EdkCompatibilityPkg/Compatibility/ReadOnlyVariableOnReadOnlyVariable2Thunk/ReadOnlyVariableOnReadOnlyVariable2Thunk.c

   1 /** @file
   2 Module produce EFI_PEI_READ_ONLY_VARIABLE_PPI on top of EFI_PEI_READ_ONLY_VARIABLE2_PPI.
   3 UEFI PI Spec supersedes Intel's Framework Specs.
   4 # EFI_PEI_READ_ONLY_VARIABLE_PPI defined in Intel Framework Pkg is replaced by EFI_PEI_READ_ONLY_VARIABLE2_PPI
   5 # in MdePkg.
   6 # This module produces EFI_PEI_READ_ONLY_VARIABLE_PPI on top of EFI_PEI_READ_ONLY_VARIABLE2_PPI.
   7 # This module is used on platform when both of these two conditions are true:
   8 # 1) Framework module consumes EFI_PEI_READ_ONLY_VARIABLE_PPI is present.
   9 # 2) The platform has a PI module that only produces EFI_PEI_READ_ONLY_VARIABLE2_PPI.
  10
  11 This module can't be used together with ReadOnlyVariable2ToReadOnlyVariableThunk module.
  12
  13 Copyright (c) 2006 - 2010, Intel Corporation. All rights reserved.<BR>
  14 This program and the accompanying materials
  15 are licensed and made available under the terms and conditions of the BSD License
  16 which accompanies this distribution.  The full text of the license may be found at
  17 http://opensource.org/licenses/bsd-license.php
  18
  19 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  20 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  21 Module Name:
  22
  23 **/
  24
  25 #include <PiPei.h>
  26 #include <Ppi/ReadOnlyVariable.h>
  27 #include <Ppi/ReadOnlyVariable2.h>
  28 #include <Library/DebugLib.h>
  29 #include <Library/PeiServicesLib.h>
  30
  31 /**
  32   Provide the read variable functionality of the variable services.
  33
  34   @param[in]  PeiServices    An indirect pointer to the PEI Services Table published by the PEI Foundation.
  35   @param[in]  VariableName   A NULL-terminated Unicode string that is the name of the vendor's variable.
  36   @param[in]  VendorGuid     A unique identifier for the vendor.
  37   @param[out] Attributes     This OPTIONAL parameter may be either NULL or
  38                              a pointer to the location in which to return
  39                              the attributes bitmask for the variable.
  40   @param[in, out]  DataSize   On input, the size in bytes of the return Data buffer.
  41                              On output, the size of data returned in Data.
  42   @param[out] Data           The buffer to return the contents of the variable.
  43
  44   @retval EFI_SUCCESS           The interface could be successfully installed
  45   @retval EFI_NOT_FOUND         The variable could not be discovered
  46   @retval EFI_BUFFER_TOO_SMALL  The caller buffer is not large enough
  47
  48 **/
  49 EFI_STATUS
  50 EFIAPI
  51 PeiGetVariable (
  52   IN  EFI_PEI_SERVICES  **PeiServices,
  53   IN  CHAR16            *VariableName,
  54   IN  EFI_GUID          *VendorGuid,
  55   OUT UINT32            *Attributes OPTIONAL,
  56   IN  OUT UINTN         *DataSize,
  57   OUT VOID              *Data
  58   )
  59 {
  60   EFI_STATUS                      Status;
  61   EFI_PEI_READ_ONLY_VARIABLE2_PPI *ReadOnlyVariable2;
  62
  63   Status = (*PeiServices)->LocatePpi (
  64                              (CONST EFI_PEI_SERVICES **)PeiServices,
  65                              &gEfiPeiReadOnlyVariable2PpiGuid,
  66                              0,
  67                              NULL,
  68                              (VOID **)&ReadOnlyVariable2
  69                              );
  70   ASSERT_EFI_ERROR (Status);
  71
  72   return ReadOnlyVariable2->GetVariable (
  73                               ReadOnlyVariable2,
  74                               VariableName,
  75                               VendorGuid,
  76                               Attributes,
  77                               DataSize,
  78                               Data
  79                               );
  80 }
  81
  82 /**
  83   Provide the get next variable functionality of the variable services.
  84
  85   @param[in]     PeiServices       An indirect pointer to the PEI Services Table published by the PEI Foundation.
  86   @param[in, out] VariableNameSize  The size of the VariableName buffer.
  87   @param[in, out] VariableName      On input, supplies the last VariableName that was
  88                                    returned by GetNextVariableName(). On output, returns the Null-terminated
  89                                    Unicode string of the current variable.
  90   @param[in, out] VendorGuid        On input, supplies the last VendorGuid that was
  91                                    returned by GetNextVariableName(). On output, returns the VendorGuid
  92                                    of the current variable.
  93
  94   @retval EFI_SUCCESS           The interface could be successfully installed
  95   @retval EFI_NOT_FOUND         The variable could not be discovered
  96
  97 **/
  98 EFI_STATUS
  99 EFIAPI
 100 PeiGetNextVariableName (
 101   IN EFI_PEI_SERVICES  **PeiServices,
 102   IN OUT UINTN         *VariableNameSize,
 103   IN OUT CHAR16        *VariableName,
 104   IN OUT EFI_GUID      *VendorGuid
 105   )
 106 {
 107   EFI_STATUS                      Status;
 108   EFI_PEI_READ_ONLY_VARIABLE2_PPI *ReadOnlyVariable2;
 109
 110   Status = (*PeiServices)->LocatePpi (
 111                              (CONST EFI_PEI_SERVICES **)PeiServices,
 112                              &gEfiPeiReadOnlyVariable2PpiGuid,
 113                              0,
 114                              NULL,
 115                              (VOID **)&ReadOnlyVariable2
 116                              );
 117   ASSERT_EFI_ERROR (Status);
 118
 119   return ReadOnlyVariable2->NextVariableName (
 120                               ReadOnlyVariable2,
 121                               VariableNameSize,
 122                               VariableName,
 123                               VendorGuid
 124                               );
 125 }
 126
 127 //
 128 // Module globals
 129 //
 130 EFI_PEI_READ_ONLY_VARIABLE_PPI mVariablePpi = {
 131   PeiGetVariable,
 132   PeiGetNextVariableName
 133 };
 134
 135 EFI_PEI_PPI_DESCRIPTOR     mPpiListVariable = {
 136   (EFI_PEI_PPI_DESCRIPTOR_PPI | EFI_PEI_PPI_DESCRIPTOR_TERMINATE_LIST),
 137   &gEfiPeiReadOnlyVariablePpiGuid,
 138   &mVariablePpi
 139 };
 140
 141 /**
 142   Standard entry point of a PEIM.
 143
 144   @param FileHandle   Handle of the file being invoked.
 145   @param PeiServices  General purpose services available to every PEIM.
 146
 147   @retval EFI_SUCCESS If the gEfiPeiReadOnlyVariablePpiGuid interface could be successfully installed.
 148
 149 **/
 150 EFI_STATUS
 151 EFIAPI
 152 PeimInitializeReadOnlyVariable (
 153   IN EFI_PEI_FILE_HANDLE     FileHandle,
 154   IN CONST EFI_PEI_SERVICES  **PeiServices
 155   )
 156 {
 157   //
 158   //Developer should make sure ReadOnlyVariableToReadOnlyVariable2 module is not present. If so, the call chain will form a
 159   // infinite loop: ReadOnlyVariable -> ReadOnlyVariable2 -> ReadOnlyVariable -> ....
 160   //
 161   //
 162   // Publish the variable capability to other modules
 163   //
 164   return (*PeiServices)->InstallPpi (PeiServices, &mPpiListVariable);
 165 }