OvmfPkg/Sec/FindPeiCore.c

   1 /** @file
   2   Locate the entry point for the PEI Core
   3
   4   Copyright (c) 2008 - 2009, Intel Corporation
   5
   6   All rights reserved. This program and the accompanying materials
   7   are licensed and made available under the terms and conditions of the BSD License
   8   which accompanies this distribution.  The full text of the license may be found at
   9   http://opensource.org/licenses/bsd-license.php
  10
  11   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  12   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  13
  14 **/
  15
  16 #include <PiPei.h>
  17 #include <Library/BaseLib.h>
  18 #include <Library/PeCoffGetEntryPointLib.h>
  19
  20 #include "SecMain.h"
  21
  22
  23 VOID
  24 EFIAPI
  25 FindPeiCoreEntryPoint (
  26   IN  EFI_FIRMWARE_VOLUME_HEADER       *BootFirmwareVolumePtr,
  27   OUT VOID                             **PeiCoreEntryPoint
  28   )
  29 {
  30   EFI_STATUS                  Status;
  31   EFI_PHYSICAL_ADDRESS        CurrentAddress;
  32   EFI_PHYSICAL_ADDRESS        EndOfFirmwareVolume;
  33   EFI_FFS_FILE_HEADER         *File;
  34   UINT32                      Size;
  35   EFI_PHYSICAL_ADDRESS        EndOfFile;
  36   EFI_COMMON_SECTION_HEADER   *Section;
  37   EFI_PHYSICAL_ADDRESS        EndOfSection;
  38
  39   *PeiCoreEntryPoint = NULL;
  40
  41   CurrentAddress = (EFI_PHYSICAL_ADDRESS)(UINTN) BootFirmwareVolumePtr;
  42   EndOfFirmwareVolume = CurrentAddress + BootFirmwareVolumePtr->FvLength;
  43
  44   //
  45   // Loop through the FFS files in the Boot Firmware Volume
  46   //
  47   for (EndOfFile = CurrentAddress + BootFirmwareVolumePtr->HeaderLength; ; ) {
  48
  49     CurrentAddress = (EndOfFile + 7) & 0xfffffffffffffff8ULL;
  50     if (CurrentAddress > EndOfFirmwareVolume) {
  51       return;
  52     }
  53
  54     File = (EFI_FFS_FILE_HEADER*)(UINTN) CurrentAddress;
  55     Size = *(UINT32*) File->Size & 0xffffff;
  56     if (Size < (sizeof (*File) + sizeof (*Section))) {
  57       return;
  58     }
  59
  60     EndOfFile = CurrentAddress + Size;
  61     if (EndOfFile > EndOfFirmwareVolume) {
  62       return;
  63     }
  64
  65     //
  66     // Look for PEI Core files
  67     //
  68     if (File->Type != EFI_FV_FILETYPE_PEI_CORE) {
  69       continue;
  70     }
  71
  72     //
  73     // Loop through the FFS file sections within the PEI Core FFS file
  74     //
  75     EndOfSection = (EFI_PHYSICAL_ADDRESS)(UINTN) (File + 1);
  76     for (;;) {
  77       CurrentAddress = (EndOfSection + 3) & 0xfffffffffffffffcULL;
  78       Section = (EFI_COMMON_SECTION_HEADER*)(UINTN) CurrentAddress;
  79
  80       Size = *(UINT32*) Section->Size & 0xffffff;
  81       if (Size < sizeof (*Section)) {
  82         return;
  83       }
  84
  85       EndOfSection = CurrentAddress + Size;
  86       if (EndOfSection > EndOfFile) {
  87         return;
  88       }
  89
  90       //
  91       // Look for executable sections
  92       //
  93       if (Section->Type == EFI_SECTION_PE32) {
  94         Status = PeCoffLoaderGetEntryPoint ((VOID*) (Section + 1), PeiCoreEntryPoint);
  95         if (!EFI_ERROR (Status)) {
  96           return;
  97         }
  98       }
  99     }
 100
 101   }
 102 }
 103