path: root/drivers/video/console/vgacon.c

/*
 *  linux/drivers/video/vgacon.c -- Low level VGA based console driver
 *
 *	Created 28 Sep 1997 by Geert Uytterhoeven
 *
 *	Rewritten by Martin Mares <mj@ucw.cz>, July 1998
 *
 *  This file is based on the old console.c, vga.c and vesa_blank.c drivers.
 *
 *	Copyright (C) 1991, 1992  Linus Torvalds
 *			    1995  Jay Estabrook
 *
 *	User definable mapping table and font loading by Eugene G. Crosser,
 *	<crosser@average.org>
 *
 *	Improved loadable font/UTF-8 support by H. Peter Anvin
 *	Feb-Sep 1995 <peter.anvin@linux.org>
 *
 *	Colour palette handling, by Simon Tatham
 *	17-Jun-95 <sgt20@cam.ac.uk>
 *
 *	if 512 char mode is already enabled don't re-enable it,
 *	because it causes screen to flicker, by Mitja Horvat
 *	5-May-96 <mitja.horvat@guest.arnes.si>
 *
 *	Use 2 outw instead of 4 outb_p to reduce erroneous text
 *	flashing on RHS of screen during heavy console scrolling .
 *	Oct 1996, Paul Gortmaker.
 *
 *
 *  This file is subject to the terms and conditions of the GNU General Public
 *  License.  See the file COPYING in the main directory of this archive for
 *  more details.
 */

#include <linux/config.h>
#include <linux/module.h>
#include <linux/types.h>
#include <linux/sched.h>
#include <linux/fs.h>
#include <linux/kernel.h>
#include <linux/tty.h>
#include <linux/console.h>
#include <linux/string.h>
#include <linux/kd.h>
#include <linux/slab.h>
#include <linux/vt_kern.h>
#include <linux/selection.h>
#include <linux/spinlock.h>
#include <linux/ioport.h>
#include <linux/init.h>
#include <linux/smp_lock.h>
#include <video/vga.h>
#include <asm/io.h>

static DEFINE_SPINLOCK(vga_lock);
static int cursor_size_lastfrom;
static int cursor_size_lastto;
static struct vgastate state;

#define BLANK 0x0020

#define CAN_LOAD_EGA_FONTS	/* undefine if the user must not do this */
#define CAN_LOAD_PALETTE	/* undefine if the user must not do this */

/* You really do _NOT_ want to define this, unless you have buggy
 * Trident VGA which will resize cursor when moving it between column
 * 15 & 16. If you define this and your VGA is OK, inverse bug will
 * appear.
 */
#undef TRIDENT_GLITCH

/*
 *  Interface used by the world
 */

static const char *vgacon_startup(void);
static void vgacon_init(struct vc_data *c, int init);
static void vgacon_deinit(struct vc_data *c);
static void vgacon_cursor(struct vc_data *c, int mode);
static int vgacon_switch(struct vc_data *c);
static int vgacon_blank(struct vc_data *c, int blank, int mode_switch);
static int vgacon_set_palette(struct vc_data *vc, unsigned char *table);
static int vgacon_scrolldelta(struct vc_data *c, int lines);
static int vgacon_set_origin(struct vc_data *c);
static void vgacon_save_screen(struct vc_data *c);
static int vgacon_scroll(struct vc_data *c, int t, int b, int dir,
			 int lines);
static u8 vgacon_build_attr(struct vc_data *c, u8 color, u8 intensity,
			    u8 blink, u8 underline, u8 reverse);
static void vgacon_invert_region(struct vc_data *c, u16 * p, int count);
static unsigned long vgacon_uni_pagedir[2];


/* Description of the hardware situation */
static unsigned long	vga_vram_base;		/* Base of video memory */
static unsigned long	vga_vram_end;		/* End of video memory */
static int		vga_vram_size;		/* Size of video memory */
static u16		vga_video_port_reg;	/* Video register select port */
static u16		vga_video_port_val;	/* Video register value port */
static unsigned int	vga_video_num_columns;	/* Number of text columns */
static unsigned int	vga_video_num_lines;	/* Number of text lines */
static int		vga_can_do_color = 0;	/* Do we support colors? */
static unsigned int	vga_default_font_height;/* Height of default screen font */
static unsigned char	vga_video_type;		/* Card type */
static unsigned char	vga_hardscroll_enabled;
static unsigned char	vga_hardscroll_user_enable = 1;