/*      $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