/** @file | |
Execute Disable feature. | |
Copyright (c) 2017, Intel Corporation. All rights reserved.<BR> | |
This program and the accompanying materials | |
are licensed and made available under the terms and conditions of the BSD License | |
which accompanies this distribution. The full text of the license may be found at | |
http://opensource.org/licenses/bsd-license.php | |
THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, | |
WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED. | |
**/ | |
#include "CpuCommonFeatures.h" | |
/** | |
Detects if Execute Disable feature supported on current processor. | |
@param[in] ProcessorNumber The index of the CPU executing this function. | |
@param[in] CpuInfo A pointer to the REGISTER_CPU_FEATURE_INFORMATION | |
structure for the CPU executing this function. | |
@param[in] ConfigData A pointer to the configuration buffer returned | |
by CPU_FEATURE_GET_CONFIG_DATA. NULL if | |
CPU_FEATURE_GET_CONFIG_DATA was not provided in | |
RegisterCpuFeature(). | |
@retval TRUE Execute Disable feature is supported. | |
@retval FALSE Execute Disable feature is not supported. | |
@note This service could be called by BSP/APs. | |
**/ | |
BOOLEAN | |
EFIAPI | |
ExecuteDisableSupport ( | |
IN UINTN ProcessorNumber, | |
IN REGISTER_CPU_FEATURE_INFORMATION *CpuInfo, | |
IN VOID *ConfigData OPTIONAL | |
) | |
{ | |
UINT32 Eax; | |
CPUID_EXTENDED_CPU_SIG_EDX Edx; | |
AsmCpuid (CPUID_EXTENDED_FUNCTION, &Eax, NULL, NULL, NULL); | |
if (Eax <= CPUID_EXTENDED_FUNCTION) { | |
// | |
// Extended CPUID functions are not supported on this processor. | |
// | |
return FALSE; | |
} | |
AsmCpuid (CPUID_EXTENDED_CPU_SIG, NULL, NULL, NULL, &Edx.Uint32); | |
return (Edx.Bits.NX != 0); | |
} | |
/** | |
Initializes Execute Disable feature to specific state. | |
@param[in] ProcessorNumber The index of the CPU executing this function. | |
@param[in] CpuInfo A pointer to the REGISTER_CPU_FEATURE_INFORMATION | |
structure for the CPU executing this function. | |
@param[in] ConfigData A pointer to the configuration buffer returned | |
by CPU_FEATURE_GET_CONFIG_DATA. NULL if | |
CPU_FEATURE_GET_CONFIG_DATA was not provided in | |
RegisterCpuFeature(). | |
@param[in] State If TRUE, then the Execute Disable feature must be enabled. | |
If FALSE, then the Execute Disable feature must be disabled. | |
@retval RETURN_SUCCESS Execute Disable feature is initialized. | |
@note This service could be called by BSP only. | |
**/ | |
RETURN_STATUS | |
EFIAPI | |
ExecuteDisableInitialize ( | |
IN UINTN ProcessorNumber, | |
IN REGISTER_CPU_FEATURE_INFORMATION *CpuInfo, | |
IN VOID *ConfigData, OPTIONAL | |
IN BOOLEAN State | |
) | |
{ | |
CPU_REGISTER_TABLE_WRITE_FIELD ( | |
ProcessorNumber, | |
Msr, | |
MSR_IA32_EFER, | |
MSR_IA32_EFER_REGISTER, | |
Bits.NXE, | |
(State) ? 1 : 0 | |
); | |
return RETURN_SUCCESS; | |
} |