SmmDebugAgentLib.c

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#include "SmmDebugAgentLib.h"
 
DEBUG_AGENT_MAILBOX       *mMailboxPointer = NULL;
DEBUG_AGENT_MAILBOX       mLocalMailbox;
UINTN                     mSavedDebugRegisters[6];
IA32_IDT_GATE_DESCRIPTOR  mIdtEntryTable[33];
BOOLEAN                   mSkipBreakpoint      = FALSE;
BOOLEAN                   mSmmDebugIdtInitFlag = FALSE;
BOOLEAN                   mApicTimerRestore    = FALSE;
BOOLEAN                   mPeriodicMode;
UINT32                    mTimerCycle;
UINTN                     mApicTimerDivisor;
UINT8                     mVector;
 
CHAR8  mWarningMsgIgnoreSmmEntryBreak[] = "Ignore smmentrybreak setting for SMI issued during DXE debugging!\r\n";
 
BOOLEAN
MultiProcessorDebugSupport (
  VOID
  )
{
  return FALSE;
}
 
EFI_STATUS
DebugReadBreakSymbol (
  IN  DEBUG_PORT_HANDLE  Handle,
  OUT UINT8              *BreakSymbol
  )
{
  //
  // Smm instance has no debug timer to poll break symbol.
  //
  return EFI_NOT_FOUND;
}
 
DEBUG_AGENT_MAILBOX *
GetMailboxFromHob (
  VOID
  )
{
  EFI_HOB_GUID_TYPE    *GuidHob;
  UINT64               *MailboxLocation;
  DEBUG_AGENT_MAILBOX  *Mailbox;
 
  GuidHob = GetFirstGuidHob (&gEfiDebugAgentGuid);
  if (GuidHob == NULL) {
    return NULL;
  }
 
  MailboxLocation = (UINT64 *)(GET_GUID_HOB_DATA (GuidHob));
  Mailbox         = (DEBUG_AGENT_MAILBOX *)(UINTN)(*MailboxLocation);
  VerifyMailboxChecksum (Mailbox);
 
  return Mailbox;
}
 
DEBUG_AGENT_MAILBOX *
GetMailboxPointer (
  VOID
  )
{
  VerifyMailboxChecksum (mMailboxPointer);
  return mMailboxPointer;
}
 
DEBUG_PORT_HANDLE
GetDebugPortHandle (
  VOID
  )
{
  return (DEBUG_PORT_HANDLE)(UINTN)(GetMailboxPointer ()->DebugPortHandle);
}
 
VOID
SaveDebugRegister (
  VOID
  )
{
  mSavedDebugRegisters[0] = AsmReadDr0 ();
  mSavedDebugRegisters[1] = AsmReadDr1 ();
  mSavedDebugRegisters[2] = AsmReadDr2 ();
  mSavedDebugRegisters[3] = AsmReadDr3 ();
  mSavedDebugRegisters[4] = AsmReadDr6 ();
  mSavedDebugRegisters[5] = AsmReadDr7 ();
}
 
VOID
RestoreDebugRegister (
  VOID
  )
{
  AsmWriteDr7 (0);
  AsmWriteDr0 (mSavedDebugRegisters[0]);
  AsmWriteDr1 (mSavedDebugRegisters[1]);
  AsmWriteDr2 (mSavedDebugRegisters[2]);
  AsmWriteDr3 (mSavedDebugRegisters[3]);
  AsmWriteDr6 (mSavedDebugRegisters[4]);
  AsmWriteDr7 (mSavedDebugRegisters[5]);
}
 
VOID
EFIAPI
InitializeDebugAgent (
  IN UINT32                InitFlag,
  IN VOID                  *Context  OPTIONAL,
  IN DEBUG_AGENT_CONTINUE  Function  OPTIONAL
  )
{
  EFI_STATUS                Status;
  UINT64                    DebugPortHandle;
  IA32_IDT_GATE_DESCRIPTOR  IdtEntry[33];
  IA32_DESCRIPTOR           IdtDescriptor;
  IA32_DESCRIPTOR           *Ia32Idtr;
  IA32_IDT_ENTRY            *Ia32IdtEntry;
  IA32_DESCRIPTOR           Idtr;
  UINT16                    IdtEntryCount;
  DEBUG_AGENT_MAILBOX       *Mailbox;
  UINT64                    *MailboxLocation;
  UINT32                    DebugTimerFrequency;
 
  switch (InitFlag) {
    case DEBUG_AGENT_INIT_SMM:
      //
      // Install configuration table for persisted vector handoff info
      //
      Status = gSmst->SmmInstallConfigurationTable (
                        gSmst,
                        &gEfiVectorHandoffTableGuid,
                        (VOID *)&mVectorHandoffInfoDebugAgent[0],
                        sizeof (EFI_VECTOR_HANDOFF_INFO) * mVectorHandoffInfoCount
                        );
      if (EFI_ERROR (Status)) {
        DEBUG ((DEBUG_ERROR, "DebugAgent: Cannot install configuration table for persisted vector handoff info!\n"));
        if (Context != NULL) {
          *(BOOLEAN *)Context = FALSE;
        }
 
        CpuDeadLoop ();
      }
 
      //
      // Check if Debug Agent initialized in DXE phase
      //
      Status = EfiGetSystemConfigurationTable (&gEfiDebugAgentGuid, (VOID **)&Mailbox);
      if ((Status == EFI_SUCCESS) && (Mailbox != NULL)) {
        VerifyMailboxChecksum (Mailbox);
        mMailboxPointer = Mailbox;
        if (Context != NULL) {
          *(BOOLEAN *)Context = TRUE;
        }
 
        break;
      }
 
      //
      // Check if Debug Agent initialized in SEC/PEI phase
      //
      Mailbox = GetMailboxFromHob ();
      if (Mailbox != NULL) {
        mMailboxPointer = Mailbox;
        if (Context != NULL) {
          *(BOOLEAN *)Context = TRUE;
        }
 
        break;
      }
 
      //
      // Debug Agent was not initialized before, use the local mailbox.
      //
      ZeroMem (&mLocalMailbox, sizeof (DEBUG_AGENT_MAILBOX));
      Mailbox = &mLocalMailbox;
      //
      // Save original IDT entries
      //
      AsmReadIdtr (&IdtDescriptor);
      CopyMem (&IdtEntry, (VOID *)IdtDescriptor.Base, 33 * sizeof (IA32_IDT_GATE_DESCRIPTOR));
      //
      // Initialized Debug Agent
      //
      InitializeDebugIdt ();
      //
      // Initialize Debug Timer hardware and save its frequency
      //
      InitializeDebugTimer (&DebugTimerFrequency, TRUE);
      UpdateMailboxContent (Mailbox, DEBUG_MAILBOX_DEBUG_TIMER_FREQUENCY, DebugTimerFrequency);
 
      DebugPortHandle = (UINT64)(UINTN)DebugPortInitialize ((DEBUG_PORT_HANDLE)(UINTN)Mailbox->DebugPortHandle, NULL);
      UpdateMailboxContent (Mailbox, DEBUG_MAILBOX_DEBUG_PORT_HANDLE_INDEX, DebugPortHandle);
      mMailboxPointer = Mailbox;
      //
      // Trigger one software interrupt to inform HOST
      //
      TriggerSoftInterrupt (SYSTEM_RESET_SIGNATURE);
 
      SetDebugFlag (DEBUG_AGENT_FLAG_MEMORY_READY, 1);
      //
      // Memory has been ready
      //
      if (IsHostAttached ()) {
        //
        // Trigger one software interrupt to inform HOST
        //
        TriggerSoftInterrupt (MEMORY_READY_SIGNATURE);
      }
 
      //
      // Find and report PE/COFF image info to HOST
      //
      FindAndReportModuleImageInfo (SIZE_4KB);
      //
      // Restore saved IDT entries
      //
      CopyMem ((VOID *)IdtDescriptor.Base, &IdtEntry, 33 * sizeof (IA32_IDT_GATE_DESCRIPTOR));
 
      if (Context != NULL) {
        *(BOOLEAN *)Context = TRUE;
      }
 
      break;
 
    case DEBUG_AGENT_INIT_ENTER_SMI:
      SaveDebugRegister ();
      if (!mSmmDebugIdtInitFlag) {
        //
        // We only need to initialize Debug IDT table at first SMI entry
        // after SMM relocation.
        //
        InitializeDebugIdt ();
        mSmmDebugIdtInitFlag = TRUE;
      }
 
      //
      // Check if CPU APIC Timer is working, otherwise initialize it.
      //
      InitializeLocalApicSoftwareEnable (TRUE);
      GetApicTimerState (&mApicTimerDivisor, &mPeriodicMode, &mVector);
      mTimerCycle = GetApicTimerInitCount ();
      if (!mPeriodicMode || (mTimerCycle == 0)) {
        mApicTimerRestore = TRUE;
        InitializeDebugTimer (NULL, FALSE);
      }
 
      Mailbox = GetMailboxPointer ();
      if (GetDebugFlag (DEBUG_AGENT_FLAG_AGENT_IN_PROGRESS) == 1) {
        //
        // If Debug Agent has been communication state with HOST, we need skip
        // any break points set in SMM, set Skip Breakpoint flag
        //
        mSkipBreakpoint = TRUE;
      }
 
      if (GetDebugFlag (DEBUG_AGENT_FLAG_BREAK_ON_NEXT_SMI) == 1) {
        if (mSkipBreakpoint) {
          //
          // Print warning message if ignore smm entry break
          //
          DebugPortWriteBuffer (
            (DEBUG_PORT_HANDLE)(UINTN)Mailbox->DebugPortHandle,
            (UINT8 *)mWarningMsgIgnoreSmmEntryBreak,
            AsciiStrLen (mWarningMsgIgnoreSmmEntryBreak)
            );
        } else {
          //
          // If SMM entry break is set, SMM code will be break at here.
          //
          CpuBreakpoint ();
        }
      }
 
      break;
 
    case DEBUG_AGENT_INIT_EXIT_SMI:
      Mailbox = GetMailboxPointer ();
      //
      // Clear Skip Breakpoint flag
      //
      mSkipBreakpoint = FALSE;
      RestoreDebugRegister ();
      //
      // Restore APIC Timer
      //
      if (mApicTimerRestore) {
        InitializeApicTimer (mApicTimerDivisor, mTimerCycle, mPeriodicMode, mVector);
        mApicTimerRestore = FALSE;
      }
 
      break;
 
    case DEBUG_AGENT_INIT_THUNK_PEI_IA32TOX64:
      if (Context == NULL) {
        DEBUG ((DEBUG_ERROR, "DebugAgent: Input parameter Context cannot be NULL!\n"));
        CpuDeadLoop ();
      } else {
        Ia32Idtr        =  (IA32_DESCRIPTOR *)Context;
        Ia32IdtEntry    = (IA32_IDT_ENTRY *)(Ia32Idtr->Base);
        MailboxLocation = (UINT64 *)((UINTN)Ia32IdtEntry[DEBUG_MAILBOX_VECTOR].Bits.OffsetLow +
                                     ((UINTN)Ia32IdtEntry[DEBUG_MAILBOX_VECTOR].Bits.OffsetHigh << 16));
        mMailboxPointer = (DEBUG_AGENT_MAILBOX *)(UINTN)(*MailboxLocation);
        VerifyMailboxChecksum (mMailboxPointer);
        //
        // Get original IDT address and size.
        //
        AsmReadIdtr ((IA32_DESCRIPTOR *)&Idtr);
        IdtEntryCount = (UINT16)((Idtr.Limit + 1) / sizeof (IA32_IDT_GATE_DESCRIPTOR));
        if (IdtEntryCount < 33) {
          Idtr.Limit = (UINT16)(sizeof (IA32_IDT_GATE_DESCRIPTOR) * 33 - 1);
          Idtr.Base  = (UINTN)&mIdtEntryTable;
          ZeroMem (&mIdtEntryTable, Idtr.Limit + 1);
          AsmWriteIdtr ((IA32_DESCRIPTOR *)&Idtr);
        }
 
        InitializeDebugIdt ();
        //
        // Initialize Debug Timer hardware and save its frequency
        //
        InitializeDebugTimer (&DebugTimerFrequency, TRUE);
        UpdateMailboxContent (mMailboxPointer, DEBUG_MAILBOX_DEBUG_TIMER_FREQUENCY, DebugTimerFrequency);
        //
        // Enable Debug Timer interrupt and CPU interrupt
        //
        SaveAndSetDebugTimerInterrupt (TRUE);
        EnableInterrupts ();
 
        FindAndReportModuleImageInfo (SIZE_4KB);
      }
 
      break;
 
    default:
      //
      // Only DEBUG_AGENT_INIT_PREMEM_SEC and DEBUG_AGENT_INIT_POSTMEM_SEC are allowed for this
      // Debug Agent library instance.
      //
      DEBUG ((DEBUG_ERROR, "Debug Agent: The InitFlag value is not allowed!\n"));
      CpuDeadLoop ();
      break;
  }
}