SmramSaveState.c

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#include <PiSmm.h>
 
#include <Library/SmmCpuFeaturesLib.h>
 
#include <Library/BaseLib.h>
#include <Library/BaseMemoryLib.h>
#include <Library/SmmServicesTableLib.h>
#include <Library/DebugLib.h>
 
#include "PiSmmCpuCommon.h"
 
typedef struct {
  UINT64    Signature;                                      // Offset 0x00
  UINT16    Reserved1;                                      // Offset 0x08
  UINT16    Reserved2;                                      // Offset 0x0A
  UINT16    Reserved3;                                      // Offset 0x0C
  UINT16    SmmCs;                                          // Offset 0x0E
  UINT16    SmmDs;                                          // Offset 0x10
  UINT16    SmmSs;                                          // Offset 0x12
  UINT16    SmmOtherSegment;                                // Offset 0x14
  UINT16    Reserved4;                                      // Offset 0x16
  UINT64    Reserved5;                                      // Offset 0x18
  UINT64    Reserved6;                                      // Offset 0x20
  UINT64    Reserved7;                                      // Offset 0x28
  UINT64    SmmGdtPtr;                                      // Offset 0x30
  UINT32    SmmGdtSize;                                     // Offset 0x38
  UINT32    Reserved8;                                      // Offset 0x3C
  UINT64    Reserved9;                                      // Offset 0x40
  UINT64    Reserved10;                                     // Offset 0x48
  UINT16    Reserved11;                                     // Offset 0x50
  UINT16    Reserved12;                                     // Offset 0x52
  UINT32    Reserved13;                                     // Offset 0x54
  UINT64    Reserved14;                                     // Offset 0x58
} PROCESSOR_SMM_DESCRIPTOR;
 
extern CONST PROCESSOR_SMM_DESCRIPTOR  gcPsd;
 
//
// EFER register LMA bit
//
#define LMA  BIT10
 
X86_ASSEMBLY_PATCH_LABEL  gPatchSmbase;
X86_ASSEMBLY_PATCH_LABEL  gPatchSmiStack;
X86_ASSEMBLY_PATCH_LABEL  gPatchSmiCr3;
extern volatile UINT8     gcSmiHandlerTemplate[];
extern CONST UINT16       gcSmiHandlerSize;
 
//
// Variables used by SMI Handler
//
IA32_DESCRIPTOR  gSmiHandlerIdtr;
 
UINT8  mSmmSaveStateRegisterLma;
 
UINTN
EFIAPI
GetSmiHandlerSize (
  VOID
  )
{
  UINTN  Size;
 
  Size = SmmCpuFeaturesGetSmiHandlerSize ();
  if (Size != 0) {
    return Size;
  }
 
  return gcSmiHandlerSize;
}
 
VOID
EFIAPI
InstallSmiHandler (
  IN UINTN   CpuIndex,
  IN UINT32  SmBase,
  IN VOID    *SmiStack,
  IN UINTN   StackSize,
  IN UINTN   GdtBase,
  IN UINTN   GdtSize,
  IN UINTN   IdtBase,
  IN UINTN   IdtSize,
  IN UINT32  Cr3
  )
{
  PROCESSOR_SMM_DESCRIPTOR  *Psd;
  UINT32                    CpuSmiStack;
 
  //
  // Initialize PROCESSOR_SMM_DESCRIPTOR
  //
  Psd = (PROCESSOR_SMM_DESCRIPTOR *)(VOID *)((UINTN)SmBase + SMM_PSD_OFFSET);
  CopyMem (Psd, &gcPsd, sizeof (gcPsd));
  Psd->SmmGdtPtr  = (UINT64)GdtBase;
  Psd->SmmGdtSize = (UINT32)GdtSize;
 
  if (SmmCpuFeaturesGetSmiHandlerSize () != 0) {
    //
    // Install SMI handler provided by library
    //
    SmmCpuFeaturesInstallSmiHandler (
      CpuIndex,
      SmBase,
      SmiStack,
      StackSize,
      GdtBase,
      GdtSize,
      IdtBase,
      IdtSize,
      Cr3
      );
    return;
  }
 
  InitShadowStack (CpuIndex, (VOID *)((UINTN)SmiStack + StackSize));
 
  //
  // Initialize values in template before copy
  //
  CpuSmiStack = (UINT32)((UINTN)SmiStack + StackSize - sizeof (UINTN));
  PatchInstructionX86 (gPatchSmiStack, CpuSmiStack, 4);
  PatchInstructionX86 (gPatchSmiCr3, Cr3, 4);
  PatchInstructionX86 (gPatchSmbase, SmBase, 4);
  gSmiHandlerIdtr.Base  = IdtBase;
  gSmiHandlerIdtr.Limit = (UINT16)(IdtSize - 1);
 
  //
  // Set the value at the top of the CPU stack to the CPU Index
  //
  *(UINTN *)(UINTN)CpuSmiStack = CpuIndex;
 
  //
  // Copy template to CPU specific SMI handler location
  //
  CopyMem (
    (VOID *)((UINTN)SmBase + SMM_HANDLER_OFFSET),
    (VOID *)gcSmiHandlerTemplate,
    gcSmiHandlerSize
    );
}