Subrata Banik | 20fe24b | 2021-12-09 02:46:38 +0530 | [diff] [blame] | 1 | /** @file |
| 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 |
| 5 | |
| 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. |
| 9 | |
| 10 | Copyright (c) 2009 - 2018, Intel Corporation. All rights reserved.<BR> |
| 11 | SPDX-License-Identifier: BSD-2-Clause-Patent |
| 12 | |
| 13 | **/ |
| 14 | |
| 15 | #ifndef _MEMORY_OVERWRITE_CONTROL_DATA_GUID_H_ |
| 16 | #define _MEMORY_OVERWRITE_CONTROL_DATA_GUID_H_ |
| 17 | |
| 18 | #define MEMORY_ONLY_RESET_CONTROL_GUID \ |
| 19 | { \ |
| 20 | 0xe20939be, 0x32d4, 0x41be, {0xa1, 0x50, 0x89, 0x7f, 0x85, 0xd4, 0x98, 0x29} \ |
| 21 | } |
| 22 | |
| 23 | /// |
| 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 |
| 29 | /// |
| 30 | #define MEMORY_OVERWRITE_REQUEST_VARIABLE_NAME L"MemoryOverwriteRequestControl" |
| 31 | |
| 32 | /// |
| 33 | /// 0 = Firmware MUST clear the MOR bit |
| 34 | /// 1 = Firmware MUST set the MOR bit |
| 35 | /// |
| 36 | #define MOR_CLEAR_MEMORY_BIT_MASK 0x01 |
| 37 | |
| 38 | /// |
| 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. |
| 41 | /// |
| 42 | #define MOR_DISABLEAUTODETECT_BIT_MASK 0x10 |
| 43 | |
| 44 | /// |
| 45 | /// MOR field bit offset |
| 46 | /// |
| 47 | #define MOR_CLEAR_MEMORY_BIT_OFFSET 0 |
| 48 | #define MOR_DISABLEAUTODETECT_BIT_OFFSET 4 |
| 49 | |
| 50 | /** |
| 51 | Return the ClearMemory bit value 0 or 1. |
| 52 | |
| 53 | @param mor 1 byte value that contains ClearMemory and DisableAutoDetect bit. |
| 54 | |
| 55 | @return ClearMemory bit value |
| 56 | **/ |
| 57 | #define MOR_CLEAR_MEMORY_VALUE(mor) (((UINT8)(mor) & MOR_CLEAR_MEMORY_BIT_MASK) >> MOR_CLEAR_MEMORY_BIT_OFFSET) |
| 58 | |
| 59 | /** |
| 60 | Return the DisableAutoDetect bit value 0 or 1. |
| 61 | |
| 62 | @param mor 1 byte value that contains ClearMemory and DisableAutoDetect bit. |
| 63 | |
| 64 | @return DisableAutoDetect bit value |
| 65 | **/ |
| 66 | #define MOR_DISABLE_AUTO_DETECT_VALUE(mor) (((UINT8)(mor) & MOR_DISABLEAUTODETECT_BIT_MASK) >> MOR_DISABLEAUTODETECT_BIT_OFFSET) |
| 67 | |
| 68 | extern EFI_GUID gEfiMemoryOverwriteControlDataGuid; |
| 69 | |
| 70 | #endif |