/*      $NetBSD: biosgetrtc.S,v 1.7 2011/06/16 13:27:59 joerg Exp $     */

/*
 * Copyright (c) 1996
 *      Matthias Drochner.  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.
 *
 * 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>

ENTRY(biosgetrtc)
        pusha
        pushl   %eax

        xorl    %ebx, %ebx

        call    _C_LABEL(prot_to_real)  # enter real mode
        .code16

        movb    $2, %ah
        int     $0x1a
        jnc     ok
        movl    $-1, %ebx

ok:
        calll   _C_LABEL(real_to_prot) # back to protected mode
        .code32

        popl    %eax
        movb    %ch, (%eax)
        movb    %cl, 1(%eax)
        movb    %dh, 2(%eax)
        movb    $0,  3(%eax)

        movl    %ebx, 28(%esp)

        popa
        ret