MdePkg/Library/BaseLib/Ia32/SetJump.c

   1 /** @file
   2   Implementation of SetJump() on IA-32.
   3
   4   Copyright (c) 2006 - 2008, Intel Corporation. All rights reserved.<BR>
   5   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 RETURNS_TWICE
  53 UINTN
  54 EFIAPI
  55 SetJump (
  56   OUT     BASE_LIBRARY_JUMP_BUFFER  *JumpBuffer
  57   )
  58 {
  59   _asm {
  60     push    [esp + 4]
  61     call    InternalAssertJumpBuffer
  62     pop     ecx
  63     pop     ecx
  64     mov     edx, [esp]
  65     mov     [edx], ebx
  66     mov     [edx + 4], esi
  67     mov     [edx + 8], edi
  68     mov     [edx + 12], ebp
  69     mov     [edx + 16], esp
  70     mov     [edx + 20], ecx
  71     xor     eax, eax
  72     jmp     ecx
  73   }
  74 }
  75