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 ; CopyMem.asm 15 ; 16 ; Abstract: 17 ; 18 ; memcpy function 19 ; 20 ; Notes: 21 ; 22 ;------------------------------------------------------------------------------ 23 24 .686 25 .model flat,C 26 .code 27 28 ;------------------------------------------------------------------------------ 29 ; VOID * 30 ; memcpy ( 31 ; IN VOID *Destination, 32 ; IN VOID *Source, 33 ; IN UINTN Count 34 ; ); 35 ;------------------------------------------------------------------------------ 36 memcpy PROC USES esi edi 37 mov esi, [esp + 16] ; esi <- Source 38 mov edi, [esp + 12] ; edi <- Destination 39 mov edx, [esp + 20] ; edx <- Count 40 cmp esi, edi 41 je @CopyDone 42 cmp edx, 0 43 je @CopyDone 44 lea eax, [esi + edx - 1] ; eax <- End of Source 45 cmp esi, edi 46 jae @F 47 cmp eax, edi 48 jb @F ; Copy backward if overlapped 49 mov esi, eax ; esi <- End of Source 50 lea edi, [edi + edx - 1] ; edi <- End of Destination 51 std 52 @@: 53 mov ecx, edx 54 rep movsb ; Copy bytes backward 55 cld 56 @CopyDone: 57 mov eax, [esp + 12] 58 ret 59 memcpy ENDP 60 61 END 62
