/** @file | |
The CPU specific programming for PiSmmCpuDxeSmm module. | |
Copyright (c) 2010 - 2016, 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 <PiSmm.h> | |
#include <Library/SmmCpuFeaturesLib.h> | |
#include <Library/BaseLib.h> | |
#include <Library/MtrrLib.h> | |
#include <Library/PcdLib.h> | |
#include <Library/MemoryAllocationLib.h> | |
#include <Library/DebugLib.h> | |
#include <Register/Cpuid.h> | |
#include <Register/SmramSaveStateMap.h> | |
// | |
// Machine Specific Registers (MSRs) | |
// | |
#define SMM_FEATURES_LIB_IA32_MTRR_CAP 0x0FE | |
#define SMM_FEATURES_LIB_IA32_FEATURE_CONTROL 0x03A | |
#define SMM_FEATURES_LIB_IA32_SMRR_PHYSBASE 0x1F2 | |
#define SMM_FEATURES_LIB_IA32_SMRR_PHYSMASK 0x1F3 | |
#define SMM_FEATURES_LIB_IA32_CORE_SMRR_PHYSBASE 0x0A0 | |
#define SMM_FEATURES_LIB_IA32_CORE_SMRR_PHYSMASK 0x0A1 | |
#define EFI_MSR_SMRR_MASK 0xFFFFF000 | |
#define EFI_MSR_SMRR_PHYS_MASK_VALID BIT11 | |
#define SMM_FEATURES_LIB_SMM_FEATURE_CONTROL 0x4E0 | |
// | |
// MSRs required for configuration of SMM Code Access Check | |
// | |
#define SMM_FEATURES_LIB_IA32_MCA_CAP 0x17D | |
#define SMM_CODE_ACCESS_CHK_BIT BIT58 | |
/** | |
Internal worker function that is called to complete CPU initialization at the | |
end of SmmCpuFeaturesInitializeProcessor(). | |
**/ | |
VOID | |
FinishSmmCpuFeaturesInitializeProcessor ( | |
VOID | |
); | |
// | |
// Set default value to assume SMRR is not supported | |
// | |
BOOLEAN mSmrrSupported = FALSE; | |
// | |
// Set default value to assume MSR_SMM_FEATURE_CONTROL is not supported | |
// | |
BOOLEAN mSmmFeatureControlSupported = FALSE; | |
// | |
// Set default value to assume IA-32 Architectural MSRs are used | |
// | |
UINT32 mSmrrPhysBaseMsr = SMM_FEATURES_LIB_IA32_SMRR_PHYSBASE; | |
UINT32 mSmrrPhysMaskMsr = SMM_FEATURES_LIB_IA32_SMRR_PHYSMASK; | |
// | |
// Set default value to assume MTRRs need to be configured on each SMI | |
// | |
BOOLEAN mNeedConfigureMtrrs = TRUE; | |
// | |
// Array for state of SMRR enable on all CPUs | |
// | |
BOOLEAN *mSmrrEnabled; | |
/** | |
The constructor function | |
@param[in] ImageHandle The firmware allocated handle for the EFI image. | |
@param[in] SystemTable A pointer to the EFI System Table. | |
@retval EFI_SUCCESS The constructor always returns EFI_SUCCESS. | |
**/ | |
EFI_STATUS | |
EFIAPI | |
SmmCpuFeaturesLibConstructor ( | |
IN EFI_HANDLE ImageHandle, | |
IN EFI_SYSTEM_TABLE *SystemTable | |
) | |
{ | |
UINT32 RegEax; | |
UINT32 RegEdx; | |
UINTN FamilyId; | |
UINTN ModelId; | |
// | |
// Retrieve CPU Family and Model | |
// | |
AsmCpuid (CPUID_VERSION_INFO, &RegEax, NULL, NULL, &RegEdx); | |
FamilyId = (RegEax >> 8) & 0xf; | |
ModelId = (RegEax >> 4) & 0xf; | |
if (FamilyId == 0x06 || FamilyId == 0x0f) { | |
ModelId = ModelId | ((RegEax >> 12) & 0xf0); | |
} | |
// | |
// Check CPUID(CPUID_VERSION_INFO).EDX[12] for MTRR capability | |
// | |
if ((RegEdx & BIT12) != 0) { | |
// | |
// Check MTRR_CAP MSR bit 11 for SMRR support | |
// | |
if ((AsmReadMsr64 (SMM_FEATURES_LIB_IA32_MTRR_CAP) & BIT11) != 0) { | |
mSmrrSupported = TRUE; | |
} | |
} | |
// | |
// Intel(R) 64 and IA-32 Architectures Software Developer's Manual | |
// Volume 3C, Section 35.3 MSRs in the Intel(R) Atom(TM) Processor Family | |
// | |
// If CPU Family/Model is 06_1CH, 06_26H, 06_27H, 06_35H or 06_36H, then | |
// SMRR Physical Base and SMM Physical Mask MSRs are not available. | |
// | |
if (FamilyId == 0x06) { | |
if (ModelId == 0x1C || ModelId == 0x26 || ModelId == 0x27 || ModelId == 0x35 || ModelId == 0x36) { | |
mSmrrSupported = FALSE; | |
} | |
} | |
// | |
// Intel(R) 64 and IA-32 Architectures Software Developer's Manual | |
// Volume 3C, Section 35.2 MSRs in the Intel(R) Core(TM) 2 Processor Family | |
// | |
// If CPU Family/Model is 06_0F or 06_17, then use Intel(R) Core(TM) 2 | |
// Processor Family MSRs | |
// | |
if (FamilyId == 0x06) { | |
if (ModelId == 0x17 || ModelId == 0x0f) { | |
mSmrrPhysBaseMsr = SMM_FEATURES_LIB_IA32_CORE_SMRR_PHYSBASE; | |
mSmrrPhysMaskMsr = SMM_FEATURES_LIB_IA32_CORE_SMRR_PHYSMASK; | |
} | |
} | |
// | |
// Intel(R) 64 and IA-32 Architectures Software Developer's Manual | |
// Volume 3C, Section 34.4.2 SMRAM Caching | |
// An IA-32 processor does not automatically write back and invalidate its | |
// caches before entering SMM or before exiting SMM. Because of this behavior, | |
// care must be taken in the placement of the SMRAM in system memory and in | |
// the caching of the SMRAM to prevent cache incoherence when switching back | |
// and forth between SMM and protected mode operation. | |
// | |
// An IA-32 processor is a processor that does not support the Intel 64 | |
// Architecture. Support for the Intel 64 Architecture can be detected from | |
// CPUID(CPUID_EXTENDED_CPU_SIG).EDX[29] | |
// | |
// If an IA-32 processor is detected, then set mNeedConfigureMtrrs to TRUE, | |
// so caches are flushed on SMI entry and SMI exit, the interrupted code | |
// MTRRs are saved/restored, and MTRRs for SMM are loaded. | |
// | |
AsmCpuid (CPUID_EXTENDED_FUNCTION, &RegEax, NULL, NULL, NULL); | |
if (RegEax >= CPUID_EXTENDED_CPU_SIG) { | |
AsmCpuid (CPUID_EXTENDED_CPU_SIG, NULL, NULL, NULL, &RegEdx); | |
if ((RegEdx & BIT29) != 0) { | |
mNeedConfigureMtrrs = FALSE; | |
} | |
} | |
// | |
// Allocate array for state of SMRR enable on all CPUs | |
// | |
mSmrrEnabled = (BOOLEAN *)AllocatePool (sizeof (BOOLEAN) * PcdGet32 (PcdCpuMaxLogicalProcessorNumber)); | |
ASSERT (mSmrrEnabled != NULL); | |
return EFI_SUCCESS; | |
} | |
/** | |
Called during the very first SMI into System Management Mode to initialize | |
CPU features, including SMBASE, for the currently executing CPU. Since this | |
is the first SMI, the SMRAM Save State Map is at the default address of | |
SMM_DEFAULT_SMBASE + SMRAM_SAVE_STATE_MAP_OFFSET. The currently executing | |
CPU is specified by CpuIndex and CpuIndex can be used to access information | |
about the currently executing CPU in the ProcessorInfo array and the | |
HotPlugCpuData data structure. | |
@param[in] CpuIndex The index of the CPU to initialize. The value | |
must be between 0 and the NumberOfCpus field in | |
the System Management System Table (SMST). | |
@param[in] IsMonarch TRUE if the CpuIndex is the index of the CPU that | |
was elected as monarch during System Management | |
Mode initialization. | |
FALSE if the CpuIndex is not the index of the CPU | |
that was elected as monarch during System | |
Management Mode initialization. | |
@param[in] ProcessorInfo Pointer to an array of EFI_PROCESSOR_INFORMATION | |
structures. ProcessorInfo[CpuIndex] contains the | |
information for the currently executing CPU. | |
@param[in] CpuHotPlugData Pointer to the CPU_HOT_PLUG_DATA structure that | |
contains the ApidId and SmBase arrays. | |
**/ | |
VOID | |
EFIAPI | |
SmmCpuFeaturesInitializeProcessor ( | |
IN UINTN CpuIndex, | |
IN BOOLEAN IsMonarch, | |
IN EFI_PROCESSOR_INFORMATION *ProcessorInfo, | |
IN CPU_HOT_PLUG_DATA *CpuHotPlugData | |
) | |
{ | |
SMRAM_SAVE_STATE_MAP *CpuState; | |
UINT64 FeatureControl; | |
UINT32 RegEax; | |
UINT32 RegEdx; | |
UINTN FamilyId; | |
UINTN ModelId; | |
// | |
// Configure SMBASE. | |
// | |
CpuState = (SMRAM_SAVE_STATE_MAP *)(UINTN)(SMM_DEFAULT_SMBASE + SMRAM_SAVE_STATE_MAP_OFFSET); | |
CpuState->x86.SMBASE = (UINT32)CpuHotPlugData->SmBase[CpuIndex]; | |
// | |
// Intel(R) 64 and IA-32 Architectures Software Developer's Manual | |
// Volume 3C, Section 35.2 MSRs in the Intel(R) Core(TM) 2 Processor Family | |
// | |
// If Intel(R) Core(TM) Core(TM) 2 Processor Family MSRs are being used, then | |
// make sure SMRR Enable(BIT3) of MSR_FEATURE_CONTROL MSR(0x3A) is set before | |
// accessing SMRR base/mask MSRs. If Lock(BIT0) of MSR_FEATURE_CONTROL MSR(0x3A) | |
// is set, then the MSR is locked and can not be modified. | |
// | |
if (mSmrrSupported && mSmrrPhysBaseMsr == SMM_FEATURES_LIB_IA32_CORE_SMRR_PHYSBASE) { | |
FeatureControl = AsmReadMsr64 (SMM_FEATURES_LIB_IA32_FEATURE_CONTROL); | |
if ((FeatureControl & BIT3) == 0) { | |
if ((FeatureControl & BIT0) == 0) { | |
AsmWriteMsr64 (SMM_FEATURES_LIB_IA32_FEATURE_CONTROL, FeatureControl | BIT3); | |
} else { | |
mSmrrSupported = FALSE; | |
} | |
} | |
} | |
// | |
// If SMRR is supported, then program SMRR base/mask MSRs. | |
// The EFI_MSR_SMRR_PHYS_MASK_VALID bit is not set until the first normal SMI. | |
// The code that initializes SMM environment is running in normal mode | |
// from SMRAM region. If SMRR is enabled here, then the SMRAM region | |
// is protected and the normal mode code execution will fail. | |
// | |
if (mSmrrSupported) { | |
// | |
// SMRR size cannot be less than 4-KBytes | |
// SMRR size must be of length 2^n | |
// SMRR base alignment cannot be less than SMRR length | |
// | |
if ((CpuHotPlugData->SmrrSize < SIZE_4KB) || | |
(CpuHotPlugData->SmrrSize != GetPowerOfTwo32 (CpuHotPlugData->SmrrSize)) || | |
((CpuHotPlugData->SmrrBase & ~(CpuHotPlugData->SmrrSize - 1)) != CpuHotPlugData->SmrrBase)) { | |
// | |
// Print message and halt if CPU is Monarch | |
// | |
if (IsMonarch) { | |
DEBUG ((DEBUG_ERROR, "SMM Base/Size does not meet alignment/size requirement!\n")); | |
CpuDeadLoop (); | |
} | |
} else { | |
AsmWriteMsr64 (mSmrrPhysBaseMsr, CpuHotPlugData->SmrrBase | MTRR_CACHE_WRITE_BACK); | |
AsmWriteMsr64 (mSmrrPhysMaskMsr, (~(CpuHotPlugData->SmrrSize - 1) & EFI_MSR_SMRR_MASK)); | |
mSmrrEnabled[CpuIndex] = FALSE; | |
} | |
} | |
// | |
// Retrieve CPU Family and Model | |
// | |
AsmCpuid (CPUID_VERSION_INFO, &RegEax, NULL, NULL, &RegEdx); | |
FamilyId = (RegEax >> 8) & 0xf; | |
ModelId = (RegEax >> 4) & 0xf; | |
if (FamilyId == 0x06 || FamilyId == 0x0f) { | |
ModelId = ModelId | ((RegEax >> 12) & 0xf0); | |
} | |
// | |
// Intel(R) 64 and IA-32 Architectures Software Developer's Manual | |
// Volume 3C, Section 35.10.1 MSRs in 4th Generation Intel(R) Core(TM) | |
// Processor Family. | |
// | |
// If CPU Family/Model is 06_3C, 06_45, or 06_46 then use 4th Generation | |
// Intel(R) Core(TM) Processor Family MSRs. | |
// | |
if (FamilyId == 0x06) { | |
if (ModelId == 0x3C || ModelId == 0x45 || ModelId == 0x46 || | |
ModelId == 0x3D || ModelId == 0x47 || ModelId == 0x4E || ModelId == 0x4F || | |
ModelId == 0x3F || ModelId == 0x56 || ModelId == 0x57 || ModelId == 0x5C) { | |
// | |
// Check to see if the CPU supports the SMM Code Access Check feature | |
// Do not access this MSR unless the CPU supports the SmmRegFeatureControl | |
// | |
if ((AsmReadMsr64 (SMM_FEATURES_LIB_IA32_MCA_CAP) & SMM_CODE_ACCESS_CHK_BIT) != 0) { | |
mSmmFeatureControlSupported = TRUE; | |
} | |
} | |
} | |
// | |
// Call internal worker function that completes the CPU initialization | |
// | |
FinishSmmCpuFeaturesInitializeProcessor (); | |
} | |
/** | |
This function updates the SMRAM save state on the currently executing CPU | |
to resume execution at a specific address after an RSM instruction. This | |
function must evaluate the SMRAM save state to determine the execution mode | |
the RSM instruction resumes and update the resume execution address with | |
either NewInstructionPointer32 or NewInstructionPoint. The auto HALT restart | |
flag in the SMRAM save state must always be cleared. This function returns | |
the value of the instruction pointer from the SMRAM save state that was | |
replaced. If this function returns 0, then the SMRAM save state was not | |
modified. | |
This function is called during the very first SMI on each CPU after | |
SmmCpuFeaturesInitializeProcessor() to set a flag in normal execution mode | |
to signal that the SMBASE of each CPU has been updated before the default | |
SMBASE address is used for the first SMI to the next CPU. | |
@param[in] CpuIndex The index of the CPU to hook. The value | |
must be between 0 and the NumberOfCpus | |
field in the System Management System Table | |
(SMST). | |
@param[in] CpuState Pointer to SMRAM Save State Map for the | |
currently executing CPU. | |
@param[in] NewInstructionPointer32 Instruction pointer to use if resuming to | |
32-bit execution mode from 64-bit SMM. | |
@param[in] NewInstructionPointer Instruction pointer to use if resuming to | |
same execution mode as SMM. | |
@retval 0 This function did modify the SMRAM save state. | |
@retval > 0 The original instruction pointer value from the SMRAM save state | |
before it was replaced. | |
**/ | |
UINT64 | |
EFIAPI | |
SmmCpuFeaturesHookReturnFromSmm ( | |
IN UINTN CpuIndex, | |
IN SMRAM_SAVE_STATE_MAP *CpuState, | |
IN UINT64 NewInstructionPointer32, | |
IN UINT64 NewInstructionPointer | |
) | |
{ | |
return 0; | |
} | |
/** | |
Hook point in normal execution mode that allows the one CPU that was elected | |
as monarch during System Management Mode initialization to perform additional | |
initialization actions immediately after all of the CPUs have processed their | |
first SMI and called SmmCpuFeaturesInitializeProcessor() relocating SMBASE | |
into a buffer in SMRAM and called SmmCpuFeaturesHookReturnFromSmm(). | |
**/ | |
VOID | |
EFIAPI | |
SmmCpuFeaturesSmmRelocationComplete ( | |
VOID | |
) | |
{ | |
} | |
/** | |
Determines if MTRR registers must be configured to set SMRAM cache-ability | |
when executing in System Management Mode. | |
@retval TRUE MTRR registers must be configured to set SMRAM cache-ability. | |
@retval FALSE MTRR registers do not need to be configured to set SMRAM | |
cache-ability. | |
**/ | |
BOOLEAN | |
EFIAPI | |
SmmCpuFeaturesNeedConfigureMtrrs ( | |
VOID | |
) | |
{ | |
return mNeedConfigureMtrrs; | |
} | |
/** | |
Disable SMRR register if SMRR is supported and SmmCpuFeaturesNeedConfigureMtrrs() | |
returns TRUE. | |
**/ | |
VOID | |
EFIAPI | |
SmmCpuFeaturesDisableSmrr ( | |
VOID | |
) | |
{ | |
if (mSmrrSupported && mNeedConfigureMtrrs) { | |
AsmWriteMsr64 (mSmrrPhysMaskMsr, AsmReadMsr64(mSmrrPhysMaskMsr) & ~EFI_MSR_SMRR_PHYS_MASK_VALID); | |
} | |
} | |
/** | |
Enable SMRR register if SMRR is supported and SmmCpuFeaturesNeedConfigureMtrrs() | |
returns TRUE. | |
**/ | |
VOID | |
EFIAPI | |
SmmCpuFeaturesReenableSmrr ( | |
VOID | |
) | |
{ | |
if (mSmrrSupported && mNeedConfigureMtrrs) { | |
AsmWriteMsr64 (mSmrrPhysMaskMsr, AsmReadMsr64(mSmrrPhysMaskMsr) | EFI_MSR_SMRR_PHYS_MASK_VALID); | |
} | |
} | |
/** | |
Processor specific hook point each time a CPU enters System Management Mode. | |
@param[in] CpuIndex The index of the CPU that has entered SMM. The value | |
must be between 0 and the NumberOfCpus field in the | |
System Management System Table (SMST). | |
**/ | |
VOID | |
EFIAPI | |
SmmCpuFeaturesRendezvousEntry ( | |
IN UINTN CpuIndex | |
) | |
{ | |
// | |
// If SMRR is supported and this is the first normal SMI, then enable SMRR | |
// | |
if (mSmrrSupported && !mSmrrEnabled[CpuIndex]) { | |
AsmWriteMsr64 (mSmrrPhysMaskMsr, AsmReadMsr64 (mSmrrPhysMaskMsr) | EFI_MSR_SMRR_PHYS_MASK_VALID); | |
mSmrrEnabled[CpuIndex] = TRUE; | |
} | |
} | |
/** | |
Processor specific hook point each time a CPU exits System Management Mode. | |
@param[in] CpuIndex The index of the CPU that is exiting SMM. The value must | |
be between 0 and the NumberOfCpus field in the System | |
Management System Table (SMST). | |
**/ | |
VOID | |
EFIAPI | |
SmmCpuFeaturesRendezvousExit ( | |
IN UINTN CpuIndex | |
) | |
{ | |
} | |
/** | |
Check to see if an SMM register is supported by a specified CPU. | |
@param[in] CpuIndex The index of the CPU to check for SMM register support. | |
The value must be between 0 and the NumberOfCpus field | |
in the System Management System Table (SMST). | |
@param[in] RegName Identifies the SMM register to check for support. | |
@retval TRUE The SMM register specified by RegName is supported by the CPU | |
specified by CpuIndex. | |
@retval FALSE The SMM register specified by RegName is not supported by the | |
CPU specified by CpuIndex. | |
**/ | |
BOOLEAN | |
EFIAPI | |
SmmCpuFeaturesIsSmmRegisterSupported ( | |
IN UINTN CpuIndex, | |
IN SMM_REG_NAME RegName | |
) | |
{ | |
if (mSmmFeatureControlSupported && RegName == SmmRegFeatureControl) { | |
return TRUE; | |
} | |
return FALSE; | |
} | |
/** | |
Returns the current value of the SMM register for the specified CPU. | |
If the SMM register is not supported, then 0 is returned. | |
@param[in] CpuIndex The index of the CPU to read the SMM register. The | |
value must be between 0 and the NumberOfCpus field in | |
the System Management System Table (SMST). | |
@param[in] RegName Identifies the SMM register to read. | |
@return The value of the SMM register specified by RegName from the CPU | |
specified by CpuIndex. | |
**/ | |
UINT64 | |
EFIAPI | |
SmmCpuFeaturesGetSmmRegister ( | |
IN UINTN CpuIndex, | |
IN SMM_REG_NAME RegName | |
) | |
{ | |
if (mSmmFeatureControlSupported && RegName == SmmRegFeatureControl) { | |
return AsmReadMsr64 (SMM_FEATURES_LIB_SMM_FEATURE_CONTROL); | |
} | |
return 0; | |
} | |
/** | |
Sets the value of an SMM register on a specified CPU. | |
If the SMM register is not supported, then no action is performed. | |
@param[in] CpuIndex The index of the CPU to write the SMM register. The | |
value must be between 0 and the NumberOfCpus field in | |
the System Management System Table (SMST). | |
@param[in] RegName Identifies the SMM register to write. | |
registers are read-only. | |
@param[in] Value The value to write to the SMM register. | |
**/ | |
VOID | |
EFIAPI | |
SmmCpuFeaturesSetSmmRegister ( | |
IN UINTN CpuIndex, | |
IN SMM_REG_NAME RegName, | |
IN UINT64 Value | |
) | |
{ | |
if (mSmmFeatureControlSupported && RegName == SmmRegFeatureControl) { | |
AsmWriteMsr64 (SMM_FEATURES_LIB_SMM_FEATURE_CONTROL, Value); | |
} | |
} | |
/** | |
Read an SMM Save State register on the target processor. If this function | |
returns EFI_UNSUPPORTED, then the caller is responsible for reading the | |
SMM Save Sate register. | |
@param[in] CpuIndex The index of the CPU to read the SMM Save State. The | |
value must be between 0 and the NumberOfCpus field in | |
the System Management System Table (SMST). | |
@param[in] Register The SMM Save State register to read. | |
@param[in] Width The number of bytes to read from the CPU save state. | |
@param[out] Buffer Upon return, this holds the CPU register value read | |
from the save state. | |
@retval EFI_SUCCESS The register was read from Save State. | |
@retval EFI_INVALID_PARAMTER Buffer is NULL. | |
@retval EFI_UNSUPPORTED This function does not support reading Register. | |
**/ | |
EFI_STATUS | |
EFIAPI | |
SmmCpuFeaturesReadSaveStateRegister ( | |
IN UINTN CpuIndex, | |
IN EFI_SMM_SAVE_STATE_REGISTER Register, | |
IN UINTN Width, | |
OUT VOID *Buffer | |
) | |
{ | |
return EFI_UNSUPPORTED; | |
} | |
/** | |
Writes an SMM Save State register on the target processor. If this function | |
returns EFI_UNSUPPORTED, then the caller is responsible for writing the | |
SMM Save Sate register. | |
@param[in] CpuIndex The index of the CPU to write the SMM Save State. The | |
value must be between 0 and the NumberOfCpus field in | |
the System Management System Table (SMST). | |
@param[in] Register The SMM Save State register to write. | |
@param[in] Width The number of bytes to write to the CPU save state. | |
@param[in] Buffer Upon entry, this holds the new CPU register value. | |
@retval EFI_SUCCESS The register was written to Save State. | |
@retval EFI_INVALID_PARAMTER Buffer is NULL. | |
@retval EFI_UNSUPPORTED This function does not support writing Register. | |
**/ | |
EFI_STATUS | |
EFIAPI | |
SmmCpuFeaturesWriteSaveStateRegister ( | |
IN UINTN CpuIndex, | |
IN EFI_SMM_SAVE_STATE_REGISTER Register, | |
IN UINTN Width, | |
IN CONST VOID *Buffer | |
) | |
{ | |
return EFI_UNSUPPORTED; | |
} | |
/** | |
This function is hook point called after the gEfiSmmReadyToLockProtocolGuid | |
notification is completely processed. | |
**/ | |
VOID | |
EFIAPI | |
SmmCpuFeaturesCompleteSmmReadyToLock ( | |
VOID | |
) | |
{ | |
} | |
/** | |
This API provides a method for a CPU to allocate a specific region for storing page tables. | |
This API can be called more once to allocate memory for page tables. | |
Allocates the number of 4KB pages of type EfiRuntimeServicesData and returns a pointer to the | |
allocated buffer. The buffer returned is aligned on a 4KB boundary. If Pages is 0, then NULL | |
is returned. If there is not enough memory remaining to satisfy the request, then NULL is | |
returned. | |
This function can also return NULL if there is no preference on where the page tables are allocated in SMRAM. | |
@param Pages The number of 4 KB pages to allocate. | |
@return A pointer to the allocated buffer for page tables. | |
@retval NULL Fail to allocate a specific region for storing page tables, | |
Or there is no preference on where the page tables are allocated in SMRAM. | |
**/ | |
VOID * | |
EFIAPI | |
SmmCpuFeaturesAllocatePageTableMemory ( | |
IN UINTN Pages | |
) | |
{ | |
return NULL; | |
} | |