xref: /netbsd-src/sys/arch/i386/stand/lib/pvcopy.S (revision fad4c9f71477ae11cea2ee75ec82151ac770a534)
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 */
53ENTRY(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 */
76ENTRY(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 */
102ENTRY(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