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   SPDX-License-Identifier: BSD-2-Clause-Patent
   8
   9 **/
  10
  11 #ifndef __VARIABLE_LOCK_H__
  12 #define __VARIABLE_LOCK_H__
  13
  14 #define EDKII_VARIABLE_LOCK_PROTOCOL_GUID \
  15   { \
  16     0xcd3d0a05, 0x9e24, 0x437c, { 0xa8, 0x91, 0x1e, 0xe0, 0x53, 0xdb, 0x76, 0x38 } \
  17   }
  18
  19 typedef struct _EDKII_VARIABLE_LOCK_PROTOCOL EDKII_VARIABLE_LOCK_PROTOCOL;
  20
  21 /**
  22   Mark a variable that will become read-only after leaving the DXE phase of execution.
  23   Write request coming from SMM environment through EFI_SMM_VARIABLE_PROTOCOL is allowed.
  24
  25   @param[in] This          The EDKII_VARIABLE_LOCK_PROTOCOL instance.
  26   @param[in] VariableName  A pointer to the variable name that will be made read-only subsequently.
  27   @param[in] VendorGuid    A pointer to the vendor GUID that will be made read-only subsequently.
  28
  29   @retval EFI_SUCCESS           The variable specified by the VariableName and the VendorGuid was marked
  30                                 as pending to be read-only.
  31   @retval EFI_INVALID_PARAMETER VariableName or VendorGuid is NULL.
  32                                 Or VariableName is an empty string.
  33   @retval EFI_ACCESS_DENIED     EFI_END_OF_DXE_EVENT_GROUP_GUID or EFI_EVENT_GROUP_READY_TO_BOOT has
  34                                 already been signaled.
  35   @retval EFI_OUT_OF_RESOURCES  There is not enough resource to hold the lock request.
  36 **/
  37 typedef
  38 EFI_STATUS
  39 (EFIAPI *EDKII_VARIABLE_LOCK_PROTOCOL_REQUEST_TO_LOCK)(
  40   IN CONST EDKII_VARIABLE_LOCK_PROTOCOL *This,
  41   IN       CHAR16                       *VariableName,
  42   IN       EFI_GUID                     *VendorGuid
  43   );
  44
  45 ///
  46 /// Variable Lock Protocol is related to EDK II-specific implementation of variables
  47 /// and intended for use as a means to mark a variable read-only after the event
  48 /// EFI_END_OF_DXE_EVENT_GUID is signaled.
  49 ///
  50 struct _EDKII_VARIABLE_LOCK_PROTOCOL {
  51   EDKII_VARIABLE_LOCK_PROTOCOL_REQUEST_TO_LOCK    RequestToLock;
  52 };
  53
  54 extern EFI_GUID  gEdkiiVariableLockProtocolGuid;
  55
  56 #endif