Home | History | Annotate | Line # | Download | only in lib
biosdelay.S revision 1.1 
      1 /*	$NetBSD: biosdelay.S,v 1.1 1997/03/14 02:40:32 perry 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 #define data32	.byte 0x66
     38 
     39 	.text
     40 
     41 /*
     42 # BIOS call "INT 15H Function 86H" to sleep for a set number of microseconds
     43 #	Call with	%ah = 0x86
     44 #			%cx = time interval (high)
     45 #			%dx = time interval (low)
     46 #	Return:
     47 #		If error
     48 #			CF  = set
     49 #		else
     50 #			CF  = clear
     51 */
     52 ENTRY(delay)
     53 	pushl	%ebp
     54 	pushl	%ebx
     55 	pushl	%esi
     56 	pushl	%edi
     57 
     58 	movw	20(%esp), %dx
     59 	movw	22(%esp), %cx
     60 
     61 	call	_C_LABEL(prot_to_real)
     62 
     63 	movb	$0x86, %ah
     64 	int	$0x15
     65 	setnc	%ah
     66 
     67 	movb	%ah, %bl	# real_to_prot uses %eax
     68 
     69 	data32
     70 	call	_C_LABEL(real_to_prot)
     71 
     72 	xorl	%eax, %eax
     73 	movb	%bl, %al
     74 
     75 	popl	%edi
     76 	popl	%esi
     77 	popl	%ebx
     78 	popl	%ebp
     79 	ret
     80