AmdSmramSaveStateConfig.c

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#include "InternalSmmRelocationLib.h"
#include <Register/Amd/SmramSaveStateMap.h>
 
UINT8
GetMmSaveStateRegisterLma (
  VOID
  )
{
  UINT8                   SmmSaveStateRegisterLma;
  MSR_IA32_EFER_REGISTER  Msr;
 
  Msr.Uint64 = AsmReadMsr64 (MSR_IA32_EFER);
 
  SmmSaveStateRegisterLma = (UINT8)EFI_MM_SAVE_STATE_REGISTER_LMA_32BIT;
 
  if (Msr.Bits.LMA) {
    SmmSaveStateRegisterLma = (UINT8)EFI_MM_SAVE_STATE_REGISTER_LMA_64BIT;
  }
 
  return SmmSaveStateRegisterLma;
}
 
VOID
EFIAPI
ConfigureSmBase (
  IN UINT64  SmBase
  )
{
  AMD_SMRAM_SAVE_STATE_MAP  *AmdCpuState;
 
  AmdCpuState = (AMD_SMRAM_SAVE_STATE_MAP *)(UINTN)(SMM_DEFAULT_SMBASE + SMRAM_SAVE_STATE_MAP_OFFSET);
 
  AmdCpuState->x64.SMBASE = (UINT32)SmBase;
}
 
UINT64
EFIAPI
HookReturnFromSmm (
  IN OUT SMRAM_SAVE_STATE_MAP  *CpuState,
  IN     UINT64                NewInstructionPointer32,
  IN     UINT64                NewInstructionPointer
  )
{
  UINT64                    OriginalInstructionPointer;
  AMD_SMRAM_SAVE_STATE_MAP  *AmdCpuState;
  MSR_IA32_EFER_REGISTER    Msr;
 
  AmdCpuState = (AMD_SMRAM_SAVE_STATE_MAP *)CpuState;
 
  OriginalInstructionPointer = AmdCpuState->x64._RIP;
  Msr.Uint64                 = AmdCpuState->x64.EFER;
 
  if (!Msr.Bits.LMA) {
    AmdCpuState->x64._RIP = NewInstructionPointer32;
  } else {
    AmdCpuState->x64._RIP = NewInstructionPointer;
  }
 
  //
  // Clear the auto HALT restart flag so the RSM instruction returns
  // program control to the instruction following the HLT instruction.
  //
  if ((AmdCpuState->x64.AutoHALTRestart & BIT0) != 0) {
    AmdCpuState->x64.AutoHALTRestart &= ~BIT0;
  }
 
  return OriginalInstructionPointer;
}