1 /*++
2
3 Copyright (c) 2007, Intel Corporation. All rights reserved.<BR>
4 This program and the accompanying materials
5 are licensed and made available under the terms and conditions of the BSD License
6 which accompanies this distribution. The full text of the license may be found at
7 http://opensource.org/licenses/bsd-license.php
8
9 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
10 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
11
12 Module Name:
13
14 EfiCopyMemRep1.c
15
16 Abstract:
17
18 This is the code that uses rep movsb CopyMem service
19
20 --*/
21
22 #include "Tiano.h"
23
24 VOID
EfiCommonLibCopyMem(IN VOID * Destination,IN VOID * Source,IN UINTN Count)25 EfiCommonLibCopyMem (
26 IN VOID *Destination,
27 IN VOID *Source,
28 IN UINTN Count
29 )
30 /*++
31
32 Routine Description:
33
34 Copy Length bytes from Source to Destination.
35
36 Arguments:
37
38 Destination - Target of copy
39
40 Source - Place to copy from
41
42 Length - Number of bytes to copy
43
44 Returns:
45
46 None
47
48 --*/
49 {
50 __asm {
51 mov esi, Source ; esi <- Source
52 mov edi, Destination ; edi <- Destination
53 mov edx, Count ; edx <- Count
54 cmp esi, edi
55 je _CopyDone
56 cmp edx, 0
57 je _CopyDone
58 lea eax, [esi + edx - 1] ; eax <- End of Source
59 cmp esi, edi
60 jae _CopyBytes
61 cmp eax, edi
62 jb _CopyBytes ; Copy backward if overlapped
63 mov esi, eax ; esi <- End of Source
64 lea edi, [edi + edx - 1] ; edi <- End of Destination
65 std
66 _CopyBytes:
67 mov ecx, edx
68 rep movsb ; Copy bytes backward
69 cld
70 _CopyDone:
71 }
72 }
73
74