UefiCpuPkg/PiSmmCpuDxeSmm: Avoid possible NULL ptr dereference

[mirror_edk2.git] / OvmfPkg / QemuFlashFvbServicesRuntimeDxe / FvbInfo.c

/**@file\r
\r
  Copyright (c) 2006, Intel Corporation. All rights reserved.<BR>\r
\r
  This program and the accompanying materials are licensed and made available\r
  under the terms and conditions of the BSD License which accompanies this\r
  distribution.  The full text of the license may be found at\r
  http://opensource.org/licenses/bsd-license.php\r
\r
  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,\r
  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r
\r
  Module Name:\r
\r
    FvbInfo.c\r
\r
  Abstract:\r
\r
    Defines data structure that is the volume header found.These data is intent\r
    to decouple FVB driver with FV header.\r
\r
**/\r
\r
//\r
// The package level header files this module uses\r
//\r
#include <Pi/PiFirmwareVolume.h>\r
\r
//\r
// The protocols, PPI and GUID defintions for this module\r
//\r
#include <Guid/SystemNvDataGuid.h>\r
//\r
// The Library classes this module consumes\r
//\r
#include <Library/BaseLib.h>\r
#include <Library/PcdLib.h>\r
\r
typedef struct {\r
  UINT64                      FvLength;\r
  EFI_FIRMWARE_VOLUME_HEADER  FvbInfo;\r
  //\r
  // EFI_FV_BLOCK_MAP_ENTRY    ExtraBlockMap[n];//n=0\r
  //\r
  EFI_FV_BLOCK_MAP_ENTRY      End[1];\r
} EFI_FVB_MEDIA_INFO;\r
\r
EFI_FVB_MEDIA_INFO  mPlatformFvbMediaInfo[] = {\r
  //\r
  // Systen NvStorage FVB\r
  //\r
  {\r
    FixedPcdGet32 (PcdFlashNvStorageVariableSize) +\r
    FixedPcdGet32 (PcdFlashNvStorageFtwWorkingSize) +\r
    FixedPcdGet32 (PcdFlashNvStorageFtwSpareSize) +\r
    FixedPcdGet32 (PcdOvmfFlashNvStorageEventLogSize),\r
    {\r
      {\r
        0,\r
      },  // ZeroVector[16]\r
      EFI_SYSTEM_NV_DATA_FV_GUID,\r
      FixedPcdGet32 (PcdFlashNvStorageVariableSize) +\r
      FixedPcdGet32 (PcdFlashNvStorageFtwWorkingSize) +\r
      FixedPcdGet32 (PcdFlashNvStorageFtwSpareSize) +\r
      FixedPcdGet32 (PcdOvmfFlashNvStorageEventLogSize),\r
      EFI_FVH_SIGNATURE,\r
      EFI_FVB2_MEMORY_MAPPED |\r
        EFI_FVB2_READ_ENABLED_CAP |\r
        EFI_FVB2_READ_STATUS |\r
        EFI_FVB2_WRITE_ENABLED_CAP |\r
        EFI_FVB2_WRITE_STATUS |\r
        EFI_FVB2_ERASE_POLARITY |\r
        EFI_FVB2_ALIGNMENT_16,\r
      sizeof (EFI_FIRMWARE_VOLUME_HEADER) + sizeof (EFI_FV_BLOCK_MAP_ENTRY),\r
      0,  // CheckSum\r
      0,  // ExtHeaderOffset\r
      {\r
        0,\r
      },  // Reserved[1]\r
      2,  // Revision\r
      {\r
        {\r
          (FixedPcdGet32 (PcdFlashNvStorageVariableSize) +\r
           FixedPcdGet32 (PcdFlashNvStorageFtwWorkingSize) +\r
           FixedPcdGet32 (PcdFlashNvStorageFtwSpareSize) +\r
           FixedPcdGet32 (PcdOvmfFlashNvStorageEventLogSize)) /\r
          FixedPcdGet32 (PcdOvmfFirmwareBlockSize),\r
          FixedPcdGet32 (PcdOvmfFirmwareBlockSize),\r
        }\r
      } // BlockMap[1]\r
    },\r
    {\r
      {\r
        0,\r
        0\r
      }\r
    }  // End[1]\r
  }\r
};\r
\r
EFI_STATUS\r
GetFvbInfo (\r
  IN  UINT64                        FvLength,\r
  OUT EFI_FIRMWARE_VOLUME_HEADER    **FvbInfo\r
  )\r
{\r
  STATIC BOOLEAN Checksummed = FALSE;\r
  UINTN Index;\r
\r
  if (!Checksummed) {\r
    for (Index = 0;\r
         Index < sizeof (mPlatformFvbMediaInfo) / sizeof (EFI_FVB_MEDIA_INFO);\r
         Index += 1) {\r
      UINT16 Checksum;\r
      mPlatformFvbMediaInfo[Index].FvbInfo.Checksum = 0;\r
      Checksum = CalculateCheckSum16 (\r
                   (UINT16*) &mPlatformFvbMediaInfo[Index].FvbInfo,\r
                   mPlatformFvbMediaInfo[Index].FvbInfo.HeaderLength\r
                   );\r
      mPlatformFvbMediaInfo[Index].FvbInfo.Checksum = Checksum;\r
    }\r
    Checksummed = TRUE;\r
  }\r
\r
  for (Index = 0;\r
       Index < sizeof (mPlatformFvbMediaInfo) / sizeof (EFI_FVB_MEDIA_INFO);\r
       Index += 1) {\r
    if (mPlatformFvbMediaInfo[Index].FvLength == FvLength) {\r
      *FvbInfo = &mPlatformFvbMediaInfo[Index].FvbInfo;\r
      return EFI_SUCCESS;\r
    }\r
  }\r
\r
  return EFI_NOT_FOUND;\r
}\r