MdePkg/Library/BaseLib/Ia32/DisablePaging32.nasm

   1 ;------------------------------------------------------------------------------
   2 ;
   3 ; Copyright (c) 2006, Intel Corporation. All rights reserved.<BR>
   4 ; SPDX-License-Identifier: BSD-2-Clause-Patent
   5 ;
   6 ; Module Name:
   7 ;
   8 ;   DisablePaging32.Asm
   9 ;
  10 ; Abstract:
  11 ;
  12 ;   AsmDisablePaging32 function
  13 ;
  14 ; Notes:
  15 ;
  16 ;------------------------------------------------------------------------------
  17
  18     SECTION .text
  19
  20 ;------------------------------------------------------------------------------
  21 ; VOID
  22 ; EFIAPI
  23 ; InternalX86DisablePaging32 (
  24 ;   IN      SWITCH_STACK_ENTRY_POINT  EntryPoint,
  25 ;   IN      VOID                      *Context1,    OPTIONAL
  26 ;   IN      VOID                      *Context2,    OPTIONAL
  27 ;   IN      VOID                      *NewStack
  28 ;   );
  29 ;------------------------------------------------------------------------------
  30 global ASM_PFX(InternalX86DisablePaging32)
  31 ASM_PFX(InternalX86DisablePaging32):
  32     mov     ebx, [esp + 4]
  33     mov     ecx, [esp + 8]
  34     mov     edx, [esp + 12]
  35     pushfd
  36     pop     edi                         ; save EFLAGS to edi
  37     cli
  38     mov     eax, cr0
  39     btr     eax, 31
  40     mov     esp, [esp + 16]
  41     mov     cr0, eax
  42     push    edi
  43     popfd                               ; restore EFLAGS from edi
  44     push    edx
  45     push    ecx
  46     call    ebx
  47     jmp     $                           ; EntryPoint() should not return
  48