MdePkg/Include/Ppi/ReadOnlyVariable2.h

   1 /** @file
   2   This file declares Read-only Variable Service PPI
   3
   4   Copyright (c) 2006 - 2007, Intel Corporation
   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   @par Revision Reference:
  14   This PPI is defined in PI
  15   Version 1.00.
  16
  17 **/
  18
  19 #ifndef __PEI_READ_ONLY_VARIABLE2_PPI_H__
  20 #define __PEI_READ_ONLY_VARIABLE2_PPI_H__
  21
  22 #define EFI_PEI_READ_ONLY_VARIABLE2_PPI_GUID \
  23   { 0x2ab86ef5, 0xecb5, 0x4134, { 0xb5, 0x56, 0x38, 0x54, 0xca, 0x1f, 0xe1, 0xb4 } }
  24
  25
  26 typedef struct _EFI_PEI_READ_ONLY_VARIABLE2_PPI  EFI_PEI_READ_ONLY_VARIABLE2_PPI;
  27
  28 /**
  29   Read the specified variable from the UEFI variable store. If the Data
  30   buffer is too small to hold the contents of the variable,
  31   the error EFI_BUFFER_TOO_SMALL is returned and DataSize is set to the
  32   required buffer size to obtain the data.
  33
  34   @param  This            A pointer to this instance of the EFI_PEI_READ_ONLY_VARIABLE2_PPI.
  35
  36   @param  VariableName    A pointer to a null-terminated string that is the variable¡¯s name.
  37
  38   @param  VendorGuid      A pointer to an EFI_GUID that is the variable¡¯s GUID. The combination of
  39                           VariableGuid and VariableName must be unique.
  40
  41   @param  Attributes      If non-NULL, on return, points to the variable¡¯s attributes. See ¡°Related Definitons¡±
  42                           below for possible attribute values.
  43
  44   @param  DataSize        On entry, points to the size in bytes of the Data buffer. On return, points to the size of
  45                           the data returned in Data.
  46
  47   @param  Data            Points to the buffer which will hold the returned variable value.
  48
  49
  50   @retval EFI_SUCCESS           The function completed successfully.
  51
  52   @retval EFI_NOT_FOUND         The variable was not found.
  53
  54   @retval EFI_BUFFER_TOO_SMALL  The DataSize is too small for the resulting data.
  55                                 DataSize is updated with the size required for
  56                                 the specified variable.
  57
  58   @retval EFI_INVALID_PARAMETER VariableName, VariableGuid, DataSize or Data is NULL.
  59
  60   @retval EFI_DEVICE_ERROR      The variable could not be retrieved because of a device error.
  61
  62 **/
  63 typedef
  64 EFI_STATUS
  65 (EFIAPI *EFI_PEI_GET_VARIABLE2)(
  66   IN CONST  EFI_PEI_READ_ONLY_VARIABLE2_PPI *This,
  67   IN CONST  CHAR16                          *VariableName,
  68   IN CONST  EFI_GUID                        *VariableGuid,
  69   OUT       UINT32                          *Attributes,
  70   IN OUT    UINTN                           *DataSize,
  71   OUT       VOID                            *Data
  72   );
  73
  74
  75 /**
  76   This function is called multiple times to retrieve the VariableName
  77   and VariableGuid of all variables currently available in the system.
  78   On each call, the previous results are passed into the interface,
  79   and, on return, the interface returns the data for the next
  80   interface. When the entire variable list has been returned,
  81   EFI_NOT_FOUND is returned.
  82
  83   @param  This              A pointer to this instance of the EFI_PEI_READ_ONLY_VARIABLE2_PPI.
  84
  85   @param  VariableNameSize  On entry, points to the size of the buffer pointed to by VariableName.
  86
  87   @param  VariableName      On entry, a pointer to a null-terminated string that is the variable¡¯s name.
  88                             On return, points to the next variable¡¯s null-terminated name string.
  89
  90   @param  VendorGuid        On entry, a pointer to an UEFI _GUID that is the variable¡¯s GUID.
  91                             On return, a pointer to the next variable¡¯s GUID.
  92
  93
  94   @retval EFI_SUCCESS           The variable was read successfully.
  95
  96   @retval EFI_NOT_FOUND         The variable could not be found.
  97
  98   @retval EFI_BUFFER_TOO_SMALL  The VariableNameSize is too small for the resulting
  99                                 data. VariableNameSize is updated with the size
 100                                 required for the specified variable.
 101
 102   @retval EFI_INVALID_PARAMETER VariableName, VariableGuid or
 103                                 VariableNameSize is NULL.
 104
 105   @retval EFI_DEVICE_ERROR      The variable could not be retrieved because of a device error.
 106
 107 **/
 108 typedef
 109 EFI_STATUS
 110 (EFIAPI *EFI_PEI_NEXT_VARIABLE_NAME2) (
 111   IN CONST  EFI_PEI_READ_ONLY_VARIABLE2_PPI *This,
 112   IN OUT    UINTN                           *VariableNameSize,
 113   IN OUT    CHAR16                          *VariableName,
 114   IN OUT    EFI_GUID                        *VariableGuid
 115   );
 116
 117 /**
 118   This PPI provides a lightweight, read-only variant of the full EFI
 119   variable services.
 120
 121   @param GetVariable
 122   A service to ascertain a given variable name.
 123
 124   @param GetNextVariableName
 125   A service to ascertain a variable based upon a given, known variable
 126
 127 **/
 128 struct _EFI_PEI_READ_ONLY_VARIABLE2_PPI {
 129   EFI_PEI_GET_VARIABLE2       GetVariable;
 130   EFI_PEI_NEXT_VARIABLE_NAME2 NextVariableName;
 131 };
 132
 133 extern EFI_GUID gEfiPeiReadOnlyVariable2PpiGuid;
 134
 135 #endif