Files
system76-edk2/UefiCpuPkg/CpuMpPei/Ia32/MpFuncs.nasm
Jeff Fan f9d30595ae UefiCpuPkg/CpuMpPei: Load GDT table on BSP
Load new GDT table and update segment accordingly.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jeff Fan <jeff.fan@intel.com>
Reviewed-by: Feng Tian <feng.tian@intel.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>

git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@17988 6f19259b-4bc3-4df7-8a09-765794883524
2015-07-15 03:29:12 +00:00

50 lines
1.3 KiB
NASM

;------------------------------------------------------------------------------ ;
; 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"
SECTION .text
global ASM_PFX(AsmInitializeGdt)
ASM_PFX(AsmInitializeGdt):
push ebp
mov ebp, esp
pushad
mov edi, [ebp + 8] ; Load GDT register
lgdt [edi] ; and update the GDTR
push PROTECT_MODE_CS
mov eax, ASM_PFX(SetCodeSelectorFarJump)
push eax
retf
ASM_PFX(SetCodeSelectorFarJump):
mov ax, PROTECT_MODE_DS ; Update the Base for the new selectors, too
mov ds, ax
mov es, ax
mov fs, ax
mov gs, ax
mov ss, ax
popad
pop ebp
ret