audk/IntelFrameworkPkg/Library/FrameworkIfrSupportLib/IfrVariable.c

/** @file
  Variable/Map manipulations routines
  
Copyright (c) 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.             

**/

#include "IfrSupportLibInternal.h"

/**
  Extracts a variable form a Pack.

  @param Pack - List of variables
  @param Name - Name of the variable/map
  @param Guid - GUID of the variable/map
  @param Id   - The index of the variable/map to retrieve
  @param Var  - Pointer to the variable/map
  @param Size - Size of the variable/map in bytes
**/
VOID
EfiLibHiiVariablePackGetMap (
  IN    EFI_HII_VARIABLE_PACK       *Pack,  
  OUT   CHAR16                      **Name,  OPTIONAL
  OUT   EFI_GUID                    **Guid,  OPTIONAL
  OUT   UINT16                      *Id,     OPTIONAL
  OUT   VOID                        **Var,   OPTIONAL
  OUT   UINTN                       *Size    OPTIONAL
  )

{
  if (NULL != Name) {
    *Name = (VOID *) (Pack + 1);
  }
    
  if (NULL != Guid) { 
    *Guid = (EFI_GUID *)(UINTN)&Pack->VariableGuid;
  }
    
    
  if (NULL != Id) {
    *Id   = Pack->VariableId;
  }
    
  if (NULL != Var) {
    *Var  = (VOID *) ((CHAR8 *) (Pack + 1) + Pack->VariableNameLength);
  }
    
  if (NULL != Size) {
    *Size = Pack->Header.Length - sizeof (*Pack) - Pack->VariableNameLength;
  }
}

/**
  Finds a count of the variables/maps in the List.

  @param List - List of variables

  @return The number of map count.
**/
UINTN
EfiLibHiiVariablePackListGetMapCnt (
  IN    EFI_HII_VARIABLE_PACK_LIST   *List
  )
{
  UINTN   Cnt = 0;
  while (NULL != List) {
    Cnt++;
    List = List->NextVariablePack;
  }
  return Cnt;
}

/**
  Will iterate all variable/maps as appearing 
  in List and for each, it will call the Callback.

  @param List     - List of variables
  @param Callback - Routine to be called for each iterated variable.

**/
VOID
EfiLibHiiVariablePackListForEachVar (
  IN    EFI_HII_VARIABLE_PACK_LIST               *List,
  IN    EFI_LIB_HII_VARIABLE_PACK_LIST_CALLBACK  *Callback
  )


{
  CHAR16    *MapName;
  EFI_GUID  *MapGuid;
  UINT16    MapId;
  VOID      *Map;
  UINTN     MapSize;

  while (NULL != List) {
    EfiLibHiiVariablePackGetMap (List->VariablePack, &MapName, &MapGuid, &MapId, &Map, &MapSize);
    //
    // call the callback
    //
    Callback (MapName, MapGuid, MapId, Map, MapSize); 
    List = List->NextVariablePack;
  }
}

/**
  Finds a variable form List given 
  the order number as appears in the List.

  @param Idx  - The index of the variable/map to retrieve
  @param List - List of variables
  @param Name - Name of the variable/map
  @param Guid - GUID of the variable/map
  @param Id   - Id of the variable/map
  @param Var  - Pointer to the variable/map
  @param Size - Size of the variable/map in bytes

  @return EFI_SUCCESS   - Variable is found, OUT parameters are valid
  @return EFI_NOT_FOUND - Variable is not found, OUT parameters are not valid
**/
EFI_STATUS
EfiLibHiiVariablePackListGetMapByIdx (
  IN    UINTN                       Idx,  
  IN    EFI_HII_VARIABLE_PACK_LIST  *List,  
  OUT   CHAR16                      **Name,  OPTIONAL
  OUT   EFI_GUID                    **Guid,  OPTIONAL
  OUT   UINT16                      *Id,     OPTIONAL
  OUT   VOID                        **Var,
  OUT   UINTN                       *Size
  )


{
  CHAR16     *MapName;
  EFI_GUID   *MapGuid;
  UINT16     MapId;
  VOID       *Map;
  UINTN      MapSize;

  while (NULL != List) {
    EfiLibHiiVariablePackGetMap (List->VariablePack, &MapName, &MapGuid, &MapId, &Map, &MapSize);
    if (0 == Idx--) {
      *Var  = Map;
      *Size = MapSize;

      if (NULL != Name) {
        *Name = MapName;
      }

      if (NULL != Guid) {
        *Guid = MapGuid;
      }
        
      if (NULL != Id) {
        *Id   = MapId;
      }
        
      return EFI_SUCCESS; // Map found
    }
    List = List->NextVariablePack;
  }
  //
  // If here, the map is not found
  //
  return EFI_NOT_FOUND; 
}

/**
  Finds a variable form List given the 
  order number as appears in the List.

  @param Id   - The ID of the variable/map to retrieve
  @param List - List of variables
  @param Name - Name of the variable/map
  @param Guid - GUID of the variable/map
  @param Var  - Pointer to the variable/map
  @param Size - Size of the variable/map in bytes

  @retval EFI_SUCCESS   - Variable is found, OUT parameters are valid
  @retval EFI_NOT_FOUND - Variable is not found, OUT parameters are not valid

**/
EFI_STATUS
EfiLibHiiVariablePackListGetMapById (
  IN    UINT16                        Id,  
  IN    EFI_HII_VARIABLE_PACK_LIST    *List,
  OUT   CHAR16                        **Name,  OPTIONAL
  OUT   EFI_GUID                      **Guid,  OPTIONAL
  OUT   VOID                          **Var,
  OUT   UINTN                         *Size
  )
{ 
  CHAR16    *MapName;
  EFI_GUID  *MapGuid;
  UINT16    MapId;
  VOID      *Map;
  UINTN     MapSize;

  while (NULL != List) {
    EfiLibHiiVariablePackGetMap (List->VariablePack, &MapName, &MapGuid, &MapId, &Map, &MapSize);
    if (MapId == Id) {
      *Var  = Map;
      *Size = MapSize;
      if (NULL != Name) {
         *Name = MapName;
      }
      if (NULL != Guid) {
        *Guid = MapGuid;
      }
      //
      // Map found
      //
      return EFI_SUCCESS; 
    }
    List = List->NextVariablePack;
  }
  //
  // If here, the map is not found
  //
  return EFI_NOT_FOUND; 
}

/**
  Finds a variable form EFI_HII_VARIABLE_PACK_LIST given name and GUID.

  @param List - List of variables
  @param Name - Name of the variable/map to be found
  @param Guid - GUID of the variable/map to be found
  @param Id   - Id of the variable/map to be found
  @param Var  - Pointer to the variable/map found
  @param Size - Size of the variable/map in bytes found

  @retval EFI_SUCCESS   - variable is found, OUT parameters are valid
  @retval EFI_NOT_FOUND - variable is not found, OUT parameters are not valid
**/
EFI_STATUS
EfiLibHiiVariablePackListGetMap (
  IN    EFI_HII_VARIABLE_PACK_LIST   *List,
  IN    CHAR16                       *Name,
  IN    EFI_GUID                     *Guid,
  OUT   UINT16                       *Id,
  OUT   VOID                         **Var, 
  OUT   UINTN                        *Size
  )
{ 
  VOID      *Map;
  UINTN     MapSize;
  UINT16    MapId;
  CHAR16    *MapName;
  EFI_GUID  *MapGuid;

  while (NULL != List) {
    EfiLibHiiVariablePackGetMap (List->VariablePack, &MapName, &MapGuid, &MapId, &Map, &MapSize);
    if ((0 == StrCmp (Name, MapName)) && CompareGuid (Guid, MapGuid)) {
      *Id   = MapId;
      *Var  = Map;
      *Size = MapSize;
      return EFI_SUCCESS;
    }
    List = List->NextVariablePack;
  }
  //
  // If here, the map is not found
  //
  return EFI_NOT_FOUND;
}

/**
  Finds out if a variable of specific Name/Guid/Size exists in NV. 
  If it does, it will retrieve it into the Var. 

  @param Name  Parameters of the variable to retrieve. Must match exactly.
  @param Guid  Parameters of the variable to retrieve. Must match exactly.
  @param Size  Parameters of the variable to retrieve. Must match exactly.
  @param Var   Variable will be retrieved into buffer pointed by this pointer.
               If pointing to NULL, the buffer will be allocated. Caller is responsible for releasing the buffer.

  @retval EFI_SUCCESS    - The variable of exact Name/Guid/Size parameters was retrieved and written to Var.
  @retval EFI_NOT_FOUND  - The variable of this Name/Guid was not found in the NV.
  @retval EFI_LOAD_ERROR - The variable in the NV was of different size, or NV API returned error.

**/
EFI_STATUS
EfiLibHiiVariableRetrieveFromNv (
  IN  CHAR16                 *Name,
  IN  EFI_GUID               *Guid,
  IN  UINTN                   Size,
  OUT VOID                  **Var
  )

{
  EFI_STATUS                  Status;
  UINTN                       SizeNv;

  //
  // Test for existence of the variable.
  //
  SizeNv = 0;
  Status = gRT->GetVariable (Name, Guid, NULL, &SizeNv, NULL);
  if (EFI_BUFFER_TOO_SMALL != Status) {
    ASSERT (EFI_SUCCESS != Status);
    return EFI_NOT_FOUND;
  }
  if (SizeNv != Size) {
    //
    // The variable is considered corrupt, as it has different size from expected.
    //
    return EFI_LOAD_ERROR; 
  }

  if (NULL == *Var) {
    *Var = AllocatePool (Size);
    ASSERT (NULL != *Var);
  }
  SizeNv = Size;
  //
  // Final read into the Var
  //
  Status = gRT->GetVariable (Name, Guid, NULL, &SizeNv, *Var); 
  //
  // No tolerance for random failures. Such behavior is undetermined and not validated.
  //
  ASSERT_EFI_ERROR (Status); 
  ASSERT (SizeNv == Size);
  return EFI_SUCCESS;
}

/**
  Overrrides the variable with NV data if found.
  But it only does it if the Name ends with specified Suffix.
  For example, if Suffix="MyOverride" and the Name="XyzSetupMyOverride",
  the Suffix matches the end of Name, so the variable will be loaded from NV
  provided the variable exists and the GUID and Size matches.

  @param Suffix             Suffix the Name should end with.
  @param Name, Guid, Size   Parameters of the variable to retrieve. Must match exactly.
  @param Var                Variable will be retrieved into this buffer.
                            Caller is responsible for providing storage of exactly Size size in bytes.

  @retval EFI_SUCCESS           - The variable was overriden with NV variable of same Name/Guid/Size.
  @retval EFI_INVALID_PARAMETER - The name of the variable does not end with <Suffix>.
  @retval EFI_NOT_FOUND         - The variable of this Name/Guid was not found in the NV.
  @retval EFI_LOAD_ERROR        - The variable in the NV was of different size, or NV API returned error.
**/
EFI_STATUS
EfiLibHiiVariableOverrideIfSuffix (
  IN  CHAR16                 *Suffix,
  IN  CHAR16                 *Name,
  IN  EFI_GUID               *Guid,
  IN  UINTN                   Size,
  OUT VOID                   *Var
  )  
{
  UINTN         StrLength;
  UINTN         StrLenSuffix;

  StrLength       = StrLen (Name);
  StrLenSuffix    = StrLen (Suffix);
  if ((StrLength <= StrLenSuffix) || (0 != StrCmp (Suffix, &Name[StrLength - StrLenSuffix]))) {
    //
    // Not ending with <Suffix>.
    //
    return EFI_INVALID_PARAMETER; 
  }
  return EfiLibHiiVariableRetrieveFromNv (Name, Guid, Size, &Var);
}

/**
  Overrrides the variable with NV data if found.
  But it only does it if the NV contains the same variable with Name is appended with Suffix.  
  For example, if Suffix="MyOverride" and the Name="XyzSetup",
  the Suffix will be appended to the end of Name, and the variable with Name="XyzSetupMyOverride"
  will be loaded from NV provided the variable exists and the GUID and Size matches.

  @param Suffix            Suffix the variable will be appended with.
  @param Name, Guid, Size  Parameters of the variable to retrieve. Must match exactly.
  @param Var               Variable will be retrieved into this buffer.
                           Caller is responsible for providing storage of exactly Size size in bytes.

  @retval EFI_SUCCESS    - The variable was overriden with NV variable of same Name/Guid/Size.
  @retval EFI_NOT_FOUND  - The variable of this Name/Guid was not found in the NV.
  @retval EFI_LOAD_ERROR - The variable in the NV was of different size, or NV API returned error.

--*/
EFI_STATUS
EfiLibHiiVariableOverrideBySuffix (
  IN  CHAR16                 *Suffix,
  IN  CHAR16                 *Name,
  IN  EFI_GUID               *Guid,
  IN  UINTN                   Size,
  OUT VOID                   *Var
  ) 

{
  EFI_STATUS    Status;
  CHAR16       *NameSuffixed;
  UINTN         NameLength;
  UINTN         SuffixLength;

  //
  // enough to concatenate both strings.
  //
  NameLength   = StrLen (Name);
  SuffixLength = StrLen (Suffix);
  NameSuffixed = AllocateZeroPool ((NameLength + SuffixLength + 1) * sizeof (CHAR16)); 
  
  StrCpy (NameSuffixed, Name);
  StrCat (NameSuffixed, Suffix);
  
  Status = EfiLibHiiVariableRetrieveFromNv (NameSuffixed, Guid, Size, &Var);
  gBS->FreePool (NameSuffixed);
  
  return Status;
}