console.c

Minix3.11的源码。[MINIX 3是一个为高可靠性应用而设计的自由且简洁的类UNIX系统。]

/* Code and data for the IBM console driver.
 *
 * The 6845 video controller used by the IBM PC shares its video memory with
 * the CPU somewhere in the 0xB0000 memory bank.  To the 6845 this memory
 * consists of 16-bit words.  Each word has a character code in the low byte
 * and a so-called attribute byte in the high byte.  The CPU directly modifies
 * video memory to display characters, and sets two registers on the 6845 that
 * specify the video origin and the cursor position.  The video origin is the
 * place in video memory where the first character (upper left corner) can
 * be found.  Moving the origin is a fast way to scroll the screen.  Some
 * video adapters wrap around the top of video memory, so the origin can
 * move without bounds.  For other adapters screen memory must sometimes be
 * moved to reset the origin.  All computations on video memory use character
 * (word) addresses for simplicity and assume there is no wrapping.  The
 * assembly support functions translate the word addresses to byte addresses
 * and the scrolling function worries about wrapping.
 */

#include "../drivers.h"
#include <termios.h>
#include <minix/callnr.h>
#include <minix/com.h>
#include "tty.h"

#include "../../kernel/const.h"
#include "../../kernel/config.h"
#include "../../kernel/type.h"

/* Definitions used by the console driver. */
#define MONO_BASE    0xB0000L	/* base of mono video memory */
#define COLOR_BASE   0xB8000L	/* base of color video memory */
#define MONO_SIZE     0x1000	/* 4K mono video memory */
#define COLOR_SIZE    0x4000	/* 16K color video memory */
#define EGA_SIZE      0x8000	/* EGA & VGA have at least 32K */
#define BLANK_COLOR   0x0700	/* determines cursor color on blank screen */
#define SCROLL_UP          0	/* scroll forward */
#define SCROLL_DOWN        1	/* scroll backward */
#define BLANK_MEM ((u16_t *) 0)	/* tells mem_vid_copy() to blank the screen */
#define CONS_RAM_WORDS    80	/* video ram buffer size */
#define MAX_ESC_PARMS      4	/* number of escape sequence params allowed */

/* Constants relating to the controller chips. */
#define M_6845         0x3B4	/* port for 6845 mono */
#define C_6845         0x3D4	/* port for 6845 color */
#define INDEX              0	/* 6845's index register */
#define DATA               1	/* 6845's data register */
#define STATUS             6	/* 6845's status register */
#define VID_ORG           12	/* 6845's origin register */
#define CURSOR            14	/* 6845's cursor register */

/* Beeper. */
#define BEEP_FREQ     0x0533	/* value to put into timer to set beep freq */
#define B_TIME		   3	/* length of CTRL-G beep is ticks */

/* definitions used for font management */
#define GA_SEQUENCER_INDEX	0x3C4
#define GA_SEQUENCER_DATA	0x3C5
#define GA_GRAPHICS_INDEX	0x3CE
#define GA_GRAPHICS_DATA	0x3CF
#define GA_VIDEO_ADDRESS	0xA0000L
#define GA_FONT_SIZE		8192

/* Global variables used by the console driver and assembly support. */
PUBLIC int vid_index;		/* index of video segment in remote mem map */
PUBLIC u16_t vid_seg;
PUBLIC vir_bytes vid_off;	/* video ram is found at vid_seg:vid_off */
PUBLIC unsigned vid_size;	/* 0x2000 for color or 0x0800 for mono */
PUBLIC unsigned vid_mask;	/* 0x1FFF for color or 0x07FF for mono */
PUBLIC unsigned blank_color = BLANK_COLOR; /* display code for blank */

/* Private variables used by the console driver. */
PRIVATE int vid_port;		/* I/O port for accessing 6845 */
PRIVATE int wrap;		/* hardware can wrap? */
PRIVATE int softscroll;		/* 1 = software scrolling, 0 = hardware */
PRIVATE int beeping;		/* speaker is beeping? */
PRIVATE unsigned font_lines;	/* font lines per character */
PRIVATE unsigned scr_width;	/* # characters on a line */
PRIVATE unsigned scr_lines;	/* # lines on the screen */
PRIVATE unsigned scr_size;	/* # characters on the screen */

/* Per console data. */
typedef struct console {
  tty_t *c_tty;			/* associated TTY struct */
  int c_column;			/* current column number (0-origin) */
  int c_row;			/* current row (0 at top of screen) */
  int c_rwords;			/* number of WORDS (not bytes) in outqueue */
  unsigned c_start;		/* start of video memory of this console */
  unsigned c_limit;		/* limit of this console's video memory */
  unsigned c_org;		/* location in RAM where 6845 base points */
  unsigned c_cur;		/* current position of cursor in video RAM */
  unsigned c_attr;		/* character attribute */
  unsigned c_blank;		/* blank attribute */
  char c_reverse;		/* reverse video */
  char c_esc_state;		/* 0=normal, 1=ESC, 2=ESC[ */
  char c_esc_intro;		/* Distinguishing character following ESC */
  int *c_esc_parmp;		/* pointer to current escape parameter */
  int c_esc_parmv[MAX_ESC_PARMS];	/* list of escape parameters */
  u16_t c_ramqueue[CONS_RAM_WORDS];	/* buffer for video RAM */
} console_t;

PRIVATE int nr_cons= 1;		/* actual number of consoles */
PRIVATE console_t cons_table[NR_CONS];
PRIVATE console_t *curcons;	/* currently visible */

/* Color if using a color controller. */
#define color	(vid_port == C_6845)

/* Map from ANSI colors to the attributes used by the PC */
PRIVATE int ansi_colors[8] = {0, 4, 2, 6, 1, 5, 3, 7};

/* Structure used for font management */
struct sequence {
	unsigned short index;
	unsigned char port;
	unsigned char value;
};

FORWARD _PROTOTYPE( int cons_write, (struct tty *tp, int try)		);
FORWARD _PROTOTYPE( void cons_echo, (tty_t *tp, int c)			);
FORWARD _PROTOTYPE( void out_char, (console_t *cons, int c)		);
FORWARD _PROTOTYPE( void cons_putk, (int c)				);
FORWARD _PROTOTYPE( void beep, (void)					);
FORWARD _PROTOTYPE( void do_escape, (console_t *cons, int c)		);
FORWARD _PROTOTYPE( void flush, (console_t *cons)			);
FORWARD _PROTOTYPE( void parse_escape, (console_t *cons, int c)		);
FORWARD _PROTOTYPE( void scroll_screen, (console_t *cons, int dir)	);
FORWARD _PROTOTYPE( void set_6845, (int reg, unsigned val)		);
FORWARD _PROTOTYPE( void get_6845, (int reg, unsigned *val)		);
FORWARD _PROTOTYPE( void stop_beep, (timer_t *tmrp)			);
FORWARD _PROTOTYPE( void cons_org0, (void)				);
FORWARD _PROTOTYPE( int ga_program, (struct sequence *seq)		);
FORWARD _PROTOTYPE( int cons_ioctl, (tty_t *tp, int)			);

/*===========================================================================*
 *				cons_write				     *
 *===========================================================================*/
PRIVATE int cons_write(tp, try)
register struct tty *tp;	/* tells which terminal is to be used */
int try;
{
/* Copy as much data as possible to the output queue, then start I/O.  On
 * memory-mapped terminals, such as the IBM console, the I/O will also be
 * finished, and the counts updated.  Keep repeating until all I/O done.
 */

  int count;
  int result;
  register char *tbuf;
  char buf[64];
  console_t *cons = tp->tty_priv;

  if (try) return 1;	/* we can always write to console */

  /* Check quickly for nothing to do, so this can be called often without
   * unmodular tests elsewhere.
   */
  if ((count = tp->tty_outleft) == 0 || tp->tty_inhibited) return;

  /* Copy the user bytes to buf[] for decent addressing. Loop over the
   * copies, since the user buffer may be much larger than buf[].
   */
  do {
	if (count > sizeof(buf)) count = sizeof(buf);
	if ((result = sys_vircopy(tp->tty_outproc, D, tp->tty_out_vir, 
			SELF, D, (vir_bytes) buf, (vir_bytes) count)) != OK)
		break;
	tbuf = buf;

	/* Update terminal data structure. */
	tp->tty_out_vir += count;
	tp->tty_outcum += count;
	tp->tty_outleft -= count;

	/* Output each byte of the copy to the screen.  Avoid calling
	 * out_char() for the "easy" characters, put them into the buffer
	 * directly.
	 */
	do {
		if ((unsigned) *tbuf < ' ' || cons->c_esc_state > 0
			|| cons->c_column >= scr_width
			|| cons->c_rwords >= buflen(cons->c_ramqueue))
		{
			out_char(cons, *tbuf++);
		} else {
			cons->c_ramqueue[cons->c_rwords++] =
					cons->c_attr | (*tbuf++ & BYTE);
			cons->c_column++;
		}
	} while (--count != 0);
  } while ((count = tp->tty_outleft) != 0 && !tp->tty_inhibited);

  flush(cons);			/* transfer anything buffered to the screen */

  /* Reply to the writer if all output is finished or if an error occured. */
  if (tp->tty_outleft == 0 || result != OK) {
	/* REVIVE is not possible. I/O on memory mapped consoles finishes. */
	tty_reply(tp->tty_outrepcode, tp->tty_outcaller, tp->tty_outproc,
							tp->tty_outcum);
	tp->tty_outcum = 0;
  }
}

/*===========================================================================*
 *				cons_echo				     *
 *===========================================================================*/
PRIVATE void cons_echo(tp, c)
register tty_t *tp;		/* pointer to tty struct */
int c;				/* character to be echoed */
{
/* Echo keyboard input (print & flush). */
  console_t *cons = tp->tty_priv;

  out_char(cons, c);
  flush(cons);
}

/*===========================================================================*
 *				out_char				     *
 *===========================================================================*/
PRIVATE void out_char(cons, c)
register console_t *cons;	/* pointer to console struct */
int c;				/* character to be output */
{
/* Output a character on the console.  Check for escape sequences first. */
  if (cons->c_esc_state > 0) {
	parse_escape(cons, c);
	return;
  }

  switch(c) {
	case 000:		/* null is typically used for padding */
		return;		/* better not do anything */

	case 007:		/* ring the bell */
		flush(cons);	/* print any chars queued for output */
		beep();
		return;

	case '\b':		/* backspace */
		if (--cons->c_column < 0) {
			if (--cons->c_row >= 0) cons->c_column += scr_width;
		}
		flush(cons);
		return;

	case '\n':		/* line feed */
		if ((cons->c_tty->tty_termios.c_oflag & (OPOST|ONLCR))
						== (OPOST|ONLCR)) {
			cons->c_column = 0;
		}
		/*FALL THROUGH*/
	case 013:		/* CTRL-K */
	case 014:		/* CTRL-L */
		if (cons->c_row == scr_lines-1) {
			scroll_screen(cons, SCROLL_UP);
		} else {
			cons->c_row++;
		}
		flush(cons);
		return;

	case '\r':		/* carriage return */
		cons->c_column = 0;
		flush(cons);
		return;

	case '\t':		/* tab */
		cons->c_column = (cons->c_column + TAB_SIZE) & ~TAB_MASK;
		if (cons->c_column > scr_width) {
			cons->c_column -= scr_width;
			if (cons->c_row == scr_lines-1) {
				scroll_screen(cons, SCROLL_UP);
			} else {
				cons->c_row++;
			}
		}
		flush(cons);
		return;

	case 033:		/* ESC - start of an escape sequence */
		flush(cons);	/* print any chars queued for output */
		cons->c_esc_state = 1;	/* mark ESC as seen */
		return;

	default:		/* printable chars are stored in ramqueue */
		if (cons->c_column >= scr_width) {
			if (!LINEWRAP) return;
			if (cons->c_row == scr_lines-1) {
				scroll_screen(cons, SCROLL_UP);
			} else {
				cons->c_row++;
			}
			cons->c_column = 0;
			flush(cons);
		}
		if (cons->c_rwords == buflen(cons->c_ramqueue)) flush(cons);
		cons->c_ramqueue[cons->c_rwords++] = cons->c_attr | (c & BYTE);
		cons->c_column++;			/* next column */
		return;
  }
}

/*===========================================================================*
 *				scroll_screen				     *
 *===========================================================================*/
PRIVATE void scroll_screen(cons, dir)
register console_t *cons;	/* pointer to console struct */
int dir;			/* SCROLL_UP or SCROLL_DOWN */
{
  unsigned new_line, new_org, chars;

  flush(cons);
  chars = scr_size - scr_width;		/* one screen minus one line */

  /* Scrolling the screen is a real nuisance due to the various incompatible
   * video cards.  This driver supports software scrolling (Hercules?),
   * hardware scrolling (mono and CGA cards) and hardware scrolling without
   * wrapping (EGA cards).  In the latter case we must make sure that
   *		c_start <= c_org && c_org + scr_size <= c_limit
   * holds, because EGA doesn't wrap around the end of video memory.
   */
  if (dir == SCROLL_UP) {
	/* Scroll one line up in 3 ways: soft, avoid wrap, use origin. */
	if (softscroll) {
		vid_vid_copy(cons->c_start + scr_width, cons->c_start, chars);
	} else
	if (!wrap && cons->c_org + scr_size + scr_width >= cons->c_limit) {
		vid_vid_copy(cons->c_org + scr_width, cons->c_start, chars);
		cons->c_org = cons->c_start;
	} else {
		cons->c_org = (cons->c_org + scr_width) & vid_mask;
	}
	new_line = (cons->c_org + chars) & vid_mask;
  } else {
	/* Scroll one line down in 3 ways: soft, avoid wrap, use origin. */
	if (softscroll) {
		vid_vid_copy(cons->c_start, cons->c_start + scr_width, chars);
	} else
	if (!wrap && cons->c_org < cons->c_start + scr_width) {
		new_org = cons->c_limit - scr_size;
		vid_vid_copy(cons->c_org, new_org + scr_width, chars);
		cons->c_org = new_org;
	} else {
		cons->c_org = (cons->c_org - scr_width) & vid_mask;
	}
	new_line = cons->c_org;
  }
  /* Blank the new line at top or bottom. */
  blank_color = cons->c_blank;
  mem_vid_copy(BLANK_MEM, new_line, scr_width);

  /* Set the new video origin. */
  if (cons == curcons) set_6845(VID_ORG, cons->c_org);
  flush(cons);
}

/*===========================================================================*
 *				flush					     *
 *===========================================================================*/
PRIVATE void flush(cons)
register console_t *cons;	/* pointer to console struct */
{
/* Send characters buffered in 'ramqueue' to screen memory, check the new
 * cursor position, compute the new hardware cursor position and set it.
 */
  unsigned cur;
  tty_t *tp = cons->c_tty;

  /* Have the characters in 'ramqueue' transferred to the screen. */
  if (cons->c_rwords > 0) {
	mem_vid_copy(cons->c_ramqueue, cons->c_cur, cons->c_rwords);
	cons->c_rwords = 0;

	/* TTY likes to know the current column and if echoing messed up. */
	tp->tty_position = cons->c_column;
	tp->tty_reprint = TRUE;
  }

  /* Check and update the cursor position. */
  if (cons->c_column < 0) cons->c_column = 0;