Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 4785 insertions, 0 deletions

diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c
new file mode 100644
index 0000000000..5c47f77804
--- /dev/null
+++ b/drivers/tty/vt/vt.c
@@ -0,0 +1,4785 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  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/signal.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/vmalloc.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>
+#include <linux/bsearch.h>
+#include <linux/gcd.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
+#define CON_DRIVER_FLAG_ZOMBIE 8
+
+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;
+
+/*
+ * Here is the default bell parameters: 750HZ, 1/8th of a second
+ */
+#define DEFAULT_BELL_PITCH	750
+#define DEFAULT_BELL_DURATION	(HZ/8)
+#define DEFAULT_CURSOR_BLINK_MS	200
+
+struct vc vc_cons [MAX_NR_CONSOLES];
+EXPORT_SYMBOL(vc_cons);
+
+static const struct consw *con_driver_map[MAX_NR_CONSOLES];
+
+static int con_open(struct tty_struct *, struct file *);
+static void vc_init(struct vc_data *vc, 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 con_driver_unregister_callback(struct work_struct *ignored);
+static void blank_screen_t(struct timer_list *unused);
+static void set_palette(struct vc_data *vc);
+static void unblank_screen(void);
+
+#define vt_get_kmsg_redirect() vt_kmsg_redirect(-1)
+
+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);
+EXPORT_SYMBOL(global_cursor_default);
+
+static int cur_default = CUR_UNDERLINE;
+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;
+EXPORT_SYMBOL(console_blanked);
+
+static int vesa_blank_mode; /* 0:none 1:suspendV 2:suspendH 3:powerdown */
+static int vesa_off_interval;
+static int blankinterval;
+core_param(consoleblank, blankinterval, int, 0444);
+
+static DECLARE_WORK(console_work, console_callback);
+static DECLARE_WORK(con_driver_unregister_work, con_driver_unregister_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;
+EXPORT_SYMBOL(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);
+EXPORT_SYMBOL(console_blank_hook);
+
+static DEFINE_TIMER(console_timer, blank_screen_t);
+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
+ */
+
+static inline bool con_is_fg(const struct vc_data *vc)
+{
+	return vc->vc_num == fg_console;
+}
+
+static inline bool con_should_update(const struct vc_data *vc)
+{
+	return con_is_visible(vc) && !console_blanked;
+}
+
+static inline unsigned short *screenpos(const struct vc_data *vc, int offset,
+		bool 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);
+}
+
+/*
+ * Code to manage unicode-based screen buffers
+ */
+
+/*
+ * Our screen buffer is preceded by an array of line pointers so that
+ * scrolling only implies some pointer shuffling.
+ */
+
+static u32 **vc_uniscr_alloc(unsigned int cols, unsigned int rows)
+{
+	u32 **uni_lines;
+	void *p;
+	unsigned int memsize, i, col_size = cols * sizeof(**uni_lines);
+
+	/* allocate everything in one go */
+	memsize = col_size * rows;
+	memsize += rows * sizeof(*uni_lines);
+	uni_lines = vzalloc(memsize);
+	if (!uni_lines)
+		return NULL;
+
+	/* initial line pointers */
+	p = uni_lines + rows;
+	for (i = 0; i < rows; i++) {
+		uni_lines[i] = p;
+		p += col_size;
+	}
+
+	return uni_lines;
+}
+
+static void vc_uniscr_free(u32 **uni_lines)
+{
+	vfree(uni_lines);
+}
+
+static void vc_uniscr_set(struct vc_data *vc, u32 **new_uni_lines)
+{
+	vc_uniscr_free(vc->vc_uni_lines);
+	vc->vc_uni_lines = new_uni_lines;
+}
+
+static void vc_uniscr_putc(struct vc_data *vc, u32 uc)
+{
+	if (vc->vc_uni_lines)
+		vc->vc_uni_lines[vc->state.y][vc->state.x] = uc;
+}
+
+static void vc_uniscr_insert(struct vc_data *vc, unsigned int nr)
+{
+	if (vc->vc_uni_lines) {
+		u32 *ln = vc->vc_uni_lines[vc->state.y];
+		unsigned int x = vc->state.x, cols = vc->vc_cols;
+
+		memmove(&ln[x + nr], &ln[x], (cols - x - nr) * sizeof(*ln));
+		memset32(&ln[x], ' ', nr);
+	}
+}
+
+static void vc_uniscr_delete(struct vc_data *vc, unsigned int nr)
+{
+	if (vc->vc_uni_lines) {
+		u32 *ln = vc->vc_uni_lines[vc->state.y];
+		unsigned int x = vc->state.x, cols = vc->vc_cols;
+
+		memcpy(&ln[x], &ln[x + nr], (cols - x - nr) * sizeof(*ln));
+		memset32(&ln[cols - nr], ' ', nr);
+	}
+}
+
+static void vc_uniscr_clear_line(struct vc_data *vc, unsigned int x,
+				 unsigned int nr)
+{
+	if (vc->vc_uni_lines)
+		memset32(&vc->vc_uni_lines[vc->state.y][x], ' ', nr);
+}
+
+static void vc_uniscr_clear_lines(struct vc_data *vc, unsigned int y,
+				  unsigned int nr)
+{
+	if (vc->vc_uni_lines)
+		while (nr--)
+			memset32(vc->vc_uni_lines[y++], ' ', vc->vc_cols);
+}
+
+/* juggling array rotation algorithm (complexity O(N), size complexity O(1)) */
+static void juggle_array(u32 **array, unsigned int size, unsigned int nr)
+{
+	unsigned int gcd_idx;
+
+	for (gcd_idx = 0; gcd_idx < gcd(nr, size); gcd_idx++) {
+		u32 *gcd_idx_val = array[gcd_idx];
+		unsigned int dst_idx = gcd_idx;
+
+		while (1) {
+			unsigned int src_idx = (dst_idx + nr) % size;
+			if (src_idx == gcd_idx)
+				break;
+
+			array[dst_idx] = array[src_idx];
+			dst_idx = src_idx;
+		}
+
+		array[dst_idx] = gcd_idx_val;
+	}
+}
+
+static void vc_uniscr_scroll(struct vc_data *vc, unsigned int top,
+			     unsigned int bottom, enum con_scroll dir,
+			     unsigned int nr)
+{
+	u32 **uni_lines = vc->vc_uni_lines;
+	unsigned int size = bottom - top;
+
+	if (!uni_lines)
+		return;
+
+	if (dir == SM_DOWN) {
+		juggle_array(&uni_lines[top], size, size - nr);
+		vc_uniscr_clear_lines(vc, top, nr);
+	} else {
+		juggle_array(&uni_lines[top], size, nr);
+		vc_uniscr_clear_lines(vc, bottom - nr, nr);
+	}
+}
+
+static void vc_uniscr_copy_area(u32 **dst_lines,
+				unsigned int dst_cols,
+				unsigned int dst_rows,
+				u32 **src_lines,
+				unsigned int src_cols,
+				unsigned int src_top_row,
+				unsigned int src_bot_row)
+{
+	unsigned int dst_row = 0;
+
+	if (!dst_lines)
+		return;
+
+	while (src_top_row < src_bot_row) {
+		u32 *src_line = src_lines[src_top_row];
+		u32 *dst_line = dst_lines[dst_row];
+
+		memcpy(dst_line, src_line, src_cols * sizeof(*src_line));
+		if (dst_cols - src_cols)
+			memset32(dst_line + src_cols, ' ', dst_cols - src_cols);
+		src_top_row++;
+		dst_row++;
+	}
+	while (dst_row < dst_rows) {
+		u32 *dst_line = dst_lines[dst_row];
+
+		memset32(dst_line, ' ', dst_cols);
+		dst_row++;
+	}
+}
+
+/*
+ * Called from vcs_read() to make sure unicode screen retrieval is possible.
+ * This will initialize the unicode screen buffer if not already done.
+ * This returns 0 if OK, or a negative error code otherwise.
+ * In particular, -ENODATA is returned if the console is not in UTF-8 mode.
+ */
+int vc_uniscr_check(struct vc_data *vc)
+{
+	u32 **uni_lines;
+	unsigned short *p;
+	int x, y, mask;
+
+	WARN_CONSOLE_UNLOCKED();
+
+	if (!vc->vc_utf)
+		return -ENODATA;
+
+	if (vc->vc_uni_lines)
+		return 0;
+
+	uni_lines = vc_uniscr_alloc(vc->vc_cols, vc->vc_rows);
+	if (!uni_lines)
+		return -ENOMEM;
+
+	/*
+	 * Let's populate it initially with (imperfect) reverse translation.
+	 * This is the next best thing we can do short of having it enabled
+	 * from the start even when no users rely on this functionality. True
+	 * unicode content will be available after a complete screen refresh.
+	 */
+	p = (unsigned short *)vc->vc_origin;
+	mask = vc->vc_hi_font_mask | 0xff;
+	for (y = 0; y < vc->vc_rows; y++) {
+		u32 *line = uni_lines[y];
+		for (x = 0; x < vc->vc_cols; x++) {
+			u16 glyph = scr_readw(p++) & mask;
+			line[x] = inverse_translate(vc, glyph, true);
+		}
+	}
+
+	vc->vc_uni_lines = uni_lines;
+
+	return 0;
+}
+
+/*
+ * Called from vcs_read() to get the unicode data from the screen.
+ * This must be preceded by a successful call to vc_uniscr_check() once
+ * the console lock has been taken.
+ */
+void vc_uniscr_copy_line(const struct vc_data *vc, void *dest, bool viewed,
+			 unsigned int row, unsigned int col, unsigned int nr)
+{
+	u32 **uni_lines = vc->vc_uni_lines;
+	int offset = row * vc->vc_size_row + col * 2;
+	unsigned long pos;
+
+	if (WARN_ON_ONCE(!uni_lines))
+		return;
+
+	pos = (unsigned long)screenpos(vc, offset, viewed);
+	if (pos >= vc->vc_origin && pos < vc->vc_scr_end) {
+		/*
+		 * Desired position falls in the main screen buffer.
+		 * However the actual row/col might be different if
+		 * scrollback is active.
+		 */
+		row = (pos - vc->vc_origin) / vc->vc_size_row;
+		col = ((pos - vc->vc_origin) % vc->vc_size_row) / 2;
+		memcpy(dest, &uni_lines[row][col], nr * sizeof(u32));
+	} else {
+		/*
+		 * Scrollback is active. For now let's simply backtranslate
+		 * the screen glyphs until the unicode screen buffer does
+		 * synchronize with console display drivers for a scrollback
+		 * buffer of its own.
+		 */
+		u16 *p = (u16 *)pos;
+		int mask = vc->vc_hi_font_mask | 0xff;
+		u32 *uni_buf = dest;
+		while (nr--) {
+			u16 glyph = scr_readw(p++) & mask;
+			*uni_buf++ = inverse_translate(vc, glyph, true);
+		}
+	}
+}
+
+static void con_scroll(struct vc_data *vc, unsigned int top,
+		       unsigned int bottom, enum con_scroll dir,
+		       unsigned int nr)
+{
+	unsigned int rows = bottom - top;
+	u16 *clear, *dst, *src;
+
+	if (top + nr >= bottom)
+		nr = rows - 1;
+	if (bottom > vc->vc_rows || top >= bottom || nr < 1)
+		return;
+
+	vc_uniscr_scroll(vc, top, bottom, dir, nr);
+	if (con_is_visible(vc) &&
+			vc->vc_sw->con_scroll(vc, top, bottom, dir, nr))
+		return;
+
+	src = clear = (u16 *)(vc->vc_origin + vc->vc_size_row * top);
+	dst = (u16 *)(vc->vc_origin + vc->vc_size_row * (top + nr));
+
+	if (dir == SM_UP) {
+		clear = src + (rows - nr) * vc->vc_cols;
+		swap(src, dst);
+	}
+	scr_memmovew(dst, src, (rows - nr) * vc->vc_size_row);
+	scr_memsetw(clear, vc->vc_video_erase_char, vc->vc_size_row * nr);
+}
+
+static void do_update_region(struct vc_data *vc, unsigned long start, int count)
+{
+	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);
+		}
+	}
+}
+
+void update_region(struct vc_data *vc, unsigned long start, int count)
+{
+	WARN_CONSOLE_UNLOCKED();
+
+	if (con_should_update(vc)) {
+		hide_cursor(vc);
+		do_update_region(vc, start, count);
+		set_cursor(vc);
+	}
+}
+EXPORT_SYMBOL(update_region);
+
+/* Structure of attributes is hardware-dependent */
+
+static u8 build_attr(struct vc_data *vc, u8 _color,
+		enum vc_intensity _intensity, bool _blink, bool _underline,
+		bool _reverse, bool _italic)
+{
+	if (vc->vc_sw->con_build_attr)
+		return vc->vc_sw->con_build_attr(vc, _color, _intensity,
+		       _blink, _underline, _reverse, _italic);
+
+/*
+ * ++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    << 1) |
+		       (_underline << 2) |
+		       (_reverse   << 3) |
+		       (_blink     << 7);
+	if (_italic)
+		a = (a & 0xF0) | vc->vc_itcolor;
+	else if (_underline)
+		a = (a & 0xf0) | vc->vc_ulcolor;
+	else if (_intensity == VCI_HALF_BRIGHT)
+		a = (a & 0xf0) | vc->vc_halfcolor;
+	if (_reverse)
+		a = (a & 0x88) | (((a >> 4) | (a << 4)) & 0x77);
+	if (_blink)
+		a ^= 0x80;
+	if (_intensity == VCI_BOLD)
+		a ^= 0x08;
+	if (vc->vc_hi_font_mask == 0x100)
+		a <<= 1;
+	return a;
+	}
+}
+
+static void update_attr(struct vc_data *vc)
+{
+	vc->vc_attr = build_attr(vc, vc->state.color, vc->state.intensity,
+	              vc->state.blink, vc->state.underline,
+	              vc->state.reverse ^ vc->vc_decscnm, vc->state.italic);
+	vc->vc_video_erase_char = ' ' | (build_attr(vc, vc->state.color,
+				VCI_NORMAL, vc->state.blink, false,
+				vc->vc_decscnm, false) << 8);
+}
+
+/* Note: inverting the screen twice should revert to the original state */
+void invert_screen(struct vc_data *vc, int offset, int count, bool 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);
+	} 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++;
+			}
+		}
+	}
+
+	if (con_should_update(vc))
+		do_update_region(vc, (unsigned long) p, count);
+	notify_update(vc);
+}
+
+/* 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, true));
+		if (con_should_update(vc))
+			vc->vc_sw->con_putc(vc, old, oldy, oldx);
+		notify_update(vc);
+	}
+
+	old_offset = offset;
+
+	if (offset != -1 && offset >= 0 &&
+	    offset < vc->vc_screenbuf_size) {
+		unsigned short new;
+		unsigned short *p;
+		p = screenpos(vc, offset, true);
+		old = scr_readw(p);
+		new = old ^ vc->vc_complement_mask;
+		scr_writew(new, p);
+		if (con_should_update(vc)) {
+			oldx = (offset >> 1) % vc->vc_cols;
+			oldy = (offset >> 1) / vc->vc_cols;
+			vc->vc_sw->con_putc(vc, new, oldy, oldx);
+		}
+		notify_update(vc);
+	}
+}
+
+static void insert_char(struct vc_data *vc, unsigned int nr)
+{
+	unsigned short *p = (unsigned short *) vc->vc_pos;
+
+	vc_uniscr_insert(vc, nr);
+	scr_memmovew(p + nr, p, (vc->vc_cols - vc->state.x - nr) * 2);
+	scr_memsetw(p, vc->vc_video_erase_char, nr * 2);
+	vc->vc_need_wrap = 0;
+	if (con_should_update(vc))
+		do_update_region(vc, (unsigned long) p,
+			vc->vc_cols - vc->state.x);
+}
+
+static void delete_char(struct vc_data *vc, unsigned int nr)
+{
+	unsigned short *p = (unsigned short *) vc->vc_pos;
+
+	vc_uniscr_delete(vc, nr);
+	scr_memmovew(p, p + nr, (vc->vc_cols - vc->state.x - nr) * 2);
+	scr_memsetw(p + vc->vc_cols - vc->state.x - nr, vc->vc_video_erase_char,
+			nr * 2);
+	vc->vc_need_wrap = 0;
+	if (con_should_update(vc))
+		do_update_region(vc, (unsigned long) p,
+			vc->vc_cols - vc->state.x);
+}
+
+static int softcursor_original = -1;
+
+static void add_softcursor(struct vc_data *vc)
+{
+	int i = scr_readw((u16 *) vc->vc_pos);
+	u32 type = vc->vc_cursor_type;
+
+	if (!(type & CUR_SW))
+		return;
+	if (softcursor_original != -1)
+		return;
+	softcursor_original = i;
+	i |= CUR_SET(type);
+	i ^= CUR_CHANGE(type);
+	if ((type & CUR_ALWAYS_BG) &&
+			(softcursor_original & CUR_BG) == (i & CUR_BG))
+		i ^= CUR_BG;
+	if ((type & CUR_INVERT_FG_BG) && (i & CUR_FG) == ((i & CUR_BG) >> 4))
+		i ^= CUR_FG;
+	scr_writew(i, (u16 *)vc->vc_pos);
+	if (con_should_update(vc))
+		vc->vc_sw->con_putc(vc, i, vc->state.y, vc->state.x);
+}
+
+static void hide_softcursor(struct vc_data *vc)
+{
+	if (softcursor_original != -1) {
+		scr_writew(softcursor_original, (u16 *)vc->vc_pos);
+		if (con_should_update(vc))
+			vc->vc_sw->con_putc(vc, softcursor_original,
+					vc->state.y, vc->state.x);
+		softcursor_original = -1;
+	}
+}
+
+static void hide_cursor(struct vc_data *vc)
+{
+	if (vc_is_sel(vc))
+		clear_selection();
+
+	vc->vc_sw->con_cursor(vc, CM_ERASE);
+	hide_softcursor(vc);
+}
+
+static void set_cursor(struct vc_data *vc)
+{
+	if (!con_is_fg(vc) || console_blanked || vc->vc_mode == KD_GRAPHICS)
+		return;
+	if (vc->vc_deccm) {
+		if (vc_is_sel(vc))
+			clear_selection();
+		add_softcursor(vc);
+		if (CUR_SIZE(vc->vc_cursor_type) != CUR_NONE)
+			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->state.y +
+		2 * vc->state.x;
+}
+
+static void save_screen(struct vc_data *vc)
+{
+	WARN_CONSOLE_UNLOCKED();
+
+	if (vc->vc_sw->con_save_screen)
+		vc->vc_sw->con_save_screen(vc);
+}
+
+static void flush_scrollback(struct vc_data *vc)
+{
+	WARN_CONSOLE_UNLOCKED();
+
+	set_origin(vc);
+	if (vc->vc_sw->con_flush_scrollback) {
+		vc->vc_sw->con_flush_scrollback(vc);
+	} else if (con_is_visible(vc)) {
+		/*
+		 * When no con_flush_scrollback method is provided then the
+		 * legacy way for flushing the scrollback buffer is to use
+		 * a side effect of the con_switch method. We do it only on
+		 * the foreground console as background consoles have no
+		 * scrollback buffers in that case and we obviously don't
+		 * want to switch to them.
+		 */
+		hide_cursor(vc);
+		vc->vc_sw->con_switch(vc);
+		set_cursor(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 ??\n", 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);
+		}
+
+		if (update && vc->vc_mode != KD_GRAPHICS)
+			do_update_region(vc, vc->vc_origin, vc->vc_screenbuf_size / 2);
+	}
+	set_cursor(vc);
+	if (is_switch) {
+		vt_set_leds_compute_shiftstate();
+		notify_update(vc);
+	}
+}
+EXPORT_SYMBOL(redraw_screen);
+
+/*
+ *	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;
+
+	if (con_driver_map[num])
+		vc->vc_sw = con_driver_map[num];
+
+	__module_get(vc->vc_sw->owner);
+	vc->vc_num = num;
+	vc->vc_display_fg = &master_display_fg;
+	if (vc->uni_pagedict_loc)
+		con_free_unimap(vc);
+	vc->uni_pagedict_loc = &vc->uni_pagedict;
+	vc->uni_pagedict = NULL;
+	vc->vc_hi_font_mask = 0;
+	vc->vc_complement_mask = 0;
+	vc->vc_can_do_color = 0;
+	vc->vc_cur_blink_ms = DEFAULT_CURSOR_BLINK_MS;
+	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;
+}
+
+
+static void visual_deinit(struct vc_data *vc)
+{
+	vc->vc_sw->con_deinit(vc);
+	module_put(vc->vc_sw->owner);
+}
+
+static void vc_port_destruct(struct tty_port *port)
+{
+	struct vc_data *vc = container_of(port, struct vc_data, port);
+
+	kfree(vc);
+}
+
+static const struct tty_port_operations vc_port_ops = {
+	.destruct = vc_port_destruct,
+};
+
+/*
+ * 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_MAXCOL (32767)
+#define VC_MAXROW (32767)
+
+int vc_allocate(unsigned int currcons)	/* return 0 on success */
+{
+	struct vt_notifier_param param;
+	struct vc_data *vc;
+	int err;
+
+	WARN_CONSOLE_UNLOCKED();
+
+	if (currcons >= MAX_NR_CONSOLES)
+		return -ENXIO;
+
+	if (vc_cons[currcons].d)
+		return 0;
+
+	/* 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);
+	vc->port.ops = &vc_port_ops;
+	INIT_WORK(&vc_cons[currcons].SAK_work, vc_SAK);
+
+	visual_init(vc, currcons, 1);
+
+	if (!*vc->uni_pagedict_loc)
+		con_set_default_unimap(vc);
+
+	err = -EINVAL;
+	if (vc->vc_cols > VC_MAXCOL || vc->vc_rows > VC_MAXROW ||
+	    vc->vc_screenbuf_size > KMALLOC_MAX_SIZE || !vc->vc_screenbuf_size)
+		goto err_free;
+	err = -ENOMEM;
+	vc->vc_screenbuf = kzalloc(vc->vc_screenbuf_size, GFP_KERNEL);
+	if (!vc->vc_screenbuf)
+		goto err_free;
+
+	/* 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, 1);
+	vcs_make_sysfs(currcons);
+	atomic_notifier_call_chain(&vt_notifier_list, VT_ALLOCATE, &param);
+
+	return 0;
+err_free:
+	visual_deinit(vc);
+	kfree(vc);
+	vc_cons[currcons].d = NULL;
+	return err;
+}
+
+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_sw->con_resize)
+		err = vc->vc_sw->con_resize(vc, width, height, user);
+
+	return err;
+}
+
+/**
+ *	vc_do_resize	-	resizing method for the tty
+ *	@tty: tty being resized
+ *	@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, first_copied_row;
+	unsigned int new_cols, new_rows, new_row_size, new_screen_size;
+	unsigned int user;
+	unsigned short *oldscreen, *newscreen;
+	u32 **new_uniscr = NULL;
+
+	WARN_CONSOLE_UNLOCKED();
+
+	if (!vc)
+		return -ENXIO;
+
+	user = vc->vc_resize_user;
+	vc->vc_resize_user = 0;
+
+	if (cols > VC_MAXCOL || lines > VC_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) {
+		/*
+		 * This function is being called here to cover the case
+		 * where the userspace calls the FBIOPUT_VSCREENINFO twice,
+		 * passing the same fb_var_screeninfo containing the fields
+		 * yres/xres equal to a number non-multiple of vc_font.height
+		 * and yres_virtual/xres_virtual equal to number lesser than the
+		 * vc_font.height and yres/xres.
+		 * In the second call, the struct fb_var_screeninfo isn't
+		 * being modified by the underlying driver because of the
+		 * if above, and this causes the fbcon_display->vrows to become
+		 * negative and it eventually leads to out-of-bound
+		 * access by the imageblit function.
+		 * To give the correct values to the struct and to not have
+		 * to deal with possible errors from the code below, we call
+		 * the resize_screen here as well.
+		 */
+		return resize_screen(vc, new_cols, new_rows, user);
+	}
+
+	if (new_screen_size > KMALLOC_MAX_SIZE || !new_screen_size)
+		return -EINVAL;
+	newscreen = kzalloc(new_screen_size, GFP_USER);
+	if (!newscreen)
+		return -ENOMEM;
+
+	if (vc->vc_uni_lines) {
+		new_uniscr = vc_uniscr_alloc(new_cols, new_rows);
+		if (!new_uniscr) {
+			kfree(newscreen);
+			return -ENOMEM;
+		}
+	}
+
+	if (vc_is_sel(vc))
+		clear_selection();
+
+	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);
+		vc_uniscr_free(new_uniscr);
+		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->state.y > new_rows) {
+		if (old_rows - vc->state.y < new_rows) {
+			/*
+			 * Cursor near the bottom, copy contents from the
+			 * bottom of buffer
+			 */
+			first_copied_row = (old_rows - new_rows);
+		} else {
+			/*
+			 * Cursor is in no man's land, copy 1/2 screenful
+			 * from the top and bottom of cursor position
+			 */
+			first_copied_row = (vc->state.y - new_rows/2);
+		}
+		old_origin += first_copied_row * old_row_size;
+	} else
+		first_copied_row = 0;
+	end = old_origin + old_row_size * min(old_rows, new_rows);
+
+	vc_uniscr_copy_area(new_uniscr, new_cols, new_rows,
+			    vc->vc_uni_lines, rlth/2, first_copied_row,
+			    min(old_rows, new_rows));
+	vc_uniscr_set(vc, new_uniscr);
+
+	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);
+	oldscreen = vc->vc_screenbuf;
+	vc->vc_screenbuf = newscreen;
+	vc->vc_screenbuf_size = new_screen_size;
+	set_origin(vc);
+	kfree(oldscreen);
+
+	/* do part of a reset_terminal() */
+	vc->vc_top = 0;
+	vc->vc_bottom = vc->vc_rows;
+	gotoxy(vc, vc->state.x, vc->state.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);
+	notify_update(vc);
+	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);
+}
+EXPORT_SYMBOL(vc_resize);
+
+/**
+ *	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);
+		visual_deinit(vc);
+		con_free_unimap(vc);
+		put_pid(vc->vt_pid);
+		vc_uniscr_set(vc, NULL);
+		kfree(vc->vc_screenbuf);
+		vc_cons[currcons].d = NULL;
+	}
+	return vc;
+}
+
+/*
+ *	VT102 emulator
+ */
+
+enum { EPecma = 0, EPdec, EPeq, EPgt, EPlt};
+
+#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
+
+const unsigned char color_table[] = { 0, 4, 2, 6, 1, 5, 3, 7,
+				       8,12,10,14, 9,13,11,15 };
+EXPORT_SYMBOL(color_table);
+
+/* the default colour table, for VGA+ colour systems */
+unsigned char default_red[] = {
+	0x00, 0xaa, 0x00, 0xaa, 0x00, 0xaa, 0x00, 0xaa,
+	0x55, 0xff, 0x55, 0xff, 0x55, 0xff, 0x55, 0xff
+};
+module_param_array(default_red, byte, NULL, S_IRUGO | S_IWUSR);
+EXPORT_SYMBOL(default_red);
+
+unsigned char default_grn[] = {
+	0x00, 0x00, 0xaa, 0x55, 0x00, 0x00, 0xaa, 0xaa,
+	0x55, 0x55, 0xff, 0xff, 0x55, 0x55, 0xff, 0xff
+};
+module_param_array(default_grn, byte, NULL, S_IRUGO | S_IWUSR);
+EXPORT_SYMBOL(default_grn);
+
+unsigned char default_blu[] = {
+	0x00, 0x00, 0x00, 0x00, 0xaa, 0xaa, 0xaa, 0xaa,
+	0x55, 0x55, 0x55, 0x55, 0xff, 0xff, 0xff, 0xff
+};
+module_param_array(default_blu, byte, NULL, S_IRUGO | S_IWUSR);
+EXPORT_SYMBOL(default_blu);
+
+/*
+ * 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->state.x = 0;
+	else {
+		if (new_x >= vc->vc_cols)
+			vc->state.x = vc->vc_cols - 1;
+		else
+			vc->state.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->state.y = min_y;
+	else if (new_y >= max_y)
+		vc->state.y = max_y - 1;
+	else
+		vc->state.y = new_y;
+	vc->vc_pos = vc->vc_origin + vc->state.y * vc->vc_size_row +
+		(vc->state.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)
+{
+	scrolldelta(-(vc->vc_rows / 2));
+}
+
+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->state.y + 1 == vc->vc_bottom)
+		con_scroll(vc, vc->vc_top, vc->vc_bottom, SM_UP, 1);
+	else if (vc->state.y < vc->vc_rows - 1) {
+		vc->state.y++;
+		vc->vc_pos += vc->vc_size_row;
+	}
+	vc->vc_need_wrap = 0;
+	notify_write(vc, '\n');
+}
+
+static void ri(struct vc_data *vc)
+{
+    	/* don't scroll if below top of scrolling region, or
+	 * if above scrolling region
+	 */
+	if (vc->state.y == vc->vc_top)
+		con_scroll(vc, vc->vc_top, vc->vc_bottom, SM_DOWN, 1);
+	else if (vc->state.y > 0) {
+		vc->state.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->state.x << 1;
+	vc->vc_need_wrap = vc->state.x = 0;
+	notify_write(vc, '\r');
+}
+
+static inline void bs(struct vc_data *vc)
+{
+	if (vc->state.x) {
+		vc->vc_pos -= 2;
+		vc->state.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 */
+			vc_uniscr_clear_line(vc, vc->state.x,
+					     vc->vc_cols - vc->state.x);
+			vc_uniscr_clear_lines(vc, vc->state.y + 1,
+					      vc->vc_rows - vc->state.y - 1);
+			count = (vc->vc_scr_end - vc->vc_pos) >> 1;
+			start = (unsigned short *)vc->vc_pos;
+			break;
+		case 1:	/* erase from start to cursor */
+			vc_uniscr_clear_line(vc, 0, vc->state.x + 1);
+			vc_uniscr_clear_lines(vc, 0, vc->state.y);
+			count = ((vc->vc_pos - vc->vc_origin) >> 1) + 1;
+			start = (unsigned short *)vc->vc_origin;
+			break;
+		case 3: /* include scrollback */
+			flush_scrollback(vc);
+			fallthrough;
+		case 2: /* erase whole display */
+			vc_uniscr_clear_lines(vc, 0, vc->vc_rows);
+			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 (con_should_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 = (unsigned short *)vc->vc_pos;
+	int offset;
+
+	switch (vpar) {
+		case 0:	/* erase from cursor to end of line */
+			offset = 0;
+			count = vc->vc_cols - vc->state.x;
+			break;
+		case 1:	/* erase from start of line to cursor */
+			offset = -vc->state.x;
+			count = vc->state.x + 1;
+			break;
+		case 2: /* erase whole line */
+			offset = -vc->state.x;
+			count = vc->vc_cols;
+			break;
+		default:
+			return;
+	}
+	vc_uniscr_clear_line(vc, vc->state.x + offset, count);
+	scr_memsetw(start + offset, vc->vc_video_erase_char, 2 * count);
+	vc->vc_need_wrap = 0;
+	if (con_should_update(vc))
+		do_update_region(vc, (unsigned long)(start + offset), count);
+}
+
+/* erase the following vpar positions */
+static void csi_X(struct vc_data *vc, unsigned int vpar)
+{					  /* not vt100? */
+	unsigned int count;
+
+	if (!vpar)
+		vpar++;
+
+	count = min(vpar, vc->vc_cols - vc->state.x);
+
+	vc_uniscr_clear_line(vc, vc->state.x, count);
+	scr_memsetw((unsigned short *)vc->vc_pos, vc->vc_video_erase_char, 2 * count);
+	if (con_should_update(vc))
+		vc->vc_sw->con_clear(vc, vc->state.y, vc->state.x, 1, count);
+	vc->vc_need_wrap = 0;
+}
+
+static void default_attr(struct vc_data *vc)
+{
+	vc->state.intensity = VCI_NORMAL;
+	vc->state.italic = false;
+	vc->state.underline = false;
+	vc->state.reverse = false;
+	vc->state.blink = false;
+	vc->state.color = vc->vc_def_color;
+}
+
+struct rgb { u8 r; u8 g; u8 b; };
+
+static void rgb_from_256(int i, struct rgb *c)
+{
+	if (i < 8) {            /* Standard colours. */
+		c->r = i&1 ? 0xaa : 0x00;
+		c->g = i&2 ? 0xaa : 0x00;
+		c->b = i&4 ? 0xaa : 0x00;
+	} else if (i < 16) {
+		c->r = i&1 ? 0xff : 0x55;
+		c->g = i&2 ? 0xff : 0x55;
+		c->b = i&4 ? 0xff : 0x55;
+	} else if (i < 232) {   /* 6x6x6 colour cube. */
+		c->r = (i - 16) / 36 * 85 / 2;
+		c->g = (i - 16) / 6 % 6 * 85 / 2;
+		c->b = (i - 16) % 6 * 85 / 2;
+	} else                  /* Grayscale ramp. */
+		c->r = c->g = c->b = i * 10 - 2312;
+}
+
+static void rgb_foreground(struct vc_data *vc, const struct rgb *c)
+{
+	u8 hue = 0, max = max3(c->r, c->g, c->b);
+
+	if (c->r > max / 2)
+		hue |= 4;
+	if (c->g > max / 2)
+		hue |= 2;
+	if (c->b > max / 2)
+		hue |= 1;
+
+	if (hue == 7 && max <= 0x55) {
+		hue = 0;
+		vc->state.intensity = VCI_BOLD;
+	} else if (max > 0xaa)
+		vc->state.intensity = VCI_BOLD;
+	else
+		vc->state.intensity = VCI_NORMAL;
+
+	vc->state.color = (vc->state.color & 0xf0) | hue;
+}
+
+static void rgb_background(struct vc_data *vc, const struct rgb *c)
+{
+	/* For backgrounds, err on the dark side. */
+	vc->state.color = (vc->state.color & 0x0f)
+		| (c->r&0x80) >> 1 | (c->g&0x80) >> 2 | (c->b&0x80) >> 3;
+}
+
+/*
+ * ITU T.416 Higher colour modes. They break the usual properties of SGR codes
+ * and thus need to be detected and ignored by hand. That standard also
+ * wants : rather than ; as separators but sequences containing : are currently
+ * completely ignored by the parser.
+ *
+ * Subcommands 3 (CMY) and 4 (CMYK) are so insane there's no point in
+ * supporting them.
+ */
+static int vc_t416_color(struct vc_data *vc, int i,
+		void(*set_color)(struct vc_data *vc, const struct rgb *c))
+{
+	struct rgb c;
+
+	i++;
+	if (i > vc->vc_npar)
+		return i;
+
+	if (vc->vc_par[i] == 5 && i + 1 <= vc->vc_npar) {
+		/* 256 colours */
+		i++;
+		rgb_from_256(vc->vc_par[i], &c);
+	} else if (vc->vc_par[i] == 2 && i + 3 <= vc->vc_npar) {
+		/* 24 bit */
+		c.r = vc->vc_par[i + 1];
+		c.g = vc->vc_par[i + 2];
+		c.b = vc->vc_par[i + 3];
+		i += 3;
+	} else
+		return i;
+
+	set_color(vc, &c);
+
+	return i;
+}
+
+/* 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->state.intensity = VCI_BOLD;
+			break;
+		case 2:
+			vc->state.intensity = VCI_HALF_BRIGHT;
+			break;
+		case 3:
+			vc->state.italic = true;
+			break;
+		case 21:
+			/*
+			 * No console drivers support double underline, so
+			 * convert it to a single underline.
+			 */
+		case 4:
+			vc->state.underline = true;
+			break;
+		case 5:
+			vc->state.blink = true;
+			break;
+		case 7:
+			vc->state.reverse = true;
+			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->state.Gx_charset[vc->state.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 22:
+			vc->state.intensity = VCI_NORMAL;
+			break;
+		case 23:
+			vc->state.italic = false;
+			break;
+		case 24:
+			vc->state.underline = false;
+			break;
+		case 25:
+			vc->state.blink = false;
+			break;
+		case 27:
+			vc->state.reverse = false;
+			break;
+		case 38:
+			i = vc_t416_color(vc, i, rgb_foreground);
+			break;
+		case 48:
+			i = vc_t416_color(vc, i, rgb_background);
+			break;
+		case 39:
+			vc->state.color = (vc->vc_def_color & 0x0f) |
+				(vc->state.color & 0xf0);
+			break;
+		case 49:
+			vc->state.color = (vc->vc_def_color & 0xf0) |
+				(vc->state.color & 0x0f);
+			break;
+		default:
+			if (vc->vc_par[i] >= 90 && vc->vc_par[i] <= 107) {
+				if (vc->vc_par[i] < 100)
+					vc->state.intensity = VCI_BOLD;
+				vc->vc_par[i] -= 60;
+			}
+			if (vc->vc_par[i] >= 30 && vc->vc_par[i] <= 37)
+				vc->state.color = color_table[vc->vc_par[i] - 30]
+					| (vc->state.color & 0xf0);
+			else if (vc->vc_par[i] >= 40 && vc->vc_par[i] <= 47)
+				vc->state.color = (color_table[vc->vc_par[i] - 40] << 4)
+					| (vc->state.color & 0x0f);
+			break;
+		}
+	update_attr(vc);
+}
+
+static void respond_string(const char *p, size_t len, struct tty_port *port)
+{
+	tty_insert_flip_string(port, p, len);
+	tty_flip_buffer_push(port);
+}
+
+static void cursor_report(struct vc_data *vc, struct tty_struct *tty)
+{
+	char buf[40];
+	int len;
+
+	len = sprintf(buf, "\033[%d;%dR", vc->state.y +
+			(vc->vc_decom ? vc->vc_top + 1 : 1),
+			vc->state.x + 1);
+	respond_string(buf, len, tty->port);
+}
+
+static inline void status_report(struct tty_struct *tty)
+{
+	static const char teminal_ok[] = "\033[0n";
+
+	respond_string(teminal_ok, strlen(teminal_ok), tty->port);
+}
+
+static inline void respond_ID(struct tty_struct *tty)
+{
+	/* terminal answer to an ESC-Z or csi0c query. */
+	static const char vt102_id[] = "\033[?6c";
+
+	respond_string(vt102_id, strlen(vt102_id), tty->port);
+}
+
+void mouse_report(struct tty_struct *tty, int butt, int mrx, int mry)
+{
+	char buf[8];
+	int len;
+
+	len = sprintf(buf, "\033[M%c%c%c", (char)(' ' + butt),
+			(char)('!' + mrx), (char)('!' + mry));
+	respond_string(buf, len, tty->port);
+}
+
+/* invoked via ioctl(TIOCLINUX) and through set_selection_user */
+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_priv == EPdec) {
+			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 */
+#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,
+							false);
+					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->state.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->state.intensity == VCI_HALF_BRIGHT)
+				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 = min(vc->vc_par[1], 60U) * 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) ?
+				msecs_to_jiffies(vc->vc_par[1]) : 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 = min(vc->vc_par[1], 60U) * 60 * HZ;
+		break;
+	case 15: /* activate the previous console */
+		set_console(last_console);
+		break;
+	case 16: /* set cursor blink duration in msec */
+		if (vc->vc_npar >= 1 && vc->vc_par[1] >= 50 &&
+				vc->vc_par[1] <= USHRT_MAX)
+			vc->vc_cur_blink_ms = vc->vc_par[1];
+		else
+			vc->vc_cur_blink_ms = DEFAULT_CURSOR_BLINK_MS;
+		break;
+	}
+}
+
+/* console_lock is held */
+static void csi_at(struct vc_data *vc, unsigned int nr)
+{
+	if (nr > vc->vc_cols - vc->state.x)
+		nr = vc->vc_cols - vc->state.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->state.y)
+		nr = vc->vc_rows - vc->state.y;
+	else if (!nr)
+		nr = 1;
+	con_scroll(vc, vc->state.y, vc->vc_bottom, SM_DOWN, 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->state.x)
+		nr = vc->vc_cols - vc->state.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->state.y)
+		nr = vc->vc_rows - vc->state.y;
+	else if (!nr)
+		nr=1;
+	con_scroll(vc, vc->state.y, vc->vc_bottom, SM_UP, nr);
+	vc->vc_need_wrap = 0;
+}
+
+/* console_lock is held (except via vc_init->reset_terminal */
+static void save_cur(struct vc_data *vc)
+{
+	memcpy(&vc->saved_state, &vc->state, sizeof(vc->state));
+}
+
+/* console_lock is held */
+static void restore_cur(struct vc_data *vc)
+{
+	memcpy(&vc->state, &vc->saved_state, sizeof(vc->state));
+
+	gotoxy(vc, vc->state.x, vc->state.y);
+	vc->vc_translate = set_translate(vc->state.Gx_charset[vc->state.charset],
+			vc);
+	update_attr(vc);
+	vc->vc_need_wrap = 0;
+}
+
+enum { ESnormal, ESesc, ESsquare, ESgetpars, ESfunckey,
+	EShash, ESsetG0, ESsetG1, ESpercent, EScsiignore, ESnonstd,
+	ESpalette, ESosc, ESapc, ESpm, ESdcs };
+
+/* console_lock is held (except via vc_init()) */
+static void reset_terminal(struct vc_data *vc, int do_clear)
+{
+	unsigned int i;
+
+	vc->vc_top		= 0;
+	vc->vc_bottom		= vc->vc_rows;
+	vc->vc_state		= ESnormal;
+	vc->vc_priv		= EPecma;
+	vc->vc_translate	= set_translate(LAT1_MAP, vc);
+	vc->state.Gx_charset[0]	= LAT1_MAP;
+	vc->state.Gx_charset[1]	= GRAF_MAP;
+	vc->state.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);
+
+	bitmap_zero(vc->vc_tab_stop, VC_TABSTOPS_COUNT);
+	for (i = 0; i < VC_TABSTOPS_COUNT; i += 8)
+		set_bit(i, vc->vc_tab_stop);
+
+	vc->vc_bell_pitch = DEFAULT_BELL_PITCH;
+	vc->vc_bell_duration = DEFAULT_BELL_DURATION;
+	vc->vc_cur_blink_ms = DEFAULT_CURSOR_BLINK_MS;
+
+	gotoxy(vc, 0, 0);
+	save_cur(vc);
+	if (do_clear)
+	    csi_J(vc, 2);
+}
+
+static void vc_setGx(struct vc_data *vc, unsigned int which, int c)
+{
+	unsigned char *charset = &vc->state.Gx_charset[which];
+
+	switch (c) {
+	case '0':
+		*charset = GRAF_MAP;
+		break;
+	case 'B':
+		*charset = LAT1_MAP;
+		break;
+	case 'U':
+		*charset = IBMPC_MAP;
+		break;
+	case 'K':
+		*charset = USER_MAP;
+		break;
+	}
+
+	if (vc->state.charset == which)
+		vc->vc_translate = set_translate(*charset, vc);
+}
+
+/* is this state an ANSI control string? */
+static bool ansi_control_string(unsigned int state)
+{
+	if (state == ESosc || state == ESapc || state == ESpm || state == ESdcs)
+		return true;
+	return false;
+}
+
+/* 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, aside from ANSI control strings.
+	 */
+	if (ansi_control_string(vc->vc_state) && c >= 8 && c <= 13)
+		return;
+	switch (c) {
+	case 0:
+		return;
+	case 7:
+		if (ansi_control_string(vc->vc_state))
+			vc->vc_state = ESnormal;
+		else 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->state.x << 1);
+
+		vc->state.x = find_next_bit(vc->vc_tab_stop,
+				min(vc->vc_cols - 1, VC_TABSTOPS_COUNT),
+				vc->state.x + 1);
+		if (vc->state.x >= VC_TABSTOPS_COUNT)
+			vc->state.x = vc->vc_cols - 1;
+
+		vc->vc_pos += (vc->state.x << 1);
+		notify_write(vc, '\t');
+		return;
+	case 10: case 11: case 12:
+		lf(vc);
+		if (!is_kbd(vc, lnm))
+			return;
+		fallthrough;
+	case 13:
+		cr(vc);
+		return;
+	case 14:
+		vc->state.charset = 1;
+		vc->vc_translate = set_translate(vc->state.Gx_charset[1], vc);
+		vc->vc_disp_ctrl = 1;
+		return;
+	case 15:
+		vc->state.charset = 0;
+		vc->vc_translate = set_translate(vc->state.Gx_charset[0], 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 = ESapc;
+			return;
+		case '^':
+			vc->vc_state = ESpm;
+			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':
+			if (vc->state.x < VC_TABSTOPS_COUNT)
+				set_bit(vc->state.x, vc->vc_tab_stop);
+			return;
+		case 'P':
+			vc->vc_state = ESdcs;
+			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 if (c>='0' && c<='9')
+			vc->vc_state = ESosc;
+		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;
+		}
+		switch (c) {
+		case '?':
+			vc->vc_priv = EPdec;
+			return;
+		case '>':
+			vc->vc_priv = EPgt;
+			return;
+		case '=':
+			vc->vc_priv = EPeq;
+			return;
+		case '<':
+			vc->vc_priv = EPlt;
+			return;
+		}
+		vc->vc_priv = EPecma;
+		fallthrough;
+	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;
+		}
+		if (c >= 0x20 && c <= 0x3f) { /* 0x2x, 0x3a and 0x3c - 0x3f */
+			vc->vc_state = EScsiignore;
+			return;
+		}
+		vc->vc_state = ESnormal;
+		switch(c) {
+		case 'h':
+			if (vc->vc_priv <= EPdec)
+				set_mode(vc, 1);
+			return;
+		case 'l':
+			if (vc->vc_priv <= EPdec)
+				set_mode(vc, 0);
+			return;
+		case 'c':
+			if (vc->vc_priv == EPdec) {
+				if (vc->vc_par[0])
+					vc->vc_cursor_type =
+						CUR_MAKE(vc->vc_par[0],
+							 vc->vc_par[1],
+							 vc->vc_par[2]);
+				else
+					vc->vc_cursor_type = cur_default;
+				return;
+			}
+			break;
+		case 'm':
+			if (vc->vc_priv == EPdec) {
+				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_priv == EPecma) {
+				if (vc->vc_par[0] == 5)
+					status_report(tty);
+				else if (vc->vc_par[0] == 6)
+					cursor_report(vc, tty);
+			}
+			return;
+		}
+		if (vc->vc_priv != EPecma) {
+			vc->vc_priv = EPecma;
+			return;
+		}
+		switch(c) {
+		case 'G': case '`':
+			if (vc->vc_par[0])
+				vc->vc_par[0]--;
+			gotoxy(vc, vc->vc_par[0], vc->state.y);
+			return;
+		case 'A':
+			if (!vc->vc_par[0])
+				vc->vc_par[0]++;
+			gotoxy(vc, vc->state.x, vc->state.y - vc->vc_par[0]);
+			return;
+		case 'B': case 'e':
+			if (!vc->vc_par[0])
+				vc->vc_par[0]++;
+			gotoxy(vc, vc->state.x, vc->state.y + vc->vc_par[0]);
+			return;
+		case 'C': case 'a':
+			if (!vc->vc_par[0])
+				vc->vc_par[0]++;
+			gotoxy(vc, vc->state.x + vc->vc_par[0], vc->state.y);
+			return;
+		case 'D':
+			if (!vc->vc_par[0])
+				vc->vc_par[0]++;
+			gotoxy(vc, vc->state.x - vc->vc_par[0], vc->state.y);
+			return;
+		case 'E':
+			if (!vc->vc_par[0])
+				vc->vc_par[0]++;
+			gotoxy(vc, 0, vc->state.y + vc->vc_par[0]);
+			return;
+		case 'F':
+			if (!vc->vc_par[0])
+				vc->vc_par[0]++;
+			gotoxy(vc, 0, vc->state.y - vc->vc_par[0]);
+			return;
+		case 'd':
+			if (vc->vc_par[0])
+				vc->vc_par[0]--;
+			gotoxay(vc, vc->state.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->state.x < VC_TABSTOPS_COUNT)
+				set_bit(vc->state.x, vc->vc_tab_stop);
+			else if (vc->vc_par[0] == 3)
+				bitmap_zero(vc->vc_tab_stop, VC_TABSTOPS_COUNT);
+			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 EScsiignore:
+		if (c >= 20 && c <= 0x3f)
+			return;
+		vc->vc_state = ESnormal;
+		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:
+		vc_setGx(vc, 0, c);
+		vc->vc_state = ESnormal;
+		return;
+	case ESsetG1:
+		vc_setGx(vc, 1, c);
+		vc->vc_state = ESnormal;
+		return;
+	case ESapc:
+		return;
+	case ESosc:
+		return;
+	case ESpm:
+		return;
+	case ESdcs:
+		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: https://www.cl.cam.ac.uk/~mgk25/ucs/wcwidth.c
+ */
+struct interval {
+	uint32_t first;
+	uint32_t last;
+};
+
+static int ucs_cmp(const void *key, const void *elt)
+{
+	uint32_t ucs = *(uint32_t *)key;
+	struct interval e = *(struct interval *) elt;
+
+	if (ucs > e.last)
+		return 1;
+	else if (ucs < e.first)
+		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 }
+	};
+	if (ucs < double_width[0].first ||
+	    ucs > double_width[ARRAY_SIZE(double_width) - 1].last)
+		return 0;
+
+	return bsearch(&ucs, double_width, ARRAY_SIZE(double_width),
+			sizeof(struct interval), ucs_cmp) != NULL;
+}
+
+struct vc_draw_region {
+	unsigned long from, to;
+	int x;
+};
+
+static void con_flush(struct vc_data *vc, struct vc_draw_region *draw)
+{
+	if (draw->x < 0)
+		return;
+
+	vc->vc_sw->con_putcs(vc, (u16 *)draw->from,
+			(u16 *)draw->to - (u16 *)draw->from, vc->state.y,
+			draw->x);
+	draw->x = -1;
+}
+
+static inline int vc_translate_ascii(const struct vc_data *vc, int c)
+{
+	if (IS_ENABLED(CONFIG_CONSOLE_TRANSLATIONS)) {
+		if (vc->vc_toggle_meta)
+			c |= 0x80;
+
+		return vc->vc_translate[c];
+	}
+
+	return c;
+}
+
+
+/**
+ * vc_sanitize_unicode -- Replace invalid Unicode code points with U+FFFD
+ * @c: the received character, or U+FFFD for invalid sequences.
+ */
+static inline int vc_sanitize_unicode(const int c)
+{
+	if ((c >= 0xd800 && c <= 0xdfff) || c == 0xfffe || c == 0xffff)
+		return 0xfffd;
+
+	return c;
+}
+
+/**
+ * vc_translate_unicode -- Combine UTF-8 into Unicode in @vc_utf_char
+ * @vc: virtual console
+ * @c: character to translate
+ * @rescan: we return true if we need more (continuation) data
+ *
+ * @vc_utf_char is the being-constructed unicode character.
+ * @vc_utf_count is the number of continuation bytes still expected to arrive.
+ * @vc_npar is the number of continuation bytes arrived so far.
+ */
+static int vc_translate_unicode(struct vc_data *vc, int c, bool *rescan)
+{
+	static const u32 utf8_length_changes[] = {
+		0x0000007f, 0x000007ff, 0x0000ffff,
+		0x001fffff, 0x03ffffff, 0x7fffffff
+	};
+
+	/* Continuation byte received */
+	if ((c & 0xc0) == 0x80) {
+		/* Unexpected continuation byte? */
+		if (!vc->vc_utf_count)
+			return 0xfffd;
+
+		vc->vc_utf_char = (vc->vc_utf_char << 6) | (c & 0x3f);
+		vc->vc_npar++;
+		if (--vc->vc_utf_count)
+			goto need_more_bytes;
+
+		/* 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])
+			return 0xfffd;
+
+		return vc_sanitize_unicode(c);
+	}
+
+	/* Single ASCII byte or first byte of a sequence received */
+	if (vc->vc_utf_count) {
+		/* Continuation byte expected */
+		*rescan = true;
+		vc->vc_utf_count = 0;
+		return 0xfffd;
+	}
+
+	/* Nothing to do if an ASCII byte was received */
+	if (c <= 0x7f)
+		return c;
+
+	/* 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 */
+		return 0xfffd;
+	}
+
+need_more_bytes:
+	return -1;
+}
+
+static int vc_translate(struct vc_data *vc, int *c, bool *rescan)
+{
+	/* Do no translation at all in control states */
+	if (vc->vc_state != ESnormal)
+		return *c;
+
+	if (vc->vc_utf && !vc->vc_disp_ctrl)
+		return *c = vc_translate_unicode(vc, *c, rescan);
+
+	/* no utf or alternate charset mode */
+	return vc_translate_ascii(vc, *c);
+}
+
+static inline unsigned char vc_invert_attr(const struct vc_data *vc)
+{
+	if (!vc->vc_can_do_color)
+		return vc->vc_attr ^ 0x08;
+
+	if (vc->vc_hi_font_mask == 0x100)
+		return   (vc->vc_attr & 0x11) |
+			((vc->vc_attr & 0xe0) >> 4) |
+			((vc->vc_attr & 0x0e) << 4);
+
+	return   (vc->vc_attr & 0x88) |
+		((vc->vc_attr & 0x70) >> 4) |
+		((vc->vc_attr & 0x07) << 4);
+}
+
+static bool vc_is_control(struct vc_data *vc, int tc, int c)
+{
+	/*
+	 * 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.
+	 */
+	static const u32 CTRL_ACTION = 0x0d00ff81;
+	/* Cannot be overridden by disp_ctrl */
+	static const u32 CTRL_ALWAYS = 0x0800f501;
+
+	if (vc->vc_state != ESnormal)
+		return true;
+
+	if (!tc)
+		return true;
+
+	/*
+	 * 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.
+	 */
+	if (c < 32) {
+		if (vc->vc_disp_ctrl)
+			return CTRL_ALWAYS & BIT(c);
+		else
+			return vc->vc_utf || (CTRL_ACTION & BIT(c));
+	}
+
+	if (c == 127 && !vc->vc_disp_ctrl)
+		return true;
+
+	if (c == 128 + 27)
+		return true;
+
+	return false;
+}
+
+static int vc_con_write_normal(struct vc_data *vc, int tc, int c,
+		struct vc_draw_region *draw)
+{
+	int next_c;
+	unsigned char vc_attr = vc->vc_attr;
+	u16 himask = vc->vc_hi_font_mask, charmask = himask ? 0x1ff : 0xff;
+	u8 width = 1;
+	bool inverse = false;
+
+	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)
+			return -1; /* 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 = true;
+				tc = conv_uni_to_pc(vc, '?');
+				if (tc < 0)
+					tc = '?';
+
+				vc_attr = vc_invert_attr(vc);
+				con_flush(vc, draw);
+			}
+		}
+	}
+
+	next_c = c;
+	while (1) {
+		if (vc->vc_need_wrap || vc->vc_decim)
+			con_flush(vc, draw);
+		if (vc->vc_need_wrap) {
+			cr(vc);
+			lf(vc);
+		}
+		if (vc->vc_decim)
+			insert_char(vc, 1);
+		vc_uniscr_putc(vc, next_c);
+
+		if (himask)
+			tc = ((tc & 0x100) ? himask : 0) |
+			      (tc &  0xff);
+		tc |= (vc_attr << 8) & ~himask;
+
+		scr_writew(tc, (u16 *)vc->vc_pos);
+
+		if (con_should_update(vc) && draw->x < 0) {
+			draw->x = vc->state.x;
+			draw->from = vc->vc_pos;
+		}
+		if (vc->state.x == vc->vc_cols - 1) {
+			vc->vc_need_wrap = vc->vc_decawm;
+			draw->to = vc->vc_pos + 2;
+		} else {
+			vc->state.x++;
+			draw->to = (vc->vc_pos += 2);
+		}
+
+		if (!--width)
+			break;
+
+		/* A space is printed in the second column */
+		tc = conv_uni_to_pc(vc, ' ');
+		if (tc < 0)
+			tc = ' ';
+		next_c = ' ';
+	}
+	notify_write(vc, c);
+
+	if (inverse)
+		con_flush(vc, draw);
+
+	return 0;
+}
+
+/* acquires console_lock */
+static int do_con_write(struct tty_struct *tty, const u8 *buf, int count)
+{
+	struct vc_draw_region draw = {
+		.x = -1,
+	};
+	int c, tc, n = 0;
+	unsigned int currcons;
+	struct vc_data *vc;
+	struct vt_notifier_param param;
+	bool rescan;
+
+	if (in_interrupt())
+		return count;
+
+	console_lock();
+	vc = tty->driver_data;
+	if (vc == NULL) {
+		pr_err("vt: argh, driver_data is NULL !\n");
+		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\n", currcons+1);
+		console_unlock();
+		return 0;
+	}
+
+
+	/* undraw cursor first */
+	if (con_is_fg(vc))
+		hide_cursor(vc);
+
+	param.vc = vc;
+
+	while (!tty->flow.stopped && count) {
+		int orig = *buf;
+		buf++;
+		n++;
+		count--;
+rescan_last_byte:
+		c = orig;
+		rescan = false;
+
+		tc = vc_translate(vc, &c, &rescan);
+		if (tc == -1)
+			continue;
+
+		param.c = tc;
+		if (atomic_notifier_call_chain(&vt_notifier_list, VT_PREWRITE,
+					&param) == NOTIFY_STOP)
+			continue;
+
+		if (vc_is_control(vc, tc, c)) {
+			con_flush(vc, &draw);
+			do_con_trol(tty, vc, orig);
+			continue;
+		}
+
+		if (vc_con_write_normal(vc, tc, c, &draw) < 0)
+			continue;
+
+		if (rescan)
+			goto rescan_last_byte;
+	}
+	con_flush(vc, &draw);
+	console_conditional_schedule();
+	notify_update(vc);
+	console_unlock();
+	return n;
+}
+
+/*
+ * 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->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 start_x, cnt;
+	int kmsg_console;
+
+	WARN_CONSOLE_UNLOCKED();
+
+	/* this protects against concurrent oops only */
+	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;
+
+	if (!vc_cons_allocated(fg_console)) {
+		/* impossible */
+		/* printk("vt_console_print: tty %d not allocated ??\n", currcons+1); */
+		goto quit;
+	}
+
+	if (vc->vc_mode != KD_TEXT)
+		goto quit;
+
+	/* undraw cursor first */
+	if (con_is_fg(vc))
+		hide_cursor(vc);
+
+	start = (ushort *)vc->vc_pos;
+	start_x = vc->state.x;
+	cnt = 0;
+	while (count--) {
+		c = *b++;
+		if (c == 10 || c == 13 || c == 8 || vc->vc_need_wrap) {
+			if (cnt && con_is_visible(vc))
+				vc->vc_sw->con_putcs(vc, start, cnt, vc->state.y, start_x);
+			cnt = 0;
+			if (c == 8) {		/* backspace */
+				bs(vc);
+				start = (ushort *)vc->vc_pos;
+				start_x = vc->state.x;
+				continue;
+			}
+			if (c != 13)
+				lf(vc);
+			cr(vc);
+			start = (ushort *)vc->vc_pos;
+			start_x = vc->state.x;
+			if (c == 10 || c == 13)
+				continue;
+		}
+		vc_uniscr_putc(vc, c);
+		scr_writew((vc->vc_attr << 8) + c, (unsigned short *)vc->vc_pos);
+		notify_write(vc, c);
+		cnt++;
+		if (vc->state.x == vc->vc_cols - 1) {
+			vc->vc_need_wrap = 1;
+		} else {
+			vc->vc_pos += 2;
+			vc->state.x++;
+		}
+	}
+	if (cnt && con_is_visible(vc))
+		vc->vc_sw->con_putcs(vc, start, cnt, vc->state.y, start_x);
+	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 int vt_console_setup(struct console *co, char *options)
+{
+	return co->index >= MAX_NR_CONSOLES ? -EINVAL : 0;
+}
+
+static struct console vt_console_driver = {
+	.name		= "tty",
+	.setup		= vt_console_setup,
+	.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_user 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:
+		return set_selection_user((struct tiocl_selection
+					 __user *)(p+1), tty);
+	case TIOCL_PASTESEL:
+		return paste_selection(tty);
+	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();
+		return put_user(data, p);
+	case TIOCL_GETMOUSEREPORTING:
+		console_lock();	/* May be overkill */
+		data = mouse_reporting();
+		console_unlock();
+		return put_user(data, p);
+	case TIOCL_SETVESABLANK:
+		console_lock();
+		ret = set_vesa_blanking(p);
+		console_unlock();
+		break;
+	case TIOCL_GETKMSGREDIRECT:
+		data = vt_get_kmsg_redirect();
+		return put_user(data, p);
+	case TIOCL_SETKMSGREDIRECT:
+		if (!capable(CAP_SYS_ADMIN))
+			return -EPERM;
+
+		if (get_user(data, p+1))
+			return -EFAULT;
+
+		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.
+		 */
+		return fg_console;
+	case TIOCL_SCROLLCONSOLE:
+		if (get_user(lines, (s32 __user *)(p+4)))
+			return -EFAULT;
+
+		/*
+		 * Needs 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();
+		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:
+		return console_blanked;
+	default:
+		return -EINVAL;
+	}
+
+	return ret;
+}
+
+/*
+ * /dev/ttyN handling
+ */
+
+static ssize_t con_write(struct tty_struct *tty, const u8 *buf, size_t 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, u8 ch)
+{
+	return do_con_write(tty, &ch, 1);
+}
+
+static unsigned int con_write_room(struct tty_struct *tty)
+{
+	if (tty->flow.stopped)
+		return 0;
+	return 32768;		/* No limit, really; 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;
+	tty_port_get(&vc->port);
+
+	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 void con_cleanup(struct tty_struct *tty)
+{
+	struct vc_data *vc = tty->driver_data;
+
+	tty_port_put(&vc->port);
+}
+
+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, int do_clear)
+{
+	int j, k ;
+
+	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)
+		conswitchp = &dummy_con;
+	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);
+		/* Assuming vc->vc_{cols,rows,screenbuf_size} are sane here. */
+		vc->vc_screenbuf = kzalloc(vc->vc_screenbuf_size, GFP_NOWAIT);
+		vc_init(vc, 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->state.x, vc->state.y);
+	csi_J(vc, 0);
+	update_screen(vc);
+	pr_info("Console: %s %s %dx%d\n",
+		vc->vc_can_do_color ? "colour" : "mono",
+		display_desc, vc->vc_cols, vc->vc_rows);
+
+	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,
+	.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,
+	.cleanup = con_cleanup,
+};
+
+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\n", fg_console + 1);
+}
+static DEVICE_ATTR(active, S_IRUGO, show_tty_active, NULL);
+
+static struct attribute *vt_dev_attrs[] = {
+	&dev_attr_active.attr,
+	NULL
+};
+
+ATTRIBUTE_GROUPS(vt_dev);
+
+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\n");
+	tty0dev = device_create_with_groups(&tty_class, NULL,
+					    MKDEV(TTY_MAJOR, 0), NULL,
+					    vt_dev_groups, "tty0");
+	if (IS_ERR(tty0dev))
+		tty0dev = NULL;
+
+	vcs_init();
+
+	console_driver = tty_alloc_driver(MAX_NR_CONSOLES, TTY_DRIVER_REAL_RAW |
+			TTY_DRIVER_RESET_TERMIOS);
+	if (IS_ERR(console_driver))
+		panic("Couldn't allocate console driver\n");
+
+	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;
+	tty_set_operations(console_driver, &con_ops);
+	if (tty_register_driver(console_driver))
+		panic("Couldn't register console driver\n");
+	kbd_init();
+	console_map_init();
+#ifdef CONFIG_MDA_CONSOLE
+	mda_console_init();
+#endif
+	return 0;
+}
+
+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)
+		pr_cont("consoles %d-%d ", first + 1, last + 1);
+	if (j >= 0) {
+		struct vc_data *vc = vc_cons[j].d;
+
+		pr_cont("to %s %s %dx%d\n",
+			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 {
+		pr_cont("to %s\n", desc);
+	}
+
+	retval = 0;
+err:
+	module_put(owner);
+	return retval;
+};
+
+
+#ifdef CONFIG_VT_HW_CONSOLE_BINDING
+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->con != csw) {
+			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))
+		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)
+			do_bind_con_driver(csw, first, last, deflt);
+
+		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;
+	int ret;
+
+ 	if (!con->con || !(con->flag & CON_DRIVER_FLAG_MODULE))
+		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) {
+			ret = do_unbind_con_driver(csw, first, last, deflt);
+			if (ret != 0)
+				return ret;
+		}
+
+		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);
+
+	console_lock();
+
+	if (bind)
+		vt_bind(con);
+	else
+		vt_unbind(con);
+
+	console_unlock();
+
+	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;
+
+	console_lock();
+	bind = con_is_bound(con->con);
+	console_unlock();
+
+	return sysfs_emit(buf, "%i\n", bind);
+}
+
+static ssize_t show_name(struct device *dev, struct device_attribute *attr,
+			 char *buf)
+{
+	struct con_driver *con = dev_get_drvdata(dev);
+
+	return sysfs_emit(buf, "%s %s\n",
+			(con->flag & CON_DRIVER_FLAG_MODULE) ? "(M)" : "(S)",
+			 con->desc);
+
+}
+
+static DEVICE_ATTR(bind, S_IRUGO|S_IWUSR, show_bind, store_bind);
+static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
+
+static struct attribute *con_dev_attrs[] = {
+	&dev_attr_bind.attr,
+	&dev_attr_name.attr,
+	NULL
+};
+
+ATTRIBUTE_GROUPS(con_dev);
+
+static int vtconsole_init_device(struct con_driver *con)
+{
+	con->flag |= CON_DRIVER_FLAG_ATTR;
+	return 0;
+}
+
+static void vtconsole_deinit_device(struct con_driver *con)
+{
+	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;
+
+	WARN_CONSOLE_UNLOCKED();
+
+	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_is_visible - checks whether the current console is visible
+ * @vc: virtual console
+ *
+ * RETURNS: zero if not visible, nonzero if visible
+ */
+bool con_is_visible(const struct vc_data *vc)
+{
+	WARN_CONSOLE_UNLOCKED();
+
+	return *vc->vc_display_fg == vc;
+}
+EXPORT_SYMBOL(con_is_visible);
+
+/**
+ * con_debug_enter - prepare the console for the kernel debugger
+ * @vc: virtual console
+ *
+ * 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
+ *
+ * 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;
+
+	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;
+			goto err;
+		}
+	}
+
+	desc = csw->con_startup();
+	if (!desc) {
+		retval = -ENODEV;
+		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->flag & CON_DRIVER_FLAG_ZOMBIE)) {
+			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_with_groups(vtconsole_class, NULL,
+					  MKDEV(0, con_driver->node),
+					  con_driver, con_dev_groups,
+					  "vtcon%i", con_driver->node);
+	if (IS_ERR(con_driver->dev)) {
+		pr_warn("Unable to create device for %s; errno = %ld\n",
+			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;
+
+	/* cannot unregister a bound driver */
+	if (con_is_bound(csw))
+		return -EBUSY;
+
+	if (csw == conswitchp)
+		return -EINVAL;
+
+	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
+		struct con_driver *con_driver = &registered_con_driver[i];
+
+		if (con_driver->con == csw) {
+			/*
+			 * Defer the removal of the sysfs entries since that
+			 * will acquire the kernfs s_active lock and we can't
+			 * acquire this lock while holding the console lock:
+			 * the unbind sysfs entry imposes already the opposite
+			 * order. Reset con already here to prevent any later
+			 * lookup to succeed and mark this slot as zombie, so
+			 * it won't get reused until we complete the removal
+			 * in the deferred work.
+			 */
+			con_driver->con = NULL;
+			con_driver->flag = CON_DRIVER_FLAG_ZOMBIE;
+			schedule_work(&con_driver_unregister_work);
+
+			return 0;
+		}
+	}
+
+	return -ENODEV;
+}
+EXPORT_SYMBOL_GPL(do_unregister_con_driver);
+
+static void con_driver_unregister_callback(struct work_struct *ignored)
+{
+	int i;
+
+	console_lock();
+
+	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
+		struct con_driver *con_driver = &registered_con_driver[i];
+
+		if (!(con_driver->flag & CON_DRIVER_FLAG_ZOMBIE))
+			continue;
+
+		console_unlock();
+
+		vtconsole_deinit_device(con_driver);
+		device_destroy(vtconsole_class, MKDEV(0, con_driver->node));
+
+		console_lock();
+
+		if (WARN_ON_ONCE(con_driver->con))
+			con_driver->con = NULL;
+		con_driver->desc = NULL;
+		con_driver->dev = NULL;
+		con_driver->node = 0;
+		WARN_ON_ONCE(con_driver->flag != CON_DRIVER_FLAG_ZOMBIE);
+		con_driver->flag = 0;
+		con_driver->first = 0;
+		con_driver->last = 0;
+	}
+
+	console_unlock();
+}
+
+/*
+ *	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 bind
+ */
+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();
+}
+EXPORT_SYMBOL(give_up_console);
+
+static int __init vtconsole_class_init(void)
+{
+	int i;
+
+	vtconsole_class = class_create("vtconsole");
+	if (IS_ERR(vtconsole_class)) {
+		pr_warn("Unable to create vt console class; errno = %ld\n",
+			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_with_groups(vtconsole_class, NULL,
+							  MKDEV(0, con->node),
+							  con, con_dev_groups,
+							  "vtcon%i", con->node);
+
+			if (IS_ERR(con->dev)) {
+				pr_warn("Unable to create device for %s; errno = %ld\n",
+					con->desc, PTR_ERR(con->dev));
+				con->dev = NULL;
+			} else {
+				vtconsole_init_device(con);
+			}
+		}
+	}
+
+	return 0;
+}
+postcore_initcall(vtconsole_class_init);
+
+/*
+ *	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;
+
+	might_sleep();
+
+	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;
+	}
+
+	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_warn("unblank_screen: tty %d not allocated ??\n",
+			fg_console + 1);
+		return;
+	}
+	vc = vc_cons[fg_console].d;
+	if (vc->vc_mode != KD_TEXT)
+		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))
+		/* 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...
+ */
+static 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(struct timer_list *unused)
+{
+	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 worst, we'll do a spurious 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->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 128 pixels wide, at a maximum height
+ *  of 128 pixels. Userspace fontdata may have to be 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_width	64
+#define max_font_height	128
+#define max_font_glyphs	512
+#define max_font_size	(max_font_glyphs*max_font_width*max_font_height)
+
+static int con_font_get(struct vc_data *vc, struct console_font_op *op)
+{
+	struct console_font font;
+	int rc = -EINVAL;
+	int c;
+	unsigned int vpitch = op->op == KD_FONT_OP_GET_TALL ? op->height : 32;
+
+	if (vpitch > max_font_height)
+		return -EINVAL;
+
+	if (op->data) {
+		font.data = kvmalloc(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, vpitch);
+	else
+		rc = -ENOSYS;
+	console_unlock();
+
+	if (rc)
+		goto out;
+
+	c = (font.width+7)/8 * vpitch * font.charcount;
+
+	if (op->data && font.charcount > op->charcount)
+		rc = -ENOSPC;
+	if (font.width > op->width || font.height > op->height)
+		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:
+	kvfree(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;
+	unsigned int vpitch = op->op == KD_FONT_OP_SET_TALL ? op->height : 32;
+
+	if (vc->vc_mode != KD_TEXT)
+		return -EINVAL;
+	if (!op->data)
+		return -EINVAL;
+	if (op->charcount > max_font_glyphs)
+		return -EINVAL;
+	if (op->width <= 0 || op->width > max_font_width || !op->height ||
+	    op->height > max_font_height)
+		return -EINVAL;
+	if (vpitch < op->height)
+		return -EINVAL;
+	size = (op->width+7)/8 * vpitch * op->charcount;
+	if (size > max_font_size)
+		return -ENOSPC;
+
+	font.data = memdup_user(op->data, size);
+	if (IS_ERR(font.data))
+		return PTR_ERR(font.data);
+
+	font.charcount = op->charcount;
+	font.width = op->width;
+	font.height = op->height;
+
+	console_lock();
+	if (vc->vc_mode != KD_TEXT)
+		rc = -EINVAL;
+	else if (vc->vc_sw->con_font_set) {
+		if (vc_is_sel(vc))
+			clear_selection();
+		rc = vc->vc_sw->con_font_set(vc, &font, vpitch, 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) {
+		if (vc_is_sel(vc))
+			clear_selection();
+		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;
+}
+
+int con_font_op(struct vc_data *vc, struct console_font_op *op)
+{
+	switch (op->op) {
+	case KD_FONT_OP_SET:
+	case KD_FONT_OP_SET_TALL:
+		return con_font_set(vc, op);
+	case KD_FONT_OP_GET:
+	case KD_FONT_OP_GET_TALL:
+		return con_font_get(vc, op);
+	case KD_FONT_OP_SET_DEFAULT:
+		return con_font_default(vc, op);
+	case KD_FONT_OP_COPY:
+		/* was buggy and never really used */
+		return -EINVAL;
+	}
+	return -ENOSYS;
+}
+
+/*
+ *	Interface exported to selection and vcs.
+ */
+
+/* used by selection */
+u16 screen_glyph(const struct vc_data *vc, int offset)
+{
+	u16 w = scr_readw(screenpos(vc, offset, true));
+	u16 c = w & 0xff;
+
+	if (w & vc->vc_hi_font_mask)
+		c |= 0x100;
+	return c;
+}
+EXPORT_SYMBOL_GPL(screen_glyph);
+
+u32 screen_glyph_unicode(const struct vc_data *vc, int n)
+{
+	u32 **uni_lines = vc->vc_uni_lines;
+
+	if (uni_lines)
+		return uni_lines[n / vc->vc_cols][n % vc->vc_cols];
+
+	return inverse_translate(vc, screen_glyph(vc, n * 2), true);
+}
+EXPORT_SYMBOL_GPL(screen_glyph_unicode);
+
+/* used by vcs - note the word offset */
+unsigned short *screen_pos(const struct vc_data *vc, int w_offset, bool viewed)
+{
+	return screenpos(vc, 2 * w_offset, viewed);
+}
+EXPORT_SYMBOL_GPL(screen_pos);
+
+void getconsxy(const struct vc_data *vc, unsigned char xy[static 2])
+{
+	/* clamp values if they don't fit */
+	xy[0] = min(vc->state.x, 0xFFu);
+	xy[1] = min(vc->state.y, 0xFFu);
+}
+
+void putconsxy(struct vc_data *vc, unsigned char xy[static const 2])
+{
+	hide_cursor(vc);
+	gotoxy(vc, xy[0], xy[1]);
+	set_cursor(vc);
+}
+
+u16 vcs_scr_readw(const 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);
+}
+
+void vc_scrolldelta_helper(struct vc_data *c, int lines,
+		unsigned int rolled_over, void *base, unsigned int size)
+{
+	unsigned long ubase = (unsigned long)base;
+	ptrdiff_t scr_end = (void *)c->vc_scr_end - base;
+	ptrdiff_t vorigin = (void *)c->vc_visible_origin - base;
+	ptrdiff_t origin = (void *)c->vc_origin - base;
+	int margin = c->vc_size_row * 4;
+	int from, wrap, from_off, avail;
+
+	/* Turn scrollback off */
+	if (!lines) {
+		c->vc_visible_origin = c->vc_origin;
+		return;
+	}
+
+	/* Do we have already enough to allow jumping from 0 to the end? */
+	if (rolled_over > scr_end + margin) {
+		from = scr_end;
+		wrap = rolled_over + c->vc_size_row;
+	} else {
+		from = 0;
+		wrap = size;
+	}
+
+	from_off = (vorigin - from + wrap) % wrap + lines * c->vc_size_row;
+	avail = (origin - from + wrap) % wrap;
+
+	/* Only a little piece would be left? Show all incl. the piece! */
+	if (avail < 2 * margin)
+		margin = 0;
+	if (from_off < margin)
+		from_off = 0;
+	if (from_off > avail - margin)
+		from_off = avail;
+
+	c->vc_visible_origin = ubase + (from + from_off) % wrap;
+}
+EXPORT_SYMBOL_GPL(vc_scrolldelta_helper);