MdeModulePkg/Include/Protocol/VariableLock.h

   1 /** @file
   2   Variable Lock Protocol is related to EDK II-specific implementation of variables
   3   and intended for use as a means to mark a variable read-only after the event
   4   EFI_END_OF_DXE_EVENT_GUID is signaled.
   5
   6   Copyright (c) 2013 - 2018, Intel Corporation. All rights reserved.<BR>
   7   This program and the accompanying materials
   8   are licensed and made available under the terms and conditions of the BSD License
   9   which accompanies this distribution.  The full text of the license may be found at
  10   http://opensource.org/licenses/bsd-license.php
  11
  12   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  13   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  14
  15 **/
  16
  17 #ifndef __VARIABLE_LOCK_H__
  18 #define __VARIABLE_LOCK_H__
  19
  20 #define EDKII_VARIABLE_LOCK_PROTOCOL_GUID \
  21   { \
  22     0xcd3d0a05, 0x9e24, 0x437c, { 0xa8, 0x91, 0x1e, 0xe0, 0x53, 0xdb, 0x76, 0x38 } \
  23   }
  24
  25 typedef struct _EDKII_VARIABLE_LOCK_PROTOCOL  EDKII_VARIABLE_LOCK_PROTOCOL;
  26
  27 /**
  28   Mark a variable that will become read-only after leaving the DXE phase of execution.
  29   Write request coming from SMM environment through EFI_SMM_VARIABLE_PROTOCOL is allowed.
  30
  31   @param[in] This          The EDKII_VARIABLE_LOCK_PROTOCOL instance.
  32   @param[in] VariableName  A pointer to the variable name that will be made read-only subsequently.
  33   @param[in] VendorGuid    A pointer to the vendor GUID that will be made read-only subsequently.
  34
  35   @retval EFI_SUCCESS           The variable specified by the VariableName and the VendorGuid was marked
  36                                 as pending to be read-only.
  37   @retval EFI_INVALID_PARAMETER VariableName or VendorGuid is NULL.
  38                                 Or VariableName is an empty string.
  39   @retval EFI_ACCESS_DENIED     EFI_END_OF_DXE_EVENT_GROUP_GUID or EFI_EVENT_GROUP_READY_TO_BOOT has
  40                                 already been signaled.
  41   @retval EFI_OUT_OF_RESOURCES  There is not enough resource to hold the lock request.
  42 **/
  43 typedef
  44 EFI_STATUS
  45 (EFIAPI * EDKII_VARIABLE_LOCK_PROTOCOL_REQUEST_TO_LOCK) (
  46   IN CONST EDKII_VARIABLE_LOCK_PROTOCOL *This,
  47   IN       CHAR16                       *VariableName,
  48   IN       EFI_GUID                     *VendorGuid
  49   );
  50
  51 ///
  52 /// Variable Lock Protocol is related to EDK II-specific implementation of variables
  53 /// and intended for use as a means to mark a variable read-only after the event
  54 /// EFI_END_OF_DXE_EVENT_GUID is signaled.
  55 ///
  56 struct _EDKII_VARIABLE_LOCK_PROTOCOL {
  57   EDKII_VARIABLE_LOCK_PROTOCOL_REQUEST_TO_LOCK RequestToLock;
  58 };
  59
  60 extern EFI_GUID gEdkiiVariableLockProtocolGuid;
  61
  62 #endif
  63