/*
 *  libsocket - BSD socket like library for DJGPP
 *  Copyright 1997, 1998 by Indrek Mandre
 *  Copyright 1997-2000 by Richard Dawe
 *
 *  Portions of libsocket Copyright 1985-1993 Regents of the University of 
 *  California.
 *  Portions of libsocket Copyright 1991, 1992 Free Software Foundation, Inc.
 *  Portions of libsocket Copyright 1997, 1998 by the Regdos Group.
 *
 *  This library is free software; you can redistribute it and/or modify it
 *  under the terms of the GNU Library General Public License as published
 *  by the Free Software Foundation; either version 2 of the License, or (at
 *  your option) any later version.
 *
 *  This library 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
 *  Library General Public License for more details.
 * 
 *  You should have received a copy of the GNU Library General Public
 *  License along with this library; if not, write to the Free Software
 *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

/*
 * Original code from Dan Hedlund's wsock library.
 */

#include <string.h>
#include <errno.h>

#include <dpmi.h>

#include <lsck/vxd.h>
#include "farptrx.h"

#define VxdLdr_DeviceID     0x0027
#define VxdLdr_LoadDevice   1
#define VxdLdr_UnLoadDevice 2

static int VxdLdrEntry[2] = {0, 0};

/* --------------
 * - VxdLdrInit -
 * -------------- */

void VxdLdrInit (void)
{
    VxdGetEntry(VxdLdrEntry, VxdLdr_DeviceID);
}

/* --------------------
 * - VxdLdrLoadDevice -
 * -------------------- */

int VxdLdrLoadDevice (char Device[])
{
    int Error;

    __dpmi_meminfo _dev;
    int dev;

    if (VxdLdrEntry[1] == 0)
	VxdLdrInit();

    if (VxdLdrEntry[1] == 0) {
        errno = ENODEV;
	return -1;
    }

    _dev.handle = 0;
    _dev.size = strlen (Device) + 1;
    _dev.address = 0;

    __dpmi_allocate_memory (&_dev);
    dev = __dpmi_allocate_ldt_descriptors (1);
    __dpmi_set_segment_base_address (dev, _dev.address);
    __dpmi_set_segment_limit (dev, _dev.size);

    _farpokex (dev, 0, Device, _dev.size);

    __asm__ __volatile__ ("pushl   %%ds            \n\
                           movw    %%cx, %%ds      \n\
                          "
#if    (GAS_MAJOR == 2) \
    && ((GAS_MINOR < 9) || ((GAS_MINOR == 9) && (GAS_MINORMINOR < 5)))
                          "lcall   %%cs:_VxdLdrEntry \n\
                          "
#else
			  "lcall   *%%cs:_VxdLdrEntry \n\
                          "
#endif			  
                          "setc    %%al            \n\
                           movzbl  %%al, %%eax     \n\
                           popl    %%ds"
			  :"=a" (Error)
			  :"a" (VxdLdr_LoadDevice), "c" (dev), "d" (0)
    );

    __dpmi_free_ldt_descriptor (dev);
    __dpmi_free_memory (_dev.handle);

    return Error;
}

/* ----------------------
 * - VxdLdrUnLoadDevice -
 * ---------------------- */

int VxdLdrUnLoadDevice (char Device[])
{
    int Error;

    __dpmi_meminfo _dev;
    int dev;

    if (VxdLdrEntry[1] == 0)
	VxdLdrInit();

    if (VxdLdrEntry[1] == 0) {
        errno = ENODEV;
	return -1;
    }

    _dev.handle = 0;
    _dev.size = strlen (Device) + 1;
    _dev.address = 0;

    __dpmi_allocate_memory (&_dev);
    dev = __dpmi_allocate_ldt_descriptors (1);
    __dpmi_set_segment_base_address (dev, _dev.address);
    __dpmi_set_segment_limit (dev, _dev.size);

    __asm__ __volatile__ ("pushl   %%ds            \n\
                           movw    %%cx, %%ds      \n\
                          "
#if    (GAS_MAJOR == 2) \
    && ((GAS_MINOR < 9) || ((GAS_MINOR == 9) && (GAS_MINORMINOR < 5)))
                          "lcall   %%cs:_VxdLdrEntry \n\
                          "
#else
			  "lcall   *%%cs:_VxdLdrEntry \n\
                          "
#endif
                          "setc    %%al            \n\
                           movzbl  %%al, %%eax     \n\
                           popl    %%ds"
			  :"=a" (Error)
			  :"a" (VxdLdr_UnLoadDevice), "c" (dev), "d" (0)
    );

    __dpmi_free_ldt_descriptor (dev);
    __dpmi_free_memory (_dev.handle);

    return Error;
}