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   Module Name:  ReadOnlyVariable.h
  14
  15   @par Revision Reference:
  16   This PPI is defined in PI
  17   Version 1.00.
  18
  19 **/
  20
  21 #ifndef __PEI_READ_ONLY_VARIABLE2_PPI_H__
  22 #define __PEI_READ_ONLY_VARIABLE2_PPI_H__
  23
  24 #define EFI_PEI_READ_ONLY_VARIABLE2_PPI_GUID \
  25         { 0x2ab86ef5, 0xecb5, 0x4134, { 0xb5, 0x56, 0x38, 0x54, 0xca, 0x1f, 0xe1, 0xb4 } }
  26
  27
  28 typedef struct _EFI_PEI_READ_ONLY_VARIABLE2_PPI  EFI_PEI_READ_ONLY_VARIABLE2_PPI;
  29
  30 /**
  31   Read the specified variable from the UEFI variable store. If the Data
  32         buffer is too small to hold the contents of the variable,
  33         the error EFI_BUFFER_TOO_SMALL is returned and DataSize is set to the
  34         required buffer size to obtain the data.
  35
  36   @param  This                                  A pointer to this instance of the EFI_PEI_READ_ONLY_VARIABLE2_PPI.
  37
  38   @param  VariableName          A pointer to a null-terminated string that is the variable¡¯s name.
  39
  40   @param  VendorGuid            A pointer to an EFI_GUID that is the variable¡¯s GUID. The combination of
  41                                                                                                         VariableGuid and VariableName must be unique.
  42
  43   @param  Attributes            If non-NULL, on return, points to the variable¡¯s attributes. See ¡°Related Definitons¡±
  44                                                                                                         below for possible attribute values.
  45
  46   @param  DataSize              On entry, points to the size in bytes of the Data buffer. On return, points to the size of
  47                                                                                                         the data returned in Data.
  48
  49   @param  Data                  Points to the buffer which will hold the returned variable value.
  50
  51
  52   @retval EFI_SUCCESS           The function completed successfully.
  53
  54   @retval EFI_NOT_FOUND         The variable was not found.
  55
  56   @retval EFI_BUFFER_TOO_SMALL  The DataSize is too small for the resulting data.
  57                                                                                                                                 DataSize is updated with the size required for
  58                                                                                                                                 the specified variable.
  59
  60   @retval EFI_INVALID_PARAMETER VariableName, VariableGuid, DataSize or Data is NULL.
  61
  62   @retval EFI_DEVICE_ERROR      The variable could not be retrieved because of a device error.
  63
  64 **/
  65 typedef
  66 EFI_STATUS
  67 (EFIAPI *EFI_PEI_GET_VARIABLE2)(
  68         IN CONST        EFI_PEI_READ_ONLY_VARIABLE2_PPI *This,
  69         IN CONST        CHAR16                                                                                                  *VariableName,
  70         IN CONST        EFI_GUID                                                                                                *VariableGuid,
  71         OUT                     UINT32                                                                                                  *Attributes,
  72         IN OUT          UINTN                                                                                                   *DataSize,
  73         OUT                     VOID                                                                                                            *Data
  74 );
  75
  76
  77 /**
  78   This function is called multiple times to retrieve the VariableName
  79         and VariableGuid of all variables currently available in the system.
  80         On each call, the previous results are passed into the interface,
  81         and, on return, the interface returns the data for the next
  82         interface. When the entire variable list has been returned,
  83         EFI_NOT_FOUND is returned.
  84
  85   @param  This                                  A pointer to this instance of the EFI_PEI_READ_ONLY_VARIABLE2_PPI.
  86
  87   @param  VariableNameSize      On entry, points to the size of the buffer pointed to by VariableName.
  88
  89   @param  VariableName          On entry, a pointer to a null-terminated string that is the variable¡¯s name.
  90                                                                                                                 On return, points to the next variable¡¯s null-terminated name string.
  91
  92   @param  VendorGuid            On entry, a pointer to an UEFI _GUID that is the variable¡¯s GUID.
  93                                                                                                                 On return, a pointer to the next variable¡¯s GUID.
  94
  95
  96   @retval EFI_SUCCESS           The variable was read successfully.
  97
  98   @retval EFI_NOT_FOUND         The variable could not be found.
  99
 100   @retval EFI_BUFFER_TOO_SMALL  The VariableNameSize is too small for the resulting
 101                                                                                                                                 data. VariableNameSize is updated with the size
 102                                                                                                                                 required for the specified variable.
 103
 104   @retval EFI_INVALID_PARAMETER VariableName, VariableGuid or
 105                                                                                                                                 VariableNameSize is NULL.
 106
 107   @retval EFI_DEVICE_ERROR      The variable could not be retrieved because of a device error.
 108
 109 **/
 110 typedef
 111 EFI_STATUS
 112 (EFIAPI *EFI_PEI_NEXT_VARIABLE_NAME2) (
 113         IN CONST        EFI_PEI_READ_ONLY_VARIABLE2_PPI *This,
 114         IN OUT          UINTN                                                                                                   *VariableNameSize,
 115         IN OUT          CHAR16                                                                                                  *VariableName,
 116         IN OUT          EFI_GUID                                                                                                *VariableGuid
 117 );
 118
 119 /**
 120   This PPI provides a lightweight, read-only variant of the full EFI
 121   variable services.
 122
 123   @param GetVariable
 124   A service to ascertain a given variable name.
 125
 126   @param GetNextVariableName
 127   A service to ascertain a variable based upon a given, known variable
 128
 129 **/
 130 struct _EFI_PEI_READ_ONLY_VARIABLE2_PPI {
 131         EFI_PEI_GET_VARIABLE2                   GetVariable;
 132         EFI_PEI_NEXT_VARIABLE_NAME2     NextVariableName;
 133 };
 134
 135 extern EFI_GUID gEfiPeiReadOnlyVariable2PpiGuid;
 136
 137 #endif