2 TCG MOR (Memory Overwrite Request) Lock Control support (DXE version).
4 This module clears MemoryOverwriteRequestControlLock variable to indicate
5 MOR lock control unsupported.
7 Copyright (c) 2016, Intel Corporation. All rights reserved.<BR>
8 This program and the accompanying materials
9 are licensed and made available under the terms and conditions of the BSD License
10 which accompanies this distribution. The full text of the license may be found at
11 http://opensource.org/licenses/bsd-license.php
13 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
14 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
19 #include <Guid/MemoryOverwriteControl.h>
20 #include <IndustryStandard/MemoryOverwriteRequestControlLock.h>
21 #include <Library/DebugLib.h>
22 #include <Library/BaseLib.h>
23 #include <Library/BaseMemoryLib.h>
26 extern EDKII_VARIABLE_LOCK_PROTOCOL mVariableLock
;
29 This service is an MOR/MorLock checker handler for the SetVariable().
31 @param[in] VariableName the name of the vendor's variable, as a
32 Null-Terminated Unicode String
33 @param[in] VendorGuid Unify identifier for vendor.
34 @param[in] Attributes Attributes bitmask to set for the variable.
35 @param[in] DataSize The size in bytes of Data-Buffer.
36 @param[in] Data Point to the content of the variable.
38 @retval EFI_SUCCESS The MOR/MorLock check pass, and Variable
39 driver can store the variable data.
40 @retval EFI_INVALID_PARAMETER The MOR/MorLock data or data size or
41 attributes is not allowed for MOR variable.
42 @retval EFI_ACCESS_DENIED The MOR/MorLock is locked.
43 @retval EFI_ALREADY_STARTED The MorLock variable is handled inside this
44 function. Variable driver can just return
48 SetVariableCheckHandlerMor (
49 IN CHAR16
*VariableName
,
50 IN EFI_GUID
*VendorGuid
,
57 // Just let it pass. No need provide protection for DXE version.
63 Initialization for MOR Control Lock.
65 @retval EFI_SUCCESS MorLock initialization success.
66 @return Others Some error occurs.
74 // Always clear variable to report unsupported to OS.
75 // The reason is that the DXE version is not proper to provide *protection*.
76 // BIOS should use SMM version variable driver to provide such capability.
78 VariableServiceSetVariable (
79 MEMORY_OVERWRITE_REQUEST_CONTROL_LOCK_NAME
,
80 &gEfiMemoryOverwriteRequestControlLockGuid
,
87 // Need set this variable to be read-only to prevent other module set it.
89 VariableLockRequestToLock (&mVariableLock
, MEMORY_OVERWRITE_REQUEST_CONTROL_LOCK_NAME
, &gEfiMemoryOverwriteRequestControlLockGuid
);
92 // The MOR variable can effectively improve platform security only when the
93 // MorLock variable protects the MOR variable. In turn MorLock cannot be made
94 // secure without SMM support in the platform firmware (see above).
96 // Thus, delete the MOR variable, should it exist for any reason (some OSes
97 // are known to create MOR unintentionally, in an attempt to set it), then
98 // also lock the MOR variable, in order to prevent other modules from
101 VariableServiceSetVariable (
102 MEMORY_OVERWRITE_REQUEST_VARIABLE_NAME
,
103 &gEfiMemoryOverwriteControlDataGuid
,
108 VariableLockRequestToLock (
110 MEMORY_OVERWRITE_REQUEST_VARIABLE_NAME
,
111 &gEfiMemoryOverwriteControlDataGuid
118 Delayed initialization for MOR Control Lock at EndOfDxe.
120 This function performs any operations queued by MorLockInit().
123 MorLockInitAtEndOfDxe (