1/*        $NetBSD: pvcopy.S,v 1.2 2008/04/28 20:23:25 martin 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 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32#include <machine/asm.h>
33
34/*
35 * Routines to copy to/from absolute virtual addresses.
36 * Needed because the boot code runs with %ds having a 64k offset
37 * whereas Unix runs with a zero offset.
38 *
39 * These routines are optimised for code space, not execution speed.
40 */
41
42/*
43 * pbzero(void *dst, int cnt)
44 *        zero absolute virtual memory
45 */
46ENTRY(pbzero)
47          .code32
48          push      %edi
49          push      %es
50          mov       12(%esp),%edi
51          mov       16(%esp),%ecx
52
53          mov       $flatdataseg, %ax   /* selector with offset == 0 */
54          mov       %ax, %es
55          xor       %eax,%eax
56
57          cld
58          rep
59          stosb
60
61          pop       %es
62          pop       %edi
63          ret
64
65/*
66 * vpbcopy(const void *src, void *dst, int cnt)
67 *        Copy to absolute virtual address
68 */
69ENTRY(vpbcopy)
70          .code32
71          push      %esi
72          push      %edi
73          push      %es
74          mov       16(%esp),%esi
75          mov       20(%esp),%edi
76          mov       24(%esp),%ecx
77
78          mov       $flatdataseg, %ax   /* selector with offset == 0 */
79          mov       %ax, %es
80          xor       %eax,%eax
81
82          cld
83          rep
84          movsb
85
86          popl      %es
87          popl      %edi
88          popl      %esi
89          ret
90
91/*
92 * pvbcopy(const void *src, void *dst, int cnt)
93 *        Copy from absolute virtual address
94 */
95ENTRY(pvbcopy)
96          .code32
97          push      %esi
98          push      %edi
99          push      %ds
100          mov       16(%esp),%esi
101          mov       20(%esp),%edi
102          mov       24(%esp),%ecx
103
104          mov       $flatdataseg, %ax   /* selector with offset == 0 */
105          mov       %ax, %ds
106          xor       %eax,%eax
107
108          cld
109          rep
110          movsb
111
112          popl      %ds
113          popl      %edi
114          popl      %esi
115          ret
116