audk/UefiCpuPkg/CpuMpPei/X64/MpFuncs.asm

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;------------------------------------------------------------------------------ ;
; Copyright (c) 2015, Intel Corporation. All rights reserved.<BR>
; This program and the accompanying materials
; are licensed and made available under the terms and conditions of the BSD License
; which accompanies this distribution. The full text of the license may be found at
; http://opensource.org/licenses/bsd-license.php.
;
; THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
; WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
;
; Module Name:
;
; MpFuncs32.asm
;
; Abstract:
;
; This is the assembly code for MP support
;
;-------------------------------------------------------------------------------
include MpEqu.inc
.code
AsmInitializeGdt PROC
push rbp
mov rbp, rsp
lgdt fword PTR [rcx] ; update the GDTR
sub rsp, 0x10
lea rax, SetCodeSelectorFarJump
mov [rsp], rax
mov rdx, LONG_MODE_CS
mov [rsp + 4], dx ; get new CS
jmp fword ptr [rsp]
SetCodeSelectorFarJump:
add rsp, 0x10
mov rax, LONG_MODE_DS ; get new DS
mov ds, ax
mov es, ax
mov fs, ax
mov gs, ax
mov ss, ax
pop rbp
ret
AsmInitializeGdt ENDP
END