MdeModulePkg/Universal/Variable/Pei/Variable.h

   1 /** @file
   2   The internal header file includes the common header files, defines
   3   internal structure and functions used by PeiVariable module.
   4
   5 Copyright (c) 2006 - 2017, Intel Corporation. All rights reserved.<BR>
   6 SPDX-License-Identifier: BSD-2-Clause-Patent
   7
   8 **/
   9
  10 #ifndef _PEI_VARIABLE_H_
  11 #define _PEI_VARIABLE_H_
  12
  13 #include <PiPei.h>
  14 #include <Ppi/ReadOnlyVariable2.h>
  15
  16 #include <Library/DebugLib.h>
  17 #include <Library/PeimEntryPoint.h>
  18 #include <Library/HobLib.h>
  19 #include <Library/PcdLib.h>
  20 #include <Library/BaseMemoryLib.h>
  21 #include <Library/PeiServicesTablePointerLib.h>
  22 #include <Library/PeiServicesLib.h>
  23
  24 #include <Guid/VariableFormat.h>
  25 #include <Guid/VariableIndexTable.h>
  26 #include <Guid/SystemNvDataGuid.h>
  27 #include <Guid/FaultTolerantWrite.h>
  28
  29 typedef enum {
  30   VariableStoreTypeHob,
  31   VariableStoreTypeNv,
  32   VariableStoreTypeMax
  33 } VARIABLE_STORE_TYPE;
  34
  35 typedef struct {
  36   VARIABLE_STORE_HEADER                   *VariableStoreHeader;
  37   VARIABLE_INDEX_TABLE                    *IndexTable;
  38   //
  39   // If it is not NULL, it means there may be an inconsecutive variable whose
  40   // partial content is still in NV storage, but another partial content is backed up
  41   // in spare block.
  42   //
  43   FAULT_TOLERANT_WRITE_LAST_WRITE_DATA    *FtwLastWriteData;
  44   BOOLEAN                                 AuthFlag;
  45 } VARIABLE_STORE_INFO;
  46
  47 //
  48 // Functions
  49 //
  50 /**
  51   Provide the functionality of the variable services.
  52
  53   @param  FileHandle  Handle of the file being invoked.
  54                       Type EFI_PEI_FILE_HANDLE is defined in FfsFindNextFile().
  55   @param  PeiServices  General purpose services available to every PEIM.
  56
  57   @retval EFI_SUCCESS  If the interface could be successfully installed
  58   @retval Others       Returned from PeiServicesInstallPpi()
  59
  60 **/
  61 EFI_STATUS
  62 EFIAPI
  63 PeimInitializeVariableServices (
  64   IN       EFI_PEI_FILE_HANDLE       FileHandle,
  65   IN CONST EFI_PEI_SERVICES          **PeiServices
  66   );
  67
  68 /**
  69   This service retrieves a variable's value using its name and GUID.
  70
  71   Read the specified variable from the UEFI variable store. If the Data
  72   buffer is too small to hold the contents of the variable, the error
  73   EFI_BUFFER_TOO_SMALL is returned and DataSize is set to the required buffer
  74   size to obtain the data.
  75
  76   @param  This                  A pointer to this instance of the EFI_PEI_READ_ONLY_VARIABLE2_PPI.
  77   @param  VariableName          A pointer to a null-terminated string that is the variable's name.
  78   @param  VariableGuid          A pointer to an EFI_GUID that is the variable's GUID. The combination of
  79                                 VariableGuid and VariableName must be unique.
  80   @param  Attributes            If non-NULL, on return, points to the variable's attributes.
  81   @param  DataSize              On entry, points to the size in bytes of the Data buffer.
  82                                 On return, points to the size of the data returned in Data.
  83   @param  Data                  Points to the buffer which will hold the returned variable value.
  84                                 May be NULL with a zero DataSize in order to determine the size of the buffer needed.
  85
  86   @retval EFI_SUCCESS           The variable was read successfully.
  87   @retval EFI_NOT_FOUND         The variable was not found.
  88   @retval EFI_BUFFER_TOO_SMALL  The DataSize is too small for the resulting data.
  89                                 DataSize is updated with the size required for
  90                                 the specified variable.
  91   @retval EFI_INVALID_PARAMETER VariableName, VariableGuid, DataSize or Data is NULL.
  92   @retval EFI_DEVICE_ERROR      The variable could not be retrieved because of a device error.
  93
  94 **/
  95 EFI_STATUS
  96 EFIAPI
  97 PeiGetVariable (
  98   IN CONST  EFI_PEI_READ_ONLY_VARIABLE2_PPI *This,
  99   IN CONST  CHAR16                          *VariableName,
 100   IN CONST  EFI_GUID                        *VariableGuid,
 101   OUT       UINT32                          *Attributes,
 102   IN OUT    UINTN                           *DataSize,
 103   OUT       VOID                            *Data OPTIONAL
 104   );
 105
 106 /**
 107   Return the next variable name and GUID.
 108
 109   This function is called multiple times to retrieve the VariableName
 110   and VariableGuid of all variables currently available in the system.
 111   On each call, the previous results are passed into the interface,
 112   and, on return, the interface returns the data for the next
 113   interface. When the entire variable list has been returned,
 114   EFI_NOT_FOUND is returned.
 115
 116   @param  This              A pointer to this instance of the EFI_PEI_READ_ONLY_VARIABLE2_PPI.
 117
 118   @param  VariableNameSize  On entry, points to the size of the buffer pointed to by VariableName.
 119   @param  VariableName      On entry, a pointer to a null-terminated string that is the variable's name.
 120                             On return, points to the next variable's null-terminated name string.
 121
 122   @param  VariableGuid      On entry, a pointer to an UEFI _GUID that is the variable's GUID.
 123                             On return, a pointer to the next variable's GUID.
 124
 125   @retval EFI_SUCCESS           The variable was read successfully.
 126   @retval EFI_NOT_FOUND         The variable could not be found.
 127   @retval EFI_BUFFER_TOO_SMALL  The VariableNameSize is too small for the resulting
 128                                 data. VariableNameSize is updated with the size
 129                                 required for the specified variable.
 130   @retval EFI_INVALID_PARAMETER VariableName, VariableGuid or
 131                                 VariableNameSize is NULL.
 132   @retval EFI_DEVICE_ERROR      The variable could not be retrieved because of a device error.
 133
 134 **/
 135 EFI_STATUS
 136 EFIAPI
 137 PeiGetNextVariableName (
 138   IN CONST  EFI_PEI_READ_ONLY_VARIABLE2_PPI *This,
 139   IN OUT UINTN                              *VariableNameSize,
 140   IN OUT CHAR16                             *VariableName,
 141   IN OUT EFI_GUID                           *VariableGuid
 142   );
 143
 144 #endif