MdeModulePkg/Universal/Variable/Pei/Variable.h

   1 /** @file
   2
   3   The internal header file includes the common header files, defines
   4   internal structure and functions used by PeiVariable module.
   5
   6 Copyright (c) 2006 - 2008, Intel Corporation
   7 All rights reserved. This program and the accompanying materials
   8 are licensed and made available under the terms and conditions of the BSD License
   9 which accompanies this distribution.  The full text of the license may be found at
  10 http://opensource.org/licenses/bsd-license.php
  11
  12 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  13 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  14
  15 **/
  16
  17 #ifndef _PEI_VARIABLE_H_
  18 #define _PEI_VARIABLE_H_
  19
  20 #include <PiPei.h>
  21 #include <Ppi/ReadOnlyVariable2.h>
  22
  23 #include <Library/DebugLib.h>
  24 #include <Library/PeimEntryPoint.h>
  25 #include <Library/HobLib.h>
  26 #include <Library/PcdLib.h>
  27 #include <Library/BaseMemoryLib.h>
  28 #include <Library/PeiServicesTablePointerLib.h>
  29 #include <Library/PeiServicesLib.h>
  30
  31 #include <Guid/VariableFormat.h>
  32
  33 typedef struct {
  34   VARIABLE_HEADER *CurrPtr;
  35   VARIABLE_HEADER *EndPtr;
  36   VARIABLE_HEADER *StartPtr;
  37 } VARIABLE_POINTER_TRACK;
  38
  39 #define VARIABLE_INDEX_TABLE_VOLUME 122
  40
  41 #define EFI_VARIABLE_INDEX_TABLE_GUID \
  42   { 0x8cfdb8c8, 0xd6b2, 0x40f3, { 0x8e, 0x97, 0x02, 0x30, 0x7c, 0xc9, 0x8b, 0x7c } }
  43
  44 typedef struct {
  45   UINT16          Length;
  46   UINT16          GoneThrough;
  47   VARIABLE_HEADER *EndPtr;
  48   VARIABLE_HEADER *StartPtr;
  49   UINT16          Index[VARIABLE_INDEX_TABLE_VOLUME];
  50 } VARIABLE_INDEX_TABLE;
  51
  52
  53 //
  54 // Functions
  55 //
  56 /**
  57   Provide the functionality of the variable services.
  58
  59   @param  FileHandle  Handle of the file being invoked.
  60                       Type EFI_PEI_FILE_HANDLE is defined in FfsFindNextFile().
  61   @param  PeiServices  General purpose services available to every PEIM.
  62
  63   @retval EFI_SUCCESS  If the interface could be successfully installed
  64   @retval Others       Returned from PeiServicesInstallPpi()
  65
  66 **/
  67 EFI_STATUS
  68 EFIAPI
  69 PeimInitializeVariableServices (
  70   IN       EFI_PEI_FILE_HANDLE       FileHandle,
  71   IN CONST EFI_PEI_SERVICES          **PeiServices
  72   );
  73
  74 /**
  75   This service retrieves a variable's value using its name and GUID.
  76
  77   Read the specified variable from the UEFI variable store. If the Data
  78   buffer is too small to hold the contents of the variable, the error
  79   EFI_BUFFER_TOO_SMALL is returned and DataSize is set to the required buffer
  80   size to obtain the data.
  81
  82   @param  This                  A pointer to this instance of the EFI_PEI_READ_ONLY_VARIABLE2_PPI.
  83   @param  VariableName          A pointer to a null-terminated string that is the variable's name.
  84   @param  VariableGuid          A pointer to an EFI_GUID that is the variable's GUID. The combination of
  85                                 VariableGuid and VariableName must be unique.
  86   @param  Attributes            If non-NULL, on return, points to the variable's attributes.
  87   @param  DataSize              On entry, points to the size in bytes of the Data buffer.
  88                                 On return, points to the size of the data returned in Data.
  89   @param  Data                  Points to the buffer which will hold the returned variable value.
  90
  91   @retval EFI_SUCCESS           The variable was read successfully.
  92   @retval EFI_NOT_FOUND         The variable could not be found.
  93   @retval EFI_BUFFER_TOO_SMALL  The DataSize is too small for the resulting data.
  94                                 DataSize is updated with the size required for
  95                                 the specified variable.
  96   @retval EFI_INVALID_PARAMETER VariableName, VariableGuid, DataSize or Data is NULL.
  97   @retval EFI_DEVICE_ERROR      The variable could not be retrieved because of a device error.
  98
  99 **/
 100 EFI_STATUS
 101 EFIAPI
 102 PeiGetVariable (
 103   IN CONST  EFI_PEI_READ_ONLY_VARIABLE2_PPI *This,
 104   IN CONST  CHAR16                          *VariableName,
 105   IN CONST  EFI_GUID                        *VariableGuid,
 106   OUT       UINT32                          *Attributes,
 107   IN OUT    UINTN                           *DataSize,
 108   OUT       VOID                            *Data
 109   );
 110
 111 /**
 112   Return the next variable name and GUID.
 113
 114   This function is called multiple times to retrieve the VariableName
 115   and VariableGuid of all variables currently available in the system.
 116   On each call, the previous results are passed into the interface,
 117   and, on return, the interface returns the data for the next
 118   interface. When the entire variable list has been returned,
 119   EFI_NOT_FOUND is returned.
 120
 121   @param  This              A pointer to this instance of the EFI_PEI_READ_ONLY_VARIABLE2_PPI.
 122
 123   @param  VariableNameSize  On entry, points to the size of the buffer pointed to by VariableName.
 124   @param  VariableName      On entry, a pointer to a null-terminated string that is the variable's name.
 125                             On return, points to the next variable's null-terminated name string.
 126
 127   @param  VariableGuid      On entry, a pointer to an UEFI _GUID that is the variable's GUID.
 128                             On return, a pointer to the next variable's GUID.
 129
 130   @retval EFI_SUCCESS           The variable was read successfully.
 131   @retval EFI_NOT_FOUND         The variable could not be found.
 132   @retval EFI_BUFFER_TOO_SMALL  The VariableNameSize is too small for the resulting
 133                                 data. VariableNameSize is updated with the size
 134                                 required for the specified variable.
 135   @retval EFI_INVALID_PARAMETER VariableName, VariableGuid or
 136                                 VariableNameSize is NULL.
 137   @retval EFI_DEVICE_ERROR      The variable could not be retrieved because of a device error.
 138
 139 **/
 140 EFI_STATUS
 141 EFIAPI
 142 PeiGetNextVariableName (
 143   IN CONST  EFI_PEI_READ_ONLY_VARIABLE2_PPI *This,
 144   IN OUT UINTN                              *VariableNameSize,
 145   IN OUT CHAR16                             *VariableName,
 146   IN OUT EFI_GUID                           *VariableGuid
 147   );
 148
 149 /**
 150   Get one variable by the index count.
 151
 152   @param  IndexTable  The pointer to variable index table.
 153   @param  Count       The index count of variable in index table.
 154
 155   @return The pointer to variable header indexed by count.
 156
 157 **/
 158 VARIABLE_HEADER *
 159 GetVariableByIndex (
 160   IN VARIABLE_INDEX_TABLE        *IndexTable,
 161   IN UINT32                      Count
 162   );
 163
 164 /**
 165   Record Variable in VariableIndex HOB.
 166
 167   Record Variable in VariableIndex HOB and update the length of variable index table.
 168
 169   @param  IndexTable  The pointer to variable index table.
 170   @param  Variable    The pointer to the variable that will be recorded.
 171
 172 **/
 173 VOID
 174 VariableIndexTableUpdate (
 175   IN OUT  VARIABLE_INDEX_TABLE   *IndexTable,
 176   IN      VARIABLE_HEADER        *Variable
 177   );
 178
 179 #endif