kbmoutput.c

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/* kbmoutput.c - kbmputc, kbmwrite */

#include <conf.h>
#include <kernel.h>
#include <io.h>
#include <tty.h>    

/*-
 * Copyright (c) 1990 The Regents of the University of California.
 * All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * William Jolitz.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *	@(#)cga.c	5.3 (Berkeley) 4/28/91
 */

#define	COL		80
#define	ROW		25
#define	CHR		2
#define MONO_BASE	0x3B4
#define MONO_BUF	0xB0000
#define CGA_BASE	0x3D4
#define CGA_BUF		0xB8000

static unsigned char	att = 0x7;
unsigned char *Crtat = (unsigned char *)CGA_BUF;

static void *addr_6845 = (void *)CGA_BASE;

unsigned char	inb(void *);
void		outb(void *, unsigned char);

static
cursor(int pos)
{
	outb(addr_6845,14);
	outb(addr_6845+1,pos >> 8);
	outb(addr_6845,15);
	outb(addr_6845+1,pos&0xff);
}

/*------------------------------------------------------------------------
 *  kbmputc - write one character to the physical monitor
 *------------------------------------------------------------------------
 */
kbmputc(struct devsw *pdev, unsigned char c )
{
	unsigned		cursorat;
	unsigned short		was;
	unsigned char		*cp;
	static unsigned char	*crtat = 0;

	if (c == 0)
		return OK;

	if (crtat == 0) {

		/* XXX probe to find if a color or monochrome display */
		was = *(unsigned short *)Crtat;
		*(unsigned short *)Crtat = 0xA55A;
		if (*(unsigned short *)Crtat != 0xA55A) {
			Crtat = (unsigned char *) MONO_BUF;
			addr_6845 = (void *)MONO_BASE;
		}
		*(unsigned short *)Crtat = was;

		/* Extract cursor location */
		outb(addr_6845,14);
		cursorat = inb(addr_6845+1)<<8 ;
		outb(addr_6845,15);
		cursorat |= inb(addr_6845+1);

		if (cursorat <= COL * ROW)
			crtat = Crtat + cursorat * CHR;
		else
			crtat = Crtat;

		/* clean display */
		for (cp = crtat; cp < Crtat+ROW*COL*CHR; cp += 2) {
			cp[0] = ' ';
			cp[1] = att;
		}
	}

	switch (c) {

	case '\t':
		do
			kbmputc(pdev, ' ');
		while ((int)crtat % (8*CHR));
		break;

	case '\010':
		crtat -= CHR;
		break;

	case '\n':
		crtat += COL*CHR ;
		/* fall through */
	case '\r':
		crtat -= (crtat - Crtat) % (COL*CHR);
		break;

	default:
		crtat[0] = c;
		crtat[1] = att;
		crtat += CHR;
		break ;
	}

	/* implement a scroll */
	if (crtat >= Crtat+COL*ROW*CHR) {
		/* move text up */
		memcpy(Crtat, Crtat+COL*CHR, COL*(ROW-1)*CHR);

		/* clear line */
		for (cp = Crtat+ COL*(ROW-1)*CHR;
			cp < Crtat + COL*ROW*CHR ; cp += 2)
			cp[0] = ' ';

		crtat -= COL*CHR ;
	}

	cursor((crtat-Crtat)/CHR);
	return OK;
}


/*------------------------------------------------------------------------
 *  kbmwrite - write to the physical monitor
 *------------------------------------------------------------------------
 */
kbmwrite(struct devsw *pdev, unsigned char *buff, unsigned count)
{
	if (count == 0)
		return OK;

	for (; count>0 ; count--)
		kbmputc(pdev, *buff++);
	return OK;
}