EdkCompatibilityPkg/Compatibility/SmmBaseHelper/X64/PageFaultHandler.asm

   1 ;------------------------------------------------------------------------------
   2 ;
   3 ; Copyright (c) 2010, 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 ;   PageFaultHandler.asm
  15 ;
  16 ; Abstract:
  17 ;
  18 ;   Defines page fault handler used to hook SMM IDT
  19 ;
  20 ;------------------------------------------------------------------------------
  21
  22 mOriginalHandler PROTO
  23 PageFaultHandler PROTO
  24
  25   .code
  26
  27 PageFaultHandlerHook PROC
  28     push    rax                         ; save all volatile registers
  29     push    rcx
  30     push    rdx
  31     push    r8
  32     push    r9
  33     push    r10
  34     push    r11
  35     add     rsp, -20h
  36     call    PageFaultHandler
  37     add     rsp, 20h
  38     test    rax, rax
  39     pop     r11
  40     pop     r10
  41     pop     r9
  42     pop     r8
  43     pop     rdx
  44     pop     rcx
  45     pop     rax                         ; restore all volatile registers
  46     jnz     @F
  47     jmp     mOriginalHandler
  48 @@:
  49     add     rsp, 08h                    ; skip error code for PF
  50     iretq
  51 PageFaultHandlerHook ENDP
  52   END