Home | History | Annotate | Line # | Download | only in lib 
      1 /*	$NetBSD: biosdelay.S,v 1.4 2005/12/11 12:17:48 christos Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1996, 1997
      5  * 	Perry E. Metzger.  All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  * 3. All advertising materials mentioning features or use of this software
     16  *    must display the following acknowledgements:
     17  *	This product includes software developed for the NetBSD Project
     18  *	by Perry E. Metzger.
     19  * 4. The names of the authors may not be used to endorse or promote products
     20  *    derived from this software without specific prior written permission.
     21  *
     22  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     23  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     24  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     25  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     26  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     27  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     28  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     29  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     30  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     31  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     32  *
     33  */
     34 
     35 #include <machine/asm.h>
     36 
     37 	.text
     38 
     39 /*
     40  * BIOS call "INT 15H Function 86H" to sleep for a set number of microseconds
     41  *	Call with	%ah = 0x86
     42  *			%cx = time interval (high)
     43  *			%dx = time interval (low)
     44  *	Return:
     45  *		If error
     46  *			CF  = set
     47  *		else
     48  *			CF  = clear
     49  */
     50 ENTRY(delay)
     51 	pushl	%ebp
     52 	pushl	%ebx
     53 	pushl	%esi
     54 	pushl	%edi
     55 
     56 	movw	20(%esp), %dx
     57 	movw	22(%esp), %cx
     58 
     59 	call	_C_LABEL(prot_to_real)
     60 	.code16
     61 
     62 	movb	$0x86, %ah
     63 	int	$0x15
     64 	setnc	%ah
     65 
     66 	movb	%ah, %bl	# real_to_prot uses %eax
     67 
     68 	calll	_C_LABEL(real_to_prot)
     69 	.code32
     70 
     71 	xorl	%eax, %eax
     72 	movb	%bl, %al
     73 
     74 	popl	%edi
     75 	popl	%esi
     76 	popl	%ebx
     77 	popl	%ebp
     78 	ret
     79