mirror of
https://github.com/CloverHackyColor/CloverBootloader.git
synced 2024-11-30 12:43:41 +01:00
60 lines
1.7 KiB
NASM
60 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:
|
|
;
|
|
;------------------------------------------------------------------------------
|
|
|
|
DEFAULT REL
|
|
SECTION .text
|
|
|
|
;------------------------------------------------------------------------------
|
|
; VOID *
|
|
; EFIAPI
|
|
; InternalMemCopyMem (
|
|
; IN VOID *Destination,
|
|
; IN VOID *Source,
|
|
; IN UINTN Count
|
|
; )
|
|
;------------------------------------------------------------------------------
|
|
global ASM_PFX(InternalMemCopyMem)
|
|
ASM_PFX(InternalMemCopyMem):
|
|
push rsi
|
|
push rdi
|
|
mov rsi, rdx ; rsi <- Source
|
|
mov rdi, rcx ; rdi <- Destination
|
|
lea r9, [rsi + r8 - 1] ; r9 <- End of Source
|
|
cmp rsi, rdi
|
|
mov rax, rdi ; rax <- Destination as return value
|
|
jae .0
|
|
cmp r9, rdi
|
|
jae @CopyBackward ; Copy backward if overlapped
|
|
.0:
|
|
mov rcx, r8
|
|
and r8, 7
|
|
shr rcx, 3
|
|
rep movsq ; Copy as many Qwords as possible
|
|
jmp @CopyBytes
|
|
@CopyBackward:
|
|
mov rsi, r9 ; rsi <- End of Source
|
|
lea rdi, [rdi + r8 - 1] ; esi <- End of Destination
|
|
std ; set direction flag
|
|
@CopyBytes:
|
|
mov rcx, r8
|
|
rep movsb ; Copy bytes backward
|
|
cld
|
|
pop rdi
|
|
pop rsi
|
|
ret
|
|
|