MdePkg: Replace BSD License with BSD+Patent License

[mirror_edk2.git] / MdePkg / Library / BaseMemoryLibOptPei / Ia32 / CopyMem.nasm

;------------------------------------------------------------------------------\r
;\r
; Copyright (c) 2006, Intel Corporation. All rights reserved.<BR>\r
; SPDX-License-Identifier: BSD-2-Clause-Patent\r
;\r
; Module Name:\r
;\r
;   CopyMem.Asm\r
;\r
; Abstract:\r
;\r
;   CopyMem function\r
;\r
; Notes:\r
;\r
;------------------------------------------------------------------------------\r
\r
    SECTION .text\r
\r
;------------------------------------------------------------------------------\r
;  VOID *\r
;  InternalMemCopyMem (\r
;    IN VOID   *Destination,\r
;    IN VOID   *Source,\r
;    IN UINTN  Count\r
;    )\r
;------------------------------------------------------------------------------\r
global ASM_PFX(InternalMemCopyMem)\r
ASM_PFX(InternalMemCopyMem):\r
    push    esi\r
    push    edi\r
    mov     esi, [esp+16]                ; esi <- Source\r
    mov     edi, [esp+12]                ; edi <- Destination\r
    mov     edx, [esp+20]                ; edx <- Count\r
    cmp     esi, edi\r
    je      @CopyDone\r
    cmp     edx, 0\r
    je      @CopyDone\r
    lea     eax, [esi + edx - 1]         ; eax <- End of Source\r
    cmp     esi, edi\r
    jae     @CopyBytes\r
    cmp     eax, edi\r
    jb      @CopyBytes                   ; Copy backward if overlapped\r
    mov     esi, eax                     ; esi <- End of Source\r
    lea     edi, [edi + edx - 1]         ; edi <- End of Destination\r
    std\r
@CopyBytes:\r
    mov     ecx, edx\r
    rep     movsb                        ; Copy bytes backward\r
    cld\r
@CopyDone:\r
    mov     eax, [esp + 12]             ; eax <- Destination as return value\r
    pop     edi\r
    pop     esi\r
    ret\r
\r