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pvcopy.S revision 1.1 
      1 /*	$NetBSD: pvcopy.S,v 1.1 2003/04/16 13:24:10 dsl Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 2003 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by David Laight.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  * 3. All advertising materials mentioning features or use of this software
     19  *    must display the following acknowledgement:
     20  *        This product includes software developed by the NetBSD
     21  *        Foundation, Inc. and its contributors.
     22  * 4. Neither the name of The NetBSD Foundation nor the names of its
     23  *    contributors may be used to endorse or promote products derived
     24  *    from this software without specific prior written permission.
     25  *
     26  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     27  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     28  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     29  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     30  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     31  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     32  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     33  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     34  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     35  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     36  * POSSIBILITY OF SUCH DAMAGE.
     37  */
     38 
     39 #include <machine/asm.h>
     40 
     41 /*
     42  * Routines to copy to/from absolute virtual addresses.
     43  * Needed because the boot code runs with %ds having a 64k offset
     44  * whereas Unix runs with a zero offset.
     45  *
     46  * These routines are optimised for code space, not execution speed.
     47  */
     48 
     49 /*
     50  * pbzero(void *dst, int cnt)
     51  *	zero absolute virtual memory
     52  */
     53 ENTRY(pbzero)
     54 	.code32
     55 	push	%edi
     56 	push	%es
     57 	mov	12(%esp),%edi
     58 	mov	16(%esp),%ecx
     59 
     60 	mov	$flatdataseg, %ax	/* selector with offset == 0 */
     61 	mov	%ax, %es
     62 	xor	%eax,%eax
     63 
     64 	cld
     65 	rep
     66 	stosb
     67 
     68 	pop	%es
     69 	pop	%edi
     70 	ret
     71 
     72 /*
     73  * vpbcopy(const void *src, void *dst, int cnt)
     74  *	Copy to absolute virtual address
     75  */
     76 ENTRY(vpbcopy)
     77 	.code32
     78 	push	%esi
     79 	push	%edi
     80 	push	%es
     81 	mov	16(%esp),%esi
     82 	mov	20(%esp),%edi
     83 	mov	24(%esp),%ecx
     84 
     85 	mov	$flatdataseg, %ax	/* selector with offset == 0 */
     86 	mov	%ax, %es
     87 	xor	%eax,%eax
     88 
     89 	cld
     90 	rep
     91 	movsb
     92 
     93 	popl	%es
     94 	popl	%edi
     95 	popl	%esi
     96 	ret
     97 
     98 /*
     99  * pvbcopy(const void *src, void *dst, int cnt)
    100  *	Copy from absolute virtual address
    101  */
    102 ENTRY(pvbcopy)
    103 	.code32
    104 	push	%esi
    105 	push	%edi
    106 	push	%ds
    107 	mov	16(%esp),%esi
    108 	mov	20(%esp),%edi
    109 	mov	24(%esp),%ecx
    110 
    111 	mov	$flatdataseg, %ax	/* selector with offset == 0 */
    112 	mov	%ax, %ds
    113 	xor	%eax,%eax
    114 
    115 	cld
    116 	rep
    117 	movsb
    118 
    119 	popl	%ds
    120 	popl	%edi
    121 	popl	%esi
    122 	ret
    123