tty.c

这是《自己动手写操作系统》的原文件和代码

/*++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
                               tty.c
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
                                                    Forrest Yu, 2005
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++*/

#include "type.h"
#include "const.h"
#include "protect.h"
#include "string.h"
#include "proc.h"
#include "tty.h"
#include "console.h"
#include "global.h"
#include "keyboard.h"
#include "proto.h"


#define TTY_FIRST	(tty_table)
#define TTY_END		(tty_table + NR_CONSOLES)


/* 本文件内函数声明 */
PRIVATE void	init_tty(TTY* p_tty);
PRIVATE void	tty_do_read(TTY* p_tty);
PRIVATE void	tty_do_write(TTY* p_tty);


/*======================================================================*
                           task_tty
 *======================================================================*/
PUBLIC void task_tty()
{
	TTY*	p_tty;

	init_keyboard();

	for (p_tty=TTY_FIRST;p_tty<TTY_END;p_tty++) {
		init_tty(p_tty);
	}

	nr_current_console = 0;

	while (1) {
		for (p_tty=TTY_FIRST;p_tty<TTY_END;p_tty++) {
			tty_do_read(p_tty);
			tty_do_write(p_tty);
		}
	}
}


/*======================================================================*
                           init_tty
 *======================================================================*/
PRIVATE void init_tty(TTY* p_tty)
{
	p_tty->inbuf_count = 0;
	p_tty->p_inbuf_head = p_tty->p_inbuf_tail = p_tty->in_buf;

	int nr_tty = p_tty - tty_table;
	p_tty->p_console = console_table + nr_tty;
}


/*======================================================================*
                           in_process
*======================================================================*/
PUBLIC void in_process(TTY* p_tty, t_32 key)
{
	if (!(key & FLAG_EXT)) {
		if (p_tty->inbuf_count < TTY_IN_BYTES) {
			*(p_tty->p_inbuf_head) = key;
			p_tty->p_inbuf_head++;
			if (p_tty->p_inbuf_head == p_tty->in_buf + TTY_IN_BYTES) {
				p_tty->p_inbuf_head = p_tty->in_buf;
			}
			p_tty->inbuf_count++;
		}
	}
	else {
		int raw_code = key & MASK_RAW;
		switch(raw_code) {
		case UP:
			if ((key & FLAG_SHIFT_L) || (key & FLAG_SHIFT_R)) {	/* Shift + Up */
				disable_int();
				out_byte(CRTC_ADDR_REG, CRTC_DATA_IDX_START_ADDR_H);
				out_byte(CRTC_DATA_REG, ((80*15) >> 8) & 0xFF);
				out_byte(CRTC_ADDR_REG, CRTC_DATA_IDX_START_ADDR_L);
				out_byte(CRTC_DATA_REG, (80*15) & 0xFF);
				enable_int();
			}
			break;
		case DOWN:
			if ((key & FLAG_SHIFT_L) || (key & FLAG_SHIFT_R)) {	/* Shift + Down */
			}
			break;
		default:
			break;
		}
	}
}


/*======================================================================*
                              tty_do_read
*======================================================================*/
PRIVATE void tty_do_read(TTY* p_tty)
{
	if (is_current_console(p_tty->p_console)) {
		keyboard_read(p_tty);
	}
}


/*======================================================================*
                              tty_do_write
*======================================================================*/
PRIVATE void tty_do_write(TTY* p_tty)
{
	if (p_tty->inbuf_count) {
		char ch = *(p_tty->p_inbuf_tail);
		p_tty->p_inbuf_tail++;
		if (p_tty->p_inbuf_tail == p_tty->in_buf + TTY_IN_BYTES) {
			p_tty->p_inbuf_tail = p_tty->in_buf;
		}
		p_tty->inbuf_count--;

		out_char(p_tty->p_console, ch);
	}
}