variable.c

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/*++

Copyright (c) 2004 - 2006, Intel Corporation                                                         
All rights reserved. This program and the accompanying materials                          
are licensed and made available under the terms and conditions of the BSD License         
which accompanies this distribution.  The full text of the license may be found at        
http://opensource.org/licenses/bsd-license.php                                            
                                                                                          
THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,                     
WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.             

Module Name:

  Variable.c

Abstract:

  Provide support functions for variable services.

--*/

#include "Variable.h"
#include "reclaim.h"
#include EFI_GUID_DEFINITION (FlashMapHob)

//
// Don't use module globals after the SetVirtualAddress map is signaled
//
ESAL_VARIABLE_GLOBAL  *mVariableModuleGlobal;

UINT32
EFIAPI
ArrayLength (
  IN CHAR16 *String
  )
/*++

Routine Description:

  Determine the length of null terminated char16 array.

Arguments:

  String    Null-terminated CHAR16 array pointer.

Returns:

  UINT32    Number of bytes in the string, including the double NULL at the end;

--*/
{
  UINT32  Count;

  if (NULL == String) {
    return 0;
  }

  Count = 0;

  while (0 != String[Count]) {
    Count++;
  }

  return (Count * 2) + 2;
}

BOOLEAN
EFIAPI
IsValidVariableHeader (
  IN  VARIABLE_HEADER   *Variable
  )
/*++

Routine Description:

  This code checks if variable header is valid or not.

Arguments:
  Variable              Pointer to the Variable Header.

Returns:
  TRUE            Variable header is valid.
  FALSE           Variable header is not valid.

--*/
{
  if (Variable == NULL ||
      Variable->StartId != VARIABLE_DATA ||
      (sizeof (VARIABLE_HEADER) + Variable->NameSize + Variable->DataSize) > MAX_VARIABLE_SIZE
      ) {
    return FALSE;
  }

  return TRUE;
}

EFI_STATUS
UpdateVariableStore (
  IN  VARIABLE_GLOBAL         *Global,
  IN  BOOLEAN                 Volatile,
  IN  BOOLEAN                 SetByIndex,
  IN  UINTN                   Instance,
  IN  UINTN                   DataPtrIndex,
  IN  UINT32                  DataSize,
  IN  UINT8                   *Buffer
  )
/*++

Routine Description:

  This function writes data to the FWH at the correct LBA even if the LBAs
  are fragmented.

Arguments:

  Global            - Pointer to VARAIBLE_GLOBAL structure
  Volatile          - If the Variable is Volatile or Non-Volatile
  SetByIndex        - TRUE: Target pointer is given as index
                      FALSE: Target pointer is absolute
  Instance          - Instance of FV Block services
  DataPtrIndex      - Pointer to the Data from the end of VARIABLE_STORE_HEADER
                      structure
  DataSize          - Size of data to be written.
  Buffer            - Pointer to the buffer from which data is written

Returns:

  EFI_INVALID_PARAMETER   - Parameters not valid
  EFI_SUCCESS             - Variable store successfully updated

--*/
{
  EFI_FV_BLOCK_MAP_ENTRY      *PtrBlockMapEntry;
  UINTN                       BlockIndex2;
  UINTN                       LinearOffset;
  UINTN                       CurrWriteSize;
  UINTN                       CurrWritePtr;
  UINT8                       *CurrBuffer;
  EFI_LBA                     LbaNumber;
  UINTN                       Size;
  EFI_FIRMWARE_VOLUME_HEADER  *FwVolHeader;
  VARIABLE_STORE_HEADER       *VolatileBase;
  EFI_PHYSICAL_ADDRESS        FvVolHdr;
  EFI_PHYSICAL_ADDRESS        DataPtr;
  EFI_STATUS                  Status;

  FwVolHeader = NULL;
  DataPtr     = DataPtrIndex;

  //
  // Check if the Data is Volatile
  //
  if (!Volatile) {
    EfiFvbGetPhysicalAddress (Instance, &FvVolHdr);
    FwVolHeader = (EFI_FIRMWARE_VOLUME_HEADER *) ((UINTN) FvVolHdr);
    //
    // Data Pointer should point to the actual Address where data is to be
    // written
    //
    if (SetByIndex) {
      DataPtr += Global->NonVolatileVariableBase;
    }

    if ((DataPtr + DataSize) >= ((EFI_PHYSICAL_ADDRESS) (UINTN) ((UINT8 *) FwVolHeader + FwVolHeader->FvLength))) {
      return EFI_INVALID_PARAMETER;
    }
  } else {
    //
    // Data Pointer should point to the actual Address where data is to be
    // written
    //
    VolatileBase = (VARIABLE_STORE_HEADER *) ((UINTN) Global->VolatileVariableBase);
    if (SetByIndex) {
      DataPtr += Global->VolatileVariableBase;
    }

    if ((DataPtr + DataSize) >= ((UINTN) ((UINT8 *) VolatileBase + VolatileBase->Size))) {
      return EFI_INVALID_PARAMETER;
    }
    
    //
    // If Volatile Variable just do a simple mem copy.
    //    
    EfiCopyMem ((UINT8 *) ((UINTN) DataPtr), Buffer, DataSize);
    return EFI_SUCCESS;
  }
  
  //
  // If we are here we are dealing with Non-Volatile Variables
  //
  LinearOffset  = (UINTN) FwVolHeader;
  CurrWritePtr  = (UINTN) DataPtr;
  CurrWriteSize = DataSize;
  CurrBuffer    = Buffer;
  LbaNumber     = 0;

  if (CurrWritePtr < LinearOffset) {
    return EFI_INVALID_PARAMETER;
  }

  for (PtrBlockMapEntry = FwVolHeader->FvBlockMap; PtrBlockMapEntry->NumBlocks != 0; PtrBlockMapEntry++) {
    for (BlockIndex2 = 0; BlockIndex2 < PtrBlockMapEntry->NumBlocks; BlockIndex2++) {
      //
      // Check to see if the Variable Writes are spanning through multiple
      // blocks.
      //
      if ((CurrWritePtr >= LinearOffset) && (CurrWritePtr < LinearOffset + PtrBlockMapEntry->BlockLength)) {
        if ((CurrWritePtr + CurrWriteSize) <= (LinearOffset + PtrBlockMapEntry->BlockLength)) {
          Status = EfiFvbWriteBlock (
                     Instance,
                     LbaNumber,
                     (UINTN) (CurrWritePtr - LinearOffset),
                     &CurrWriteSize,
                     CurrBuffer
                     );
            return Status;
        } else {
          Size = (UINT32) (LinearOffset + PtrBlockMapEntry->BlockLength - CurrWritePtr);
          Status = EfiFvbWriteBlock (
                     Instance,
                     LbaNumber,
                     (UINTN) (CurrWritePtr - LinearOffset),
                     &Size,
                     CurrBuffer
                     );
          if (EFI_ERROR (Status)) {
            return Status;
          }

          CurrWritePtr  = LinearOffset + PtrBlockMapEntry->BlockLength;
          CurrBuffer    = CurrBuffer + Size;
          CurrWriteSize = CurrWriteSize - Size;
        }
      }

      LinearOffset += PtrBlockMapEntry->BlockLength;
      LbaNumber++;
    }
  }

  return EFI_SUCCESS;
}

VARIABLE_STORE_STATUS
EFIAPI
GetVariableStoreStatus (
  IN VARIABLE_STORE_HEADER *VarStoreHeader
  )
/*++

Routine Description:

  This code gets the current status of Variable Store.

Arguments:

  VarStoreHeader  Pointer to the Variable Store Header.

Returns:

  EfiRaw        Variable store status is raw
  EfiValid      Variable store status is valid
  EfiInvalid    Variable store status is invalid  

--*/
{
  if (VarStoreHeader->Signature == VARIABLE_STORE_SIGNATURE &&
      VarStoreHeader->Format == VARIABLE_STORE_FORMATTED &&
      VarStoreHeader->State == VARIABLE_STORE_HEALTHY
      ) {

    return EfiValid;
  } else if (VarStoreHeader->Signature == 0xffffffff &&
           VarStoreHeader->Size == 0xffffffff &&
           VarStoreHeader->Format == 0xff &&
           VarStoreHeader->State == 0xff
          ) {

    return EfiRaw;
  } else {
    return EfiInvalid;
  }
}

UINT8 *
EFIAPI
GetVariableDataPtr (
  IN  VARIABLE_HEADER   *Variable
  )
/*++

Routine Description:

  This code gets the pointer to the variable data.

Arguments:

  Variable            Pointer to the Variable Header.

Returns:

  UINT8*              Pointer to Variable Data

--*/
{
  //
  // Be careful about pad size for alignment
  //
  return (UINT8 *) ((UINTN) GET_VARIABLE_NAME_PTR (Variable) + Variable->NameSize + GET_PAD_SIZE (Variable->NameSize));
}

VARIABLE_HEADER *
EFIAPI
GetNextVariablePtr (
  IN  VARIABLE_HEADER   *Variable
  )
/*++

Routine Description:

  This code gets the pointer to the next variable header.

Arguments:

  Variable              Pointer to the Variable Header.

Returns:

  VARIABLE_HEADER*      Pointer to next variable header.

--*/
{
  if (!IsValidVariableHeader (Variable)) {
    return NULL;
  }
  //
  // Be careful about pad size for alignment
  //
  return (VARIABLE_HEADER *) ((UINTN) GetVariableDataPtr (Variable) + Variable->DataSize + GET_PAD_SIZE (Variable->DataSize));
}

VARIABLE_HEADER *
EFIAPI
GetEndPointer (
  IN VARIABLE_STORE_HEADER       *VarStoreHeader
  )
/*++

Routine Description:

  This code gets the pointer to the last variable memory pointer byte

Arguments:

  VarStoreHeader        Pointer to the Variable Store Header.

Returns:

  VARIABLE_HEADER*      Pointer to last unavailable Variable Header

--*/
{
  //
  // The end of variable store
  //
  return (VARIABLE_HEADER *) ((UINTN) VarStoreHeader + VarStoreHeader->Size);
}

EFI_STATUS
EFIAPI
Reclaim (
  IN  EFI_PHYSICAL_ADDRESS  VariableBase,
  OUT UINTN                 *LastVariableOffset,
  IN  BOOLEAN               IsVolatile,
  IN  VARIABLE_HEADER       *CurrentVariable OPTIONAL
  )
/*++

Routine Description:

  Variable store garbage collection and reclaim operation

Arguments:

  VariableBase                Base address of variable store
  LastVariableOffset          Offset of last variable
  IsVolatile                  The variable store is volatile or not,
                              if it is non-volatile, need FTW
  CurrentVairable             If it is not NULL, it means not to process
                              current variable for Reclaim.

Returns:

  EFI STATUS

--*/
{
  VARIABLE_HEADER       *Variable;
  VARIABLE_HEADER       *NextVariable;
  VARIABLE_STORE_HEADER *VariableStoreHeader;
  UINT8                 *ValidBuffer;
  UINTN                 ValidBufferSize;
  UINTN                 VariableSize;
  UINT8                 *CurrPtr;
  EFI_STATUS            Status;

  VariableStoreHeader = (VARIABLE_STORE_HEADER *) ((UINTN) VariableBase);

  //
  // Start Pointers for the variable.
  //
  Variable        = (VARIABLE_HEADER *) (VariableStoreHeader + 1);

  ValidBufferSize = sizeof (VARIABLE_STORE_HEADER);

  while (IsValidVariableHeader (Variable)) {
    NextVariable = GetNextVariablePtr (Variable);
    if ((Variable->State == VAR_ADDED) ||
        ((Variable != CurrentVariable) &&
         (Variable->State == (VAR_ADDED & VAR_IN_DELETED_TRANSITION)))) {
      VariableSize = (UINTN) NextVariable - (UINTN) Variable;
      ValidBufferSize += VariableSize;
    }

    Variable = NextVariable;
  }

  Status = gBS->AllocatePool (
                  EfiBootServicesData,
                  ValidBufferSize,
                  &ValidBuffer
                  );
  if (EFI_ERROR (Status)) {
    return Status;
  }

  EfiSetMem (ValidBuffer, ValidBufferSize, 0xff);

  CurrPtr = ValidBuffer;

  //
  // Copy variable store header
  //
  EfiCopyMem (CurrPtr, VariableStoreHeader, sizeof (VARIABLE_STORE_HEADER));
  CurrPtr += sizeof (VARIABLE_STORE_HEADER);

  //
  // Start Pointers for the variable.
  //
  Variable = (VARIABLE_HEADER *) (VariableStoreHeader + 1);

  while (IsValidVariableHeader (Variable)) {
    NextVariable = GetNextVariablePtr (Variable);
    if ((Variable->State == VAR_ADDED) ||
        ((Variable != CurrentVariable) &&
         (Variable->State == (VAR_ADDED & VAR_IN_DELETED_TRANSITION)))) {
      VariableSize = (UINTN) NextVariable - (UINTN) Variable;
      EfiCopyMem (CurrPtr, (UINT8 *) Variable, VariableSize);
      //
      // Mark all variable as VAR_ADDED
      //
      ((VARIABLE_HEADER *)CurrPtr)->State = VAR_ADDED;
      CurrPtr += VariableSize;
    }

    Variable = NextVariable;
  }

  if (IsVolatile) {
    //
    // If volatile variable store, just copy valid buffer
    //
    EfiSetMem ((UINT8 *) (UINTN) VariableBase, VariableStoreHeader->Size, 0xff);
    EfiCopyMem ((UINT8 *) (UINTN) VariableBase, ValidBuffer, ValidBufferSize);
    *LastVariableOffset = ValidBufferSize;
    Status              = EFI_SUCCESS;
  } else {
    //
    // If non-volatile variable store, perform FTW here.
    //
    Status = FtwVariableSpace (
              VariableBase,
              ValidBuffer,
              ValidBufferSize
              );
    if (!EFI_ERROR (Status)) {
      *LastVariableOffset = ValidBufferSize;
    }
  }

  gBS->FreePool (ValidBuffer);

  if (EFI_ERROR (Status)) {
    *LastVariableOffset = 0;
  }

  return Status;
}

EFI_STATUS
EFIAPI
FindVariable (
  IN  CHAR16                  *VariableName,
  IN  EFI_GUID                *VendorGuid,
  OUT VARIABLE_POINTER_TRACK  *PtrTrack,
  IN  VARIABLE_GLOBAL         *Global
  )
/*++

Routine Description:

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

Arguments: