/*
 * VBMouse - Interface to the Windows int 2Fh services
 * Copyright (C) 2022 Javier S. Pedro
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.

 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 */

#ifndef INT2FWIN_H
#define INT2FWIN_H

#include <stdbool.h>
#include <stdint.h>
#include <dos.h>

typedef void (__far *LPFN)(void);

enum int2f_functions
{
	INT2F_NOTIFY_BACKGROUND_SWITCH = 0x4001,
	INT2F_NOTIFY_FOREGROUND_SWITCH = 0x4002
};

static bool windows_386_enhanced_mode(void);
#pragma aux windows_386_enhanced_mode = \
	"mov ax, 0x1600" \
	"int 0x2F" \
	"test al, 0x7F" /* return value is either 0x80 or 0x00 if win386 is not running */ \
	"setnz al" \
	__value [al] \
	__modify [ax]

static inline void hook_int2f(LPFN *prev, LPFN new)
{
	*prev = _dos_getvect(0x2F);
	_dos_setvect(0x2F, new);
}

static inline void unhook_int2f(LPFN prev)
{
	_dos_setvect(0x2F, prev);
}

#endif