1*f439973dSWarner Losh /** @file 2*f439973dSWarner Losh GUID used for MemoryOverwriteRequestControl UEFI variable defined in 3*f439973dSWarner Losh TCG Platform Reset Attack Mitigation Specification 1.00. 4*f439973dSWarner Losh See http://trustedcomputinggroup.org for the latest specification 5*f439973dSWarner Losh 6*f439973dSWarner Losh The purpose of the MemoryOverwriteRequestControl UEFI variable is to give users (e.g., OS, loader) the ability to 7*f439973dSWarner Losh indicate to the platform that secrets are present in memory and that the platform firmware must clear memory upon 8*f439973dSWarner Losh a restart. The OS loader should not create the variable. Rather, the firmware is required to create it. 9*f439973dSWarner Losh 10*f439973dSWarner Losh Copyright (c) 2009 - 2018, Intel Corporation. All rights reserved.<BR> 11*f439973dSWarner Losh SPDX-License-Identifier: BSD-2-Clause-Patent 12*f439973dSWarner Losh 13*f439973dSWarner Losh **/ 14*f439973dSWarner Losh 15*f439973dSWarner Losh #ifndef _MEMORY_OVERWRITE_CONTROL_DATA_GUID_H_ 16*f439973dSWarner Losh #define _MEMORY_OVERWRITE_CONTROL_DATA_GUID_H_ 17*f439973dSWarner Losh 18*f439973dSWarner Losh #define MEMORY_ONLY_RESET_CONTROL_GUID \ 19*f439973dSWarner Losh { \ 20*f439973dSWarner Losh 0xe20939be, 0x32d4, 0x41be, {0xa1, 0x50, 0x89, 0x7f, 0x85, 0xd4, 0x98, 0x29} \ 21*f439973dSWarner Losh } 22*f439973dSWarner Losh 23*f439973dSWarner Losh /// 24*f439973dSWarner Losh /// Variable name is "MemoryOverwriteRequestControl" and it is a 1 byte unsigned value. 25*f439973dSWarner Losh /// The attributes should be: 26*f439973dSWarner Losh /// EFI_VARIABLE_NON_VOLATILE | 27*f439973dSWarner Losh /// EFI_VARIABLE_BOOTSERVICE_ACCESS | 28*f439973dSWarner Losh /// EFI_VARIABLE_RUNTIME_ACCESS 29*f439973dSWarner Losh /// 30*f439973dSWarner Losh #define MEMORY_OVERWRITE_REQUEST_VARIABLE_NAME L"MemoryOverwriteRequestControl" 31*f439973dSWarner Losh 32*f439973dSWarner Losh /// 33*f439973dSWarner Losh /// 0 = Firmware MUST clear the MOR bit 34*f439973dSWarner Losh /// 1 = Firmware MUST set the MOR bit 35*f439973dSWarner Losh /// 36*f439973dSWarner Losh #define MOR_CLEAR_MEMORY_BIT_MASK 0x01 37*f439973dSWarner Losh 38*f439973dSWarner Losh /// 39*f439973dSWarner Losh /// 0 = Firmware MAY autodetect a clean shutdown of the Static RTM OS. 40*f439973dSWarner Losh /// 1 = Firmware MUST NOT autodetect a clean shutdown of the Static RTM OS. 41*f439973dSWarner Losh /// 42*f439973dSWarner Losh #define MOR_DISABLEAUTODETECT_BIT_MASK 0x10 43*f439973dSWarner Losh 44*f439973dSWarner Losh /// 45*f439973dSWarner Losh /// MOR field bit offset 46*f439973dSWarner Losh /// 47*f439973dSWarner Losh #define MOR_CLEAR_MEMORY_BIT_OFFSET 0 48*f439973dSWarner Losh #define MOR_DISABLEAUTODETECT_BIT_OFFSET 4 49*f439973dSWarner Losh 50*f439973dSWarner Losh /** 51*f439973dSWarner Losh Return the ClearMemory bit value 0 or 1. 52*f439973dSWarner Losh 53*f439973dSWarner Losh @param mor 1 byte value that contains ClearMemory and DisableAutoDetect bit. 54*f439973dSWarner Losh 55*f439973dSWarner Losh @return ClearMemory bit value 56*f439973dSWarner Losh **/ 57*f439973dSWarner Losh #define MOR_CLEAR_MEMORY_VALUE(mor) (((UINT8)(mor) & MOR_CLEAR_MEMORY_BIT_MASK) >> MOR_CLEAR_MEMORY_BIT_OFFSET) 58*f439973dSWarner Losh 59*f439973dSWarner Losh /** 60*f439973dSWarner Losh Return the DisableAutoDetect bit value 0 or 1. 61*f439973dSWarner Losh 62*f439973dSWarner Losh @param mor 1 byte value that contains ClearMemory and DisableAutoDetect bit. 63*f439973dSWarner Losh 64*f439973dSWarner Losh @return DisableAutoDetect bit value 65*f439973dSWarner Losh **/ 66*f439973dSWarner Losh #define MOR_DISABLE_AUTO_DETECT_VALUE(mor) (((UINT8)(mor) & MOR_DISABLEAUTODETECT_BIT_MASK) >> MOR_DISABLEAUTODETECT_BIT_OFFSET) 67*f439973dSWarner Losh 68*f439973dSWarner Losh extern EFI_GUID gEfiMemoryOverwriteControlDataGuid; 69*f439973dSWarner Losh 70*f439973dSWarner Losh #endif 71