/*      $NetBSD: biosdelay.S,v 1.4 2005/12/11 12:17:48 christos Exp $   */

/*
 * Copyright (c) 1996, 1997
 *      Perry E. Metzger.  All rights reserved.
 *
 * 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 acknowledgements:
 *      This product includes software developed for the NetBSD Project
 *      by Perry E. Metzger.
 * 4. The names of the authors may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
 *
 */

#include <machine/asm.h>

        .text

/*
 * BIOS call "INT 15H Function 86H" to sleep for a set number of microseconds
 *      Call with       %ah = 0x86
 *                      %cx = time interval (high)
 *                      %dx = time interval (low)
 *      Return:
 *              If error
 *                      CF  = set
 *              else
 *                      CF  = clear
 */
ENTRY(delay)
        pushl   %ebp
        pushl   %ebx
        pushl   %esi
        pushl   %edi

        movw    20(%esp), %dx
        movw    22(%esp), %cx

        call    _C_LABEL(prot_to_real)
        .code16

        movb    $0x86, %ah
        int     $0x15
        setnc   %ah

        movb    %ah, %bl        # real_to_prot uses %eax

        calll   _C_LABEL(real_to_prot)
        .code32

        xorl    %eax, %eax
        movb    %bl, %al

        popl    %edi
        popl    %esi
        popl    %ebx
        popl    %ebp
        ret