MdePkg/Library/BasePeCoffGetEntryPointLib/PeCoffGetEntryPoint.c

   1 /** @file
   2   Tiano PE/COFF loader.
   3
   4   Copyright (c) 2006, 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   Module Name:  PeCoffGetEntryPoint.c
  14
  15 **/
  16
  17
  18
  19 /**
  20   Retrieves and returns a pointer to the entry point to a PE/COFF image that has been loaded
  21   into system memory with the PE/COFF Loader Library functions.
  22
  23   Retrieves the entry point to the PE/COFF image specified by Pe32Data and returns this entry
  24   point in EntryPoint.  If the entry point could not be retrieved from the PE/COFF image, then
  25   return RETURN_INVALID_PARAMETER.  Otherwise return RETURN_SUCCESS.
  26   If Pe32Data is NULL, then ASSERT().
  27   If EntryPoint is NULL, then ASSERT().
  28
  29   @param  Pe32Data                  Pointer to the PE/COFF image that is loaded in system memory.
  30   @param  EntryPoint                Pointer to entry point to the PE/COFF image to return.
  31
  32   @retval RETURN_SUCCESS            EntryPoint was returned.
  33   @retval RETURN_INVALID_PARAMETER  The entry point could not be found in the PE/COFF image.
  34
  35 **/
  36 RETURN_STATUS
  37 EFIAPI
  38 PeCoffLoaderGetEntryPoint (
  39   IN  VOID  *Pe32Data,
  40   OUT VOID  **EntryPoint
  41   )
  42 {
  43   EFI_IMAGE_DOS_HEADER  *DosHeader;
  44   EFI_IMAGE_NT_HEADERS  *PeHeader;
  45
  46   ASSERT (Pe32Data   != NULL);
  47   ASSERT (EntryPoint != NULL);
  48
  49   DosHeader = (EFI_IMAGE_DOS_HEADER *)Pe32Data;
  50
  51   if (DosHeader->e_magic == EFI_IMAGE_DOS_SIGNATURE) {
  52     //
  53     // DOS image header is present, so read the PE header after the DOS image header.
  54     //
  55     PeHeader = (EFI_IMAGE_NT_HEADERS *) ((UINTN) Pe32Data + (UINTN) ((DosHeader->e_lfanew) & 0x0ffff));
  56   } else {
  57     //
  58     // DOS image header is not present, so PE header is at the image base.
  59     //
  60     PeHeader = (EFI_IMAGE_NT_HEADERS *) Pe32Data;
  61   }
  62
  63   *EntryPoint = (VOID *) ((UINTN) Pe32Data + (UINTN) (PeHeader->OptionalHeader.AddressOfEntryPoint & 0x0ffffffff));
  64   return RETURN_SUCCESS;
  65 }