mirror of
https://github.com/CloverHackyColor/CloverBootloader.git
synced 2024-12-27 16:58:09 +01:00
59 lines
1.7 KiB
NASM
59 lines
1.7 KiB
NASM
;------------------------------------------------------------------------------
|
|
;
|
|
; Copyright (c) 2006, Intel Corporation. All rights reserved.<BR>
|
|
; SPDX-License-Identifier: BSD-2-Clause-Patent
|
|
;
|
|
; Module Name:
|
|
;
|
|
; CopyMem.Asm
|
|
;
|
|
; Abstract:
|
|
;
|
|
; CopyMem function
|
|
;
|
|
; Notes:
|
|
;
|
|
;------------------------------------------------------------------------------
|
|
|
|
SECTION .text
|
|
|
|
;------------------------------------------------------------------------------
|
|
; VOID *
|
|
; InternalMemCopyMem (
|
|
; IN VOID *Destination,
|
|
; IN VOID *Source,
|
|
; IN UINTN Count
|
|
; )
|
|
;------------------------------------------------------------------------------
|
|
global ASM_PFX(InternalMemCopyMem)
|
|
ASM_PFX(InternalMemCopyMem):
|
|
push esi
|
|
push edi
|
|
mov esi, [esp + 16] ; esi <- Source
|
|
mov edi, [esp + 12] ; edi <- Destination
|
|
mov edx, [esp + 20] ; edx <- Count
|
|
lea eax, [esi + edx - 1] ; eax <- End of Source
|
|
cmp esi, edi
|
|
jae .0
|
|
cmp eax, edi
|
|
jae @CopyBackward ; Copy backward if overlapped
|
|
.0:
|
|
mov ecx, edx
|
|
and edx, 3
|
|
shr ecx, 2
|
|
rep movsd ; Copy as many Dwords as possible
|
|
jmp @CopyBytes
|
|
@CopyBackward:
|
|
mov esi, eax ; esi <- End of Source
|
|
lea edi, [edi + edx - 1] ; edi <- End of Destination
|
|
std
|
|
@CopyBytes:
|
|
mov ecx, edx
|
|
rep movsb ; Copy bytes backward
|
|
cld
|
|
mov eax, [esp + 12] ; eax <- Destination as return value
|
|
pop edi
|
|
pop esi
|
|
ret
|
|
|