console.c

LINUX1.0内核源代码,学习LINUX编程的一定要看。

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

/*
 *	console.c
 *
 * This module exports the console io functions:
 * 
 *	'long con_init(long)'
 *	'int con_open(struct tty_struct *tty, struct file * filp)'
 * 	'void update_screen(int new_console)'
 * 	'void blank_screen(void)'
 * 	'void unblank_screen(void)'
 *
 *      'int  con_get_font(char *)' 
 *      'int  con_set_font(char *)' 
 *      'int  con_get_trans(char *)'
 *      'int  con_set_trans(char *)'
 * 
 * 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.
 *
 * User definable mapping table and font loading by Eugene G. Crosser,
 * <[e-mail]>
 *
 * Code to check for different video-cards mostly by Galen Hunt,
 * <[e-mail]>
 *
 */

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

/*
 *  NOTE!!! We sometimes disable and enable interrupts for a short while
 * (to put a word in video IO), but this will work even for keyboard
 * interrupts. We know interrupts aren't enabled when getting a keyboard
 * interrupt, as we use trap-gates. Hopefully all is well.
 */

#include <linux/sched.h>
#include <linux/timer.h>
#include <linux/tty.h>
#include <linux/config.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/kd.h>

#include <asm/io.h>
#include <asm/system.h>
#include <asm/segment.h>

#include "kbd_kern.h"
#include "vt_kern.h"

#ifdef CONFIG_SELECTION
#include <linux/ctype.h>

/* Routines for selection control. */
int set_selection(const int arg);
int paste_selection(struct tty_struct *tty);
static void clear_selection(void);

/* Variables for selection control. */
#define SEL_BUFFER_SIZE TTY_BUF_SIZE
static int sel_cons;
static int sel_start = -1;
static int sel_end;
static char sel_buffer[SEL_BUFFER_SIZE] = { '\0' };
#endif /* CONFIG_SELECTION */

#define NPAR 16

extern void vt_init(void);
extern void register_console(void (*proc)(const char *));
extern void compute_shiftstate(void);

unsigned long	video_num_columns;		/* Number of text columns	*/
unsigned long	video_num_lines;		/* Number of text lines		*/

static unsigned char	video_type;		/* Type of display being used	*/
static unsigned long	video_mem_base;		/* Base of video memory		*/
static unsigned long	video_mem_term;		/* End of video memory		*/
static unsigned long	video_size_row;		/* Bytes per row		*/
static unsigned char	video_page;		/* Initial video page		*/
static unsigned short	video_port_reg;		/* Video register select port	*/
static unsigned short	video_port_val;		/* Video register value port	*/
static int can_do_color = 0;
static int printable = 0;

static struct {
	unsigned short	vc_video_erase_char;	/* Background erase character */
	unsigned char	vc_attr;		/* Current attributes */
	unsigned char	vc_def_color;		/* Default colors */
	unsigned char	vc_color;		/* Foreground & background */
	unsigned char	vc_s_color;		/* Saved foreground & background */
	unsigned char	vc_ulcolor;		/* Colour for underline mode */
	unsigned char	vc_halfcolor;		/* Colour for half intensity mode */
	unsigned long	vc_origin;		/* Used for EGA/VGA fast scroll	*/
	unsigned long	vc_scr_end;		/* Used for EGA/VGA fast scroll	*/
	unsigned long	vc_pos;
	unsigned long	vc_x,vc_y;
	unsigned long	vc_top,vc_bottom;
	unsigned long	vc_state;
	unsigned long	vc_npar,vc_par[NPAR];
	unsigned long	vc_video_mem_start;	/* Start of video RAM		*/
	unsigned long	vc_video_mem_end;	/* End of video RAM (sort of)	*/
	unsigned long	vc_saved_x;
	unsigned long	vc_saved_y;
	/* mode flags */
	unsigned long	vc_charset	: 1;	/* Character set G0 / G1 */
	unsigned long	vc_s_charset	: 1;	/* Saved character set */
	unsigned long	vc_decscnm	: 1;	/* Screen Mode */
	unsigned long	vc_decom	: 1;	/* Origin Mode */
	unsigned long	vc_decawm	: 1;	/* Autowrap Mode */
	unsigned long	vc_deccm	: 1;	/* Cursor Visible */
	unsigned long	vc_decim	: 1;	/* Insert Mode */
	/* attribute flags */
	unsigned long	vc_intensity	: 2;	/* 0=half-bright, 1=normal, 2=bold */
	unsigned long	vc_underline	: 1;
	unsigned long	vc_blink	: 1;
	unsigned long	vc_reverse	: 1;
	unsigned long	vc_s_intensity	: 2;	/* saved rendition */
	unsigned long	vc_s_underline	: 1;
	unsigned long	vc_s_blink	: 1;
	unsigned long	vc_s_reverse	: 1;
	/* misc */
	unsigned long	vc_ques		: 1;
	unsigned long	vc_need_wrap	: 1;
	unsigned long	vc_tab_stop[5];		/* Tab stops. 160 columns. */
	unsigned char * vc_translate;
	unsigned char *	vc_G0_charset;
	unsigned char *	vc_G1_charset;
	unsigned char *	vc_saved_G0;
	unsigned char *	vc_saved_G1;
	/* additional information is in vt_kern.h */
} vc_cons [NR_CONSOLES];

unsigned short *vc_scrbuf[NR_CONSOLES];
static unsigned short * vc_scrmembuf;
static int console_blanked = 0;

#define origin		(vc_cons[currcons].vc_origin)
#define scr_end		(vc_cons[currcons].vc_scr_end)
#define pos		(vc_cons[currcons].vc_pos)
#define top		(vc_cons[currcons].vc_top)
#define bottom		(vc_cons[currcons].vc_bottom)
#define x		(vc_cons[currcons].vc_x)
#define y		(vc_cons[currcons].vc_y)
#define state		(vc_cons[currcons].vc_state)
#define npar		(vc_cons[currcons].vc_npar)
#define par		(vc_cons[currcons].vc_par)
#define ques		(vc_cons[currcons].vc_ques)
#define attr		(vc_cons[currcons].vc_attr)
#define saved_x		(vc_cons[currcons].vc_saved_x)
#define saved_y		(vc_cons[currcons].vc_saved_y)
#define translate	(vc_cons[currcons].vc_translate)
#define G0_charset	(vc_cons[currcons].vc_G0_charset)
#define G1_charset	(vc_cons[currcons].vc_G1_charset)
#define saved_G0	(vc_cons[currcons].vc_saved_G0)
#define saved_G1	(vc_cons[currcons].vc_saved_G1)
#define video_mem_start	(vc_cons[currcons].vc_video_mem_start)
#define video_mem_end	(vc_cons[currcons].vc_video_mem_end)
#define video_erase_char (vc_cons[currcons].vc_video_erase_char)	
#define decscnm		(vc_cons[currcons].vc_decscnm)
#define decom		(vc_cons[currcons].vc_decom)
#define decawm		(vc_cons[currcons].vc_decawm)
#define deccm		(vc_cons[currcons].vc_deccm)
#define decim		(vc_cons[currcons].vc_decim)
#define need_wrap	(vc_cons[currcons].vc_need_wrap)
#define color		(vc_cons[currcons].vc_color)
#define s_color		(vc_cons[currcons].vc_s_color)
#define def_color	(vc_cons[currcons].vc_def_color)
#define	foreground	(color & 0x0f)
#define background	(color & 0xf0)
#define charset		(vc_cons[currcons].vc_charset)
#define s_charset	(vc_cons[currcons].vc_s_charset)
#define	intensity	(vc_cons[currcons].vc_intensity)
#define	underline	(vc_cons[currcons].vc_underline)
#define	blink		(vc_cons[currcons].vc_blink)
#define	reverse		(vc_cons[currcons].vc_reverse)
#define	s_intensity	(vc_cons[currcons].vc_s_intensity)
#define	s_underline	(vc_cons[currcons].vc_s_underline)
#define	s_blink		(vc_cons[currcons].vc_s_blink)
#define	s_reverse	(vc_cons[currcons].vc_s_reverse)
#define	ulcolor		(vc_cons[currcons].vc_ulcolor)
#define	halfcolor	(vc_cons[currcons].vc_halfcolor)
#define tab_stop	(vc_cons[currcons].vc_tab_stop)
#define vcmode		(vt_cons[currcons].vc_mode)
#define vtmode		(vt_cons[currcons].vt_mode)
#define vtpid		(vt_cons[currcons].vt_pid)
#define vtnewvt		(vt_cons[currcons].vt_newvt)

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

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

int blankinterval = 10*60*HZ;
static int screen_size = 0;

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

static unsigned char * translations[] = {
/* 8-bit Latin-1 mapped to the PC character set: '\0' means non-printable */
(unsigned char *)
	"\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"
	"\0\0\0\0\0\0\0\0\0\0\376\0\0\0\0\0"
	" !\"#$%&'()*+,-./0123456789:;<=>?"
	"@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_"
	"`abcdefghijklmnopqrstuvwxyz{|}~\0"
	"\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"
	"\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"
	"\377\255\233\234\376\235\174\025\376\376\246\256\252\055\376\376"
	"\370\361\375\376\376\346\024\371\376\376\247\257\254\253\376\250"
	"\376\376\376\376\216\217\222\200\376\220\376\376\376\376\376\376"
	"\376\245\376\376\376\376\231\376\350\376\376\376\232\376\376\341"
	"\205\240\203\376\204\206\221\207\212\202\210\211\215\241\214\213"
	"\376\244\225\242\223\376\224\366\355\227\243\226\201\376\376\230",
/* vt100 graphics */
(unsigned char *)
	"\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"
	"\0\0\0\0\0\0\0\0\0\0\376\0\0\0\0\0"
	" !\"#$%&'()*+,-./0123456789:;<=>?"
	"@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^ "
	"\004\261\007\007\007\007\370\361\007\007\331\277\332\300\305\304"
	"\304\304\137\137\303\264\301\302\263\363\362\343\330\234\007\0"
	"\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"
	"\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"
	"\377\255\233\234\376\235\174\025\376\376\246\256\252\055\376\376"
	"\370\361\375\376\376\346\024\371\376\376\247\257\254\253\376\250"
	"\376\376\376\376\216\217\222\200\376\220\376\376\376\376\376\376"
	"\376\245\376\376\376\376\231\376\376\376\376\376\232\376\376\341"
	"\205\240\203\376\204\206\221\207\212\202\210\211\215\241\214\213"
	"\376\244\225\242\223\376\224\366\376\227\243\226\201\376\376\230",
/* IBM graphics: minimal translations (BS, CR, LF, LL, SO, SI and ESC) */
(unsigned char *)
	"\000\001\002\003\004\005\006\007\000\011\000\013\000\000\000\000"
	"\020\021\022\023\024\025\026\027\030\031\032\000\034\035\036\037"
	"\040\041\042\043\044\045\046\047\050\051\052\053\054\055\056\057"
	"\060\061\062\063\064\065\066\067\070\071\072\073\074\075\076\077"
	"\100\101\102\103\104\105\106\107\110\111\112\113\114\115\116\117"
	"\120\121\122\123\124\125\126\127\130\131\132\133\134\135\136\137"
	"\140\141\142\143\144\145\146\147\150\151\152\153\154\155\156\157"
	"\160\161\162\163\164\165\166\167\170\171\172\173\174\175\176\177"
	"\200\201\202\203\204\205\206\207\210\211\212\213\214\215\216\217"
	"\220\221\222\223\224\225\226\227\230\231\232\233\234\235\236\237"
	"\240\241\242\243\244\245\246\247\250\251\252\253\254\255\256\257"
	"\260\261\262\263\264\265\266\267\270\271\272\273\274\275\276\277"
	"\300\301\302\303\304\305\306\307\310\311\312\313\314\315\316\317"
	"\320\321\322\323\324\325\326\327\330\331\332\333\334\335\336\337"
	"\340\341\342\343\344\345\346\347\350\351\352\353\354\355\356\357"
	"\360\361\362\363\364\365\366\367\370\371\372\373\374\375\376\377",
 /* USER: customizable mappings, initialized as the previous one (IBM) */
(unsigned char *)
	"\000\001\002\003\004\005\006\007\010\011\000\013\000\000\016\017"
	"\020\021\022\023\024\025\026\027\030\031\032\000\034\035\036\037"
	"\040\041\042\043\044\045\046\047\050\051\052\053\054\055\056\057"
	"\060\061\062\063\064\065\066\067\070\071\072\073\074\075\076\077"
	"\100\101\102\103\104\105\106\107\110\111\112\113\114\115\116\117"
	"\120\121\122\123\124\125\126\127\130\131\132\133\134\135\136\137"
	"\140\141\142\143\144\145\146\147\150\151\152\153\154\155\156\157"
	"\160\161\162\163\164\165\166\167\170\171\172\173\174\175\176\177"
	"\200\201\202\203\204\205\206\207\210\211\212\213\214\215\216\217"
	"\220\221\222\223\224\225\226\227\230\231\232\233\234\235\236\237"
	"\240\241\242\243\244\245\246\247\250\251\252\253\254\255\256\257"
	"\260\261\262\263\264\265\266\267\270\271\272\273\274\275\276\277"
	"\300\301\302\303\304\305\306\307\310\311\312\313\314\315\316\317"
	"\320\321\322\323\324\325\326\327\330\331\332\333\334\335\336\337"
	"\340\341\342\343\344\345\346\347\350\351\352\353\354\355\356\357"
	"\360\361\362\363\364\365\366\367\370\371\372\373\374\375\376\377"
};

#define NORM_TRANS (translations[0])
#define GRAF_TRANS (translations[1])
#define NULL_TRANS (translations[2])
#define USER_TRANS (translations[3])

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

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

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

/*
 * *Very* limited hardware scrollback support..
 */
static unsigned short __real_origin;
static unsigned short __origin;

static inline void __set_origin(unsigned short offset)
{
	unsigned long flags;
#ifdef CONFIG_SELECTION
	clear_selection();
#endif /* CONFIG_SELECTION */
	save_flags(flags); cli();
	__origin = offset;
	outb_p(12, video_port_reg);
	outb_p(offset >> 8, video_port_val);
	outb_p(13, video_port_reg);
	outb_p(offset, video_port_val);
	restore_flags(flags);
}

void scrollback(int lines)
{
	if (!lines)
		lines = video_num_lines/2;
	lines *= video_num_columns;
	lines = __origin - lines;
	if (lines < 0)
		lines = 0;
	__set_origin(lines);
}

void scrollfront(int lines)
{
	if (!lines)
		lines = video_num_lines/2;
	lines *= video_num_columns;
	lines = __origin + lines;
	if (lines > __real_origin)
		lines = __real_origin;
	__set_origin(lines);
}

static void set_origin(int currcons)
{
	if (video_type != VIDEO_TYPE_EGAC && video_type != VIDEO_TYPE_EGAM)
		return;
	if (currcons != fg_console || console_blanked || vcmode == KD_GRAPHICS)
		return;
	__real_origin = (origin-video_mem_base) >> 1;
	__set_origin(__real_origin);
}

/*
 * Put the cursor just beyond the end of the display adaptor memory.
 */
static inline void hide_cursor(void)
{
  /* This is inefficient, we could just put the cursor at 0xffff,
     but perhaps the delays due to the inefficiency are useful for
     some hardware... */
	outb_p(14, video_port_reg);
	outb_p(0xff&((video_mem_term-video_mem_base)>>9), video_port_val);
	outb_p(15, video_port_reg);
	outb_p(0xff&((video_mem_term-video_mem_base)>>1), video_port_val);
}

static inline void set_cursor(int currcons)
{
	unsigned long flags;

	if (currcons != fg_console || console_blanked || vcmode == KD_GRAPHICS)
		return;
	if (__real_origin != __origin)
		set_origin(__real_origin);
	save_flags(flags); cli();
	if (deccm) {
		outb_p(14, video_port_reg);
		outb_p(0xff&((pos-video_mem_base)>>9), video_port_val);
		outb_p(15, video_port_reg);
		outb_p(0xff&((pos-video_mem_base)>>1), video_port_val);
	} else
		hide_cursor();
	restore_flags(flags);
}

static void scrup(int currcons, unsigned int t, unsigned int b)
{
	int hardscroll = 1;

	if (b > video_num_lines || t >= b)
		return;
	if (video_type != VIDEO_TYPE_EGAC && video_type != VIDEO_TYPE_EGAM)
		hardscroll = 0;
	else if (t || b != video_num_lines)
		hardscroll = 0;
	if (hardscroll) {
		origin += video_size_row;
		pos += video_size_row;
		scr_end += video_size_row;
		if (scr_end > video_mem_end) {
			__asm__("cld\n\t"
				"rep\n\t"
				"movsl\n\t"
				"movl _video_num_columns,%1\n\t"
				"rep\n\t"
				"stosw"
				: /* no output */
				:"a" (video_erase_char),
				"c" ((video_num_lines-1)*video_num_columns>>1),
				"D" (video_mem_start),
				"S" (origin)
				:"cx","di","si");
			scr_end -= origin-video_mem_start;
			pos -= origin-video_mem_start;
			origin = video_mem_start;
		} else {
			__asm__("cld\n\t"
				"rep\n\t"
				"stosw"
				: /* no output */
				:"a" (video_erase_char),
				"c" (video_num_columns),
				"D" (scr_end-video_size_row)
				:"cx","di");
		}
		set_origin(currcons);
	} else {
		__asm__("cld\n\t"
			"rep\n\t"
			"movsl\n\t"
			"movl _video_num_columns,%%ecx\n\t"
			"rep\n\t"
			"stosw"
			: /* no output */
			:"a" (video_erase_char),
			"c" ((b-t-1)*video_num_columns>>1),
			"D" (origin+video_size_row*t),
			"S" (origin+video_size_row*(t+1))
			:"cx","di","si");
	}
}

static void scrdown(int currcons, unsigned int t, unsigned int b)
{
	if (b > video_num_lines || t >= b)
		return;
	__asm__("std\n\t"
		"rep\n\t"
		"movsl\n\t"
		"addl $2,%%edi\n\t"	/* %edi has been decremented by 4 */
		"movl _video_num_columns,%%ecx\n\t"
		"rep\n\t"
		"stosw\n\t"
		"cld"
		: /* no output */
		:"a" (video_erase_char),
		"c" ((b-t-1)*video_num_columns>>1),
		"D" (origin+video_size_row*b-4),
		"S" (origin+video_size_row*(b-1)-4)
		:"ax","cx","di","si");