dummy.c.svn-base

SImple Microkernel Distributed Operating System

#include <stdio.h>

#define	BSPACE	0x08
#define TSPACE	0x09
#define CRETURN	'\r'
#define NLINE	'\n'
#define	SPACE	' '

#define WD	80
#define LN	25
#define TAB	8

/* Misplaced - Place it where it should be*/
extern unsigned csr_x;
extern unsigned csr_y;
extern unsigned attrib;
extern unsigned short *textmemptr;
/* End misplaced */

extern void outportb(unsigned short _port, unsigned char _data);
extern unsigned short *memsetw(unsigned short *s,\
		unsigned short c, size_t n);

void move_cs(void)
{
	unsigned temp;

	temp = csr_y * 80 + csr_x;

	outportb(0x3D4, 14);
	outportb(0x3D5, temp >> 8);
	outportb(0x3D4, 15);
	outportb(0x3D5, temp);
}

void clear(void)
{
	int i;
	unsigned blank;

	blank = 0x20 | (attrib << 8);
	
	csr_x = 0;
	csr_y = 0;

	for(i = 0; i < 25; i++)
		memsetw(textmemptr + i * 80, blank, 80);

	csr_x = csr_y = 0;
	move_cs();
}

/*
void init_video(void)
{
	vga_addr = (unsigned short *)0xB8000;
	clear();
}
*/
int dummy(int c, FILE *stream)
{
	if(c == BSPACE){	// Backspace
		if(csr_x == 0){
			csr_x = WD;
			csr_y--;
		}
		else	csr_x--;
	}
	else if(c == TSPACE){	//Tab		
		if(csr_x > (WD - TAB))
			csr_y++;
		csr_x %= WD;
		csr_x += TAB;
	}
	else if(c == CRETURN){	// Carriage Return
		csr_x = 0;
	}
	else if(c == NLINE){	// New Line
		csr_x = 0;
		csr_y++;
	}
	else if(c >= SPACE){ 	//Any character greater than space is printable
		memcpy(textmemptr + (csr_y * WD) + csr_x, \
				&c, sizeof(int));
		csr_x++;
	}

	return 0;
}