
  		return;
  	if (console_blanked)
  		unblank_screen();
  	else if (blankinterval) {
  		mod_timer(&console_timer, jiffies + (blankinterval * HZ));
  		blank_state = blank_normal_wait;
  	}
  }
  
  /*
   *	Palettes
   */
  
  static void set_palette(struct vc_data *vc)
  {
  	WARN_CONSOLE_UNLOCKED();
  
  	if (vc->vc_mode != KD_GRAPHICS)
  		vc->vc_sw->con_set_palette(vc, color_table);
  }
  
  /*
   * 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 __user *arg)
  {
  	int i, j, k;
  	unsigned char colormap[3*16];
  
  	if (copy_from_user(colormap, arg, sizeof(colormap)))
  		return -EFAULT;
  
  	console_lock();
  	for (i = k = 0; i < 16; i++) {
  		default_red[i] = colormap[k++];
  		default_grn[i] = colormap[k++];
  		default_blu[i] = colormap[k++];
  	}
  	for (i = 0; i < MAX_NR_CONSOLES; i++) {
  		if (!vc_cons_allocated(i))
  			continue;
  		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(vc_cons[i].d);
  	}
  	console_unlock();
  
  	return 0;
  }
  
  int con_get_cmap(unsigned char __user *arg)
  {
  	int i, k;
  	unsigned char colormap[3*16];
  
  	console_lock();
  	for (i = k = 0; i < 16; i++) {
  		colormap[k++] = default_red[i];
  		colormap[k++] = default_grn[i];
  		colormap[k++] = default_blu[i];
  	}
  	console_unlock();
  
  	if (copy_to_user(arg, colormap, sizeof(colormap)))
  		return -EFAULT;
  
  	return 0;
  }
  
  void reset_palette(struct vc_data *vc)
  {
  	int j, k;
  	for (j=k=0; j<16; j++) {
  		vc->vc_palette[k++] = default_red[j];
  		vc->vc_palette[k++] = default_grn[j];
  		vc->vc_palette[k++] = default_blu[j];
  	}
  	set_palette(vc);
  }
  
  /*
   *  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 up to 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 won't have to convert the fontdata all the time.
   *  /Jes
   */
  
  #define max_font_size 65536
  
  static int con_font_get(struct vc_data *vc, struct console_font_op *op)
  {
  	struct console_font font;
  	int rc = -EINVAL;
  	int c;
  
  	if (op->data) {
  		font.data = kmalloc(max_font_size, GFP_KERNEL);
  		if (!font.data)
  			return -ENOMEM;
  	} else
  		font.data = NULL;
  
  	console_lock();
  	if (vc->vc_mode != KD_TEXT)
  		rc = -EINVAL;
  	else if (vc->vc_sw->con_font_get)
  		rc = vc->vc_sw->con_font_get(vc, &font);
  	else
  		rc = -ENOSYS;
  	console_unlock();
  
  	if (rc)
  		goto out;
  
  	c = (font.width+7)/8 * 32 * font.charcount;
  
  	if (op->data && font.charcount > op->charcount)
  		rc = -ENOSPC;
  	if (!(op->flags & KD_FONT_FLAG_OLD)) {
  		if (font.width > op->width || font.height > op->height) 
  			rc = -ENOSPC;
  	} else {
  		if (font.width != 8)
  			rc = -EIO;
  		else if ((op->height && font.height > op->height) ||
  			 font.height > 32)
  			rc = -ENOSPC;
  	}
  	if (rc)
  		goto out;
  
  	op->height = font.height;
  	op->width = font.width;
  	op->charcount = font.charcount;
  
  	if (op->data && copy_to_user(op->data, font.data, c))
  		rc = -EFAULT;
  
  out:
  	kfree(font.data);
  	return rc;
  }
  
  static int con_font_set(struct vc_data *vc, struct console_font_op *op)
  {
  	struct console_font font;
  	int rc = -EINVAL;
  	int size;
  
  	if (vc->vc_mode != KD_TEXT)
  		return -EINVAL;
  	if (!op->data)
  		return -EINVAL;
  	if (op->charcount > 512)
  		return -EINVAL;
  	if (!op->height) {		/* Need to guess font height [compat] */
  		int h, i;
  		u8 __user *charmap = op->data;
  		u8 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))
  			return -EINVAL;
  		for (h = 32; h > 0; h--)
  			for (i = 0; i < op->charcount; i++) {
  				if (get_user(tmp, &charmap[32*i+h-1]))
  					return -EFAULT;
  				if (tmp)
  					goto nonzero;
  			}
  		return -EINVAL;
  	nonzero:
  		op->height = h;
  	}
  	if (op->width <= 0 || op->width > 32 || op->height > 32)
  		return -EINVAL;
  	size = (op->width+7)/8 * 32 * op->charcount;
  	if (size > max_font_size)
  		return -ENOSPC;
  	font.charcount = op->charcount;
  	font.height = op->height;
  	font.width = op->width;
  	font.data = memdup_user(op->data, size);
  	if (IS_ERR(font.data))
  		return PTR_ERR(font.data);
  	console_lock();
  	if (vc->vc_mode != KD_TEXT)
  		rc = -EINVAL;
  	else if (vc->vc_sw->con_font_set)
  		rc = vc->vc_sw->con_font_set(vc, &font, op->flags);
  	else
  		rc = -ENOSYS;
  	console_unlock();
  	kfree(font.data);
  	return rc;
  }
  
  static int con_font_default(struct vc_data *vc, struct console_font_op *op)
  {
  	struct console_font font = {.width = op->width, .height = op->height};
  	char name[MAX_FONT_NAME];
  	char *s = name;
  	int rc;
  
  
  	if (!op->data)
  		s = NULL;
  	else if (strncpy_from_user(name, op->data, MAX_FONT_NAME - 1) < 0)
  		return -EFAULT;
  	else
  		name[MAX_FONT_NAME - 1] = 0;
  
  	console_lock();
  	if (vc->vc_mode != KD_TEXT) {
  		console_unlock();
  		return -EINVAL;
  	}
  	if (vc->vc_sw->con_font_default)
  		rc = vc->vc_sw->con_font_default(vc, &font, s);
  	else
  		rc = -ENOSYS;
  	console_unlock();
  	if (!rc) {
  		op->width = font.width;
  		op->height = font.height;
  	}
  	return rc;
  }
  
  static int con_font_copy(struct vc_data *vc, struct console_font_op *op)
  {
  	int con = op->height;
  	int rc;
  
  
  	console_lock();
  	if (vc->vc_mode != KD_TEXT)
  		rc = -EINVAL;
  	else if (!vc->vc_sw->con_font_copy)
  		rc = -ENOSYS;
  	else if (con < 0 || !vc_cons_allocated(con))
  		rc = -ENOTTY;
  	else if (con == vc->vc_num)	/* nothing to do */
  		rc = 0;
  	else
  		rc = vc->vc_sw->con_font_copy(vc, con);
  	console_unlock();
  	return rc;
  }
  
  int con_font_op(struct vc_data *vc, struct console_font_op *op)
  {
  	switch (op->op) {
  	case KD_FONT_OP_SET:
  		return con_font_set(vc, op);
  	case KD_FONT_OP_GET:
  		return con_font_get(vc, op);
  	case KD_FONT_OP_SET_DEFAULT:
  		return con_font_default(vc, op);
  	case KD_FONT_OP_COPY:
  		return con_font_copy(vc, op);
  	}
  	return -ENOSYS;
  }
  
  /*
   *	Interface exported to selection and vcs.
   */
  
  /* used by selection */
  u16 screen_glyph(struct vc_data *vc, int offset)
  {
  	u16 w = scr_readw(screenpos(vc, offset, 1));
  	u16 c = w & 0xff;
  
  	if (w & vc->vc_hi_font_mask)
  		c |= 0x100;
  	return c;
  }
  EXPORT_SYMBOL_GPL(screen_glyph);
  
  /* used by vcs - note the word offset */
  unsigned short *screen_pos(struct vc_data *vc, int w_offset, int viewed)
  {
  	return screenpos(vc, 2 * w_offset, viewed);
  }
  
  void getconsxy(struct vc_data *vc, unsigned char *p)
  {
  	p[0] = vc->vc_x;
  	p[1] = vc->vc_y;
  }
  
  void putconsxy(struct vc_data *vc, unsigned char *p)
  {
  	hide_cursor(vc);
  	gotoxy(vc, p[0], p[1]);
  	set_cursor(vc);
  }
  
  u16 vcs_scr_readw(struct vc_data *vc, const u16 *org)
  {
  	if ((unsigned long)org == vc->vc_pos && softcursor_original != -1)
  		return softcursor_original;
  	return scr_readw(org);
  }
  
  void vcs_scr_writew(struct vc_data *vc, u16 val, u16 *org)
  {
  	scr_writew(val, org);
  	if ((unsigned long)org == vc->vc_pos) {
  		softcursor_original = -1;
  		add_softcursor(vc);
  	}
  }
  
  void vcs_scr_updated(struct vc_data *vc)
  {
  	notify_update(vc);
  }
  
  /*
   *	Visible symbols for modules
   */
  
  EXPORT_SYMBOL(color_table);
  EXPORT_SYMBOL(default_red);
  EXPORT_SYMBOL(default_grn);
  EXPORT_SYMBOL(default_blu);
  EXPORT_SYMBOL(update_region);
  EXPORT_SYMBOL(redraw_screen);
  EXPORT_SYMBOL(vc_resize);
  EXPORT_SYMBOL(fg_console);
  EXPORT_SYMBOL(console_blank_hook);
  EXPORT_SYMBOL(console_blanked);
  EXPORT_SYMBOL(vc_cons);
  EXPORT_SYMBOL(global_cursor_default);
  #ifndef VT_SINGLE_DRIVER
  EXPORT_SYMBOL(give_up_console);
  #endif