Source to i386/stand/cga.c
/*-
* Copyright (c) 1990, 1993
* 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 8.1 (Berkeley) 6/11/93
*/
#include <sys/param.h>
#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 u_char att = 0x7 ;
u_char *Crtat = (u_char *)CGA_BUF;
static unsigned int addr_6845 = CGA_BASE;
cursor(pos)
int pos;
{
outb(addr_6845,14);
outb(addr_6845+1,pos >> 8);
outb(addr_6845,15);
outb(addr_6845+1,pos&0xff);
}
sput(c)
u_char c;
{
static u_char *crtat = 0;
unsigned cursorat; u_short was;
u_char *cp;
if (crtat == 0) {
/* XXX probe to find if a color or monochrome display */
was = *(u_short *)Crtat;
*(u_short *)Crtat = 0xA55A;
if (*(u_short *)Crtat != 0xA55A) {
Crtat = (u_char *) MONO_BUF;
addr_6845 = MONO_BASE;
}
*(u_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;
att = crtat[1]; /* use current attribute present */
} 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
sput(' ');
while ((int)crtat % (8*CHR));
break;
case '\010':
crtat -= CHR;
break;
case '\r':
crtat -= (crtat - Crtat) % (COL*CHR);
break;
case '\n':
crtat += COL*CHR ;
break;
default:
crtat[0] = c;
crtat[1] = att;
crtat += CHR;
break ;
}
#ifndef SMALL
/* implement a scroll */
if (crtat >= Crtat+COL*ROW*CHR) {
/* move text up */
bcopy(Crtat+COL*CHR, Crtat, 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 ;
}
#endif
cursor((crtat-Crtat)/CHR);
}