[mirror_edk2.git] / EmbeddedPkg / GdbStub / GdbStub.c

/** @file\r
  UEFI driver that implements a GDB stub\r
\r
  Note: Any code in the path of the Serial IO output can not call DEBUG as will\r
  will blow out the stack. Serial IO calls DEBUG, debug calls Serial IO, ...\r
\r
\r
  Copyright (c) 2008 - 2009, Apple Inc. All rights reserved.<BR>\r
\r
  SPDX-License-Identifier: BSD-2-Clause-Patent\r
\r
**/\r
\r
#include <GdbStubInternal.h>\r
#include <Protocol/DebugPort.h>\r
\r
\r
UINTN     gMaxProcessorIndex = 0;\r
\r
//\r
// Buffers for basic gdb communication\r
//\r
CHAR8 gInBuffer[MAX_BUF_SIZE];\r
CHAR8 gOutBuffer[MAX_BUF_SIZE];\r
\r
// Assume gdb does a "qXfer:libraries:read::offset,length" when it connects so we can default\r
// this value to FALSE. Since gdb can reconnect its self a global default is not good enough\r
BOOLEAN   gSymbolTableUpdate = FALSE;\r
EFI_EVENT gEvent;\r
VOID      *gGdbSymbolEventHandlerRegistration = NULL;\r
\r
//\r
// Globals for returning XML from qXfer:libraries:read packet\r
//\r
UINTN                             gPacketqXferLibraryOffset = 0;\r
UINTN                             gEfiDebugImageTableEntry = 0;\r
EFI_DEBUG_IMAGE_INFO_TABLE_HEADER *gDebugImageTableHeader = NULL;\r
EFI_DEBUG_IMAGE_INFO              *gDebugTable = NULL;\r
CHAR8                             gXferLibraryBuffer[2000];\r
\r
GLOBAL_REMOVE_IF_UNREFERENCED CONST CHAR8 mHexToStr[] = {'0','1','2','3','4','5','6','7','8','9','A','B','C','D','E','F'};\r
\r
\r
VOID\r
EFIAPI\r
GdbSymbolEventHandler (\r
  IN  EFI_EVENT       Event,\r
  IN  VOID            *Context\r
  )\r
{\r
}\r
\r
\r
/**\r
  The user Entry Point for Application. The user code starts with this function\r
  as the real entry point for the image goes into a library that calls this\r
  function.\r
\r
  @param[in] ImageHandle    The firmware allocated handle for the EFI image.\r
  @param[in] SystemTable    A pointer to the EFI System Table.\r
\r
  @retval EFI_SUCCESS       The entry point is executed successfully.\r
  @retval other             Some error occurs when executing this entry point.\r
\r
**/\r
EFI_STATUS\r
EFIAPI\r
GdbStubEntry (\r
  IN EFI_HANDLE        ImageHandle,\r
  IN EFI_SYSTEM_TABLE  *SystemTable\r
  )\r
{\r
  EFI_STATUS                  Status;\r
  EFI_DEBUG_SUPPORT_PROTOCOL  *DebugSupport;\r
  UINTN                       HandleCount;\r
  EFI_HANDLE                  *Handles;\r
  UINTN                       Index;\r
  UINTN                       Processor;\r
  BOOLEAN                     IsaSupported;\r
\r
  Status = EfiGetSystemConfigurationTable (&gEfiDebugImageInfoTableGuid, (VOID **)&gDebugImageTableHeader);\r
  if (EFI_ERROR (Status)) {\r
    gDebugImageTableHeader = NULL;\r
  }\r
\r
  Status = gBS->LocateHandleBuffer (\r
                  ByProtocol,\r
                  &gEfiDebugSupportProtocolGuid,\r
                  NULL,\r
                  &HandleCount,\r
                  &Handles\r
                  );\r
  if (EFI_ERROR (Status)) {\r
    DEBUG ((EFI_D_ERROR, "Debug Support Protocol not found\n"));\r
\r
    return Status;\r
  }\r
\r
  DebugSupport = NULL;\r
  IsaSupported = FALSE;\r
  do {\r
    HandleCount--;\r
    Status = gBS->HandleProtocol (\r
                    Handles[HandleCount],\r
                    &gEfiDebugSupportProtocolGuid,\r
                    (VOID **) &DebugSupport\r
                    );\r
    if (!EFI_ERROR (Status)) {\r
      if (CheckIsa (DebugSupport->Isa)) {\r
        // We found what we are looking for so break out of the loop\r
        IsaSupported = TRUE;\r
        break;\r
      }\r
    }\r
  } while (HandleCount > 0);\r
  FreePool (Handles);\r
\r
  if (!IsaSupported) {\r
    DEBUG ((EFI_D_ERROR, "Debug Support Protocol does not support our ISA\n"));\r
\r
    return EFI_NOT_FOUND;\r
  }\r
\r
  Status = DebugSupport->GetMaximumProcessorIndex (DebugSupport, &gMaxProcessorIndex);\r
  ASSERT_EFI_ERROR (Status);\r
\r
  DEBUG ((EFI_D_INFO, "Debug Support Protocol ISA %x\n", DebugSupport->Isa));\r
  DEBUG ((EFI_D_INFO, "Debug Support Protocol Processor Index %d\n", gMaxProcessorIndex));\r
\r
  // Call processor-specific init routine\r
  InitializeProcessor ();\r
\r
  for (Processor = 0; Processor <= gMaxProcessorIndex; Processor++) {\r
    for (Index = 0; Index < MaxEfiException (); Index++) {\r
      Status = DebugSupport->RegisterExceptionCallback (DebugSupport, Processor,  GdbExceptionHandler, gExceptionType[Index].Exception);\r
      ASSERT_EFI_ERROR (Status);\r
    }\r
    //\r
    // Current edk2 DebugPort is not interrupt context safe so we can not use it\r
    //\r
    Status = DebugSupport->RegisterPeriodicCallback (DebugSupport, Processor, GdbPeriodicCallBack);\r
    ASSERT_EFI_ERROR (Status);\r
  }\r
\r
  //\r
  // This even fires every time an image is added. This allows the stub to know when gdb needs\r
  // to update the symbol table.\r
  //\r
  Status = gBS->CreateEvent (\r
                  EVT_NOTIFY_SIGNAL,\r
                  TPL_CALLBACK,\r
                  GdbSymbolEventHandler,\r
                  NULL,\r
                  &gEvent\r
                  );\r
  ASSERT_EFI_ERROR (Status);\r
\r
  //\r
  // Register for protocol notifications on this event\r
  //\r
  Status = gBS->RegisterProtocolNotify (\r
                  &gEfiLoadedImageProtocolGuid,\r
                  gEvent,\r
                  &gGdbSymbolEventHandlerRegistration\r
                  );\r
  ASSERT_EFI_ERROR (Status);\r
\r
\r
 if (PcdGetBool (PcdGdbSerial)) {\r
   GdbInitializeSerialConsole ();\r
 }\r
\r
  return EFI_SUCCESS;\r
}\r
\r
/**\r
 Transfer length bytes of input buffer, starting at Address, to memory.\r
\r
 @param     length                  the number of the bytes to be transferred/written\r
 @param     *address                the start address of the transferring/writing the memory\r
 @param     *new_data               the new data to be written to memory\r
 **/\r
\r
VOID\r
TransferFromInBufToMem (\r
  IN    UINTN                       Length,\r
  IN    unsigned char               *Address,\r
  IN    CHAR8                       *NewData\r
  )\r
{\r
  CHAR8 c1;\r
  CHAR8 c2;\r
\r
  while (Length-- > 0) {\r
    c1 = (CHAR8)HexCharToInt (*NewData++);\r
    c2 = (CHAR8)HexCharToInt (*NewData++);\r
\r
    if ((c1 < 0) || (c2 < 0)) {\r
      Print ((CHAR16 *)L"Bad message from write to memory..\n");\r
      SendError (GDB_EBADMEMDATA);\r
      return;\r
    }\r
    *Address++ = (UINT8)((c1 << 4) + c2);\r
  }\r
\r
  SendSuccess();\r
}\r
\r
\r
/**\r
 Transfer Length bytes of memory starting at Address to an output buffer, OutBuffer. This function will finally send the buffer\r
 as a packet.\r
\r
 @param     Length                  the number of the bytes to be transferred/read\r
 @param     *address                pointer to the start address of the transferring/reading the memory\r
 **/\r
\r
VOID\r
TransferFromMemToOutBufAndSend (\r
  IN    UINTN                       Length,\r
  IN    unsigned char               *Address\r
  )\r
{\r
  // there are Length bytes and every byte is represented as 2 hex chars\r
  CHAR8   OutBuffer[MAX_BUF_SIZE];\r
  CHAR8   *OutBufPtr;             // pointer to the output buffer\r
  CHAR8   Char;\r
\r
  if (ValidateAddress(Address) == FALSE) {\r
    SendError(14);\r
    return;\r
  }\r
\r
  OutBufPtr = OutBuffer;\r
  while (Length > 0) {\r
\r
    Char = mHexToStr[*Address >> 4];\r
    if ((Char >= 'A') && (Char <= 'F')) {\r
      Char = Char - 'A' + 'a';\r
    }\r
    *OutBufPtr++ = Char;\r
\r
    Char = mHexToStr[*Address & 0x0f];\r
    if ((Char >= 'A') && (Char <= 'F')) {\r
      Char = Char - 'A' + 'a';\r
    }\r
    *OutBufPtr++ = Char;\r
\r
    Address++;\r
    Length--;\r
  }\r
\r
  *OutBufPtr = '\0' ;  // the end of the buffer\r
  SendPacket (OutBuffer);\r
}\r
\r
\r
\r
/**\r
  Send a GDB Remote Serial Protocol Packet\r
\r
  $PacketData#checksum PacketData is passed in and this function adds the packet prefix '$',\r
  the packet terminating character '#' and the two digit checksum.\r
\r
  If an ack '+' is not sent resend the packet, but timeout eventually so we don't end up\r
  in an infinite loop. This is so if you unplug the debugger code just keeps running\r
\r
  @param PacketData   Payload data for the packet\r
\r
\r
  @retval             Number of bytes of packet data sent.\r
\r
**/\r
UINTN\r
SendPacket (\r
  IN  CHAR8 *PacketData\r
  )\r
{\r
  UINT8 CheckSum;\r
  UINTN Timeout;\r
  CHAR8 *Ptr;\r
  CHAR8 TestChar;\r
  UINTN Count;\r
\r
  Timeout = PcdGet32 (PcdGdbMaxPacketRetryCount);\r
\r
  Count = 0;\r
  do {\r
\r
    Ptr = PacketData;\r
\r
    if (Timeout-- == 0) {\r
      // Only try a finite number of times so we don't get stuck in the loop\r
      return Count;\r
    }\r
\r
    // Packet prefix\r
    GdbPutChar ('$');\r
\r
    for (CheckSum = 0, Count =0 ; *Ptr != '\0'; Ptr++, Count++) {\r
      GdbPutChar (*Ptr);\r
      CheckSum = CheckSum + *Ptr;\r
    }\r
\r
    // Packet terminating character and checksum\r
    GdbPutChar ('#');\r
    GdbPutChar (mHexToStr[CheckSum >> 4]);\r
    GdbPutChar (mHexToStr[CheckSum & 0x0F]);\r
\r
    TestChar =  GdbGetChar ();\r
  } while (TestChar != '+');\r
\r
  return Count;\r
}\r
\r
/**\r
  Receive a GDB Remote Serial Protocol Packet\r
\r
  $PacketData#checksum PacketData is passed in and this function adds the packet prefix '$',\r
  the packet terminating character '#' and the two digit checksum.\r
\r
  If host re-starts sending a packet without ending the previous packet, only the last valid packet is processed.\r
  (In other words, if received packet is '$12345$12345$123456#checksum', only '$123456#checksum' will be processed.)\r
\r
  If an ack '+' is not sent resend the packet\r
\r
  @param PacketData   Payload data for the packet\r
\r
  @retval             Number of bytes of packet data received.\r
\r
**/\r
UINTN\r
ReceivePacket (\r
  OUT  CHAR8 *PacketData,\r
  IN   UINTN PacketDataSize\r
 )\r
{\r
  UINT8 CheckSum;\r
  UINTN Index;\r
  CHAR8 Char;\r
  CHAR8 SumString[3];\r
  CHAR8 TestChar;\r
\r
  ZeroMem (PacketData, PacketDataSize);\r
\r
  for (;;) {\r
      // wait for the start of a packet\r
    TestChar = GdbGetChar ();\r
    while (TestChar != '$') {\r
      TestChar = GdbGetChar ();\r
    };\r
\r
  retry:\r
    for (Index = 0, CheckSum = 0; Index < (PacketDataSize - 1); Index++) {\r
      Char = GdbGetChar ();\r
      if (Char == '$') {\r
        goto retry;\r
      }\r
      if (Char == '#') {\r
        break;\r
      }\r
\r
      PacketData[Index] = Char;\r
      CheckSum = CheckSum + Char;\r
    }\r
    PacketData[Index] = '\0';\r
\r
    if (Index == PacketDataSize) {\r
      continue;\r
    }\r
\r
    SumString[0] = GdbGetChar ();\r
    SumString[1] = GdbGetChar ();\r
    SumString[2] = '\0';\r
\r
    if (AsciiStrHexToUintn (SumString) == CheckSum) {\r
      // Ack: Success\r
      GdbPutChar ('+');\r
\r
      // Null terminate the callers string\r
      PacketData[Index] = '\0';\r
      return Index;\r
    } else {\r
      // Ack: Failure\r
      GdbPutChar ('-');\r
    }\r
  }\r
\r
  //return 0;\r
}\r
\r
\r
/**\r
 Empties the given buffer\r
 @param   Buf          pointer to the first element in buffer to be emptied\r
 **/\r
VOID\r
EmptyBuffer (\r
  IN  CHAR8           *Buf\r
  )\r
{\r
  *Buf = '\0';\r
}\r
\r
\r
/**\r
 Converts an 8-bit Hex Char into a INTN.\r
\r
 @param   Char the hex character to be converted into UINTN\r
 @retval  a INTN, from 0 to 15, that corresponds to Char\r
 -1 if Char is not a hex character\r
 **/\r
INTN\r
HexCharToInt (\r
  IN  CHAR8           Char\r
  )\r
{\r
  if ((Char >= 'A') && (Char <= 'F')) {\r
    return Char - 'A' + 10;\r
  } else if ((Char >= 'a') && (Char <= 'f')) {\r
    return Char - 'a' + 10;\r
  } else if ((Char >= '0') && (Char <= '9')) {\r
    return Char - '0';\r
  } else { // if not a hex value, return a negative value\r
    return -1;\r
  }\r
}\r
\r
  // 'E' + the biggest error number is 255, so its 2 hex digits + buffer end\r
CHAR8 *gError = "E__";\r
\r
/** 'E NN'\r
 Send an error with the given error number after converting to hex.\r
 The error number is put into the buffer in hex. '255' is the biggest errno we can send.\r
 ex: 162 will be sent as A2.\r
\r
 @param   errno           the error number that will be sent\r
 **/\r
VOID\r
EFIAPI\r
SendError (\r
  IN  UINT8              ErrorNum\r
  )\r
{\r
  //\r
  // Replace _, or old data, with current errno\r
  //\r
  gError[1] = mHexToStr [ErrorNum >> 4];\r
  gError[2] = mHexToStr [ErrorNum & 0x0f];\r
\r
  SendPacket (gError); // send buffer\r
}\r
\r
\r
\r
/**\r
 Send 'OK' when the function is done executing successfully.\r
 **/\r
VOID\r
EFIAPI\r
SendSuccess (\r
  VOID\r
  )\r
{\r
  SendPacket ("OK"); // send buffer\r
}\r
\r
\r
/**\r
 Send empty packet to specify that particular command/functionality is not supported.\r
 **/\r
VOID\r
EFIAPI\r
SendNotSupported (\r
  VOID\r
  )\r
{\r
  SendPacket ("");\r
}\r
\r
\r
/**\r
 Send the T signal with the given exception type (in gdb order) and possibly with n:r pairs related to the watchpoints\r
\r
 @param  SystemContext        Register content at time of the exception\r
 @param  GdbExceptionType     GDB exception type\r
 **/\r
VOID\r
GdbSendTSignal (\r
  IN  EFI_SYSTEM_CONTEXT  SystemContext,\r
  IN  UINT8               GdbExceptionType\r
  )\r
{\r
  CHAR8 TSignalBuffer[128];\r
  CHAR8 *TSignalPtr;\r
  UINTN BreakpointDetected;\r
  BREAK_TYPE BreakType;\r
  UINTN DataAddress;\r
  CHAR8 *WatchStrPtr = NULL;\r
  UINTN RegSize;\r
\r
  TSignalPtr = &TSignalBuffer[0];\r
\r
  //Construct TSignal packet\r
  *TSignalPtr++ = 'T';\r
\r
  //\r
  // replace _, or previous value, with Exception type\r
  //\r
  *TSignalPtr++ = mHexToStr [GdbExceptionType >> 4];\r
  *TSignalPtr++ = mHexToStr [GdbExceptionType & 0x0f];\r
\r
  if (GdbExceptionType == GDB_SIGTRAP) {\r
    if (gSymbolTableUpdate) {\r
      //\r
      // We can only send back on reason code. So if the flag is set it means the breakpoint is from our event handler\r
      //\r
      WatchStrPtr = "library:;";\r
      while (*WatchStrPtr != '\0') {\r
        *TSignalPtr++ = *WatchStrPtr++;\r
      }\r
      gSymbolTableUpdate = FALSE;\r
    } else {\r
\r
\r
      //\r
      // possible n:r pairs\r
      //\r
\r
      //Retrieve the breakpoint number\r
      BreakpointDetected = GetBreakpointDetected (SystemContext);\r
\r
      //Figure out if the exception is happend due to watch, rwatch or awatch.\r
      BreakType = GetBreakpointType (SystemContext, BreakpointDetected);\r
\r
      //INFO: rwatch is not supported due to the way IA32 debug registers work\r
      if ((BreakType == DataWrite) || (BreakType == DataRead) || (BreakType == DataReadWrite)) {\r
\r
        //Construct n:r pair\r
        DataAddress = GetBreakpointDataAddress (SystemContext, BreakpointDetected);\r
\r
        //Assign appropriate buffer to print particular watchpoint type\r
        if (BreakType == DataWrite) {\r
          WatchStrPtr = "watch";\r
        } else if (BreakType == DataRead) {\r
          WatchStrPtr = "rwatch";\r
        } else if (BreakType == DataReadWrite) {\r
          WatchStrPtr = "awatch";\r
        }\r
\r
        while (*WatchStrPtr != '\0') {\r
          *TSignalPtr++ = *WatchStrPtr++;\r
        }\r
\r
        *TSignalPtr++ = ':';\r
\r
        //Set up series of bytes in big-endian byte order. "awatch" won't work with little-endian byte order.\r
        RegSize = REG_SIZE;\r
        while (RegSize > 0) {\r
          RegSize = RegSize-4;\r
          *TSignalPtr++ = mHexToStr[(UINT8)(DataAddress >> RegSize) & 0xf];\r
        }\r
\r
        //Always end n:r pair with ';'\r
        *TSignalPtr++ = ';';\r
      }\r
    }\r
  }\r
\r
  *TSignalPtr = '\0';\r
\r
  SendPacket (TSignalBuffer);\r
}\r
\r
\r
/**\r
 Translates the EFI mapping to GDB mapping\r
\r
 @param   EFIExceptionType    EFI Exception that is being processed\r
 @retval  UINTN that corresponds to EFIExceptionType's GDB exception type number\r
 **/\r
UINT8\r
ConvertEFItoGDBtype (\r
  IN  EFI_EXCEPTION_TYPE      EFIExceptionType\r
  )\r
{\r
  UINTN Index;\r
\r
  for (Index = 0; Index < MaxEfiException () ; Index++) {\r
    if (gExceptionType[Index].Exception == EFIExceptionType) {\r
      return gExceptionType[Index].SignalNo;\r
    }\r
  }\r
  return GDB_SIGTRAP; // this is a GDB trap\r
}\r
\r
\r
/** "m addr,length"\r
 Find the Length of the area to read and the start address. Finally, pass them to\r
 another function, TransferFromMemToOutBufAndSend, that will read from that memory space and\r
 send it as a packet.\r
 **/\r
\r
VOID\r
EFIAPI\r
ReadFromMemory (\r
  CHAR8 *PacketData\r
  )\r
{\r
  UINTN Address;\r
  UINTN Length;\r
  CHAR8 AddressBuffer[MAX_ADDR_SIZE]; // the buffer that will hold the address in hex chars\r
  CHAR8 *AddrBufPtr; // pointer to the address buffer\r
  CHAR8 *InBufPtr; /// pointer to the input buffer\r
\r
  AddrBufPtr = AddressBuffer;\r
  InBufPtr = &PacketData[1];\r
  while (*InBufPtr != ',') {\r
    *AddrBufPtr++ = *InBufPtr++;\r
  }\r
  *AddrBufPtr = '\0';\r
\r
  InBufPtr++; // this skips ',' in the buffer\r
\r
  /* Error checking */\r
  if (AsciiStrLen (AddressBuffer) >= MAX_ADDR_SIZE) {\r
    Print((CHAR16 *)L"Address is too long\n");\r
    SendError (GDB_EBADMEMADDRBUFSIZE);\r
    return;\r
  }\r
\r
  // 2 = 'm' + ','\r
  if (AsciiStrLen (PacketData) - AsciiStrLen (AddressBuffer) - 2 >= MAX_LENGTH_SIZE) {\r
    Print((CHAR16 *)L"Length is too long\n");\r
    SendError (GDB_EBADMEMLENGTH);\r
    return;\r
  }\r
\r
  Address = AsciiStrHexToUintn (AddressBuffer);\r
  Length = AsciiStrHexToUintn (InBufPtr);\r
\r
  TransferFromMemToOutBufAndSend (Length, (unsigned char *)Address);\r
}\r
\r
\r
/** "M addr,length :XX..."\r
 Find the Length of the area in bytes to write and the start address. Finally, pass them to\r
 another function, TransferFromInBufToMem, that will write to that memory space the info in\r
 the input buffer.\r
 **/\r
VOID\r
EFIAPI\r
WriteToMemory (\r
  IN CHAR8 *PacketData\r
  )\r
{\r
  UINTN Address;\r
  UINTN Length;\r
  UINTN MessageLength;\r
  CHAR8 AddressBuffer[MAX_ADDR_SIZE]; // the buffer that will hold the Address in hex chars\r
  CHAR8 LengthBuffer[MAX_LENGTH_SIZE]; // the buffer that will hold the Length in hex chars\r
  CHAR8 *AddrBufPtr; // pointer to the Address buffer\r
  CHAR8 *LengthBufPtr; // pointer to the Length buffer\r
  CHAR8 *InBufPtr; /// pointer to the input buffer\r
\r
  AddrBufPtr = AddressBuffer;\r
  LengthBufPtr = LengthBuffer;\r
  InBufPtr = &PacketData[1];\r
\r
  while (*InBufPtr != ',') {\r
    *AddrBufPtr++ = *InBufPtr++;\r
  }\r
  *AddrBufPtr = '\0';\r
\r
  InBufPtr++; // this skips ',' in the buffer\r
\r
  while (*InBufPtr != ':') {\r
    *LengthBufPtr++ = *InBufPtr++;\r
  }\r
  *LengthBufPtr = '\0';\r
\r
  InBufPtr++; // this skips ':' in the buffer\r
\r
  Address = AsciiStrHexToUintn (AddressBuffer);\r
  Length = AsciiStrHexToUintn (LengthBuffer);\r
\r
  /* Error checking */\r
\r
  //Check if Address is not too long.\r
  if (AsciiStrLen (AddressBuffer) >= MAX_ADDR_SIZE) {\r
    Print ((CHAR16 *)L"Address too long..\n");\r
    SendError (GDB_EBADMEMADDRBUFSIZE);\r
    return;\r
  }\r
\r
  //Check if message length is not too long\r
  if (AsciiStrLen (LengthBuffer) >= MAX_LENGTH_SIZE) {\r
    Print ((CHAR16 *)L"Length too long..\n");\r
    SendError (GDB_EBADMEMLENGBUFSIZE);\r
    return;\r
  }\r
\r
  // Check if Message is not too long/short.\r
  // 3 = 'M' + ',' + ':'\r
  MessageLength = (AsciiStrLen (PacketData) - AsciiStrLen (AddressBuffer) - AsciiStrLen (LengthBuffer) - 3);\r
  if (MessageLength != (2*Length)) {\r
    //Message too long/short. New data is not the right size.\r
    SendError (GDB_EBADMEMDATASIZE);\r
    return;\r
  }\r
  TransferFromInBufToMem (Length, (unsigned char *)Address, InBufPtr);\r
}\r
\r
/**\r
  Parses breakpoint packet data and captures Breakpoint type, Address and length.\r
  In case of an error, function returns particular error code. Returning 0 meaning\r
  no error.\r
\r
  @param  PacketData  Pointer to the payload data for the packet.\r
  @param  Type        Breakpoint type\r
  @param  Address     Breakpoint address\r
  @param  Length      Breakpoint length in Bytes (1 byte, 2 byte, 4 byte)\r
\r
  @retval 1           Success\r
  @retval {other}     Particular error code\r
\r
**/\r
UINTN\r
ParseBreakpointPacket (\r
  IN  CHAR8 *PacketData,\r
  OUT UINTN *Type,\r
  OUT UINTN *Address,\r
  OUT UINTN *Length\r
  )\r
{\r
  CHAR8 AddressBuffer[MAX_ADDR_SIZE];\r
  CHAR8 *AddressBufferPtr;\r
  CHAR8 *PacketDataPtr;\r
\r
  PacketDataPtr = &PacketData[1];\r
  AddressBufferPtr = AddressBuffer;\r
\r
  *Type = AsciiStrHexToUintn (PacketDataPtr);\r
\r
  //Breakpoint/watchpoint type should be between 0 to 4\r
  if (*Type > 4) {\r
    Print ((CHAR16 *)L"Type is invalid\n");\r
    return 22; //EINVAL: Invalid argument.\r
  }\r
\r
  //Skip ',' in the buffer.\r
  while (*PacketDataPtr++ != ',');\r
\r
  //Parse Address information\r
  while (*PacketDataPtr != ',') {\r
    *AddressBufferPtr++ = *PacketDataPtr++;\r
  }\r
  *AddressBufferPtr = '\0';\r
\r
  //Check if Address is not too long.\r
  if (AsciiStrLen (AddressBuffer) >= MAX_ADDR_SIZE) {\r
    Print ((CHAR16 *)L"Address too long..\n");\r
    return 40; //EMSGSIZE: Message size too long.\r
  }\r
\r
  *Address = AsciiStrHexToUintn (AddressBuffer);\r
\r
  PacketDataPtr++; //This skips , in the buffer\r
\r
  //Parse Length information\r
  *Length = AsciiStrHexToUintn (PacketDataPtr);\r
\r
  //Length should be 1, 2 or 4 bytes\r
  if (*Length > 4) {\r
    Print ((CHAR16 *)L"Length is invalid\n");\r
    return 22; //EINVAL: Invalid argument\r
  }\r
\r
  return 0; //0 = No error\r
}\r
\r
UINTN\r
gXferObjectReadResponse (\r
  IN  CHAR8         Type,\r
  IN  CHAR8         *Str\r
  )\r
{\r
  CHAR8   *OutBufPtr;             // pointer to the output buffer\r
  CHAR8   Char;\r
  UINTN   Count;\r
\r
  // Response starts with 'm' or 'l' if it is the end\r
  OutBufPtr = gOutBuffer;\r
  *OutBufPtr++ = Type;\r
  Count = 1;\r
\r
  // Binary data encoding\r
  OutBufPtr = gOutBuffer;\r
  while (*Str != '\0') {\r
    Char = *Str++;\r
    if ((Char == 0x7d) || (Char == 0x23) || (Char == 0x24) || (Char == 0x2a)) {\r
      // escape character\r
      *OutBufPtr++ = 0x7d;\r
\r
      Char ^= 0x20;\r
    }\r
    *OutBufPtr++ = Char;\r
    Count++;\r
  }\r
\r
  *OutBufPtr = '\0' ;  // the end of the buffer\r
  SendPacket (gOutBuffer);\r
\r
  return Count;\r
}\r
\r
\r
/**\r
  Note: This should be a library function.  In the Apple case you have to add\r
  the size of the PE/COFF header into the starting address to make things work\r
  right as there is no way to pad the Mach-O for the size of the PE/COFF header.\r
\r
\r
  Returns a pointer to the PDB file name for a PE/COFF image that has been\r
  loaded into system memory with the PE/COFF Loader Library functions.\r
\r
  Returns the PDB file name for the PE/COFF image specified by Pe32Data.  If\r
  the PE/COFF image specified by Pe32Data is not a valid, then NULL is\r
  returned.  If the PE/COFF image specified by Pe32Data does not contain a\r
  debug directory entry, then NULL is returned.  If the debug directory entry\r
  in the PE/COFF image specified by Pe32Data does not contain a PDB file name,\r
  then NULL is returned.\r
  If Pe32Data is NULL, then ASSERT().\r
\r
  @param  Pe32Data   Pointer to the PE/COFF image that is loaded in system\r
                     memory.\r
  @param  DebugBase  Address that the debugger would use as the base of the image\r
\r
  @return The PDB file name for the PE/COFF image specified by Pe32Data or NULL\r
          if it cannot be retrieved. DebugBase is only valid if PDB file name is\r
          valid.\r
\r
**/\r
VOID *\r
EFIAPI\r
PeCoffLoaderGetDebuggerInfo (\r
  IN VOID     *Pe32Data,\r
  OUT VOID    **DebugBase\r
  )\r
{\r
  EFI_IMAGE_DOS_HEADER                  *DosHdr;\r
  EFI_IMAGE_OPTIONAL_HEADER_PTR_UNION   Hdr;\r
  EFI_IMAGE_DATA_DIRECTORY              *DirectoryEntry;\r
  EFI_IMAGE_DEBUG_DIRECTORY_ENTRY       *DebugEntry;\r
  UINTN                                 DirCount;\r
  VOID                                  *CodeViewEntryPointer;\r
  INTN                                  TEImageAdjust;\r
  UINT32                                NumberOfRvaAndSizes;\r
  UINT16                                Magic;\r
  UINTN                                 SizeOfHeaders;\r
\r
  ASSERT (Pe32Data   != NULL);\r
\r
  TEImageAdjust       = 0;\r
  DirectoryEntry      = NULL;\r
  DebugEntry          = NULL;\r
  NumberOfRvaAndSizes = 0;\r
  SizeOfHeaders       = 0;\r
\r
  DosHdr = (EFI_IMAGE_DOS_HEADER *)Pe32Data;\r
  if (DosHdr->e_magic == EFI_IMAGE_DOS_SIGNATURE) {\r
    //\r
    // DOS image header is present, so read the PE header after the DOS image header.\r
    //\r
    Hdr.Pe32 = (EFI_IMAGE_NT_HEADERS32 *)((UINTN) Pe32Data + (UINTN) ((DosHdr->e_lfanew) & 0x0ffff));\r
  } else {\r
    //\r
    // DOS image header is not present, so PE header is at the image base.\r
    //\r
    Hdr.Pe32 = (EFI_IMAGE_NT_HEADERS32 *)Pe32Data;\r
  }\r
\r
  if (Hdr.Te->Signature == EFI_TE_IMAGE_HEADER_SIGNATURE) {\r
    if (Hdr.Te->DataDirectory[EFI_TE_IMAGE_DIRECTORY_ENTRY_DEBUG].VirtualAddress != 0) {\r
      DirectoryEntry  = &Hdr.Te->DataDirectory[EFI_TE_IMAGE_DIRECTORY_ENTRY_DEBUG];\r
      TEImageAdjust   = sizeof (EFI_TE_IMAGE_HEADER) - Hdr.Te->StrippedSize;\r
      DebugEntry = (EFI_IMAGE_DEBUG_DIRECTORY_ENTRY *)((UINTN) Hdr.Te +\r
                    Hdr.Te->DataDirectory[EFI_TE_IMAGE_DIRECTORY_ENTRY_DEBUG].VirtualAddress +\r
                    TEImageAdjust);\r
    }\r
    SizeOfHeaders = sizeof (EFI_TE_IMAGE_HEADER) + (UINTN)Hdr.Te->BaseOfCode - (UINTN)Hdr.Te->StrippedSize;\r
\r
    // __APPLE__ check this math...\r
    *DebugBase = ((CHAR8 *)Pe32Data) -  TEImageAdjust;\r
  } else if (Hdr.Pe32->Signature == EFI_IMAGE_NT_SIGNATURE) {\r
\r
    *DebugBase = Pe32Data;\r
\r
\r
    //\r
    // NOTE: We use Machine field to identify PE32/PE32+, instead of Magic.\r
    //       It is due to backward-compatibility, for some system might\r
    //       generate PE32+ image with PE32 Magic.\r
    //\r
    switch (Hdr.Pe32->FileHeader.Machine) {\r
    case EFI_IMAGE_MACHINE_IA32:\r
      //\r
      // Assume PE32 image with IA32 Machine field.\r
      //\r
      Magic = EFI_IMAGE_NT_OPTIONAL_HDR32_MAGIC;\r
      break;\r
    case EFI_IMAGE_MACHINE_X64:\r
    case EFI_IMAGE_MACHINE_IA64:\r
      //\r
      // Assume PE32+ image with X64 or IPF Machine field\r
      //\r
      Magic = EFI_IMAGE_NT_OPTIONAL_HDR64_MAGIC;\r
      break;\r
    default:\r
      //\r
      // For unknown Machine field, use Magic in optional Header\r
      //\r
      Magic = Hdr.Pe32->OptionalHeader.Magic;\r
    }\r
\r
    if (Magic == EFI_IMAGE_NT_OPTIONAL_HDR32_MAGIC) {\r
      //\r
      // Use PE32 offset get Debug Directory Entry\r
      //\r
      SizeOfHeaders = Hdr.Pe32->OptionalHeader.SizeOfHeaders;\r
      NumberOfRvaAndSizes = Hdr.Pe32->OptionalHeader.NumberOfRvaAndSizes;\r
      DirectoryEntry = (EFI_IMAGE_DATA_DIRECTORY *)&(Hdr.Pe32->OptionalHeader.DataDirectory[EFI_IMAGE_DIRECTORY_ENTRY_DEBUG]);\r
      DebugEntry     = (EFI_IMAGE_DEBUG_DIRECTORY_ENTRY *) ((UINTN) Pe32Data + DirectoryEntry->VirtualAddress);\r
    } else if (Hdr.Pe32->OptionalHeader.Magic == EFI_IMAGE_NT_OPTIONAL_HDR64_MAGIC) {\r
      //\r
      // Use PE32+ offset get Debug Directory Entry\r
      //\r
      SizeOfHeaders = Hdr.Pe32Plus->OptionalHeader.SizeOfHeaders;\r
      NumberOfRvaAndSizes = Hdr.Pe32Plus->OptionalHeader.NumberOfRvaAndSizes;\r
      DirectoryEntry = (EFI_IMAGE_DATA_DIRECTORY *)&(Hdr.Pe32Plus->OptionalHeader.DataDirectory[EFI_IMAGE_DIRECTORY_ENTRY_DEBUG]);\r
      DebugEntry     = (EFI_IMAGE_DEBUG_DIRECTORY_ENTRY *) ((UINTN) Pe32Data + DirectoryEntry->VirtualAddress);\r
    }\r
\r
    if (NumberOfRvaAndSizes <= EFI_IMAGE_DIRECTORY_ENTRY_DEBUG) {\r
      DirectoryEntry = NULL;\r
      DebugEntry = NULL;\r
    }\r
  } else {\r
    return NULL;\r
  }\r
\r
  if (DebugEntry == NULL || DirectoryEntry == NULL) {\r
    return NULL;\r
  }\r
\r
  for (DirCount = 0; DirCount < DirectoryEntry->Size; DirCount += sizeof (EFI_IMAGE_DEBUG_DIRECTORY_ENTRY), DebugEntry++) {\r
    if (DebugEntry->Type == EFI_IMAGE_DEBUG_TYPE_CODEVIEW) {\r
      if (DebugEntry->SizeOfData > 0) {\r
        CodeViewEntryPointer = (VOID *) ((UINTN) DebugEntry->RVA + ((UINTN)Pe32Data) + (UINTN)TEImageAdjust);\r
        switch (* (UINT32 *) CodeViewEntryPointer) {\r
        case CODEVIEW_SIGNATURE_NB10:\r
          return (VOID *) ((CHAR8 *)CodeViewEntryPointer + sizeof (EFI_IMAGE_DEBUG_CODEVIEW_NB10_ENTRY));\r
        case CODEVIEW_SIGNATURE_RSDS:\r
          return (VOID *) ((CHAR8 *)CodeViewEntryPointer + sizeof (EFI_IMAGE_DEBUG_CODEVIEW_RSDS_ENTRY));\r
        case CODEVIEW_SIGNATURE_MTOC:\r
          *DebugBase = (VOID *)(UINTN)((UINTN)DebugBase - SizeOfHeaders);\r
          return (VOID *) ((CHAR8 *)CodeViewEntryPointer + sizeof (EFI_IMAGE_DEBUG_CODEVIEW_MTOC_ENTRY));\r
        default:\r
          break;\r
        }\r
      }\r
    }\r
  }\r
\r
  (void)SizeOfHeaders;\r
  return NULL;\r
}\r
\r
\r
/**\r
  Process "qXfer:object:read:annex:offset,length" request.\r
\r
  Returns an XML document that contains loaded libraries. In our case it is\r
  information in the EFI Debug Image Table converted into an XML document.\r
\r
  GDB will call with an arbitrary length (it can't know the real length and\r
  will reply with chunks of XML that are easy for us to deal with. Gdb will\r
  keep calling until we say we are done. XML doc looks like:\r
\r
  <library-list>\r
    <library name="/a/a/c/d.dSYM"><segment address="0x10000000"/></library>\r
    <library name="/a/m/e/e.pdb"><segment address="0x20000000"/></library>\r
    <library name="/a/l/f/f.dll"><segment address="0x30000000"/></library>\r
  </library-list>\r
\r
  Since we can not allocate memory in interrupt context this module has\r
  assumptions about how it will get called:\r
  1) Length will generally be max remote packet size (big enough)\r
  2) First Offset of an XML document read needs to be 0\r
  3) This code will return back small chunks of the XML document on every read.\r
     Each subsequent call will ask for the next available part of the document.\r
\r
  Note: The only variable size element in the XML is:\r
  "  <library name=\"%s\"><segment address=\"%p\"/></library>\n" and it is\r
  based on the file path and name of the symbol file. If the symbol file name\r
  is bigger than the max gdb remote packet size we could update this code\r
  to respond back in chunks.\r
\r
 @param Offset  offset into special data area\r
 @param Length  number of bytes to read starting at Offset\r
\r
 **/\r
VOID\r
QxferLibrary (\r
  IN  UINTN   Offset,\r
  IN  UINTN   Length\r
  )\r
{\r
  VOID                              *LoadAddress;\r
  CHAR8                             *Pdb;\r
  UINTN                             Size;\r
\r
  if (Offset != gPacketqXferLibraryOffset) {\r
    SendError (GDB_EINVALIDARG);\r
    Print (L"\nqXferLibrary (%d, %d) != %d\n", Offset, Length, gPacketqXferLibraryOffset);\r
\r
    // Force a retry from the beginning\r
    gPacketqXferLibraryOffset = 0;\r
\r
    return;\r
  }\r
\r
  if (Offset == 0) {\r
    gPacketqXferLibraryOffset += gXferObjectReadResponse ('m', "<library-list>\n");\r
\r
    // The owner of the table may have had to ralloc it so grab a fresh copy every time\r
    // we assume qXferLibrary will get called over and over again until the entire XML table is\r
    // returned in a tight loop. Since we are in the debugger the table should not get updated\r
    gDebugTable = gDebugImageTableHeader->EfiDebugImageInfoTable;\r
    gEfiDebugImageTableEntry = 0;\r
    return;\r
  }\r
\r
  if (gDebugTable != NULL) {\r
    for (; gEfiDebugImageTableEntry < gDebugImageTableHeader->TableSize; gEfiDebugImageTableEntry++, gDebugTable++) {\r
      if (gDebugTable->NormalImage != NULL) {\r
        if ((gDebugTable->NormalImage->ImageInfoType == EFI_DEBUG_IMAGE_INFO_TYPE_NORMAL) &&\r
            (gDebugTable->NormalImage->LoadedImageProtocolInstance != NULL)) {\r
          Pdb = PeCoffLoaderGetDebuggerInfo (\r
                 gDebugTable->NormalImage->LoadedImageProtocolInstance->ImageBase,\r
                 &LoadAddress\r
                 );\r
          if (Pdb != NULL) {\r
            Size = AsciiSPrint (\r
                    gXferLibraryBuffer,\r
                    sizeof (gXferLibraryBuffer),\r
                    "  <library name=\"%a\"><segment address=\"0x%p\"/></library>\n",\r
                    Pdb,\r
                    LoadAddress\r
                    );\r
            if ((Size != 0) && (Size != (sizeof (gXferLibraryBuffer) - 1))) {\r
              gPacketqXferLibraryOffset += gXferObjectReadResponse ('m', gXferLibraryBuffer);\r
\r
              // Update loop variables so we are in the right place when we get back\r
              gEfiDebugImageTableEntry++;\r
              gDebugTable++;\r
              return;\r
            } else {\r
              // We could handle <library> entires larger than sizeof (gXferLibraryBuffer) here if\r
              // needed by breaking up into N packets\r
              // "<library name=\"%s\r
              // the rest of the string (as many packets as required\r
              // \"><segment address=\"%d\"/></library> (fixed size)\r
              //\r
              // But right now we just skip any entry that is too big\r
            }\r
          }\r
        }\r
      }\r
    }\r
  }\r
\r
\r
  gXferObjectReadResponse ('l', "</library-list>\n");\r
  gPacketqXferLibraryOffset = 0;\r
  return;\r
}\r
\r
\r
/**\r
 Exception Handler for GDB. It will be called for all exceptions\r
 registered via the gExceptionType[] array.\r
\r
 @param ExceptionType     Exception that is being processed\r
 @param SystemContext     Register content at time of the exception\r
 **/\r
VOID\r
EFIAPI\r
GdbExceptionHandler (\r
  IN  EFI_EXCEPTION_TYPE        ExceptionType,\r
  IN OUT EFI_SYSTEM_CONTEXT     SystemContext\r
  )\r
{\r
  UINT8   GdbExceptionType;\r
  CHAR8   *Ptr;\r
\r
\r
  if (ValidateException (ExceptionType, SystemContext) == FALSE) {\r
    return;\r
  }\r
\r
  RemoveSingleStep (SystemContext);\r
\r
  GdbExceptionType = ConvertEFItoGDBtype (ExceptionType);\r
  GdbSendTSignal (SystemContext, GdbExceptionType);\r
\r
  for( ; ; ) {\r
    ReceivePacket (gInBuffer, MAX_BUF_SIZE);\r
\r
    switch (gInBuffer[0]) {\r
      case '?':\r
        GdbSendTSignal (SystemContext, GdbExceptionType);\r
        break;\r
\r
      case 'c':\r
        ContinueAtAddress (SystemContext, gInBuffer);\r
        return;\r
\r
      case 'g':\r
        ReadGeneralRegisters (SystemContext);\r
        break;\r
\r
      case 'G':\r
        WriteGeneralRegisters (SystemContext, gInBuffer);\r
        break;\r
\r
      case 'H':\r
        //Return "OK" packet since we don't have more than one thread.\r
        SendSuccess ();\r
        break;\r
\r
      case 'm':\r
        ReadFromMemory (gInBuffer);\r
        break;\r
\r
      case 'M':\r
        WriteToMemory (gInBuffer);\r
        break;\r
\r
      case 'P':\r
        WriteNthRegister (SystemContext, gInBuffer);\r
        break;\r
\r
      //\r
      // Still debugging this code. Not used in Darwin\r
      //\r
      case 'q':\r
        // General Query Packets\r
        if (AsciiStrnCmp (gInBuffer, "qSupported", 10) == 0) {\r
          // return what we currently support, we don't parse what gdb supports\r
          AsciiSPrint (gOutBuffer, MAX_BUF_SIZE, "qXfer:libraries:read+;PacketSize=%d", MAX_BUF_SIZE);\r
          SendPacket (gOutBuffer);\r
        } else if (AsciiStrnCmp (gInBuffer, "qXfer:libraries:read::", 22) == 0) {\r
          // ‘qXfer:libraries:read::offset,length\r
          // gInBuffer[22] is offset string, ++Ptr is length string’\r
          for (Ptr = &gInBuffer[22]; *Ptr != ','; Ptr++);\r
\r
          // Not sure if multi-radix support is required. Currently only support decimal\r
          QxferLibrary (AsciiStrHexToUintn (&gInBuffer[22]), AsciiStrHexToUintn (++Ptr));\r
        } if (AsciiStrnCmp (gInBuffer, "qOffsets", 10) == 0) {\r
          AsciiSPrint (gOutBuffer, MAX_BUF_SIZE, "Text=1000;Data=f000;Bss=f000");\r
          SendPacket (gOutBuffer);\r
        } else {\r
          //Send empty packet\r
          SendNotSupported ();\r
        }\r
        break;\r
\r
      case 's':\r
        SingleStep (SystemContext, gInBuffer);\r
        return;\r
\r
      case 'z':\r
        RemoveBreakPoint (SystemContext, gInBuffer);\r
        break;\r
\r
      case 'Z':\r
        InsertBreakPoint (SystemContext, gInBuffer);\r
        break;\r
\r
      default:\r
        //Send empty packet\r
        SendNotSupported ();\r
        break;\r
    }\r
  }\r
}\r
\r
\r
/**\r
 Periodic callback for GDB. This function is used to catch a ctrl-c or other\r
 break in type command from GDB.\r
\r
 @param SystemContext     Register content at time of the call\r
 **/\r
VOID\r
EFIAPI\r
GdbPeriodicCallBack (\r
  IN OUT EFI_SYSTEM_CONTEXT     SystemContext\r
  )\r
{\r
  //\r
  // gCtrlCBreakFlag may have been set from a previous F response package\r
  // and we set the global as we need to process it at a point where we\r
  // can update the system context. If we are in the middle of processing\r
  // a F Packet it is not safe to read the GDB serial stream so we need\r
  // to skip it on this check\r
  //\r
  if (!gCtrlCBreakFlag && !gProcessingFPacket) {\r
    //\r
    // Ctrl-C was not pending so grab any pending characters and see if they\r
    // are a Ctrl-c (0x03). If so set the Ctrl-C global.\r
    //\r
    while (TRUE) {\r
      if (!GdbIsCharAvailable ()) {\r
        //\r
        // No characters are pending so exit the loop\r
        //\r
        break;\r
      }\r
\r
      if (GdbGetChar () == 0x03) {\r
        gCtrlCBreakFlag = TRUE;\r
        //\r
        // We have a ctrl-c so exit the loop\r
        //\r
        break;\r
      }\r
    }\r
  }\r
\r
  if (gCtrlCBreakFlag) {\r
    //\r
    // Update the context to force a single step trap when we exit the GDB\r
    // stub. This will transfer control to GdbExceptionHandler () and let\r
    // us break into the program. We don't want to break into the GDB stub.\r
    //\r
    AddSingleStep (SystemContext);\r
    gCtrlCBreakFlag = FALSE;\r
  }\r
}\r