MdePkg/Library/BaseLib/Ia32/SetJump.c

   1 /** @file
   2   Implementation of SetJump() on IA-32.
   3
   4   Copyright (c) 2006 - 2007, 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 common header file for this module.
  17 //
  18 #include <BaseLibInternals.h>
  19
  20 /**
  21   Worker function that checks ASSERT condition for JumpBuffer
  22
  23   Checks ASSERT condition for JumpBuffer.
  24
  25   If JumpBuffer is NULL, then ASSERT().
  26   For IPF CPUs, if JumpBuffer is not aligned on a 16-byte boundary, then ASSERT().
  27
  28   @param  JumpBuffer    A pointer to CPU context buffer.
  29
  30 **/
  31 VOID
  32 EFIAPI
  33 InternalAssertJumpBuffer (
  34   IN      BASE_LIBRARY_JUMP_BUFFER  *JumpBuffer
  35   );
  36
  37 /**
  38   Saves the current CPU context that can be restored with a call to LongJump()
  39   and returns 0.
  40
  41   Saves the current CPU context in the buffer specified by JumpBuffer and
  42   returns 0. The initial call to SetJump() must always return 0. Subsequent
  43   calls to LongJump() cause a non-zero value to be returned by SetJump().
  44
  45   If JumpBuffer is NULL, then ASSERT().
  46   For IPF CPUs, if JumpBuffer is not aligned on a 16-byte boundary, then ASSERT().
  47
  48   @param  JumpBuffer  A pointer to CPU context buffer.
  49
  50   @retval 0 Indicates a return from SetJump().
  51
  52 **/
  53 _declspec (naked)
  54 UINTN
  55 EFIAPI
  56 SetJump (
  57   OUT     BASE_LIBRARY_JUMP_BUFFER  *JumpBuffer
  58   )
  59 {
  60   _asm {
  61     push    [esp + 4]
  62     call    InternalAssertJumpBuffer
  63     pop     ecx
  64     pop     ecx
  65     mov     edx, [esp]
  66     mov     [edx], ebx
  67     mov     [edx + 4], esi
  68     mov     [edx + 8], edi
  69     mov     [edx + 12], ebp
  70     mov     [edx + 16], esp
  71     mov     [edx + 20], ecx
  72     xor     eax, eax
  73     jmp     ecx
  74   }
  75 }
  76