MdePkg/Library/BaseLib/X64/EnablePaging64.asm

   1 ;------------------------------------------------------------------------------
   2 ;
   3 ; Copyright (c) 2006, Intel Corporation
   4 ; All rights reserved. This program and the accompanying materials
   5 ; are licensed and made available under the terms and conditions of the BSD License
   6 ; which accompanies this distribution.  The full text of the license may be found at
   7 ; http://opensource.org/licenses/bsd-license.php
   8 ;
   9 ; THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  10 ; WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  11 ;
  12 ; Module Name:
  13 ;
  14 ;   EnablePaging64.Asm
  15 ;
  16 ; Abstract:
  17 ;
  18 ;   AsmEnablePaging64 function
  19 ;
  20 ; Notes:
  21 ;
  22 ;------------------------------------------------------------------------------
  23
  24     .code
  25
  26 ;------------------------------------------------------------------------------
  27 ; VOID
  28 ; EFIAPI
  29 ; InternalX86EnablePaging64 (
  30 ;   IN      UINT16                    Cs,
  31 ;   IN      UINT64                    EntryPoint,
  32 ;   IN      UINT64                    Context1,  OPTIONAL
  33 ;   IN      UINT64                    Context2,  OPTIONAL
  34 ;   IN      UINT64                    NewStack
  35 ;   );
  36 ;------------------------------------------------------------------------------
  37 InternalX86EnablePaging64 PROC
  38     cli
  39     mov     dword ptr [rsp], @F         ; offset for far retf, seg is the 1st arg
  40     mov     rax, cr4                    ; mov eax, cr4
  41     or      al, (1 SHL 5)
  42     mov     cr4, rax                    ; enable PAE
  43     mov     ecx, 0c0000080h
  44     rdmsr
  45     or      ah, 1                       ; set LME
  46     wrmsr
  47     mov     rax, cr0                    ; mov eax, cr0
  48     bts     eax, 31
  49     mov     cr0, rax                    ; enable paging
  50     retf
  51 @@:                                     ; long mode starts here
  52     mov     rbx, [esp]
  53     mov     rcx, [esp + 8]
  54     mov     rdx, [esp + 10h]
  55     mov     rsp, [esp + 18h]
  56     add     rsp, -20h
  57     call    rbx
  58     jmp     $                           ; halt processor if EntryPoint() returned
  59 InternalX86EnablePaging64 ENDP
  60
  61     END