UefiCpuPkg/CpuMpPei/Ia32/MpFuncs.nasm

   1 ;------------------------------------------------------------------------------ ;
   2 ; Copyright (c) 2015, Intel Corporation. All rights reserved.<BR>
   3 ; This program and the accompanying materials
   4 ; are licensed and made available under the terms and conditions of the BSD License
   5 ; which accompanies this distribution.  The full text of the license may be found at
   6 ; http://opensource.org/licenses/bsd-license.php.
   7 ;
   8 ; THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
   9 ; WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  10 ;
  11 ; Module Name:
  12 ;
  13 ;   MpFuncs.nasm
  14 ;
  15 ; Abstract:
  16 ;
  17 ;   This is the assembly code for MP support
  18 ;
  19 ;-------------------------------------------------------------------------------
  20
  21 %include "MpEqu.inc"
  22
  23 SECTION .text
  24
  25
  26 global ASM_PFX(AsmInitializeGdt)
  27 ASM_PFX(AsmInitializeGdt):
  28   push         ebp
  29   mov          ebp, esp
  30   pushad
  31   mov          edi, [ebp + 8]      ; Load GDT register
  32
  33   lgdt         [edi]      ; and update the GDTR
  34
  35   push         PROTECT_MODE_CS
  36   mov          eax, ASM_PFX(SetCodeSelectorFarJump)
  37   push         eax
  38   retf
  39 ASM_PFX(SetCodeSelectorFarJump):
  40   mov          ax, PROTECT_MODE_DS ; Update the Base for the new selectors, too
  41   mov          ds, ax
  42   mov          es, ax
  43   mov          fs, ax
  44   mov          gs, ax
  45   mov          ss, ax
  46
  47   popad
  48   pop          ebp
  49   ret