UefiCpuPkg/CpuMpPei/Ia32/MpFuncs.asm

   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 ;   MpFuncs32.asm
  14 ;
  15 ; Abstract:
  16 ;
  17 ;   This is the assembly code for MP support
  18 ;
  19 ;-------------------------------------------------------------------------------
  20
  21 .686p
  22 .model  flat
  23
  24 include  MpEqu.inc
  25 .code
  26
  27
  28 AsmInitializeGdt   PROC  near C  PUBLIC
  29   push         ebp
  30   mov          ebp, esp
  31   pushad
  32   mov          edi, [ebp + 8]      ; Load GDT register
  33
  34   mov          ax,cs               ; Get the selector data from our code image
  35   mov          es,ax
  36   lgdt         FWORD PTR es:[edi]  ; and update the GDTR
  37
  38   push         PROTECT_MODE_CS
  39   lea          eax, SetCodeSelectorFarJump
  40   push         eax
  41   retf
  42 SetCodeSelectorFarJump:
  43   mov          ax, PROTECT_MODE_DS ; Update the Base for the new selectors, too
  44   mov          ds, ax
  45   mov          es, ax
  46   mov          fs, ax
  47   mov          gs, ax
  48   mov          ss, ax
  49
  50   popad
  51   pop          ebp
  52   ret
  53 AsmInitializeGdt  ENDP
  54
  55 END