console.c

linux0.02源代码用于研究linux操作系统

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

/*
 *	console.c
 *
 * This module implements the console io functions
 *	'void con_init(void)'
 *	'void con_write(struct tty_queue * queue)'
 * 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.
 */

/*
 *  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.
 */

/*
 * Code to check for different video-cards mostly by Galen Hunt,
 * <[e-mail]>
 */

#include <linux/sched.h>
#include <linux/tty.h>
#include <linux/config.h>
#include <linux/kernel.h>

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

#include <string.h>
#include <errno.h>

#define DEF_TERMIOS \
(struct termios) { \
	ICRNL, \
	OPOST | ONLCR, \
	0, \
	IXON | ISIG | ICANON | ECHO | ECHOCTL | ECHOKE, \
	0, \
	INIT_C_CC \
}


/*
 * These are set up by the setup-routine at boot-time:
 */

#define ORIG_X			(*(unsigned char *)0x90000)
#define ORIG_Y			(*(unsigned char *)0x90001)
#define ORIG_VIDEO_PAGE		(*(unsigned short *)0x90004)
#define ORIG_VIDEO_MODE		((*(unsigned short *)0x90006) & 0xff)
#define ORIG_VIDEO_COLS 	(((*(unsigned short *)0x90006) & 0xff00) >> 8)
#define ORIG_VIDEO_LINES	((*(unsigned short *)0x9000e) & 0xff)
#define ORIG_VIDEO_EGA_AX	(*(unsigned short *)0x90008)
#define ORIG_VIDEO_EGA_BX	(*(unsigned short *)0x9000a)
#define ORIG_VIDEO_EGA_CX	(*(unsigned short *)0x9000c)

#define VIDEO_TYPE_MDA		0x10	/* Monochrome Text Display	*/
#define VIDEO_TYPE_CGA		0x11	/* CGA Display 			*/
#define VIDEO_TYPE_EGAM		0x20	/* EGA/VGA in Monochrome Mode	*/
#define VIDEO_TYPE_EGAC		0x21	/* EGA/VGA in Color Mode	*/

#define NPAR 16

int NR_CONSOLES = 0;

extern void keyboard_interrupt(void);

static unsigned char	video_type;		/* Type of display being used	*/
static unsigned long	video_num_columns;	/* Number of text columns	*/
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 long	video_num_lines;	/* Number of test lines		*/
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_colour = 0;

static struct {
	unsigned short	vc_video_erase_char;	
	unsigned char	vc_attr;
	unsigned char	vc_def_attr;
	int		vc_bold_attr;
	unsigned long	vc_ques;
	unsigned long	vc_state;
	unsigned long	vc_restate;
	unsigned long	vc_checkin;
	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_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 int	vc_saved_x;
	unsigned int	vc_saved_y;
	unsigned int	vc_iscolor;
	char *		vc_translate;
} vc_cons [MAX_CONSOLES];

#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 restate		(vc_cons[currcons].vc_restate)
#define checkin		(vc_cons[currcons].vc_checkin)
#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 video_mem_start	(vc_cons[currcons].vc_video_mem_start)
#define video_mem_end	(vc_cons[currcons].vc_video_mem_end)
#define def_attr	(vc_cons[currcons].vc_def_attr)
#define video_erase_char  (vc_cons[currcons].vc_video_erase_char)	
#define iscolor		(vc_cons[currcons].vc_iscolor)

int blankinterval = 0;
int blankcount = 0;

static void sysbeep(void);

/*
 * this is what the terminal answers to a ESC-Z or csi0c
 * query (= vt100 response).
 */
#define RESPONSE "\033[?1;2c"

static char * translations[] = {
/* normal 7-bit ascii */
	" !\"#$%&'()*+,-./0123456789:;<=>?"
	"@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_"
	"`abcdefghijklmnopqrstuvwxyz{|}~ ",
/* vt100 graphics */
	" !\"#$%&'()*+,-./0123456789:;<=>?"
	"@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^ "
	"\004\261\007\007\007\007\370\361\007\007\275\267\326\323\327\304"
	"\304\304\304\304\307\266\320\322\272\363\362\343\\007\234\007 "
};

#define NORM_TRANS (translations[0])
#define GRAF_TRANS (translations[1])

/* NOTE! gotoxy thinks x==video_num_columns is ok */
static inline void gotoxy(int currcons, int new_x,unsigned int new_y)
{
	if (new_x > video_num_columns || new_y >= video_num_lines)
		return;
	x = new_x;
	y = new_y;
	pos = origin + y*video_size_row + (x<<1);
}

static inline void set_origin(int currcons)
{
	if (video_type != VIDEO_TYPE_EGAC && video_type != VIDEO_TYPE_EGAM)
		return;
	if (currcons != fg_console)
		return;
	cli();
	outb_p(12, video_port_reg);
	outb_p(0xff&((origin-video_mem_base)>>9), video_port_val);
	outb_p(13, video_port_reg);
	outb_p(0xff&((origin-video_mem_base)>>1), video_port_val);
	sti();
}

static void scrup(int currcons)
{
	if (bottom<=top)
		return;
	if (video_type == VIDEO_TYPE_EGAC || video_type == VIDEO_TYPE_EGAM)
	{
		if (!top && bottom == video_num_lines) {
			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"
					::"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"
					::"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"
				::"a" (video_erase_char),
				"c" ((bottom-top-1)*video_num_columns>>1),
				"D" (origin+video_size_row*top),
				"S" (origin+video_size_row*(top+1))
				:"cx","di","si");
		}
	}
	else		/* Not EGA/VGA */
	{
		__asm__("cld\n\t"
			"rep\n\t"
			"movsl\n\t"
			"movl _video_num_columns,%%ecx\n\t"
			"rep\n\t"
			"stosw"
			::"a" (video_erase_char),
			"c" ((bottom-top-1)*video_num_columns>>1),
			"D" (origin+video_size_row*top),
			"S" (origin+video_size_row*(top+1))
			:"cx","di","si");
	}
}

static void scrdown(int currcons)
{
	if (bottom <= top)
		return;
	if (video_type == VIDEO_TYPE_EGAC || video_type == VIDEO_TYPE_EGAM)
	{
		__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"
			::"a" (video_erase_char),
			"c" ((bottom-top-1)*video_num_columns>>1),
			"D" (origin+video_size_row*bottom-4),
			"S" (origin+video_size_row*(bottom-1)-4)
			:"ax","cx","di","si");
	}
	else		/* Not EGA/VGA */
	{
		__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"
			::"a" (video_erase_char),
			"c" ((bottom-top-1)*video_num_columns>>1),
			"D" (origin+video_size_row*bottom-4),
			"S" (origin+video_size_row*(bottom-1)-4)
			:"ax","cx","di","si");
	}
}

static void lf(int currcons)
{
	if (y+1<bottom) {
		y++;
		pos += video_size_row;
		return;
	}
	scrup(currcons);
}

static void ri(int currcons)
{
	if (y>top) {
		y--;
		pos -= video_size_row;
		return;
	}
	scrdown(currcons);
}

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

static void del(int currcons)
{
	if (x) {
		pos -= 2;
		x--;
		*(unsigned short *)pos = video_erase_char;
	}
}

static void csi_J(int currcons, int vpar)
{
	long count __asm__("cx");
	long start __asm__("di");

	switch (vpar) {
		case 0:	/* erase from cursor to end of display */
			count = (scr_end-pos)>>1;
			start = pos;
			break;
		case 1:	/* erase from start to cursor */
			count = (pos-origin)>>1;
			start = origin;
			break;
		case 2: /* erase whole display */
			count = video_num_columns * video_num_lines;
			start = origin;
			break;
		default:
			return;
	}
	__asm__("cld\n\t"
		"rep\n\t"
		"stosw\n\t"
		::"c" (count),
		"D" (start),"a" (video_erase_char)
		:"cx","di");
}

static void csi_K(int currcons, int vpar)
{
	long count __asm__("cx");
	long start __asm__("di");

	switch (vpar) {
		case 0:	/* erase from cursor to end of line */
			if (x>=video_num_columns)
				return;
			count = video_num_columns-x;
			start = pos;
			break;
		case 1:	/* erase from start of line to cursor */
			start = pos - (x<<1);
			count = (x<video_num_columns)?x:video_num_columns;
			break;
		case 2: /* erase whole line */
			start = pos - (x<<1);
			count = video_num_columns;
			break;
		default:
			return;
	}
	__asm__("cld\n\t"
		"rep\n\t"
		"stosw\n\t"
		::"c" (count),
		"D" (start),"a" (video_erase_char)
		:"cx","di");
}

void csi_m(int currcons )
{
	int i;

	for (i=0;i<=npar;i++)
		switch (par[i]) {
			case 0: attr=def_attr;break;  /* default */
			case 1: attr=(iscolor?attr|0x08:attr|0x0f);break;  /* bold */
			/*case 4: attr=attr|0x01;break;*/  /* underline */
			case 4: /* bold */ 
			  if (!iscolor)
			    attr |= 0x01;
			  else
			  { /* check if forground == background */
			    if (vc_cons[currcons].vc_bold_attr != -1)
			      attr = (vc_cons[currcons].vc_bold_attr&0x0f)|(0xf0&(attr));
			    else
			    { short newattr = (attr&0xf0)|(0xf&(~attr));
			      attr = ((newattr&0xf)==((attr>>4)&0xf)? 
			        (attr&0xf0)|(((attr&0xf)+1)%0xf):
			        newattr);
			    }    
			  }
			  break;
			case 5: attr=attr|0x80;break;  /* blinking */
			case 7: attr=(attr<<4)|(attr>>4);break;  /* negative */
			case 22: attr=attr&0xf7;break; /* not bold */ 
			case 24: attr=attr&0xfe;break;  /* not underline */
			case 25: attr=attr&0x7f;break;  /* not blinking */
			case 27: attr=def_attr;break; /* positive image */
			case 39: attr=(attr & 0xf0)|(def_attr & 0x0f); break;
			case 49: attr=(attr & 0x0f)|(def_attr & 0xf0); break;
			default:
			  if (!can_do_colour)
			    break;
			  iscolor = 1;
			  if ((par[i]>=30) && (par[i]<=38))
			    attr = (attr & 0xf0) | (par[i]-30);
			  else  /* Background color */
			    if ((par[i]>=40) && (par[i]<=48))
			      attr = (attr & 0x0f) | ((par[i]-40)<<4);
			    else
				break;
		}
}

static inline void set_cursor(int currcons)
{
	blankcount = blankinterval;
	if (currcons != fg_console)
		return;
	cli();
	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);
	sti();
}

static inline void hide_cursor(int currcons)
{
	outb_p(14, video_port_reg);
	outb_p(0xff&((scr_end-video_mem_base)>>9), video_port_val);
	outb_p(15, video_port_reg);
	outb_p(0xff&((scr_end-video_mem_base)>>1), video_port_val);
}

static void respond(int currcons, struct tty_struct * tty)
{
	char * p = RESPONSE;

	cli();
	while (*p) {
		PUTCH(*p,tty->read_q);
		p++;
	}
	sti();
	copy_to_cooked(tty);
}

static void insert_char(int currcons)
{
	int i=x;
	unsigned short tmp, old = video_erase_char;
	unsigned short * p = (unsigned short *) pos;

	while (i++<video_num_columns) {
		tmp=*p;
		*p=old;
		old=tmp;
		p++;
	}
}

static void insert_line(int currcons)
{
	int oldtop,oldbottom;

	oldtop=top;
	oldbottom=bottom;
	top=y;
	bottom = video_num_lines;
	scrdown(currcons);
	top=oldtop;
	bottom=oldbottom;
}

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

	if (x>=video_num_columns)
		return;
	i = x;
	while (++i < video_num_columns) {
		*p = *(p+1);
		p++;
	}
	*p = video_erase_char;
}

static void delete_line(int currcons)
{
	int oldtop,oldbottom;

	oldtop=top;
	oldbottom=bottom;
	top=y;
	bottom = video_num_lines;