Files
system76-edk2/UefiCpuPkg/CpuMpPei/X64/MpFuncs.asm
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

52 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:
;
; 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