/** @file

Copyright (c) 2007 - 2016, Intel Corporation. All rights reserved.<BR>
SPDX-License-Identifier: BSD-2-Clause-Patent

**/

#include <Uefi.h>
#include "Edb.h"

EFI_DEBUGGER_PRIVATE_DATA mDebuggerPrivate = {
  EFI_DEBUGGER_SIGNATURE,                    // Signature
  IsaEbc,                                    // Isa
  (EBC_DEBUGGER_MAJOR_VERSION << 16) |
    EBC_DEBUGGER_MINOR_VERSION,              // EfiDebuggerRevision
  (VM_MAJOR_VERSION << 16) |
    VM_MINOR_VERSION,                        // EbcVmRevision
  {
    EFI_DEBUGGER_CONFIGURATION_VERSION,
    &mDebuggerPrivate,
  },                                         // DebuggerConfiguration
  NULL,                                      // DebugImageInfoTableHeader
  NULL,                                      // Vol
  NULL,                                      // PciRootBridgeIo
  mDebuggerCommandSet,                       // DebuggerCommandSet
  {0},                                       // DebuggerSymbolContext
  0,                                         // DebuggerBreakpointCount
  {{0}},                                     // DebuggerBreakpointContext
  0,                                         // CallStackEntryCount
  {{0}},                                     // CallStackEntry
  0,                                         // TraceEntryCount
  {{0}},                                     // TraceEntry
  {0},                                       // StepContext
  {0},                                       // GoTilContext
  0,                                         // InstructionScope
  EFI_DEBUG_DEFAULT_INSTRUCTION_NUMBER,      // InstructionNumber
  EFI_DEBUG_FLAG_EBC_BOE | EFI_DEBUG_FLAG_EBC_BOT, // FeatureFlags
  0,                                               // StatusFlags
  FALSE,                                           // EnablePageBreak
  NULL                                             // BreakEvent
};

CHAR16 *mExceptionStr[] = {
  L"EXCEPT_EBC_UNDEFINED",
  L"EXCEPT_EBC_DIVIDE_ERROR",
  L"EXCEPT_EBC_DEBUG",
  L"EXCEPT_EBC_BREAKPOINT",
  L"EXCEPT_EBC_OVERFLOW",
  L"EXCEPT_EBC_INVALID_OPCODE",
  L"EXCEPT_EBC_STACK_FAULT",
  L"EXCEPT_EBC_ALIGNMENT_CHECK",
  L"EXCEPT_EBC_INSTRUCTION_ENCODING",
  L"EXCEPT_EBC_BAD_BREAK",
  L"EXCEPT_EBC_SINGLE_STEP",
};

/**

  Clear all the breakpoint.

  @param DebuggerPrivate    EBC Debugger private data structure
  @param NeedRemove         Whether need to remove all the breakpoint

**/
VOID
EdbClearAllBreakpoint (
  IN     EFI_DEBUGGER_PRIVATE_DATA *DebuggerPrivate,
  IN     BOOLEAN                   NeedRemove
  )
{
  UINTN    Index;

  //
  // Patch all the breakpoint
  //
  for (Index = 0; (Index < DebuggerPrivate->DebuggerBreakpointCount) && (Index < EFI_DEBUGGER_BREAKPOINT_MAX); Index++) {
    if (DebuggerPrivate->DebuggerBreakpointContext[Index].State) {
      CopyMem (
        (VOID *)(UINTN)DebuggerPrivate->DebuggerBreakpointContext[Index].BreakpointAddress,
        &DebuggerPrivate->DebuggerBreakpointContext[Index].OldInstruction,
        sizeof(UINT16)
        );
    }
  }

  //
  // Zero Breakpoint context, if need to remove all breakpoint
  //
  if (NeedRemove) {
    DebuggerPrivate->DebuggerBreakpointCount = 0;
    ZeroMem (DebuggerPrivate->DebuggerBreakpointContext, sizeof(DebuggerPrivate->DebuggerBreakpointContext));
  }

  //
  // Done
  //
  return ;
}

/**

  Set all the breakpoint.

  @param DebuggerPrivate    EBC Debugger private data structure

**/
VOID
EdbSetAllBreakpoint (
  IN     EFI_DEBUGGER_PRIVATE_DATA *DebuggerPrivate
  )
{
  UINTN    Index;
  UINT16   Data16;

  //
  // Set all the breakpoint (BREAK(3) : 0x0300)
  //
  Data16 = 0x0300;
  for (Index = 0; (Index < DebuggerPrivate->DebuggerBreakpointCount) && (Index < EFI_DEBUGGER_BREAKPOINT_MAX); Index++) {
    if (DebuggerPrivate->DebuggerBreakpointContext[Index].State) {
      CopyMem (
        (VOID *)(UINTN)DebuggerPrivate->DebuggerBreakpointContext[Index].BreakpointAddress,
        &Data16,
        sizeof(UINT16)
        );
    }
  }

  //
  // Check if current break is caused by breakpoint set.
  // If so, we need to patch memory back to let user see the real memory.
  //
  if (DebuggerPrivate->DebuggerBreakpointContext[EFI_DEBUGGER_BREAKPOINT_MAX].BreakpointAddress != 0) {
    CopyMem (
      (VOID *)(UINTN)DebuggerPrivate->DebuggerBreakpointContext[EFI_DEBUGGER_BREAKPOINT_MAX].BreakpointAddress,
      &DebuggerPrivate->DebuggerBreakpointContext[EFI_DEBUGGER_BREAKPOINT_MAX].OldInstruction,
      sizeof(UINT16)
      );
    DebuggerPrivate->StatusFlags &= ~EFI_DEBUG_FLAG_EBC_B_BP;
  }

  //
  // Done
  //
  return ;
}

/**

  Check all the breakpoint, if match, then set status flag, and record current breakpoint.
  Then clear all breakpoint to let user see a clean memory

  @param   DebuggerPrivate    EBC Debugger private data structure
  @param   SystemContext      EBC system context.

**/
VOID
EdbCheckBreakpoint (
  IN     EFI_DEBUGGER_PRIVATE_DATA *DebuggerPrivate,
  IN     EFI_SYSTEM_CONTEXT        SystemContext
  )
{
  UINT64   Address;
  UINTN    Index;
  BOOLEAN  IsHitBreakpoint;

  //
  // Roll back IP for breakpoint instruction (BREAK(3) : 0x0300)
  //
  Address = SystemContext.SystemContextEbc->Ip - sizeof(UINT16);

  //
  // Check if the breakpoint is hit
  //
  IsHitBreakpoint = FALSE;
  for (Index = 0; (Index < DebuggerPrivate->DebuggerBreakpointCount) && (Index < EFI_DEBUGGER_BREAKPOINT_MAX); Index++) {
    if ((DebuggerPrivate->DebuggerBreakpointContext[Index].BreakpointAddress == Address) &&
        (DebuggerPrivate->DebuggerBreakpointContext[Index].State)) {
      IsHitBreakpoint = TRUE;
      break;
    }
  }

  if (IsHitBreakpoint) {
    //
    // If hit, record current breakpoint
    //
    DebuggerPrivate->DebuggerBreakpointContext[EFI_DEBUGGER_BREAKPOINT_MAX] = DebuggerPrivate->DebuggerBreakpointContext[Index];
    DebuggerPrivate->DebuggerBreakpointContext[EFI_DEBUGGER_BREAKPOINT_MAX].State = TRUE;
    //
    // Update: IP and Instruction (NOTE: Since we not allow set breakpoint to BREAK 3, this update is safe)
    //
    SystemContext.SystemContextEbc->Ip = Address;
    //
    // Set Flags
    //
    DebuggerPrivate->StatusFlags |= EFI_DEBUG_FLAG_EBC_BP;
  } else {
    //
    // If not hit, check whether current IP is in breakpoint list,
    // because STEP will be triggered before execute the instruction.
    // We should not patch it in de-init.
    //
    Address = SystemContext.SystemContextEbc->Ip;

    //
    // Check if the breakpoint is hit
    //
    IsHitBreakpoint = FALSE;
    for (Index = 0; (Index < DebuggerPrivate->DebuggerBreakpointCount) && (Index < EFI_DEBUGGER_BREAKPOINT_MAX); Index++) {
      if ((DebuggerPrivate->DebuggerBreakpointContext[Index].BreakpointAddress == Address) &&
          (DebuggerPrivate->DebuggerBreakpointContext[Index].State)) {
        IsHitBreakpoint = TRUE;
        break;
      }
    }

    if (IsHitBreakpoint) {
      //
      // If hit, record current breakpoint
      //
      DebuggerPrivate->DebuggerBreakpointContext[EFI_DEBUGGER_BREAKPOINT_MAX] = DebuggerPrivate->DebuggerBreakpointContext[Index];
      DebuggerPrivate->DebuggerBreakpointContext[EFI_DEBUGGER_BREAKPOINT_MAX].State = TRUE;
      //
      // Do not set Breakpoint flag. We record the address here just let it not patch breakpoint address when de-init.
      //
    } else {
      //
      // Zero current breakpoint
      //
      ZeroMem (
        &DebuggerPrivate->DebuggerBreakpointContext[EFI_DEBUGGER_BREAKPOINT_MAX],
        sizeof(DebuggerPrivate->DebuggerBreakpointContext[EFI_DEBUGGER_BREAKPOINT_MAX])
        );
    }
  }

  //
  // Done
  //
  return ;
}

/**
  clear all the symbol.

  @param DebuggerPrivate    EBC Debugger private data structure

**/
VOID
EdbClearSymbol (
  IN     EFI_DEBUGGER_PRIVATE_DATA *DebuggerPrivate
  )
{
  EFI_DEBUGGER_SYMBOL_CONTEXT *DebuggerSymbolContext;
  EFI_DEBUGGER_SYMBOL_OBJECT  *Object;
  UINTN                       ObjectIndex;
  UINTN                       Index;

  //
  // Go throuth each object
  //
  DebuggerSymbolContext = &DebuggerPrivate->DebuggerSymbolContext;
  for (ObjectIndex = 0; ObjectIndex < DebuggerSymbolContext->ObjectCount; ObjectIndex++) {
    Object = &DebuggerSymbolContext->Object[ObjectIndex];
    //
    // Go throuth each entry
    //
    for (Index = 0; Index < Object->EntryCount; Index++) {
      ZeroMem (&Object->Entry[Index], sizeof(Object->Entry[Index]));
    }
    ZeroMem (Object->Name, sizeof(Object->Name));
    Object->EntryCount = 0;
    Object->BaseAddress = 0;
    Object->StartEntrypointRVA = 0;
    Object->MainEntrypointRVA = 0;
    //
    // Free source buffer
    //
    for (Index = 0; Object->SourceBuffer[Index] != NULL; Index++) {
      gBS->FreePool (Object->SourceBuffer[Index]);
      Object->SourceBuffer[Index] = NULL;
    }
  }
  DebuggerSymbolContext->ObjectCount = 0;

  return ;
}

/**

  Initialize Debugger private data structure

  @param DebuggerPrivate   EBC Debugger private data structure
  @param ExceptionType     Exception type.
  @param SystemContext     EBC system context.
  @param Initialized       Whether the DebuggerPrivate data is initialized.

**/
EFI_STATUS
InitDebuggerPrivateData (
  IN     EFI_DEBUGGER_PRIVATE_DATA *DebuggerPrivate,
  IN     EFI_EXCEPTION_TYPE        ExceptionType,
  IN     EFI_SYSTEM_CONTEXT        SystemContext,
  IN     BOOLEAN                   Initialized
  )
{
  //
  // clear STEP flag in any condition.
  //
  if (SystemContext.SystemContextEbc->Flags & ((UINT64) VMFLAGS_STEP)) {
    SystemContext.SystemContextEbc->Flags &= ~((UINT64) VMFLAGS_STEP);
  }

  if (!Initialized) {
    //
    // Initialize everything
    //
    DebuggerPrivate->InstructionNumber = EFI_DEBUG_DEFAULT_INSTRUCTION_NUMBER;

    DebuggerPrivate->DebuggerBreakpointCount = 0;
    ZeroMem (DebuggerPrivate->DebuggerBreakpointContext, sizeof(DebuggerPrivate->DebuggerBreakpointContext));

//    DebuggerPrivate->StatusFlags = 0;

    DebuggerPrivate->DebuggerSymbolContext.DisplaySymbol = TRUE;
    DebuggerPrivate->DebuggerSymbolContext.DisplayCodeOnly = FALSE;
    DebuggerPrivate->DebuggerSymbolContext.ObjectCount = 0;
  } else {
    //
    // Already initialized, just check Breakpoint here.
    //
    if (ExceptionType == EXCEPT_EBC_BREAKPOINT) {
      EdbCheckBreakpoint (DebuggerPrivate, SystemContext);
    }

    //
    // Clear all breakpoint
    //
    EdbClearAllBreakpoint (DebuggerPrivate, FALSE);
  }

  //
  // Set Scope to currentl IP. (Note: Check Breakpoint may change Ip)
  //
  DebuggerPrivate->InstructionScope = SystemContext.SystemContextEbc->Ip;

  //
  // Done
  //
  return EFI_SUCCESS;
}

/**

  De-initialize Debugger private data structure.

  @param DebuggerPrivate   EBC Debugger private data structure
  @param ExceptionType     Exception type.
  @param SystemContext     EBC system context.
  @param Initialized       Whether the DebuggerPrivate data is initialized.

**/
EFI_STATUS
DeinitDebuggerPrivateData (
  IN     EFI_DEBUGGER_PRIVATE_DATA *DebuggerPrivate,
  IN     EFI_EXCEPTION_TYPE        ExceptionType,
  IN     EFI_SYSTEM_CONTEXT        SystemContext,
  IN     BOOLEAN                   Initialized
  )
{
  if (!Initialized) {
    //
    // If it does not want initialized state, de-init everything
    //
    DebuggerPrivate->FeatureFlags = EFI_DEBUG_FLAG_EBC_BOE | EFI_DEBUG_FLAG_EBC_BOT;
    DebuggerPrivate->CallStackEntryCount = 0;
    DebuggerPrivate->TraceEntryCount = 0;
    ZeroMem (DebuggerPrivate->CallStackEntry, sizeof(DebuggerPrivate->CallStackEntry));
    ZeroMem (DebuggerPrivate->TraceEntry, sizeof(DebuggerPrivate->TraceEntry));

    //
    // Clear all breakpoint
    //
    EdbClearAllBreakpoint (DebuggerPrivate, TRUE);

    //
    // Clear symbol
    //
    EdbClearSymbol (DebuggerPrivate);
  } else {
    //
    // If it wants to keep initialized state, just set breakpoint.
    //
    EdbSetAllBreakpoint (DebuggerPrivate);
  }

  //
  // Clear Step context
  //
  ZeroMem (&mDebuggerPrivate.StepContext, sizeof(mDebuggerPrivate.StepContext));
  DebuggerPrivate->StatusFlags = 0;

  //
  // Done
  //
  return EFI_SUCCESS;
}

/**

  Print the reason of current break to EbcDebugger.

  @param DebuggerPrivate   EBC Debugger private data structure
  @param ExceptionType     Exception type.
  @param SystemContext     EBC system context.
  @param Initialized       Whether the DebuggerPrivate data is initialized.

**/
VOID
PrintExceptionReason (
  IN     EFI_DEBUGGER_PRIVATE_DATA *DebuggerPrivate,
  IN     EFI_EXCEPTION_TYPE        ExceptionType,
  IN     EFI_SYSTEM_CONTEXT        SystemContext,
  IN     BOOLEAN                   Initialized
  )
{
  //
  // Print break status
  //
  if ((DebuggerPrivate->StatusFlags & EFI_DEBUG_FLAG_EBC_GT) == EFI_DEBUG_FLAG_EBC_GT) {
    EDBPrint (L"Break on GoTil\n");
  } else if ((DebuggerPrivate->StatusFlags & EFI_DEBUG_FLAG_EBC_BOC) == EFI_DEBUG_FLAG_EBC_BOC) {
    EDBPrint (L"Break on CALL\n");
  } else if ((DebuggerPrivate->StatusFlags & EFI_DEBUG_FLAG_EBC_BOCX) == EFI_DEBUG_FLAG_EBC_BOCX) {
    EDBPrint (L"Break on CALLEX\n");
  } else if ((DebuggerPrivate->StatusFlags & EFI_DEBUG_FLAG_EBC_BOR) == EFI_DEBUG_FLAG_EBC_BOR) {
    EDBPrint (L"Break on RET\n");
  } else if ((DebuggerPrivate->StatusFlags & EFI_DEBUG_FLAG_EBC_BOE) == EFI_DEBUG_FLAG_EBC_BOE) {
    EDBPrint (L"Break on Entrypoint\n");
  } else if ((DebuggerPrivate->StatusFlags & EFI_DEBUG_FLAG_EBC_BOT) == EFI_DEBUG_FLAG_EBC_BOT) {
    EDBPrint (L"Break on Thunk\n");
  } else if ((DebuggerPrivate->StatusFlags & EFI_DEBUG_FLAG_EBC_STEPOVER) == EFI_DEBUG_FLAG_EBC_STEPOVER) {
    EDBPrint (L"Break on StepOver\n");
  } else if ((DebuggerPrivate->StatusFlags & EFI_DEBUG_FLAG_EBC_STEPOUT) == EFI_DEBUG_FLAG_EBC_STEPOUT) {
    EDBPrint (L"Break on StepOut\n");
  } else if ((DebuggerPrivate->StatusFlags & EFI_DEBUG_FLAG_EBC_BP) == EFI_DEBUG_FLAG_EBC_BP) {
    EDBPrint (L"Break on Breakpoint\n");
  } else if ((DebuggerPrivate->StatusFlags & EFI_DEBUG_FLAG_EBC_BOK) == EFI_DEBUG_FLAG_EBC_BOK) {
    EDBPrint (L"Break on Key\n");
  } else {
    EDBPrint (L"Exception Type - %x", (UINTN)ExceptionType);
    if ((ExceptionType >= EXCEPT_EBC_UNDEFINED) && (ExceptionType <= EXCEPT_EBC_STEP)) {
      EDBPrint (L" (%s)\n", mExceptionStr[ExceptionType]);
    } else {
      EDBPrint (L"\n");
    }
  }

  return ;
}

/**

  The default Exception Callback for the VM interpreter.
  In this function, we report status code, and print debug information
  about EBC_CONTEXT, then dead loop.

  @param ExceptionType    Exception type.
  @param SystemContext    EBC system context.

**/
VOID
EFIAPI
EdbExceptionHandler (
  IN     EFI_EXCEPTION_TYPE   ExceptionType,
  IN OUT EFI_SYSTEM_CONTEXT   SystemContext
  )
{
  CHAR16                  InputBuffer[EFI_DEBUG_INPUS_BUFFER_SIZE];
  CHAR16                  *CommandArg;
  EFI_DEBUGGER_COMMAND    DebuggerCommand;
  EFI_DEBUG_STATUS        DebugStatus;
  STATIC BOOLEAN          mInitialized;

  mInitialized = FALSE;

  DEBUG ((DEBUG_ERROR, "Hello EBC Debugger!\n"));

  if (!mInitialized) {
    //
    // Print version
    //
    EDBPrint (
      L"EBC Interpreter Version - %d.%d\n",
      (UINTN)VM_MAJOR_VERSION,
      (UINTN)VM_MINOR_VERSION
      );
    EDBPrint (
      L"EBC Debugger Version - %d.%d\n",
      (UINTN)EBC_DEBUGGER_MAJOR_VERSION,
      (UINTN)EBC_DEBUGGER_MINOR_VERSION
      );
  }
  //
  // Init Private Data
  //
  InitDebuggerPrivateData (&mDebuggerPrivate, ExceptionType, SystemContext, mInitialized);

  //
  // EDBPrint basic info
  //
  PrintExceptionReason (&mDebuggerPrivate, ExceptionType, SystemContext, mInitialized);

  EdbShowDisasm (&mDebuggerPrivate, SystemContext);
  // EFI_BREAKPOINT ();

  if (!mInitialized) {
    //
    // Interactive with user
    //
    EDBPrint (L"\nPlease enter command now, \'h\' for help.\n");
    EDBPrint (L"(Using <Command> -b <...> to enable page break.)\n");
  }
  mInitialized = TRUE;

  //
  // Dispatch each command
  //
  while (TRUE) {
    //
    // Get user input
    //
    Input (L"\n\r" EFI_DEBUG_PROMPT_STRING, InputBuffer, EFI_DEBUG_INPUS_BUFFER_SIZE);
    EDBPrint (L"\n");

    //
    // Get command
    //
    DebuggerCommand = MatchDebuggerCommand (InputBuffer, &CommandArg);
    if (DebuggerCommand == NULL) {
      EDBPrint (L"ERROR: Command not found!\n");
      continue;
    }

    //
    // Check PageBreak;
    //
    if (CommandArg != NULL) {
      if (StriCmp (CommandArg, L"-b") == 0) {
        CommandArg = StrGetNextTokenLine (L" ");
        mDebuggerPrivate.EnablePageBreak = TRUE;
      }
    }

    //
    // Dispatch command
    //
    DebugStatus = DebuggerCommand (CommandArg, &mDebuggerPrivate, ExceptionType, SystemContext);
    mDebuggerPrivate.EnablePageBreak = FALSE;

    //
    // Check command return status
    //
    if (DebugStatus == EFI_DEBUG_RETURN) {
      mInitialized = FALSE;
      break;
    } else if (DebugStatus == EFI_DEBUG_BREAK) {
      break;
    } else if (DebugStatus == EFI_DEBUG_CONTINUE) {
      continue;
    } else {
      ASSERT (FALSE);
    }
  }

  //
  // Deinit Private Data
  //
  DeinitDebuggerPrivateData (&mDebuggerPrivate, ExceptionType, SystemContext, mInitialized);

  DEBUG ((DEBUG_ERROR, "Goodbye EBC Debugger!\n"));

  return;
}