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_OPTIONAL_HEADER_PTR_UNION   Header;
  45
  46   ASSERT (Pe32Data   != NULL);
  47   ASSERT (EntryPoint != NULL);
  48
  49   DosHeader = (EFI_IMAGE_DOS_HEADER *)Pe32Data;
  50   if (DosHeader->e_magic == EFI_IMAGE_DOS_SIGNATURE) {
  51     //
  52     // DOS image header is present, so read the PE header after the DOS image header.
  53     //
  54     Header.Pe32 = (EFI_IMAGE_NT_HEADERS32 *)((UINTN) Pe32Data + (UINTN) ((DosHeader->e_lfanew) & 0x0ffff));
  55   } else {
  56     //
  57     // DOS image header is not present, so PE header is at the image base.
  58     //
  59     Header.Pe32 = (EFI_IMAGE_NT_HEADERS32 *)Pe32Data;
  60   }
  61
  62   //
  63   // Calculate the entry point relative to the start of the image.
  64   // AddressOfEntryPoint is common for PE32 & PE32+
  65   //
  66   *EntryPoint = (VOID *)((UINTN)Pe32Data + (UINTN)(Header.Pe32->OptionalHeader.AddressOfEntryPoint & 0x0ffffffff));
  67   return RETURN_SUCCESS;
  68 }
  69
  70
  71 /**
  72   Returns the machine type of PE/COFF image.
  73
  74   @param  Image   Pointer to a PE/COFF header
  75
  76   @return         Machine type or zero if not a valid iamge
  77
  78 **/
  79 UINT16
  80 EFIAPI
  81 PeCoffLoaderGetMachineType (
  82   IN  VOID  *Pe32Data
  83   )
  84 {
  85   EFI_IMAGE_OPTIONAL_HEADER_PTR_UNION  Hdr;
  86   EFI_IMAGE_DOS_HEADER                 *DosHdr;
  87
  88   DosHdr = (EFI_IMAGE_DOS_HEADER  *)Pe32Data;
  89   if (DosHdr->e_magic == EFI_IMAGE_DOS_SIGNATURE) {
  90     Hdr.Pe32 = (EFI_IMAGE_NT_HEADERS32 *)((UINTN)Pe32Data + DosHdr->e_lfanew);
  91   } else {
  92     Hdr.Pe32 = (EFI_IMAGE_NT_HEADERS32 *)((UINTN)Pe32Data);
  93   }
  94
  95   if (Hdr.Pe32->Signature == EFI_IMAGE_NT_SIGNATURE)  {
  96     return Hdr.Pe32->FileHeader.Machine;
  97   }
  98
  99   return 0x0000;
 100 }
 101
 102