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/** @file
Config SMRAM Save State for SmmBases Relocation.
Copyright (c) 2024, Intel Corporation. All rights reserved.<BR>
SPDX-License-Identifier: BSD-2-Clause-Patent
**/
#include "InternalSmmRelocationLib.h"
#include <Library/CpuLib.h>
/**
Get the mode of the CPU at the time an SMI occurs
@retval EFI_MM_SAVE_STATE_REGISTER_LMA_32BIT 32 bit.
@retval EFI_MM_SAVE_STATE_REGISTER_LMA_64BIT 64 bit.
**/
UINT8
GetMmSaveStateRegisterLma (
VOID
)
{
CPUID_VERSION_INFO_EAX RegEax;
CPUID_EXTENDED_CPU_SIG_EDX RegEdx;
UINTN FamilyId;
UINTN ModelId;
UINT32 Eax;
UINT8 SmmSaveStateRegisterLma;
//
// Determine the mode of the CPU at the time an SMI occurs
// Intel(R) 64 and IA-32 Architectures Software Developer's Manual
// Volume 3C, Section 34.4.1.1
//
RegEax.Uint32 = GetCpuFamilyModel ();
FamilyId = RegEax.Bits.FamilyId;
ModelId = RegEax.Bits.Model;
if ((FamilyId == 0x06) || (FamilyId == 0x0f)) {
ModelId = ModelId | RegEax.Bits.ExtendedModelId << 4;
}
RegEdx.Uint32 = 0;
AsmCpuid (CPUID_EXTENDED_FUNCTION, &Eax, NULL, NULL, NULL);
if (Eax >= CPUID_EXTENDED_CPU_SIG) {
AsmCpuid (CPUID_EXTENDED_CPU_SIG, NULL, NULL, NULL, &(RegEdx.Uint32));
}
SmmSaveStateRegisterLma = (UINT8)EFI_MM_SAVE_STATE_REGISTER_LMA_32BIT;
if (RegEdx.Bits.LM) {
SmmSaveStateRegisterLma = (UINT8)EFI_MM_SAVE_STATE_REGISTER_LMA_64BIT;
}
if (FamilyId == 0x06) {
if ((ModelId == 0x17) || (ModelId == 0x0f) || (ModelId == 0x1c)) {
SmmSaveStateRegisterLma = (UINT8)EFI_MM_SAVE_STATE_REGISTER_LMA_64BIT;
}
}
return SmmSaveStateRegisterLma;
}
/**
This function configures the SmBase on the currently executing CPU.
@param[in] SmBase The SmBase on the currently executing CPU.
**/
VOID
EFIAPI
ConfigureSmBase (
IN UINT64 SmBase
)
{
SMRAM_SAVE_STATE_MAP *CpuState;
CpuState = (SMRAM_SAVE_STATE_MAP *)(UINTN)(SMM_DEFAULT_SMBASE + SMRAM_SAVE_STATE_MAP_OFFSET);
CpuState->x86.SMBASE = (UINT32)SmBase;
}
/**
Hook the code executed immediately after an RSM instruction on the currently
executing CPU. The mode of code executed immediately after RSM must be
detected, and the appropriate hook must be selected. Always clear the auto
HALT restart flag if it is set.
@param[in] CpuIndex The processor index for the currently
executing CPU.
@param[in,out] CpuState Pointer to SMRAM Save State Map for the
currently executing CPU.
@param[in] NewInstructionPointer32 Instruction pointer to use if resuming to
32-bit mode from 64-bit SMM.
@param[in] NewInstructionPointer Instruction pointer to use if resuming to
same mode as SMM.
@retval The value of the original instruction pointer before it was hooked.
**/
UINT64
EFIAPI
HookReturnFromSmm (
IN UINTN CpuIndex,
IN OUT SMRAM_SAVE_STATE_MAP *CpuState,
IN UINT64 NewInstructionPointer32,
IN UINT64 NewInstructionPointer
)
{
UINT64 OriginalInstructionPointer;
if (GetMmSaveStateRegisterLma () == EFI_MM_SAVE_STATE_REGISTER_LMA_32BIT) {
OriginalInstructionPointer = (UINT64)CpuState->x86._EIP;
CpuState->x86._EIP = (UINT32)NewInstructionPointer;
//
// Clear the auto HALT restart flag so the RSM instruction returns
// program control to the instruction following the HLT instruction.
//
if ((CpuState->x86.AutoHALTRestart & BIT0) != 0) {
CpuState->x86.AutoHALTRestart &= ~BIT0;
}
} else {
OriginalInstructionPointer = CpuState->x64._RIP;
if ((CpuState->x64.IA32_EFER & LMA) == 0) {
CpuState->x64._RIP = (UINT32)NewInstructionPointer32;
} else {
CpuState->x64._RIP = (UINT32)NewInstructionPointer;
}
//
// Clear the auto HALT restart flag so the RSM instruction returns
// program control to the instruction following the HLT instruction.
//
if ((CpuState->x64.AutoHALTRestart & BIT0) != 0) {
CpuState->x64.AutoHALTRestart &= ~BIT0;
}
}
return OriginalInstructionPointer;
}
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