EmbeddedPkg/GdbStub/GdbStubInternal.h - edk2 - Git at Google

 /** @file
   Private include file for GDB stub

   Copyright (c) 2008 - 2009, Apple Inc. All rights reserved.<BR>

   This program and the accompanying materials
   are licensed and made available under the terms and conditions of the BSD License
   which accompanies this distribution.  The full text of the license may be found at
   http://opensource.org/licenses/bsd-license.php

   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.

 **/

 #ifndef __GDB_STUB_INTERNAL__
 #define __GDB_STUB_INTERNAL__

 #include <Uefi.h>
 #include <Library/BaseLib.h>
 #include <Library/BaseMemoryLib.h>
 #include <Library/MemoryAllocationLib.h>
 #include <Library/DebugLib.h>
 #include <Library/UefiLib.h>
 #include <Library/UefiBootServicesTableLib.h>
 #include <Library/PcdLib.h>
 #include <Library/GdbSerialLib.h>
 #include <Library/PrintLib.h>

 #include <Protocol/DebugSupport.h>
 #include <Protocol/SerialIo.h>
 #include <Protocol/LoadedImage.h>
 #include <Protocol/LoadedImage.h>
 #include <Guid/DebugImageInfoTable.h>
 #include <IndustryStandard/PeImage.h>

 extern CONST CHAR8 mHexToStr[];

 // maximum size of input and output buffers
 // This value came from the show remote command of the gdb we tested against
 #define MAX_BUF_SIZE 2000

 // maximum size of address buffer
 #define MAX_ADDR_SIZE 32

 // maximum size of register number buffer
 #define MAX_REG_NUM_BUF_SIZE 32

 // maximum size of length buffer
 #define MAX_LENGTH_SIZE 32

 // maximum size of T signal members
 #define MAX_T_SIGNAL_SIZE 64

 // the mask used to clear all the cache
 #define TF_BIT 0x00000100


 //
 // GDB Signal definitions - generic names for interrupts
 //
 #define GDB_SIGILL      4  // Illegal instruction
 #define GDB_SIGTRAP     5  // Trace Trap (Breakpoint and SingleStep)
 #define GDB_SIGEMT      7  // Emulator Trap
 #define GDB_SIGFPE      8  // Floating point exception
 #define GDB_SIGSEGV     11 // Segment violation, page fault


 //
 // GDB File I/O Error values, zero means no error
 // Includes all general GDB Unix like error values
 //
 #define GDB_EBADMEMADDRBUFSIZE   11  // the buffer that stores memory Address to be read from/written to is not the right size
 #define GDB_EBADMEMLENGBUFSIZE   12  // the buffer that stores Length is not the right size
 #define GDB_EBADMEMLENGTH        13  // Length, the given number of bytes to read or write, is not the right size
 #define GDB_EBADMEMDATA          14  // one of the bytes or nibbles of the memory is leess than 0
 #define GDB_EBADMEMDATASIZE      15  // the memory data, 'XX..', is too short or too long
 #define GDB_EBADBUFSIZE          21  // the buffer created is not the correct size
 #define GDB_EINVALIDARG          31  // argument is invalid
 #define GDB_ENOSPACE             41  //
 #define GDB_EINVALIDBRKPOINTTYPE 51  // the breakpoint type is not recognized
 #define GDB_EINVALIDREGNUM       61  // given register number is not valid: either <0 or >=Number of Registers
 #define GDB_EUNKNOWN             255 // unknown


 //
 // These devices are open by GDB so we can just read and write to them
 //
 #define GDB_STDIN   0x00
 #define GDB_STDOUT  0x01
 #define GDB_STDERR  0x02

 //
 //Define Register size for different architectures
 //
 #if defined (MDE_CPU_IA32)
 #define REG_SIZE  32
 #elif defined (MDE_CPU_X64)
 #define REG_SIZE  64
 #elif defined (MDE_CPU_ARM)
 #define REG_SIZE  32
 #endif

 #define GDB_SERIAL_DEV_SIGNATURE    SIGNATURE_32 ('g', 'd', 'b', 's')

 typedef struct {
   VENDOR_DEVICE_PATH                     VendorDevice;
   UINT32                                 Index;         // Suport more than one
   EFI_DEVICE_PATH_PROTOCOL               End;
 } GDB_SERIAL_DEVICE_PATH;

 //
 //  Name:   SERIAL_DEV
 //  Purpose:  To provide device specific information
 //  Fields:
 //      Signature UINTN: The identity of the serial device
 //      SerialIo  SERIAL_IO_PROTOCOL: Serial I/O protocol interface
 //      SerialMode  SERIAL_IO_MODE:
 //      DevicePath  EFI_DEVICE_PATH_PROTOCOL *: Device path of the serial device
 //
 typedef struct {
   UINTN                                  Signature;
   EFI_HANDLE                             Handle;
   EFI_SERIAL_IO_PROTOCOL                 SerialIo;
   EFI_SERIAL_IO_MODE                     SerialMode;
   GDB_SERIAL_DEVICE_PATH                 DevicePath;
   INTN                                   InFileDescriptor;
   INTN                                   OutFileDescriptor;
 } GDB_SERIAL_DEV;


 #define GDB_SERIAL_DEV_FROM_THIS(a) CR (a, GDB_SERIAL_DEV, SerialIo, GDB_SERIAL_DEV_SIGNATURE)


 typedef struct {
     EFI_EXCEPTION_TYPE  Exception;
     UINT8               SignalNo;
 } EFI_EXCEPTION_TYPE_ENTRY;


 #if defined (MDE_CPU_IA32) || defined (MDE_CPU_X64)

 //
 // Byte packed structure for DR6
 // 32-bits on IA-32
 // 64-bits on X64.  The upper 32-bits on X64 are reserved
 //
 typedef union {
   struct {
     UINT32  B0:1;           // Breakpoint condition detected
     UINT32  B1:1;           // Breakpoint condition detected
     UINT32  B2:1;           // Breakpoint condition detected
     UINT32  B3:1;           // Breakpoint condition detected
     UINT32  Reserved_1:9;   // Reserved
     UINT32  BD:1;           // Debug register access detected
     UINT32  BS:1;           // Single step
     UINT32  BT:1;           // Task switch
     UINT32  Reserved_2:16;  // Reserved
   } Bits;
   UINTN     UintN;
 } IA32_DR6;

 //
 // Byte packed structure for DR7
 // 32-bits on IA-32
 // 64-bits on X64.  The upper 32-bits on X64 are reserved
 //
 typedef union {
   struct {
     UINT32  L0:1;           // Local breakpoint enable
     UINT32  G0:1;           // Global breakpoint enable
     UINT32  L1:1;           // Local breakpoint enable
     UINT32  G1:1;           // Global breakpoint enable
     UINT32  L2:1;           // Local breakpoint enable
     UINT32  G2:1;           // Global breakpoint enable
     UINT32  L3:1;           // Local breakpoint enable
     UINT32  G3:1;           // Global breakpoint enable
     UINT32  LE:1;           // Local exact breakpoint enable
     UINT32  GE:1;           // Global exact breakpoint enable
     UINT32  Reserved_1:3;   // Reserved
     UINT32  GD:1;           // Global detect enable
     UINT32  Reserved_2:2;   // Reserved
     UINT32  RW0:2;          // Read/Write field
     UINT32  LEN0:2;         // Length field
     UINT32  RW1:2;          // Read/Write field
     UINT32  LEN1:2;         // Length field
     UINT32  RW2:2;          // Read/Write field
     UINT32  LEN2:2;         // Length field
     UINT32  RW3:2;          // Read/Write field
     UINT32  LEN3:2;         // Length field
   } Bits;
   UINTN     UintN;
 } IA32_DR7;

 #endif /* if defined (MDE_CPU_IA32) || defined (MDE_CPU_X64) */

 typedef enum {
   InstructionExecution,   //Hardware breakpoint
   DataWrite,              //watch
   DataRead,               //rwatch
   DataReadWrite,          //awatch
   SoftwareBreakpoint,     //Software breakpoint
   NotSupported
 } BREAK_TYPE;

 //
 // Array of exception types that need to be hooked by the debugger
 //
 extern EFI_EXCEPTION_TYPE_ENTRY gExceptionType[];

 //
 // Set TRUE if F Reply package signals a ctrl-c. We can not process the Ctrl-c
 // here we need to wait for the periodic callback to do this.
 //
 extern BOOLEAN gCtrlCBreakFlag;

 //
 // If the periodic callback is called while we are processing an F packet we need
 // to let the callback know to not read from the serail stream as it could steal
 // characters from the F reponse packet
 //
 extern BOOLEAN gProcessingFPacket;


 // The offsets of registers SystemContext.
 // The fields in the array are in the gdb ordering.
 //
 extern UINTN    gRegisterOffsets[];

 /**
  Return the number of entries in the gExceptionType[]

  @retval    UINTN, the number of entries in the gExceptionType[] array.
  **/
 UINTN
 MaxEfiException (
   VOID
   );


 /**
  Return the number of entries in the gRegisters[]

  @retval    UINTN, the number of entries (registers) in the gRegisters[] array.
  **/
 UINTN
 MaxRegisterCount (
   VOID
   );


 /**
  Check to see if the ISA is supported.
  ISA = Instruction Set Architecture

  @retval    TRUE if Isa is supported,
  FALSE otherwise.
  **/
 BOOLEAN
 CheckIsa (
   IN    EFI_INSTRUCTION_SET_ARCHITECTURE    Isa
   );


 /**
  Send the T signal with the given exception type (in gdb order) and possibly with n:r pairs related to the watchpoints

  @param  SystemContext        Register content at time of the exception
  @param  GdbExceptionType     GDB exception type
  **/

 VOID
 GdbSendTSignal (
   IN  EFI_SYSTEM_CONTEXT  SystemContext,
   IN  UINT8               GdbExceptionType
   );


 /**
  Translates the EFI mapping to GDB mapping

  @param     EFIExceptionType        EFI Exception that is being processed
  @retval    UINTN that corresponds to EFIExceptionType's GDB exception type number
  **/
 UINT8
 ConvertEFItoGDBtype (
   IN  EFI_EXCEPTION_TYPE EFIExceptionType
   );


 /**
  Empties the given buffer
  @param *Buf pointer to the first element in buffer to be emptied
  **/
 VOID
 EmptyBuffer (
   IN CHAR8  *Buf
   );


 /**
  Converts an 8-bit Hex Char into a INTN.

  @param     Char  - the hex character to be converted into UINTN
  @retval    a INTN, from 0 to 15, that corressponds to Char
  -1 if Char is not a hex character
  **/
 INTN
 HexCharToInt (
   IN  CHAR8 Char
   );


 /** 'E NN'
  Send an error with the given error number after converting to hex.
  The error number is put into the buffer in hex. '255' is the biggest errno we can send.
  ex: 162 will be sent as A2.

  @param   errno    the error number that will be sent
  **/
 VOID
 EFIAPI
 SendError (
   IN  UINT8     ErrorNum
   );


 /**
  Send 'OK' when the function is done executing successfully.
  **/
 VOID
 SendSuccess (
   VOID
   );


 /**
  Send empty packet to specify that particular command/functionality is not supported.
  **/
 VOID
 SendNotSupported (
   VOID
   );

 /** ‘p n’
  Reads the n-th register's value into an output buffer and sends it as a packet
  @param     SystemContext       Register content at time of the exception
  @param     InBuffer            This is the input buffer received from gdb server
  **/
 VOID
 ReadNthRegister (
   IN    EFI_SYSTEM_CONTEXT  SystemContext,
   IN    CHAR8               *InBuffer
   );


 /** ‘g’
  Reads the general registers into an output buffer  and sends it as a packet
  @param     SystemContext           Register content at time of the exception
  **/
 VOID
 ReadGeneralRegisters (
   IN    EFI_SYSTEM_CONTEXT  SystemContext
   );


 /** ‘P n...=r...’
  Writes the new value of n-th register received into the input buffer to the n-th register
  @param     SystemContext       Register content at time of the exception
  @param     InBuffer            This is the input buffer received from gdb server
  **/
 VOID
 WriteNthRegister (
   IN    EFI_SYSTEM_CONTEXT  SystemContext,
   IN    CHAR8               *InBuffer
   );


 /** ‘G XX...’
  Writes the new values received into the input buffer to the general registers
  @param     SystemContext               Register content at time of the exception
  @param     InBuffer                    Pointer to the input buffer received from gdb server
  **/

 VOID
 WriteGeneralRegisters (
   IN    EFI_SYSTEM_CONTEXT  SystemContext,
   IN    CHAR8               *InBuffer
   );


 /** ‘m addr,length ’
  Find the Length of the area to read and the start addres. Finally, pass them to
  another function, TransferFromMemToOutBufAndSend, that will read from that memory space and
  send it as a packet.

  @param  *PacketData  Pointer to Payload data for the packet
  **/
 VOID
 ReadFromMemory (
   IN  CHAR8  *PacketData
   );


 /** ‘M addr,length :XX...’
  Find the Length of the area in bytes to write and the start addres. Finally, pass them to
  another function, TransferFromInBufToMem, that will write to that memory space the info in
  the input buffer.

  @param   PacketData     Pointer to Payload data for the packet
  **/
 VOID
 WriteToMemory (
   IN CHAR8 *PacketData
   );


 /** ‘c [addr ]’
  Continue. addr is Address to resume. If addr is omitted, resume at current
  Address.

  @param SystemContext Register content at time of the exception
  @param *PacketData   Pointer to PacketData
  **/

 VOID
 ContinueAtAddress (
   IN  EFI_SYSTEM_CONTEXT   SystemContext,
   IN  CHAR8                *PacketData
   );


 /** ‘s [addr ]’
  Single step. addr is the Address at which to resume. If addr is omitted, resume
  at same Address.

  @param SystemContext   Register content at time of the exception
  @param PacketData      Pointer to Payload data for the packet
  **/
 VOID
 SingleStep (
   IN  EFI_SYSTEM_CONTEXT  SystemContext,
   IN  CHAR8               *PacketData
   );

 /**
  Insert Single Step in the SystemContext

  @param SystemContext   Register content at time of the exception
  **/
 VOID
 AddSingleStep (
   IN  EFI_SYSTEM_CONTEXT  SystemContext
   );

 /**
  Remove Single Step in the SystemContext

  @param SystemContext   Register content at time of the exception
  **/
 VOID
 RemoveSingleStep (
   IN  EFI_SYSTEM_CONTEXT  SystemContext
   );


 /**
   ‘Z1, [addr], [length]’
   ‘Z2, [addr], [length]’
   ‘Z3, [addr], [length]’
   ‘Z4, [addr], [length]’

   Insert hardware breakpoint/watchpoint at address addr of size length

   @param SystemContext  Register content at time of the exception
   @param *PacketData    Pointer to the Payload data for the packet

 **/
 VOID
 EFIAPI
 InsertBreakPoint(
   IN  EFI_SYSTEM_CONTEXT  SystemContext,
   IN  CHAR8               *PacketData
   );


 /**
   ‘z1, [addr], [length]’
   ‘z2, [addr], [length]’
   ‘z3, [addr], [length]’
   ‘z4, [addr], [length]’

   Remove hardware breakpoint/watchpoint at address addr of size length

   @param SystemContext  Register content at time of the exception
   @param *PacketData    Pointer to the Payload data for the packet

 **/
 VOID
 EFIAPI
 RemoveBreakPoint(
   IN  EFI_SYSTEM_CONTEXT  SystemContext,
   IN  CHAR8               *PacketData
   );


 /**
  Exception Hanldler for GDB. It will be called for all exceptions
  registered via the gExceptionType[] array.

  @param ExceptionType   Exception that is being processed
  @param SystemContext   Register content at time of the exception

  **/
 VOID
 EFIAPI
 GdbExceptionHandler (
   IN     EFI_EXCEPTION_TYPE  ExceptionType,
   IN OUT EFI_SYSTEM_CONTEXT  SystemContext
   );


 /**
  Periodic callback for GDB. This function is used to catch a ctrl-c or other
  break in type command from GDB.

  @param SystemContext           Register content at time of the call

  **/
 VOID
 EFIAPI
 GdbPeriodicCallBack (
   IN OUT EFI_SYSTEM_CONTEXT  SystemContext
   );


 /**
   Make two serail consoles: 1) StdIn and StdOut via GDB. 2) StdErr via GDB.

   These console show up on the remote system running GDB

 **/

 VOID
 GdbInitializeSerialConsole (
   VOID
   );


 /**
   Send a GDB Remote Serial Protocol Packet

   $PacketData#checksum PacketData is passed in and this function adds the packet prefix '$',
   the packet teminating character '#' and the two digit checksum.

   If an ack '+' is not sent resend the packet, but timeout eventually so we don't end up
   in an infinit loop. This is so if you unplug the debugger code just keeps running

   @param PacketData   Payload data for the packet

   @retval             Number of bytes of packet data sent.

 **/
 UINTN
 SendPacket (
   IN  CHAR8 *PacketData
   );


 /**
  Receive a GDB Remote Serial Protocol Packet

  $PacketData#checksum PacketData is passed in and this function adds the packet prefix '$',
  the packet teminating character '#' and the two digit checksum.

  If host re-starts sending a packet without ending the previous packet, only the last valid packet is proccessed.
  (In other words, if received packet is '$12345$12345$123456#checksum', only '$123456#checksum' will be processed.)

  If an ack '+' is not sent resend the packet

  @param PacketData   Payload data for the packet

  @retval             Number of bytes of packet data received.

  **/
 UINTN
 ReceivePacket (
  OUT  CHAR8 *PacketData,
  IN   UINTN PacketDataSize
  );


 /**
   Read data from a FileDescriptor. On success number of bytes read is returned. Zero indicates
   the end of a file. On error -1 is returned. If count is zero, GdbRead returns zero.

   @param  FileDescriptor   Device to talk to.
   @param  Buffer           Buffer to hold Count bytes that were read
   @param  Count            Number of bytes to transfer.

   @retval -1               Error
   @retval {other}          Number of bytes read.

 **/
 INTN
 GdbRead (
   IN  INTN    FileDescriptor,
   OUT VOID    *Buffer,
   IN  UINTN   Count
   );


 /**
   Write data to a FileDescriptor. On success number of bytes written is returned. Zero indicates
   nothing was written. On error -1 is returned.

   @param  FileDescriptor   Device to talk to.
   @param  Buffer           Buffer to hold Count bytes that are to be written
   @param  Count            Number of bytes to transfer.

   @retval -1               Error
   @retval {other}          Number of bytes written.

 **/
 INTN
 GdbWrite (
   IN  INTN          FileDescriptor,
   OUT CONST VOID    *Buffer,
   IN  UINTN         Count
   );

 UINTN *
 FindPointerToRegister (
   IN  EFI_SYSTEM_CONTEXT    SystemContext,
   IN  UINTN                 RegNumber
   );

 CHAR8 *
 BasicReadRegister (
   IN  EFI_SYSTEM_CONTEXT      SystemContext,
   IN  UINTN                   RegNumber,
   IN  CHAR8                   *OutBufPtr
   );

 VOID
 TransferFromInBufToMem (
   IN  UINTN   Length,
   IN  UINT8   *Address,
   IN  CHAR8   *NewData
   );

 VOID
 TransferFromMemToOutBufAndSend (
   IN  UINTN  Length,
   IN  UINT8  *Address
   );

 CHAR8 *
 BasicWriteRegister (
   IN  EFI_SYSTEM_CONTEXT    SystemContext,
   IN  UINTN                 RegNumber,
   IN  CHAR8                 *InBufPtr
   );

 VOID
 PrintReg (
   EFI_SYSTEM_CONTEXT SystemContext
   );

 UINTN
 ParseBreakpointPacket (
   IN  CHAR8 *PacketData,
   OUT UINTN *Type,
   OUT UINTN *Address,
   OUT UINTN *Length
   );

 UINTN
 GetBreakpointDataAddress (
   IN  EFI_SYSTEM_CONTEXT  SystemContext,
   IN  UINTN               BreakpointNumber
   );

 UINTN
 GetBreakpointDetected (
   IN  EFI_SYSTEM_CONTEXT  SystemContext
   );

 BREAK_TYPE
 GetBreakpointType (
   IN  EFI_SYSTEM_CONTEXT  SystemContext,
   IN  UINTN               BreakpointNumber
   );

 UINTN
 ConvertLengthData (
   IN  UINTN  Length
   );

 EFI_STATUS
 FindNextFreeDebugRegister (
   IN  EFI_SYSTEM_CONTEXT  SystemContext,
   OUT UINTN               *Register
   );

 EFI_STATUS
 EnableDebugRegister (
   IN  EFI_SYSTEM_CONTEXT  SystemContext,
   IN  UINTN               Register,
   IN  UINTN               Address,
   IN  UINTN               Length,
   IN  UINTN               Type
   );

 EFI_STATUS
 FindMatchingDebugRegister (
  IN  EFI_SYSTEM_CONTEXT  SystemContext,
  IN  UINTN               Address,
  IN  UINTN               Length,
  IN  UINTN               Type,
  OUT UINTN               *Register
  );

 EFI_STATUS
 DisableDebugRegister (
  IN  EFI_SYSTEM_CONTEXT  SystemContext,
  IN  UINTN               Register
  );

 VOID
 InitializeProcessor (
   VOID
   );

 BOOLEAN
 ValidateAddress (
   IN  VOID  *Address
   );

 BOOLEAN
 ValidateException (
   IN  EFI_EXCEPTION_TYPE    ExceptionType,
   IN OUT EFI_SYSTEM_CONTEXT SystemContext
   );

 #endif
	/** @file
	Private include file for GDB stub

	Copyright (c) 2008 - 2009, Apple Inc. All rights reserved.<BR>

	This program and the accompanying materials
	are licensed and made available under the terms and conditions of the BSD License
	which accompanies this distribution. The full text of the license may be found at
	http://opensource.org/licenses/bsd-license.php

	THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
	WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.

	**/

	#ifndef __GDB_STUB_INTERNAL__
	#define __GDB_STUB_INTERNAL__

	#include <Uefi.h>
	#include <Library/BaseLib.h>
	#include <Library/BaseMemoryLib.h>
	#include <Library/MemoryAllocationLib.h>
	#include <Library/DebugLib.h>
	#include <Library/UefiLib.h>
	#include <Library/UefiBootServicesTableLib.h>
	#include <Library/PcdLib.h>
	#include <Library/GdbSerialLib.h>
	#include <Library/PrintLib.h>

	#include <Protocol/DebugSupport.h>
	#include <Protocol/SerialIo.h>
	#include <Protocol/LoadedImage.h>
	#include <Protocol/LoadedImage.h>
	#include <Guid/DebugImageInfoTable.h>
	#include <IndustryStandard/PeImage.h>

	extern CONST CHAR8 mHexToStr[];

	// maximum size of input and output buffers
	// This value came from the show remote command of the gdb we tested against
	#define MAX_BUF_SIZE 2000

	// maximum size of address buffer
	#define MAX_ADDR_SIZE 32

	// maximum size of register number buffer
	#define MAX_REG_NUM_BUF_SIZE 32

	// maximum size of length buffer
	#define MAX_LENGTH_SIZE 32

	// maximum size of T signal members
	#define MAX_T_SIGNAL_SIZE 64

	// the mask used to clear all the cache
	#define TF_BIT 0x00000100


	//
	// GDB Signal definitions - generic names for interrupts
	//
	#define GDB_SIGILL 4 // Illegal instruction
	#define GDB_SIGTRAP 5 // Trace Trap (Breakpoint and SingleStep)
	#define GDB_SIGEMT 7 // Emulator Trap
	#define GDB_SIGFPE 8 // Floating point exception
	#define GDB_SIGSEGV 11 // Segment violation, page fault


	//
	// GDB File I/O Error values, zero means no error
	// Includes all general GDB Unix like error values
	//
	#define GDB_EBADMEMADDRBUFSIZE 11 // the buffer that stores memory Address to be read from/written to is not the right size
	#define GDB_EBADMEMLENGBUFSIZE 12 // the buffer that stores Length is not the right size
	#define GDB_EBADMEMLENGTH 13 // Length, the given number of bytes to read or write, is not the right size
	#define GDB_EBADMEMDATA 14 // one of the bytes or nibbles of the memory is leess than 0
	#define GDB_EBADMEMDATASIZE 15 // the memory data, 'XX..', is too short or too long
	#define GDB_EBADBUFSIZE 21 // the buffer created is not the correct size
	#define GDB_EINVALIDARG 31 // argument is invalid
	#define GDB_ENOSPACE 41 //
	#define GDB_EINVALIDBRKPOINTTYPE 51 // the breakpoint type is not recognized
	#define GDB_EINVALIDREGNUM 61 // given register number is not valid: either <0 or >=Number of Registers
	#define GDB_EUNKNOWN 255 // unknown


	//
	// These devices are open by GDB so we can just read and write to them
	//
	#define GDB_STDIN 0x00
	#define GDB_STDOUT 0x01
	#define GDB_STDERR 0x02

	//
	//Define Register size for different architectures
	//
	#if defined (MDE_CPU_IA32)
	#define REG_SIZE 32
	#elif defined (MDE_CPU_X64)
	#define REG_SIZE 64
	#elif defined (MDE_CPU_ARM)
	#define REG_SIZE 32
	#endif

	#define GDB_SERIAL_DEV_SIGNATURE SIGNATURE_32 ('g', 'd', 'b', 's')

	typedef struct {
	VENDOR_DEVICE_PATH VendorDevice;
	UINT32 Index; // Suport more than one
	EFI_DEVICE_PATH_PROTOCOL End;
	} GDB_SERIAL_DEVICE_PATH;

	//
	// Name: SERIAL_DEV
	// Purpose: To provide device specific information
	// Fields:
	// Signature UINTN: The identity of the serial device
	// SerialIo SERIAL_IO_PROTOCOL: Serial I/O protocol interface
	// SerialMode SERIAL_IO_MODE:
	// DevicePath EFI_DEVICE_PATH_PROTOCOL *: Device path of the serial device
	//
	typedef struct {
	UINTN Signature;
	EFI_HANDLE Handle;
	EFI_SERIAL_IO_PROTOCOL SerialIo;
	EFI_SERIAL_IO_MODE SerialMode;
	GDB_SERIAL_DEVICE_PATH DevicePath;
	INTN InFileDescriptor;
	INTN OutFileDescriptor;
	} GDB_SERIAL_DEV;


	#define GDB_SERIAL_DEV_FROM_THIS(a) CR (a, GDB_SERIAL_DEV, SerialIo, GDB_SERIAL_DEV_SIGNATURE)


	typedef struct {
	EFI_EXCEPTION_TYPE Exception;
	UINT8 SignalNo;
	} EFI_EXCEPTION_TYPE_ENTRY;


	#if defined (MDE_CPU_IA32) \|\| defined (MDE_CPU_X64)

	//
	// Byte packed structure for DR6
	// 32-bits on IA-32
	// 64-bits on X64. The upper 32-bits on X64 are reserved
	//
	typedef union {
	struct {
	UINT32 B0:1; // Breakpoint condition detected
	UINT32 B1:1; // Breakpoint condition detected
	UINT32 B2:1; // Breakpoint condition detected
	UINT32 B3:1; // Breakpoint condition detected
	UINT32 Reserved_1:9; // Reserved
	UINT32 BD:1; // Debug register access detected
	UINT32 BS:1; // Single step
	UINT32 BT:1; // Task switch
	UINT32 Reserved_2:16; // Reserved
	} Bits;
	UINTN UintN;
	} IA32_DR6;

	//
	// Byte packed structure for DR7
	// 32-bits on IA-32
	// 64-bits on X64. The upper 32-bits on X64 are reserved
	//
	typedef union {
	struct {
	UINT32 L0:1; // Local breakpoint enable
	UINT32 G0:1; // Global breakpoint enable
	UINT32 L1:1; // Local breakpoint enable
	UINT32 G1:1; // Global breakpoint enable
	UINT32 L2:1; // Local breakpoint enable
	UINT32 G2:1; // Global breakpoint enable
	UINT32 L3:1; // Local breakpoint enable
	UINT32 G3:1; // Global breakpoint enable
	UINT32 LE:1; // Local exact breakpoint enable
	UINT32 GE:1; // Global exact breakpoint enable
	UINT32 Reserved_1:3; // Reserved
	UINT32 GD:1; // Global detect enable
	UINT32 Reserved_2:2; // Reserved
	UINT32 RW0:2; // Read/Write field
	UINT32 LEN0:2; // Length field
	UINT32 RW1:2; // Read/Write field
	UINT32 LEN1:2; // Length field
	UINT32 RW2:2; // Read/Write field
	UINT32 LEN2:2; // Length field
	UINT32 RW3:2; // Read/Write field
	UINT32 LEN3:2; // Length field
	} Bits;
	UINTN UintN;
	} IA32_DR7;

	#endif /* if defined (MDE_CPU_IA32) \|\| defined (MDE_CPU_X64) */

	typedef enum {
	InstructionExecution, //Hardware breakpoint
	DataWrite, //watch
	DataRead, //rwatch
	DataReadWrite, //awatch
	SoftwareBreakpoint, //Software breakpoint
	NotSupported
	} BREAK_TYPE;

	//
	// Array of exception types that need to be hooked by the debugger
	//
	extern EFI_EXCEPTION_TYPE_ENTRY gExceptionType[];

	//
	// Set TRUE if F Reply package signals a ctrl-c. We can not process the Ctrl-c
	// here we need to wait for the periodic callback to do this.
	//
	extern BOOLEAN gCtrlCBreakFlag;

	//
	// If the periodic callback is called while we are processing an F packet we need
	// to let the callback know to not read from the serail stream as it could steal
	// characters from the F reponse packet
	//
	extern BOOLEAN gProcessingFPacket;


	// The offsets of registers SystemContext.
	// The fields in the array are in the gdb ordering.
	//
	extern UINTN gRegisterOffsets[];

	/**
	Return the number of entries in the gExceptionType[]

	@retval UINTN, the number of entries in the gExceptionType[] array.
	**/
	UINTN
	MaxEfiException (
	VOID
	);


	/**
	Return the number of entries in the gRegisters[]

	@retval UINTN, the number of entries (registers) in the gRegisters[] array.
	**/
	UINTN
	MaxRegisterCount (
	VOID
	);


	/**
	Check to see if the ISA is supported.
	ISA = Instruction Set Architecture

	@retval TRUE if Isa is supported,
	FALSE otherwise.
	**/
	BOOLEAN
	CheckIsa (
	IN EFI_INSTRUCTION_SET_ARCHITECTURE Isa
	);


	/**
	Send the T signal with the given exception type (in gdb order) and possibly with n:r pairs related to the watchpoints

	@param SystemContext Register content at time of the exception
	@param GdbExceptionType GDB exception type
	**/

	VOID
	GdbSendTSignal (
	IN EFI_SYSTEM_CONTEXT SystemContext,
	IN UINT8 GdbExceptionType
	);


	/**
	Translates the EFI mapping to GDB mapping

	@param EFIExceptionType EFI Exception that is being processed
	@retval UINTN that corresponds to EFIExceptionType's GDB exception type number
	**/
	UINT8
	ConvertEFItoGDBtype (
	IN EFI_EXCEPTION_TYPE EFIExceptionType
	);


	/**
	Empties the given buffer
	@param *Buf pointer to the first element in buffer to be emptied
	**/
	VOID
	EmptyBuffer (
	IN CHAR8 *Buf
	);


	/**
	Converts an 8-bit Hex Char into a INTN.

	@param Char - the hex character to be converted into UINTN
	@retval a INTN, from 0 to 15, that corressponds to Char
	-1 if Char is not a hex character
	**/
	INTN
	HexCharToInt (
	IN CHAR8 Char
	);


	/** 'E NN'
	Send an error with the given error number after converting to hex.
	The error number is put into the buffer in hex. '255' is the biggest errno we can send.
	ex: 162 will be sent as A2.

	@param errno the error number that will be sent
	**/
	VOID
	EFIAPI
	SendError (
	IN UINT8 ErrorNum
	);


	/**
	Send 'OK' when the function is done executing successfully.
	**/
	VOID
	SendSuccess (
	VOID
	);


	/**
	Send empty packet to specify that particular command/functionality is not supported.
	**/
	VOID
	SendNotSupported (
	VOID
	);

	/** ‘p n’
	Reads the n-th register's value into an output buffer and sends it as a packet
	@param SystemContext Register content at time of the exception
	@param InBuffer This is the input buffer received from gdb server
	**/
	VOID
	ReadNthRegister (
	IN EFI_SYSTEM_CONTEXT SystemContext,
	IN CHAR8 *InBuffer
	);


	/** ‘g’
	Reads the general registers into an output buffer and sends it as a packet
	@param SystemContext Register content at time of the exception
	**/
	VOID
	ReadGeneralRegisters (
	IN EFI_SYSTEM_CONTEXT SystemContext
	);


	/** ‘P n...=r...’
	Writes the new value of n-th register received into the input buffer to the n-th register
	@param SystemContext Register content at time of the exception
	@param InBuffer This is the input buffer received from gdb server
	**/
	VOID
	WriteNthRegister (
	IN EFI_SYSTEM_CONTEXT SystemContext,
	IN CHAR8 *InBuffer
	);


	/** ‘G XX...’
	Writes the new values received into the input buffer to the general registers
	@param SystemContext Register content at time of the exception
	@param InBuffer Pointer to the input buffer received from gdb server
	**/

	VOID
	WriteGeneralRegisters (
	IN EFI_SYSTEM_CONTEXT SystemContext,
	IN CHAR8 *InBuffer
	);


	/** ‘m addr,length ’
	Find the Length of the area to read and the start addres. Finally, pass them to
	another function, TransferFromMemToOutBufAndSend, that will read from that memory space and
	send it as a packet.

	@param *PacketData Pointer to Payload data for the packet
	**/
	VOID
	ReadFromMemory (
	IN CHAR8 *PacketData
	);


	/** ‘M addr,length :XX...’
	Find the Length of the area in bytes to write and the start addres. Finally, pass them to
	another function, TransferFromInBufToMem, that will write to that memory space the info in
	the input buffer.

	@param PacketData Pointer to Payload data for the packet
	**/
	VOID
	WriteToMemory (
	IN CHAR8 *PacketData
	);


	/** ‘c [addr ]’
	Continue. addr is Address to resume. If addr is omitted, resume at current
	Address.

	@param SystemContext Register content at time of the exception
	@param *PacketData Pointer to PacketData
	**/

	VOID
	ContinueAtAddress (
	IN EFI_SYSTEM_CONTEXT SystemContext,
	IN CHAR8 *PacketData
	);


	/** ‘s [addr ]’
	Single step. addr is the Address at which to resume. If addr is omitted, resume
	at same Address.

	@param SystemContext Register content at time of the exception
	@param PacketData Pointer to Payload data for the packet
	**/
	VOID
	SingleStep (
	IN EFI_SYSTEM_CONTEXT SystemContext,
	IN CHAR8 *PacketData
	);

	/**
	Insert Single Step in the SystemContext

	@param SystemContext Register content at time of the exception
	**/
	VOID
	AddSingleStep (
	IN EFI_SYSTEM_CONTEXT SystemContext
	);

	/**
	Remove Single Step in the SystemContext

	@param SystemContext Register content at time of the exception
	**/
	VOID
	RemoveSingleStep (
	IN EFI_SYSTEM_CONTEXT SystemContext
	);


	/**
	‘Z1, [addr], [length]’
	‘Z2, [addr], [length]’
	‘Z3, [addr], [length]’
	‘Z4, [addr], [length]’

	Insert hardware breakpoint/watchpoint at address addr of size length

	@param SystemContext Register content at time of the exception
	@param *PacketData Pointer to the Payload data for the packet

	**/
	VOID
	EFIAPI
	InsertBreakPoint(
	IN EFI_SYSTEM_CONTEXT SystemContext,
	IN CHAR8 *PacketData
	);


	/**
	‘z1, [addr], [length]’
	‘z2, [addr], [length]’
	‘z3, [addr], [length]’
	‘z4, [addr], [length]’

	Remove hardware breakpoint/watchpoint at address addr of size length

	@param SystemContext Register content at time of the exception
	@param *PacketData Pointer to the Payload data for the packet

	**/
	VOID
	EFIAPI
	RemoveBreakPoint(
	IN EFI_SYSTEM_CONTEXT SystemContext,
	IN CHAR8 *PacketData
	);


	/**
	Exception Hanldler for GDB. It will be called for all exceptions
	registered via the gExceptionType[] array.

	@param ExceptionType Exception that is being processed
	@param SystemContext Register content at time of the exception

	**/
	VOID
	EFIAPI
	GdbExceptionHandler (
	IN EFI_EXCEPTION_TYPE ExceptionType,
	IN OUT EFI_SYSTEM_CONTEXT SystemContext
	);


	/**
	Periodic callback for GDB. This function is used to catch a ctrl-c or other
	break in type command from GDB.

	@param SystemContext Register content at time of the call

	**/
	VOID
	EFIAPI
	GdbPeriodicCallBack (
	IN OUT EFI_SYSTEM_CONTEXT SystemContext
	);


	/**
	Make two serail consoles: 1) StdIn and StdOut via GDB. 2) StdErr via GDB.

	These console show up on the remote system running GDB

	**/

	VOID
	GdbInitializeSerialConsole (
	VOID
	);


	/**
	Send a GDB Remote Serial Protocol Packet

	$PacketData#checksum PacketData is passed in and this function adds the packet prefix '$',
	the packet teminating character '#' and the two digit checksum.

	If an ack '+' is not sent resend the packet, but timeout eventually so we don't end up
	in an infinit loop. This is so if you unplug the debugger code just keeps running

	@param PacketData Payload data for the packet

	@retval Number of bytes of packet data sent.

	**/
	UINTN
	SendPacket (
	IN CHAR8 *PacketData
	);


	/**
	Receive a GDB Remote Serial Protocol Packet

	$PacketData#checksum PacketData is passed in and this function adds the packet prefix '$',
	the packet teminating character '#' and the two digit checksum.

	If host re-starts sending a packet without ending the previous packet, only the last valid packet is proccessed.
	(In other words, if received packet is '$12345$12345$123456#checksum', only '$123456#checksum' will be processed.)

	If an ack '+' is not sent resend the packet

	@param PacketData Payload data for the packet

	@retval Number of bytes of packet data received.

	**/
	UINTN
	ReceivePacket (
	OUT CHAR8 *PacketData,
	IN UINTN PacketDataSize
	);


	/**
	Read data from a FileDescriptor. On success number of bytes read is returned. Zero indicates
	the end of a file. On error -1 is returned. If count is zero, GdbRead returns zero.

	@param FileDescriptor Device to talk to.
	@param Buffer Buffer to hold Count bytes that were read
	@param Count Number of bytes to transfer.

	@retval -1 Error
	@retval {other} Number of bytes read.

	**/
	INTN
	GdbRead (
	IN INTN FileDescriptor,
	OUT VOID *Buffer,
	IN UINTN Count
	);


	/**
	Write data to a FileDescriptor. On success number of bytes written is returned. Zero indicates
	nothing was written. On error -1 is returned.

	@param FileDescriptor Device to talk to.
	@param Buffer Buffer to hold Count bytes that are to be written
	@param Count Number of bytes to transfer.

	@retval -1 Error
	@retval {other} Number of bytes written.

	**/
	INTN
	GdbWrite (
	IN INTN FileDescriptor,
	OUT CONST VOID *Buffer,
	IN UINTN Count
	);

	UINTN *
	FindPointerToRegister (
	IN EFI_SYSTEM_CONTEXT SystemContext,
	IN UINTN RegNumber
	);

	CHAR8 *
	BasicReadRegister (
	IN EFI_SYSTEM_CONTEXT SystemContext,
	IN UINTN RegNumber,
	IN CHAR8 *OutBufPtr
	);

	VOID
	TransferFromInBufToMem (
	IN UINTN Length,
	IN UINT8 *Address,
	IN CHAR8 *NewData
	);

	VOID
	TransferFromMemToOutBufAndSend (
	IN UINTN Length,
	IN UINT8 *Address
	);

	CHAR8 *
	BasicWriteRegister (
	IN EFI_SYSTEM_CONTEXT SystemContext,
	IN UINTN RegNumber,
	IN CHAR8 *InBufPtr
	);

	VOID
	PrintReg (
	EFI_SYSTEM_CONTEXT SystemContext
	);

	UINTN
	ParseBreakpointPacket (
	IN CHAR8 *PacketData,
	OUT UINTN *Type,
	OUT UINTN *Address,
	OUT UINTN *Length
	);

	UINTN
	GetBreakpointDataAddress (
	IN EFI_SYSTEM_CONTEXT SystemContext,
	IN UINTN BreakpointNumber
	);

	UINTN
	GetBreakpointDetected (
	IN EFI_SYSTEM_CONTEXT SystemContext
	);

	BREAK_TYPE
	GetBreakpointType (
	IN EFI_SYSTEM_CONTEXT SystemContext,
	IN UINTN BreakpointNumber
	);

	UINTN
	ConvertLengthData (
	IN UINTN Length
	);

	EFI_STATUS
	FindNextFreeDebugRegister (
	IN EFI_SYSTEM_CONTEXT SystemContext,
	OUT UINTN *Register
	);

	EFI_STATUS
	EnableDebugRegister (
	IN EFI_SYSTEM_CONTEXT SystemContext,
	IN UINTN Register,
	IN UINTN Address,
	IN UINTN Length,
	IN UINTN Type
	);

	EFI_STATUS
	FindMatchingDebugRegister (
	IN EFI_SYSTEM_CONTEXT SystemContext,
	IN UINTN Address,
	IN UINTN Length,
	IN UINTN Type,
	OUT UINTN *Register
	);

	EFI_STATUS
	DisableDebugRegister (
	IN EFI_SYSTEM_CONTEXT SystemContext,
	IN UINTN Register
	);

	VOID
	InitializeProcessor (
	VOID
	);

	BOOLEAN
	ValidateAddress (
	IN VOID *Address
	);

	BOOLEAN
	ValidateException (
	IN EFI_EXCEPTION_TYPE ExceptionType,
	IN OUT EFI_SYSTEM_CONTEXT SystemContext
	);

	#endif