emuvariable.c

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        continue;
      }
    }
    //
    // Variable is found
    //
    if (Variable.CurrPtr->StartId == VARIABLE_DATA && Variable.CurrPtr->State == VAR_ADDED) {
      if (!(EfiAtRuntime () && !(Variable.CurrPtr->Attributes & EFI_VARIABLE_RUNTIME_ACCESS))) {
        VarNameSize = Variable.CurrPtr->NameSize;
        if (VarNameSize <= *VariableNameSize) {
          EfiCopyMem (
            VariableName,
            GET_VARIABLE_NAME_PTR (Variable.CurrPtr),
            VarNameSize
            );
          EfiCopyMem (
            VendorGuid,
            &Variable.CurrPtr->VendorGuid,
            sizeof (EFI_GUID)
            );
          Status = EFI_SUCCESS;
        } else {
          Status = EFI_BUFFER_TOO_SMALL;
        }

        *VariableNameSize = VarNameSize;
        return Status;
      }
    }
  }

  return EFI_NOT_FOUND;
}

EFI_STATUS
EFIAPI
SetVariable (
  IN CHAR16                  *VariableName,
  IN EFI_GUID                *VendorGuid,
  IN UINT32                  Attributes,
  IN UINTN                   DataSize,
  IN VOID                    *Data,
  IN VARIABLE_GLOBAL         *Global,
  IN UINTN                   *VolatileOffset,
  IN UINTN                   *NonVolatileOffset,
  IN UINT32                  Instance
  )
/*++

Routine Description:

  This code sets variable in storage blocks (Volatile or Non-Volatile)

Arguments:

  VariableName                    Name of Variable to be found
  VendorGuid                      Variable vendor GUID
  Attributes                      Attribute value of the variable found
  DataSize                        Size of Data found. If size is less than the
                                  data, this value contains the required size.
  Data                            Data pointer
  Global                          Pointer to VARIABLE_GLOBAL structure
  VolatileOffset                  The offset of last volatile variable
  NonVolatileOffset               The offset of last non-volatile variable
  Instance                        Instance of the Firmware Volume.

Returns:

  EFI STATUS

--*/
{
  VARIABLE_POINTER_TRACK  Variable;
  EFI_STATUS              Status;
  VARIABLE_HEADER         *NextVariable;
  UINTN                   VarNameSize;
  UINTN                   VarNameOffset;
  UINTN                   VarDataOffset;
  UINTN                   VarSize;

  if (VariableName == NULL || VariableName[0] == 0 || VendorGuid == NULL) {
    return EFI_INVALID_PARAMETER;
  }

  Status = FindVariable (VariableName, VendorGuid, &Variable, Global);

  if (Status == EFI_INVALID_PARAMETER) {
    return Status;
  }
  //
  //  The size of the VariableName, including the Unicode Null in bytes plus
  //  the DataSize is limited to maximum size of MAX_VARIABLE_SIZE (1024) bytes.
  //
  else if (sizeof (VARIABLE_HEADER) + (ArrayLength (VariableName) + DataSize) > MAX_VARIABLE_SIZE) {
    return EFI_INVALID_PARAMETER;
  }
  //
  //  Make sure if runtime bit is set, boot service bit is set also
  //
  else if ((Attributes & (EFI_VARIABLE_RUNTIME_ACCESS | EFI_VARIABLE_BOOTSERVICE_ACCESS)) == EFI_VARIABLE_RUNTIME_ACCESS
          ) {
    return EFI_INVALID_PARAMETER;
  }
  //
  // Runtime but Attribute is not Runtime
  //
  else if (EfiAtRuntime () && Attributes && !(Attributes & EFI_VARIABLE_RUNTIME_ACCESS)) {
    return EFI_INVALID_PARAMETER;
  }
  //
  // Cannot set volatile variable in Runtime
  //
  else if (EfiAtRuntime () && Attributes && !(Attributes & EFI_VARIABLE_NON_VOLATILE)) {
    return EFI_INVALID_PARAMETER;
  }
  //
  // Setting a data variable with no access, or zero DataSize attributes
  // specified causes it to be deleted.
  //
  else if (DataSize == 0 || Attributes == 0) {
    if (!EFI_ERROR (Status)) {
      Variable.CurrPtr->State &= VAR_DELETED;
      return EFI_SUCCESS;
    }

    return EFI_NOT_FOUND;
  } else {
    if (!EFI_ERROR (Status)) {
      //
      // If the variable is marked valid and the same data has been passed in
      // then return to the caller immediately.
      //
      if (Variable.CurrPtr->DataSize == DataSize &&
          !EfiCompareMem (Data, GetVariableDataPtr (Variable.CurrPtr), DataSize)
            ) {
        return EFI_SUCCESS;
      } else if (Variable.CurrPtr->State == VAR_ADDED) {
        //
        // Mark the old variable as in delete transition
        //
        Variable.CurrPtr->State &= VAR_IN_DELETED_TRANSITION;
      }
    }
    //
    // Create a new variable and copy the data.
    //
    VarNameOffset = sizeof (VARIABLE_HEADER);
    VarNameSize   = ArrayLength (VariableName);
    VarDataOffset = VarNameOffset + VarNameSize + GetPadSize (VarNameSize);
    VarSize       = VarDataOffset + DataSize + GetPadSize (DataSize);

    if (Attributes & EFI_VARIABLE_NON_VOLATILE) {
      if ((UINT32) (VarSize +*NonVolatileOffset) >
            ((VARIABLE_STORE_HEADER *) ((UINTN) (Global->NonVolatileVariableBase)))->Size
            ) {
        return EFI_OUT_OF_RESOURCES;
      }

      NextVariable        = (VARIABLE_HEADER *) (UINT8 *) (*NonVolatileOffset + (UINTN) Global->NonVolatileVariableBase);
      *NonVolatileOffset  = *NonVolatileOffset + VarSize;
    } else {
      if (EfiAtRuntime ()) {
        return EFI_INVALID_PARAMETER;
      }

      if ((UINT32) (VarSize +*VolatileOffset) >
            ((VARIABLE_STORE_HEADER *) ((UINTN) (Global->VolatileVariableBase)))->Size
            ) {
        return EFI_OUT_OF_RESOURCES;
      }

      NextVariable    = (VARIABLE_HEADER *) (UINT8 *) (*VolatileOffset + (UINTN) Global->VolatileVariableBase);
      *VolatileOffset = *VolatileOffset + VarSize;
    }

    NextVariable->StartId     = VARIABLE_DATA;
    NextVariable->Attributes  = Attributes;
    NextVariable->State       = VAR_ADDED;
    NextVariable->Reserved    = 0;

    //
    // There will be pad bytes after Data, the NextVariable->NameSize and
    // NextVariable->NameSize should not include pad size so that variable
    // service can get actual size in GetVariable
    //
    NextVariable->NameSize  = (UINT32)VarNameSize;
    NextVariable->DataSize  = (UINT32)DataSize;

    EfiCopyMem (&NextVariable->VendorGuid, VendorGuid, sizeof (EFI_GUID));
    EfiCopyMem (
      (UINT8 *) ((UINTN) NextVariable + VarNameOffset),
      VariableName,
      VarNameSize
      );
    EfiCopyMem (
      (UINT8 *) ((UINTN) NextVariable + VarDataOffset),
      Data,
      DataSize
      );

    //
    // Mark the old variable as deleted
    //
    if (!EFI_ERROR (Status)) {
      Variable.CurrPtr->State &= VAR_DELETED;
    }
  }

  return EFI_SUCCESS;
}

#if (EFI_SPECIFICATION_VERSION >= 0x00020000)
EFI_STATUS
EFIAPI
QueryVariableInfo (
  IN  UINT32                 Attributes,
  OUT UINT64                 *MaximumVariableStorageSize,
  OUT UINT64                 *RemainingVariableStorageSize,
  OUT UINT64                 *MaximumVariableSize,
  IN  VARIABLE_GLOBAL        *Global,
  IN  UINT32                 Instance
  )
/*++

Routine Description:

  This code returns information about the EFI variables.

Arguments:

  Attributes                      Attributes bitmask to specify the type of variables 
                                  on which to return information.
  MaximumVariableStorageSize      Pointer to the maximum size of the storage space available
                                  for the EFI variables associated with the attributes specified.
  RemainingVariableStorageSize    Pointer to the remaining size of the storage space available 
                                  for the EFI variables associated with the attributes specified.
  MaximumVariableSize             Pointer to the maximum size of the individual EFI variables
                                  associated with the attributes specified.
  Global                          Pointer to VARIABLE_GLOBAL structure.
  Instance                        Instance of the Firmware Volume.

Returns:

  EFI STATUS
  EFI_INVALID_PARAMETER           - An invalid combination of attribute bits was supplied.
  EFI_SUCCESS                     - Query successfully.
  EFI_UNSUPPORTED                 - The attribute is not supported on this platform.

--*/
{
  VARIABLE_HEADER        *Variable;
  VARIABLE_HEADER        *NextVariable;
  UINT64                 VariableSize;
  VARIABLE_STORE_HEADER  *VariableStoreHeader;
  
  if(MaximumVariableStorageSize == NULL || RemainingVariableStorageSize == NULL || MaximumVariableSize == NULL) {
    return EFI_INVALID_PARAMETER;
  }

  if((Attributes & (EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_RUNTIME_ACCESS)) == 0) {
    //
    // Make sure the Attributes combination is supported by the platform.
    //
    return EFI_UNSUPPORTED;
  } else if ((Attributes & (EFI_VARIABLE_RUNTIME_ACCESS | EFI_VARIABLE_BOOTSERVICE_ACCESS)) == EFI_VARIABLE_RUNTIME_ACCESS) {
    //
    // Make sure if runtime bit is set, boot service bit is set also.
    //
    return EFI_INVALID_PARAMETER;
  } else if (EfiAtRuntime () && !(Attributes & EFI_VARIABLE_RUNTIME_ACCESS)) {
    //
    //   Make sure RT Attribute is set if we are in Runtime phase.
    //
    return EFI_INVALID_PARAMETER;
  } else if (EfiAtRuntime () && Attributes && !(Attributes & EFI_VARIABLE_NON_VOLATILE)) {
    //
    // Cannot Query volatile variable in Runtime
    //
    return EFI_INVALID_PARAMETER;
  }

  if((Attributes & EFI_VARIABLE_NON_VOLATILE) == 0) {
    //
    // Query is Volatile related.
    //
    VariableStoreHeader = (VARIABLE_STORE_HEADER *) ((UINTN) Global->VolatileVariableBase);    
  } else {
    //
    // Query is Non-Volatile related.
    //
    VariableStoreHeader = (VARIABLE_STORE_HEADER *) ((UINTN) Global->NonVolatileVariableBase);
  }

  //
  // Now let's fill *MaximumVariableStorageSize *RemainingVariableStorageSize 
  // with the storage size (excluding the storage header size)
  //
  *MaximumVariableStorageSize   = VariableStoreHeader->Size - sizeof (VARIABLE_STORE_HEADER);
  *RemainingVariableStorageSize = VariableStoreHeader->Size - sizeof (VARIABLE_STORE_HEADER);

  //
  // Let *MaximumVariableSize be MAX_VARIABLE_SIZE 
  //
  *MaximumVariableSize = MAX_VARIABLE_SIZE;

  //
  // Point to the starting address of the variables.
  //
  Variable = (VARIABLE_HEADER *) (VariableStoreHeader + 1);

  //
  // Now walk through the related variable store.
  //
  while (Variable < GetEndPointer (VariableStoreHeader)) {
    if (Variable->StartId != VARIABLE_DATA) {
      break;
    }

    NextVariable = (VARIABLE_HEADER *) (GetVariableDataPtr (Variable) + Variable->DataSize + GET_PAD_SIZE (Variable->DataSize));
    VariableSize = (UINT64) (UINTN) NextVariable - (UINT64) (UINTN) Variable;

    if (Variable->State == VAR_ADDED) {
      *RemainingVariableStorageSize -= VariableSize;
    }

    //
    // Go to the next one.
    //
    Variable = NextVariable;
  }

  return EFI_SUCCESS;
}
#endif

EFI_STATUS
EFIAPI
InitializeVariableStore (
  OUT EFI_PHYSICAL_ADDRESS  *VariableBase,
  OUT UINTN                 *LastVariableOffset
  )
/*++

Routine Description:
  This function initializes variable store

Arguments:

Returns:

--*/
{
  VARIABLE_STORE_HEADER *VariableStore;
  EFI_STATUS            Status;

  //
  // Allocate memory for volatile variable store
  //
  Status = gBS->AllocatePool (
                  EfiRuntimeServicesData,
                  VARIABLE_STORE_SIZE,
                  &VariableStore
                  );
  if (EFI_ERROR (Status)) {
    return Status;
  }

  EfiSetMem (VariableStore, VARIABLE_STORE_SIZE, 0xff);

  //
  // Variable Specific Data
  //
  *VariableBase             = (EFI_PHYSICAL_ADDRESS) (UINTN) VariableStore;
  *LastVariableOffset       = sizeof (VARIABLE_STORE_HEADER);

  VariableStore->Signature  = VARIABLE_STORE_SIGNATURE;
  VariableStore->Size       = VARIABLE_STORE_SIZE;
  VariableStore->Format     = VARIABLE_STORE_FORMATTED;
  VariableStore->State      = VARIABLE_STORE_HEALTHY;
  VariableStore->Reserved   = 0;
  VariableStore->Reserved1  = 0;

  return EFI_SUCCESS;
}

EFI_STATUS
EFIAPI
VariableCommonInitialize (
  IN EFI_HANDLE         ImageHandle,
  IN EFI_SYSTEM_TABLE   *SystemTable
  )
/*++

Routine Description:
  This function does common initialization for variable services

Arguments:

Returns:

--*/
{
  EFI_STATUS  Status;

  EfiInitializeRuntimeDriverLib (
    ImageHandle,
    SystemTable,
    VariableClassAddressChangeEvent
    );

  //
  // Allocate memory for mVariableModuleGlobal
  //
  Status = gBS->AllocatePool (
                  EfiRuntimeServicesData,
                  sizeof (ESAL_VARIABLE_GLOBAL),
                  &mVariableModuleGlobal
                  );
  if (EFI_ERROR (Status)) {
    EfiShutdownRuntimeDriverLib ();
    return Status;
  }
  //
  // Intialize volatile variable store
  //
  Status = InitializeVariableStore (
            &mVariableModuleGlobal->VariableBase[Physical].VolatileVariableBase,
            &mVariableModuleGlobal->VolatileLastVariableOffset
            );

  if (EFI_ERROR (Status)) {
    gBS->FreePool (mVariableModuleGlobal);
    EfiShutdownRuntimeDriverLib ();
    return Status;
  }
  //
  // Intialize non volatile variable store
  //
  Status = InitializeVariableStore (
            &mVariableModuleGlobal->VariableBase[Physical].NonVolatileVariableBase,
            &mVariableModuleGlobal->NonVolatileLastVariableOffset
            );
  if (EFI_ERROR (Status)) {
    gBS->FreePool ((VOID*) (UINTN) (mVariableModuleGlobal->VariableBase[Physical].VolatileVariableBase));
    gBS->FreePool (mVariableModuleGlobal);
    EfiShutdownRuntimeDriverLib ();
  }

  return Status;
}