EdkCompatibilityPkg/Compatibility/ReadOnlyVariable2ToReadOnlyVariableThunk/ReadOnlyVariable2ToReadOnlyVariableThunk.c

   1 /** @file
   2 Module produce EFI_PEI_READ_ONLY_VARIABLE2_PPI on top of EFI_PEI_READ_ONLY_VARIABLE_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_VARIABLE2_PPI on top of EFI_PEI_READ_ONLY_VARIABLE_PPI.
   7 This module is used on platform when both of these two conditions are true:
   8 1) Framework module produces EFI_PEI_READ_ONLY_VARIABLE_PPI is present.
   9 2) The platform has PI modules that only consumes EFI_PEI_READ_ONLY_VARIABLE2_PPI.
  10
  11 This module can't be used together with ReadOnlyVariableToReadOnlyVariable2Thunk module.
  12
  13
  14 Copyright (c) 2006 - 2008 Intel Corporation. <BR>
  15 All rights reserved. This program and the accompanying materials
  16 are licensed and made available under the terms and conditions of the BSD License
  17 which accompanies this distribution.  The full text of the license may be found at
  18 http://opensource.org/licenses/bsd-license.php
  19
  20 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  21 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  22 Module Name:
  23
  24 **/
  25
  26 #include <PiPei.h>
  27 #include <Ppi/ReadOnlyVariable2.h>
  28 #include <Ppi/ReadOnlyVariable.h>
  29 #include <Ppi/ReadOnlyVariableThunkPresent.h>
  30 #include <Library/DebugLib.h>
  31 #include <Library/PeiServicesTablePointerLib.h>
  32 #include <Library/PeiServicesLib.h>
  33
  34 //
  35 // Function Prototypes
  36 //
  37 EFI_STATUS
  38 EFIAPI
  39 PeiGetVariable (
  40   IN CONST  EFI_PEI_READ_ONLY_VARIABLE2_PPI *This,
  41   IN CONST  CHAR16                          *VariableName,
  42   IN CONST  EFI_GUID                        *VariableGuid,
  43   OUT       UINT32                          *Attributes,
  44   IN OUT    UINTN                           *DataSize,
  45   OUT       VOID                            *Data
  46   );
  47
  48 EFI_STATUS
  49 EFIAPI
  50 PeiGetNextVariableName (
  51   IN CONST  EFI_PEI_READ_ONLY_VARIABLE2_PPI *This,
  52   IN OUT UINTN                              *VariableNameSize,
  53   IN OUT CHAR16                             *VariableName,
  54   IN OUT EFI_GUID                           *VariableGuid
  55   );
  56
  57 //
  58 // Module globals
  59 //
  60 EFI_PEI_READ_ONLY_VARIABLE2_PPI mVariablePpi = {
  61   PeiGetVariable,
  62   PeiGetNextVariableName
  63 };
  64
  65 EFI_PEI_PPI_DESCRIPTOR     mPpiListVariable = {
  66   (EFI_PEI_PPI_DESCRIPTOR_PPI | EFI_PEI_PPI_DESCRIPTOR_TERMINATE_LIST),
  67   &gEfiPeiReadOnlyVariable2PpiGuid,
  68   &mVariablePpi
  69 };
  70
  71
  72 EFI_PEI_PPI_DESCRIPTOR     mReadOnlyVariableThunkPresent = {
  73     (EFI_PEI_PPI_DESCRIPTOR_PPI | EFI_PEI_PPI_DESCRIPTOR_TERMINATE_LIST),
  74     &gPeiReadonlyVariableThunkPresentPpiGuid,
  75     NULL
  76 };
  77
  78 /**
  79   User entry for this PEIM driver.
  80
  81   @param  FileHandle  Handle of the file being invoked.
  82   @param  PeiServices Describes the list of possible PEI Services.
  83
  84   @retval EFI_SUCCESS ReadOnlyVariable2 PPI is successfully installed.
  85   @return Others      ReadOnlyVariable2 PPI is not successfully installed.
  86
  87 **/
  88 EFI_STATUS
  89 EFIAPI
  90 PeimInitializeReadOnlyVariable2 (
  91   IN EFI_PEI_FILE_HANDLE       FfsHeader,
  92   IN CONST EFI_PEI_SERVICES    **PeiServices
  93   )
  94 {
  95   VOID        *Interface;
  96   EFI_STATUS  Status;
  97   //
  98   // This thunk module can only be used together with a PI PEI core, as we
  99   // assume PeiServices Pointer Table can be located in a standard way defined
 100   // in PI spec.
 101   //
 102   ASSERT ((*PeiServices)->Hdr.Revision >= 0x00010000);
 103
 104   //
 105   // Make sure ReadOnlyVariable2ToReadOnlyVariable module is not present. If so, the call chain will form a
 106   // infinite loop: ReadOnlyVariable2 -> ReadOnlyVariable -> ReadOnlyVariable2 -> ....
 107   //
 108   Status = PeiServicesLocatePpi (&gPeiReadonlyVariableThunkPresentPpiGuid, 0, NULL, &Interface);
 109   ASSERT (Status == EFI_NOT_FOUND);
 110
 111   Status = PeiServicesInstallPpi (&mReadOnlyVariableThunkPresent);
 112   ASSERT_EFI_ERROR (Status);
 113
 114   //
 115   // Publish the variable capability to other modules
 116   //
 117   return PeiServicesInstallPpi (&mPpiListVariable);
 118 }
 119
 120 /**
 121   Provide the read variable functionality of the variable services.
 122
 123   @param  PeiServices           General purpose services available to every PEIM.
 124   @param  VariableName          The variable name
 125   @param  VendorGuid            The vendor's GUID
 126   @param  Attributes            Pointer to the attribute
 127   @param  DataSize              Size of data
 128   @param  Data                  Pointer to data
 129
 130   @retval EFI_SUCCESS           The interface could be successfully installed
 131   @retval EFI_NOT_FOUND         The variable could not be discovered
 132   @retval EFI_BUFFER_TOO_SMALL  The caller buffer is not large enough
 133
 134 **/
 135 EFI_STATUS
 136 EFIAPI
 137 PeiGetVariable (
 138   IN CONST  EFI_PEI_READ_ONLY_VARIABLE2_PPI *This,
 139   IN CONST  CHAR16                          *VariableName,
 140   IN CONST  EFI_GUID                        *VariableGuid,
 141   OUT       UINT32                          *Attributes,
 142   IN OUT    UINTN                           *DataSize,
 143   OUT       VOID                            *Data
 144   )
 145 {
 146   EFI_STATUS                     Status;
 147   EFI_PEI_READ_ONLY_VARIABLE_PPI *ReadOnlyVariable;
 148
 149   Status = PeiServicesLocatePpi (
 150              &gEfiPeiReadOnlyVariablePpiGuid,
 151              0,
 152              NULL,
 153              (VOID **)&ReadOnlyVariable
 154              );
 155   ASSERT_EFI_ERROR (Status);
 156
 157   return ReadOnlyVariable->PeiGetVariable (
 158                              (EFI_PEI_SERVICES **) GetPeiServicesTablePointer (),
 159                              (CHAR16 *)VariableName,
 160                              (EFI_GUID *)VariableGuid,
 161                              Attributes,
 162                              DataSize,
 163                              Data
 164                              );
 165 }
 166
 167 /**
 168   Provide the get next variable functionality of the variable services.
 169
 170   @param  PeiServices           General purpose services available to every PEIM.
 171   @param  VariabvleNameSize     The variable name's size.
 172   @param  VariableName          A pointer to the variable's name.
 173   @param  VariableGuid          A pointer to the EFI_GUID structure.
 174   @param  VariableNameSize      Size of the variable name
 175   @param  VariableName          The variable name
 176   @param  VendorGuid            The vendor's GUID
 177
 178   @retval EFI_SUCCESS           The interface could be successfully installed
 179   @retval EFI_NOT_FOUND         The variable could not be discovered
 180
 181 **/
 182 EFI_STATUS
 183 EFIAPI
 184 PeiGetNextVariableName (
 185   IN CONST  EFI_PEI_READ_ONLY_VARIABLE2_PPI *This,
 186   IN OUT UINTN                              *VariableNameSize,
 187   IN OUT CHAR16                             *VariableName,
 188   IN OUT EFI_GUID                           *VariableGuid
 189   )
 190 {
 191   EFI_STATUS                     Status;
 192   EFI_PEI_READ_ONLY_VARIABLE_PPI *ReadOnlyVariable;
 193
 194   Status = PeiServicesLocatePpi (
 195              &gEfiPeiReadOnlyVariablePpiGuid,
 196              0,
 197              NULL,
 198              (VOID **)&ReadOnlyVariable
 199              );
 200   ASSERT_EFI_ERROR (Status);
 201
 202   return ReadOnlyVariable->PeiGetNextVariableName (
 203                              (EFI_PEI_SERVICES **) GetPeiServicesTablePointer (),
 204                              VariableNameSize,
 205                              VariableName,
 206                              VariableGuid
 207                              );
 208 }