2 GUID used for MemoryOverwriteRequestControl UEFI variable defined in
3 TCG Platform Reset Attack Mitigation Specification 1.00.
4 See http://trustedcomputinggroup.org for the latest specification
6 The purpose of the MemoryOverwriteRequestControl UEFI variable is to give users (e.g., OS, loader) the ability to
7 indicate to the platform that secrets are present in memory and that the platform firmware must clear memory upon
8 a restart. The OS loader should not create the variable. Rather, the firmware is required to create it.
10 Copyright (c) 2009 - 2018, Intel Corporation. All rights reserved.<BR>
11 SPDX-License-Identifier: BSD-2-Clause-Patent
15 #ifndef _MEMORY_OVERWRITE_CONTROL_DATA_GUID_H_
16 #define _MEMORY_OVERWRITE_CONTROL_DATA_GUID_H_
18 #define MEMORY_ONLY_RESET_CONTROL_GUID \
20 0xe20939be, 0x32d4, 0x41be, {0xa1, 0x50, 0x89, 0x7f, 0x85, 0xd4, 0x98, 0x29} \
24 /// Variable name is "MemoryOverwriteRequestControl" and it is a 1 byte unsigned value.
25 /// The attributes should be:
26 /// EFI_VARIABLE_NON_VOLATILE |
27 /// EFI_VARIABLE_BOOTSERVICE_ACCESS |
28 /// EFI_VARIABLE_RUNTIME_ACCESS
30 #define MEMORY_OVERWRITE_REQUEST_VARIABLE_NAME L"MemoryOverwriteRequestControl"
33 /// 0 = Firmware MUST clear the MOR bit
34 /// 1 = Firmware MUST set the MOR bit
36 #define MOR_CLEAR_MEMORY_BIT_MASK 0x01
39 /// 0 = Firmware MAY autodetect a clean shutdown of the Static RTM OS.
40 /// 1 = Firmware MUST NOT autodetect a clean shutdown of the Static RTM OS.
42 #define MOR_DISABLEAUTODETECT_BIT_MASK 0x10
45 /// MOR field bit offset
47 #define MOR_CLEAR_MEMORY_BIT_OFFSET 0
48 #define MOR_DISABLEAUTODETECT_BIT_OFFSET 4
51 Return the ClearMemory bit value 0 or 1.
53 @param mor 1 byte value that contains ClearMemory and DisableAutoDetect bit.
55 @return ClearMemory bit value
57 #define MOR_CLEAR_MEMORY_VALUE(mor) (((UINT8)(mor) & MOR_CLEAR_MEMORY_BIT_MASK) >> MOR_CLEAR_MEMORY_BIT_OFFSET)
60 Return the DisableAutoDetect bit value 0 or 1.
62 @param mor 1 byte value that contains ClearMemory and DisableAutoDetect bit.
64 @return DisableAutoDetect bit value
66 #define MOR_DISABLE_AUTO_DETECT_VALUE(mor) (((UINT8)(mor) & MOR_DISABLEAUTODETECT_BIT_MASK) >> MOR_DISABLEAUTODETECT_BIT_OFFSET)
68 extern EFI_GUID gEfiMemoryOverwriteControlDataGuid
;