harvey/sys/src/cmd/gs/src/gdevevga.c

/* Copyright (C) 1993, 1994 Aladdin Enterprises.  All rights reserved.
  
  This software is provided AS-IS with no warranty, either express or
  implied.
  
  This software is distributed under license and may not be copied,
  modified or distributed except as expressly authorized under the terms
  of the license contained in the file LICENSE in this distribution.
  
  For more information about licensing, please refer to
  http://www.ghostscript.com/licensing/. For information on
  commercial licensing, go to http://www.artifex.com/licensing/ or
  contact Artifex Software, Inc., 101 Lucas Valley Road #110,
  San Rafael, CA  94903, U.S.A., +1(415)492-9861.
*/

/* $Id: gdevevga.c,v 1.4 2002/02/21 22:24:51 giles Exp $ */
/* IBM PC EGA and VGA display drivers */
/* All of the real code is in gdevpcfb.c. */
#include "memory_.h"
#include "gx.h"
#include "gserrors.h"
#include "gxdevice.h"
#include "gdevpcfb.h"

/* ------ Internal routines ------ */

/* We can't catch signals.... */
void
pcfb_set_signals(gx_device * dev)
{
}

/* Read the device state */
void
pcfb_get_state(pcfb_bios_state * pbs)
{
    registers regs;

    regs.h.ah = 0xf;
    int86(0x10, &regs, &regs);
    pbs->display_mode = regs.h.al;
    pbs->text_page = regs.h.bh;
    regs.h.ah = 0x3;
    int86(0x10, &regs, &regs);
    pbs->text_cursor_mode = regs.rshort.cx;
    regs.rshort.ax = 0x1130;
    regs.h.bh = 0;
    int86(0x10, &regs, &regs);
    switch (regs.rshort.cx) {
	case 0x08:
	    pbs->text_font = 0x1112;
	    break;		/* 8 x 8 */
	case 0x10:
	    pbs->text_font = 0x1114;
	    break;		/* 8 x 16 */
	default:
	    pbs->text_font = 0x1111;	/* 8 x 14 */
    }
    regs.h.ah = 0x8;
    regs.h.bh = pbs->text_page;
    int86(0x10, &regs, &regs);
    pbs->text_attribute = regs.h.ah;
    pbs->border_color = (regs.h.ah >> 4);
    regs.rshort.ax = 0x1a00;
    int86(0x10, &regs, &regs);
    if (regs.h.al == 0x1a && regs.h.bl == 0x8) {
	regs.rshort.ax = 0x1008;
	int86(0x10, &regs, &regs);
	pbs->border_color = regs.h.bh;
    }
    if (pbs->display_mode != 3) {
	pbs->display_mode = 3;
	pbs->text_font = 0x1112;
	pbs->text_cursor_mode = 0x0607;
	pbs->text_attribute = 7;
	pbs->text_page = 0;
    }
}

/* Set the device mode */
void
pcfb_set_mode(int mode)
{
    registers regs;

    regs.h.ah = 0;
    regs.h.al = mode;
    int86(0x10, &regs, &regs);
}

/* Restore the device state */
void
pcfb_set_state(const pcfb_bios_state * pbs)
{
    registers regs;

    pcfb_set_mode(pbs->display_mode);
    regs.rshort.ax = 0x500;	/* force display of page 0 */
    int86(0x10, &regs, &regs);
    regs.rshort.ax = pbs->text_font;
    regs.h.bl = 0;
    int86(0x10, &regs, &regs);
    regs.h.ah = 0x3;
    regs.h.bh = 0;
    int86(0x10, &regs, &regs);	/* Get cursor to reset MCGA */
    regs.h.al = pbs->text_page;
    regs.h.ah = 0x5;
    int86(0x10, &regs, &regs);
    regs.rshort.cx = pbs->text_cursor_mode;
    regs.h.ah = 0x1;
    int86(0x10, &regs, &regs);
    regs.rshort.ax = 0x1001;
    regs.h.bh = pbs->border_color;
    int86(0x10, &regs, &regs);
}