audk/UefiCpuPkg/CpuMpPei/X64/MpFuncs.nasm

51 lines
1.4 KiB
NASM
Raw Normal View History

;------------------------------------------------------------------------------ ;
; 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:
;
; MpFuncs.nasm
;
; Abstract:
;
; This is the assembly code for MP support
;
;-------------------------------------------------------------------------------
%include "MpEqu.inc"
DEFAULT REL
SECTION .text
global ASM_PFX(AsmInitializeGdt)
ASM_PFX(AsmInitializeGdt):
push rbp
mov rbp, rsp
lgdt [rcx] ; update the GDTR
sub rsp, 0x10
mov rax, ASM_PFX(SetCodeSelectorFarJump)
mov [rsp], rax
mov rdx, LONG_MODE_CS
mov [rsp + 4], dx ; get new CS
jmp far dword [rsp] ; far jump with new CS
ASM_PFX(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