MdePkg/Library/BaseLib/Ia32/SetJump.c

   1 /** @file
   2   Implementation of SetJump() on IA-32.
   3
   4   Copyright (c) 2006 - 2008, Intel Corporation<BR>
   5   All rights reserved. This program and the accompanying materials
   6   are licensed and made available under the terms and conditions of the BSD License
   7   which accompanies this distribution.  The full text of the license may be found at
   8   http://opensource.org/licenses/bsd-license.php
   9
  10   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  11   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  12
  13 **/
  14
  15
  16 #include "BaseLibInternals.h"
  17
  18 /**
  19   Worker function that checks ASSERT condition for JumpBuffer
  20
  21   Checks ASSERT condition for JumpBuffer.
  22
  23   If JumpBuffer is NULL, then ASSERT().
  24   For IPF CPUs, if JumpBuffer is not aligned on a 16-byte boundary, then ASSERT().
  25
  26   @param  JumpBuffer    A pointer to CPU context buffer.
  27
  28 **/
  29 VOID
  30 EFIAPI
  31 InternalAssertJumpBuffer (
  32   IN      BASE_LIBRARY_JUMP_BUFFER  *JumpBuffer
  33   );
  34
  35 /**
  36   Saves the current CPU context that can be restored with a call to LongJump()
  37   and returns 0.
  38
  39   Saves the current CPU context in the buffer specified by JumpBuffer and
  40   returns 0. The initial call to SetJump() must always return 0. Subsequent
  41   calls to LongJump() cause a non-zero value to be returned by SetJump().
  42
  43   If JumpBuffer is NULL, then ASSERT().
  44   For IPF CPUs, if JumpBuffer is not aligned on a 16-byte boundary, then ASSERT().
  45
  46   @param  JumpBuffer  A pointer to CPU context buffer.
  47
  48   @retval 0 Indicates a return from SetJump().
  49
  50 **/
  51 _declspec (naked)
  52 UINTN
  53 EFIAPI
  54 SetJump (
  55   OUT     BASE_LIBRARY_JUMP_BUFFER  *JumpBuffer
  56   )
  57 {
  58   _asm {
  59     push    [esp + 4]
  60     call    InternalAssertJumpBuffer
  61     pop     ecx
  62     pop     ecx
  63     mov     edx, [esp]
  64     mov     [edx], ebx
  65     mov     [edx + 4], esi
  66     mov     [edx + 8], edi
  67     mov     [edx + 12], ebp
  68     mov     [edx + 16], esp
  69     mov     [edx + 20], ecx
  70     xor     eax, eax
  71     jmp     ecx
  72   }
  73 }
  74