[mirror_edk2.git] / EmbeddedPkg / GdbStub / X64 / Processor.c

/** @file\r
  Processor specific parts of the GDB stub\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
\r
//\r
// Array of exception types that need to be hooked by the debugger\r
//\r
EFI_EXCEPTION_TYPE_ENTRY  gExceptionType[] = {\r
  { EXCEPT_X64_DIVIDE_ERROR,    GDB_SIGFPE  },\r
  { EXCEPT_X64_DEBUG,           GDB_SIGTRAP },\r
  { EXCEPT_X64_NMI,             GDB_SIGEMT  },\r
  { EXCEPT_X64_BREAKPOINT,      GDB_SIGTRAP },\r
  { EXCEPT_X64_OVERFLOW,        GDB_SIGSEGV },\r
  { EXCEPT_X64_BOUND,           GDB_SIGSEGV },\r
  { EXCEPT_X64_INVALID_OPCODE,  GDB_SIGILL  },\r
  { EXCEPT_X64_DOUBLE_FAULT,    GDB_SIGEMT  },\r
  { EXCEPT_X64_STACK_FAULT,     GDB_SIGSEGV },\r
  { EXCEPT_X64_GP_FAULT,        GDB_SIGSEGV },\r
  { EXCEPT_X64_PAGE_FAULT,      GDB_SIGSEGV },\r
  { EXCEPT_X64_FP_ERROR,        GDB_SIGEMT  },\r
  { EXCEPT_X64_ALIGNMENT_CHECK, GDB_SIGEMT  },\r
  { EXCEPT_X64_MACHINE_CHECK,   GDB_SIGEMT  }\r
};\r
\r
// The offsets of registers SystemContextX64.\r
// The fields in the array are in the gdb ordering.\r
// HAVE TO DOUBLE-CHECK THE ORDER of the 24 regs\r
//\r
UINTN  gRegisterOffsets[] = {\r
  OFFSET_OF (EFI_SYSTEM_CONTEXT_X64, Rax),\r
  OFFSET_OF (EFI_SYSTEM_CONTEXT_X64, Rcx),\r
  OFFSET_OF (EFI_SYSTEM_CONTEXT_X64, Rdx),\r
  OFFSET_OF (EFI_SYSTEM_CONTEXT_X64, Rbx),\r
  OFFSET_OF (EFI_SYSTEM_CONTEXT_X64, Rsp),\r
  OFFSET_OF (EFI_SYSTEM_CONTEXT_X64, Rbp),\r
  OFFSET_OF (EFI_SYSTEM_CONTEXT_X64, Rsi),\r
  OFFSET_OF (EFI_SYSTEM_CONTEXT_X64, Rdi),\r
  OFFSET_OF (EFI_SYSTEM_CONTEXT_X64, Rip),\r
  OFFSET_OF (EFI_SYSTEM_CONTEXT_X64, Rflags),\r
  OFFSET_OF (EFI_SYSTEM_CONTEXT_X64, Cs),\r
  OFFSET_OF (EFI_SYSTEM_CONTEXT_X64, Ss),\r
  OFFSET_OF (EFI_SYSTEM_CONTEXT_X64, Ds),\r
  OFFSET_OF (EFI_SYSTEM_CONTEXT_X64, Es),\r
  OFFSET_OF (EFI_SYSTEM_CONTEXT_X64, Fs),\r
  OFFSET_OF (EFI_SYSTEM_CONTEXT_X64, Gs),\r
  OFFSET_OF (EFI_SYSTEM_CONTEXT_X64, R8),\r
  OFFSET_OF (EFI_SYSTEM_CONTEXT_X64, R9),\r
  OFFSET_OF (EFI_SYSTEM_CONTEXT_X64, R10),\r
  OFFSET_OF (EFI_SYSTEM_CONTEXT_X64, R11),\r
  OFFSET_OF (EFI_SYSTEM_CONTEXT_X64, R12),\r
  OFFSET_OF (EFI_SYSTEM_CONTEXT_X64, R13),\r
  OFFSET_OF (EFI_SYSTEM_CONTEXT_X64, R14),\r
  OFFSET_OF (EFI_SYSTEM_CONTEXT_X64, R15)\r
};\r
\r
/**\r
 Return the number of entries in the gExceptionType[]\r
\r
 @retval  UINTN, the number of entries in the gExceptionType[] array.\r
 **/\r
UINTN\r
MaxEfiException (\r
  VOID\r
  )\r
{\r
  return sizeof (gExceptionType)/sizeof (EFI_EXCEPTION_TYPE_ENTRY);\r
}\r
\r
/**\r
 Return the number of entries in the gRegisters[]\r
\r
 @retval  UINTN, the number of entries (registers) in the gRegisters[] array.\r
 **/\r
UINTN\r
MaxRegisterCount (\r
  VOID\r
  )\r
{\r
  return sizeof (gRegisterOffsets)/sizeof (UINTN);\r
}\r
\r
/**\r
  Check to see if the ISA is supported.\r
  ISA = Instruction Set Architecture\r
\r
  @retval TRUE if Isa is supported\r
**/\r
BOOLEAN\r
CheckIsa (\r
  IN  EFI_INSTRUCTION_SET_ARCHITECTURE  Isa\r
  )\r
{\r
  return (BOOLEAN)(Isa == IsaX64);\r
}\r
\r
/**\r
 This takes in the register number and the System Context, and returns a pointer to the RegNumber-th register in gdb ordering\r
 It is, by default, set to find the register pointer of the X64 member\r
 @param   SystemContext     Register content at time of the exception\r
 @param   RegNumber       The register to which we want to find a pointer\r
 @retval  the pointer to the RegNumber-th pointer\r
 **/\r
UINTN *\r
FindPointerToRegister (\r
  IN  EFI_SYSTEM_CONTEXT  SystemContext,\r
  IN  UINTN               RegNumber\r
  )\r
{\r
  UINT8  *TempPtr;\r
\r
  TempPtr = ((UINT8 *)SystemContext.SystemContextX64) + gRegisterOffsets[RegNumber];\r
  return (UINTN *)TempPtr;\r
}\r
\r
/**\r
 Adds the RegNumber-th register's value to the output buffer, starting at the given OutBufPtr\r
 @param   SystemContext     Register content at time of the exception\r
 @param   RegNumber       the number of the register that we want to read\r
 @param   OutBufPtr       pointer to the output buffer's end. the new data will be added from this point on.\r
 @retval  the pointer to the next character of the output buffer that is available to be written on.\r
 **/\r
CHAR8 *\r
BasicReadRegister (\r
  IN  EFI_SYSTEM_CONTEXT  SystemContext,\r
  IN  UINTN               RegNumber,\r
  IN  CHAR8               *OutBufPtr\r
  )\r
{\r
  UINTN  RegSize;\r
\r
  RegSize = 0;\r
  while (RegSize < 64) {\r
    *OutBufPtr++ = mHexToStr[((*FindPointerToRegister (SystemContext, RegNumber) >> (RegSize+4)) & 0xf)];\r
    *OutBufPtr++ = mHexToStr[((*FindPointerToRegister (SystemContext, RegNumber) >> RegSize) & 0xf)];\r
    RegSize      = RegSize + 8;\r
  }\r
\r
  return OutBufPtr;\r
}\r
\r
/** ‘p n’\r
 Reads the n-th register's value into an output buffer and sends it as a packet\r
 @param   SystemContext   Register content at time of the exception\r
 @param   InBuffer      Pointer to the input buffer received from gdb server\r
 **/\r
VOID\r
ReadNthRegister (\r
  IN  EFI_SYSTEM_CONTEXT  SystemContext,\r
  IN  CHAR8               *InBuffer\r
  )\r
{\r
  UINTN  RegNumber;\r
  CHAR8  OutBuffer[17]; // 1 reg=16 hex chars, and the end '\0' (escape seq)\r
  CHAR8  *OutBufPtr;    // pointer to the output buffer\r
\r
  RegNumber = AsciiStrHexToUintn (&InBuffer[1]);\r
\r
  if ((RegNumber < 0) || (RegNumber >= MaxRegisterCount ())) {\r
    SendError (GDB_EINVALIDREGNUM);\r
    return;\r
  }\r
\r
  OutBufPtr = OutBuffer;\r
  OutBufPtr = BasicReadRegister (SystemContext, RegNumber, OutBufPtr);\r
\r
  *OutBufPtr = '\0';  // the end of the buffer\r
  SendPacket (OutBuffer);\r
}\r
\r
/** ‘g’\r
 Reads the general registers into an output buffer  and sends it as a packet\r
\r
 @param   SystemContext     Register content at time of the exception\r
 **/\r
VOID\r
EFIAPI\r
ReadGeneralRegisters (\r
  IN  EFI_SYSTEM_CONTEXT  SystemContext\r
  )\r
{\r
  UINTN  i;\r
  CHAR8  OutBuffer[385]; // 24 regs, 16 hex chars each, and the end '\0' (escape seq)\r
  CHAR8  *OutBufPtr;     // pointer to the output buffer\r
\r
  OutBufPtr = OutBuffer;\r
  for (i = 0; i < MaxRegisterCount (); i++) {\r
    // there are only 24 registers to read\r
    OutBufPtr = BasicReadRegister (SystemContext, i, OutBufPtr);\r
  }\r
\r
  *OutBufPtr = '\0';  // the end of the buffer\r
  SendPacket (OutBuffer);\r
}\r
\r
/**\r
 Adds the RegNumber-th register's value to the output buffer, starting at the given OutBufPtr\r
\r
 @param   SystemContext       Register content at time of the exception\r
 @param   RegNumber         the number of the register that we want to write\r
 @param   InBufPtr          pointer to the output buffer. the new data will be extracted from the input buffer from this point on.\r
 @retval  the pointer to the next character of the input buffer that can be used\r
 **/\r
CHAR8 *\r
BasicWriteRegister (\r
  IN  EFI_SYSTEM_CONTEXT  SystemContext,\r
  IN  UINTN               RegNumber,\r
  IN  CHAR8               *InBufPtr\r
  )\r
{\r
  UINTN   RegSize;\r
  UINTN   TempValue; // the value transferred from a hex char\r
  UINT64  NewValue;  // the new value of the RegNumber-th Register\r
\r
  NewValue = 0;\r
  RegSize  = 0;\r
  while (RegSize < 64) {\r
    TempValue = HexCharToInt (*InBufPtr++);\r
\r
    if (TempValue < 0) {\r
      SendError (GDB_EBADMEMDATA);\r
      return NULL;\r
    }\r
\r
    NewValue += (TempValue << (RegSize+4));\r
    TempValue = HexCharToInt (*InBufPtr++);\r
\r
    if (TempValue < 0) {\r
      SendError (GDB_EBADMEMDATA);\r
      return NULL;\r
    }\r
\r
    NewValue += (TempValue << RegSize);\r
    RegSize   = RegSize + 8;\r
  }\r
\r
  *(FindPointerToRegister (SystemContext, RegNumber)) = NewValue;\r
  return InBufPtr;\r
}\r
\r
/** ‘P n...=r...’\r
 Writes the new value of n-th register received into the input buffer to the n-th register\r
\r
 @param   SystemContext   Register content at time of the exception\r
 @param   InBuffer      Pointer to the input buffer received from gdb server\r
 **/\r
VOID\r
EFIAPI\r
WriteNthRegister (\r
  IN  EFI_SYSTEM_CONTEXT  SystemContext,\r
  IN  CHAR8               *InBuffer\r
  )\r
{\r
  UINTN  RegNumber;\r
  CHAR8  RegNumBuffer[MAX_REG_NUM_BUF_SIZE]; // put the 'n..' part of the message into this array\r
  CHAR8  *RegNumBufPtr;\r
  CHAR8  *InBufPtr; // pointer to the input buffer\r
\r
  // find the register number to write\r
  InBufPtr     = &InBuffer[1];\r
  RegNumBufPtr = RegNumBuffer;\r
  while (*InBufPtr != '=') {\r
    *RegNumBufPtr++ = *InBufPtr++;\r
  }\r
\r
  *RegNumBufPtr = '\0';\r
  RegNumber     = AsciiStrHexToUintn (RegNumBuffer);\r
\r
  // check if this is a valid Register Number\r
  if ((RegNumber < 0) || (RegNumber >= MaxRegisterCount ())) {\r
    SendError (GDB_EINVALIDREGNUM);\r
    return;\r
  }\r
\r
  InBufPtr++;  // skips the '=' character\r
  BasicWriteRegister (SystemContext, RegNumber, InBufPtr);\r
  SendSuccess ();\r
}\r
\r
/** ‘G XX...’\r
 Writes the new values received into the input buffer to the general registers\r
\r
 @param   SystemContext       Register content at time of the exception\r
 @param   InBuffer          Pointer to the input buffer received from gdb server\r
 **/\r
VOID\r
EFIAPI\r
WriteGeneralRegisters (\r
  IN  EFI_SYSTEM_CONTEXT  SystemContext,\r
  IN  CHAR8               *InBuffer\r
  )\r
{\r
  UINTN  i;\r
  CHAR8  *InBufPtr; /// pointer to the input buffer\r
\r
  // check to see if the buffer is the right size which is\r
  // 1 (for 'G') + 16 (for 16 registers) * 8 ( for 8 hex chars each) = 385\r
  if (AsciiStrLen (InBuffer) != 385) {\r
    // 24 regs, 16 hex chars each, and the end '\0' (escape seq)\r
    // Bad message. Message is not the right length\r
    SendError (GDB_EBADBUFSIZE);\r
    return;\r
  }\r
\r
  InBufPtr = &InBuffer[1];\r
\r
  // Read the new values for the registers from the input buffer to an array, NewValueArray.\r
  // The values in the array are in the gdb ordering\r
  for (i = 0; i < MaxRegisterCount (); i++) {\r
    // there are only 16 registers to write\r
    InBufPtr = BasicWriteRegister (SystemContext, i, InBufPtr);\r
  }\r
\r
  SendSuccess ();\r
}\r
\r
/**\r
Insert Single Step in the SystemContext\r
\r
@param SystemContext Register content at time of the exception\r
**/\r
VOID\r
AddSingleStep (\r
  IN  EFI_SYSTEM_CONTEXT  SystemContext\r
  )\r
{\r
  SystemContext.SystemContextX64->Rflags |= TF_BIT; // Setting the TF bit.\r
}\r
\r
/**\r
 Remove Single Step in the SystemContext\r
\r
 @param SystemContext Register content at time of the exception\r
 **/\r
VOID\r
RemoveSingleStep (\r
  IN  EFI_SYSTEM_CONTEXT  SystemContext\r
  )\r
{\r
  SystemContext.SystemContextX64->Rflags &= ~TF_BIT;  // clearing the TF bit.\r
}\r
\r
/** ‘c [addr ]’\r
 Continue. addr is Address to resume. If addr is omitted, resume at current\r
 Address.\r
\r
 @param   SystemContext     Register content at time of the exception\r
 **/\r
VOID\r
EFIAPI\r
ContinueAtAddress (\r
  IN  EFI_SYSTEM_CONTEXT  SystemContext,\r
  IN    CHAR8             *PacketData\r
  )\r
{\r
  if (PacketData[1] != '\0') {\r
    SystemContext.SystemContextX64->Rip = AsciiStrHexToUintn (&PacketData[1]);\r
  }\r
}\r
\r
/** ‘s [addr ]’\r
 Single step. addr is the Address at which to resume. If addr is omitted, resume\r
 at same Address.\r
\r
 @param   SystemContext     Register content at time of the exception\r
 **/\r
VOID\r
EFIAPI\r
SingleStep (\r
  IN  EFI_SYSTEM_CONTEXT  SystemContext,\r
  IN    CHAR8             *PacketData\r
  )\r
{\r
  if (PacketData[1] != '\0') {\r
    SystemContext.SystemContextX64->Rip = AsciiStrHexToUintn (&PacketData[1]);\r
  }\r
\r
  AddSingleStep (SystemContext);\r
}\r
\r
/**\r
  Returns breakpoint data address from DR0-DR3 based on the input breakpoint\r
  number\r
\r
  @param  SystemContext      Register content at time of the exception\r
  @param  BreakpointNumber   Breakpoint number\r
\r
  @retval Address            Data address from DR0-DR3 based on the\r
                             breakpoint number.\r
\r
**/\r
UINTN\r
GetBreakpointDataAddress (\r
  IN  EFI_SYSTEM_CONTEXT  SystemContext,\r
  IN  UINTN               BreakpointNumber\r
  )\r
{\r
  UINTN  Address;\r
\r
  if (BreakpointNumber == 1) {\r
    Address = SystemContext.SystemContextIa32->Dr0;\r
  } else if (BreakpointNumber == 2) {\r
    Address = SystemContext.SystemContextIa32->Dr1;\r
  } else if (BreakpointNumber == 3) {\r
    Address = SystemContext.SystemContextIa32->Dr2;\r
  } else if (BreakpointNumber == 4) {\r
    Address = SystemContext.SystemContextIa32->Dr3;\r
  } else {\r
    Address = 0;\r
  }\r
\r
  return Address;\r
}\r
\r
/**\r
  Returns currently detected breakpoint value based on the register\r
  DR6 B0-B3 field.\r
  If no breakpoint is detected then it returns 0.\r
\r
  @param  SystemContext  Register content at time of the exception\r
\r
  @retval {1-4}          Currently detected breakpoint value\r
  @retval 0              No breakpoint detected.\r
\r
**/\r
UINTN\r
GetBreakpointDetected (\r
  IN  EFI_SYSTEM_CONTEXT  SystemContext\r
  )\r
{\r
  IA32_DR6  Dr6;\r
  UINTN     BreakpointNumber;\r
\r
  Dr6.UintN = SystemContext.SystemContextIa32->Dr6;\r
\r
  if (Dr6.Bits.B0 == 1) {\r
    BreakpointNumber = 1;\r
  } else if (Dr6.Bits.B1 == 1) {\r
    BreakpointNumber = 2;\r
  } else if (Dr6.Bits.B2 == 1) {\r
    BreakpointNumber = 3;\r
  } else if (Dr6.Bits.B3 == 1) {\r
    BreakpointNumber = 4;\r
  } else {\r
    BreakpointNumber = 0;  // No breakpoint detected\r
  }\r
\r
  return BreakpointNumber;\r
}\r
\r
/**\r
  Returns Breakpoint type (InstructionExecution, DataWrite, DataRead\r
  or DataReadWrite) based on the Breakpoint number\r
\r
  @param  SystemContext      Register content at time of the exception\r
  @param  BreakpointNumber   Breakpoint number\r
\r
  @retval BREAK_TYPE         Breakpoint type value read from register DR7 RWn\r
                             field. For unknown value, it returns NotSupported.\r
\r
**/\r
BREAK_TYPE\r
GetBreakpointType (\r
  IN  EFI_SYSTEM_CONTEXT  SystemContext,\r
  IN  UINTN               BreakpointNumber\r
  )\r
{\r
  IA32_DR7    Dr7;\r
  BREAK_TYPE  Type = NotSupported; // Default is NotSupported type\r
\r
  Dr7.UintN = SystemContext.SystemContextIa32->Dr7;\r
\r
  if (BreakpointNumber == 1) {\r
    Type = (BREAK_TYPE)Dr7.Bits.RW0;\r
  } else if (BreakpointNumber == 2) {\r
    Type = (BREAK_TYPE)Dr7.Bits.RW1;\r
  } else if (BreakpointNumber == 3) {\r
    Type = (BREAK_TYPE)Dr7.Bits.RW2;\r
  } else if (BreakpointNumber == 4) {\r
    Type = (BREAK_TYPE)Dr7.Bits.RW3;\r
  }\r
\r
  return Type;\r
}\r
\r
/**\r
  Parses Length and returns the length which DR7 LENn field accepts.\r
  For example: If we receive 1-Byte length then we should return 0.\r
               Zero gets written to DR7 LENn field.\r
\r
  @param  Length  Breakpoint length in Bytes (1 byte, 2 byte, 4 byte)\r
\r
  @retval Length  Appropriate converted values which DR7 LENn field accepts.\r
\r
**/\r
UINTN\r
ConvertLengthData (\r
  IN     UINTN  Length\r
  )\r
{\r
  if (Length == 1) {\r
    // 1-Byte length\r
    return 0;\r
  } else if (Length == 2) {\r
    // 2-Byte length\r
    return 1;\r
  } else if (Length == 4) {\r
    // 4-Byte length\r
    return 3;\r
  } else {\r
    // Undefined or 8-byte length\r
    return 2;\r
  }\r
}\r
\r
/**\r
  Finds the next free debug register. If all the registers are occupied then\r
  EFI_OUT_OF_RESOURCES is returned.\r
\r
  @param  SystemContext  Register content at time of the exception\r
  @param  Register       Register value (0 - 3 for the first free debug register)\r
\r
  @retval EFI_STATUS     Appropriate status value.\r
\r
**/\r
EFI_STATUS\r
FindNextFreeDebugRegister (\r
  IN  EFI_SYSTEM_CONTEXT  SystemContext,\r
  OUT UINTN               *Register\r
  )\r
{\r
  IA32_DR7  Dr7;\r
\r
  Dr7.UintN = SystemContext.SystemContextIa32->Dr7;\r
\r
  if (Dr7.Bits.G0 == 0) {\r
    *Register = 0;\r
  } else if (Dr7.Bits.G1 == 0) {\r
    *Register = 1;\r
  } else if (Dr7.Bits.G2 == 0) {\r
    *Register = 2;\r
  } else if (Dr7.Bits.G3 == 0) {\r
    *Register = 3;\r
  } else {\r
    return EFI_OUT_OF_RESOURCES;\r
  }\r
\r
  return EFI_SUCCESS;\r
}\r
\r
/**\r
  Enables the debug register. Writes Address value to appropriate DR0-3 register.\r
  Sets LENn, Gn, RWn bits in DR7 register.\r
\r
  @param  SystemContext   Register content at time of the exception\r
  @param  Register        Register value (0 - 3)\r
  @param  Address         Breakpoint address value\r
  @param  Type            Breakpoint type (Instruction, Data write,\r
                          Data read or write etc.)\r
\r
  @retval EFI_STATUS      Appropriate status value.\r
\r
**/\r
EFI_STATUS\r
EnableDebugRegister (\r
  IN  EFI_SYSTEM_CONTEXT  SystemContext,\r
  IN  UINTN               Register,\r
  IN  UINTN               Address,\r
  IN  UINTN               Length,\r
  IN  UINTN               Type\r
  )\r
{\r
  IA32_DR7  Dr7;\r
\r
  // Convert length data\r
  Length = ConvertLengthData (Length);\r
\r
  // For Instruction execution, length should be 0\r
  // (Ref. Intel reference manual 18.2.4)\r
  if ((Type == 0) && (Length != 0)) {\r
    return EFI_INVALID_PARAMETER;\r
  }\r
\r
  // Hardware doesn't support ReadWatch (z3 packet) type. GDB can handle\r
  // software breakpoint. We should send empty packet in both these cases.\r
  if ((Type == (BREAK_TYPE)DataRead) ||\r
      (Type == (BREAK_TYPE)SoftwareBreakpoint))\r
  {\r
    return EFI_UNSUPPORTED;\r
  }\r
\r
  // Read DR7 so appropriate Gn, RWn and LENn bits can be modified.\r
  Dr7.UintN = SystemContext.SystemContextIa32->Dr7;\r
\r
  if (Register == 0) {\r
    SystemContext.SystemContextIa32->Dr0 = Address;\r
    Dr7.Bits.G0                          = 1;\r
    Dr7.Bits.RW0                         = Type;\r
    Dr7.Bits.LEN0                        = Length;\r
  } else if (Register == 1) {\r
    SystemContext.SystemContextIa32->Dr1 = Address;\r
    Dr7.Bits.G1                          = 1;\r
    Dr7.Bits.RW1                         = Type;\r
    Dr7.Bits.LEN1                        = Length;\r
  } else if (Register == 2) {\r
    SystemContext.SystemContextIa32->Dr2 = Address;\r
    Dr7.Bits.G2                          = 1;\r
    Dr7.Bits.RW2                         = Type;\r
    Dr7.Bits.LEN2                        = Length;\r
  } else if (Register == 3) {\r
    SystemContext.SystemContextIa32->Dr3 = Address;\r
    Dr7.Bits.G3                          = 1;\r
    Dr7.Bits.RW3                         = Type;\r
    Dr7.Bits.LEN3                        = Length;\r
  } else {\r
    return EFI_INVALID_PARAMETER;\r
  }\r
\r
  // Update Dr7 with appropriate Gn, RWn and LENn bits\r
  SystemContext.SystemContextIa32->Dr7 = Dr7.UintN;\r
\r
  return EFI_SUCCESS;\r
}\r
\r
/**\r
  Returns register number 0 - 3 for the matching debug register.\r
  This function compares incoming Address, Type, Length and\r
  if there is a match then it returns the appropriate register number.\r
  In case of mismatch, function returns EFI_NOT_FOUND message.\r
\r
  @param  SystemContext  Register content at time of the exception\r
  @param  Address        Breakpoint address value\r
  @param  Length         Breakpoint length value\r
  @param  Type           Breakpoint type (Instruction, Data write, Data read\r
                         or write etc.)\r
  @param  Register       Register value to be returned\r
\r
  @retval EFI_STATUS     Appropriate status value.\r
\r
**/\r
EFI_STATUS\r
FindMatchingDebugRegister (\r
  IN  EFI_SYSTEM_CONTEXT  SystemContext,\r
  IN  UINTN               Address,\r
  IN  UINTN               Length,\r
  IN  UINTN               Type,\r
  OUT UINTN               *Register\r
  )\r
{\r
  IA32_DR7  Dr7;\r
\r
  // Hardware doesn't support ReadWatch (z3 packet) type. GDB can handle\r
  // software breakpoint. We should send empty packet in both these cases.\r
  if ((Type == (BREAK_TYPE)DataRead) ||\r
      (Type == (BREAK_TYPE)SoftwareBreakpoint))\r
  {\r
    return EFI_UNSUPPORTED;\r
  }\r
\r
  // Convert length data\r
  Length = ConvertLengthData (Length);\r
\r
  Dr7.UintN = SystemContext.SystemContextIa32->Dr7;\r
\r
  if ((Dr7.Bits.G0 == 1) &&\r
      (Dr7.Bits.LEN0 == Length) &&\r
      (Dr7.Bits.RW0 == Type) &&\r
      (Address == SystemContext.SystemContextIa32->Dr0))\r
  {\r
    *Register = 0;\r
  } else if ((Dr7.Bits.G1 == 1) &&\r
             (Dr7.Bits.LEN1 == Length) &&\r
             (Dr7.Bits.RW1 == Type) &&\r
             (Address == SystemContext.SystemContextIa32->Dr1))\r
  {\r
    *Register = 1;\r
  } else if ((Dr7.Bits.G2 == 1) &&\r
             (Dr7.Bits.LEN2 == Length) &&\r
             (Dr7.Bits.RW2 == Type) &&\r
             (Address == SystemContext.SystemContextIa32->Dr2))\r
  {\r
    *Register = 2;\r
  } else if ((Dr7.Bits.G3 == 1) &&\r
             (Dr7.Bits.LEN3 == Length) &&\r
             (Dr7.Bits.RW3 == Type) &&\r
             (Address == SystemContext.SystemContextIa32->Dr3))\r
  {\r
    *Register = 3;\r
  } else {\r
    Print ((CHAR16 *)L"No match found..\n");\r
    return EFI_NOT_FOUND;\r
  }\r
\r
  return EFI_SUCCESS;\r
}\r
\r
/**\r
  Disables the particular debug register.\r
\r
  @param  SystemContext   Register content at time of the exception\r
  @param  Register        Register to be disabled\r
\r
  @retval EFI_STATUS      Appropriate status value.\r
\r
**/\r
EFI_STATUS\r
DisableDebugRegister (\r
  IN  EFI_SYSTEM_CONTEXT  SystemContext,\r
  IN  UINTN               Register\r
  )\r
{\r
  IA32_DR7  Dr7;\r
  UINTN     Address = 0;\r
\r
  // Read DR7 register so appropriate Gn, RWn and LENn bits can be turned off.\r
  Dr7.UintN = SystemContext.SystemContextIa32->Dr7;\r
\r
  if (Register == 0) {\r
    SystemContext.SystemContextIa32->Dr0 = Address;\r
    Dr7.Bits.G0                          = 0;\r
    Dr7.Bits.RW0                         = 0;\r
    Dr7.Bits.LEN0                        = 0;\r
  } else if (Register == 1) {\r
    SystemContext.SystemContextIa32->Dr1 = Address;\r
    Dr7.Bits.G1                          = 0;\r
    Dr7.Bits.RW1                         = 0;\r
    Dr7.Bits.LEN1                        = 0;\r
  } else if (Register == 2) {\r
    SystemContext.SystemContextIa32->Dr2 = Address;\r
    Dr7.Bits.G2                          = 0;\r
    Dr7.Bits.RW2                         = 0;\r
    Dr7.Bits.LEN2                        = 0;\r
  } else if (Register == 3) {\r
    SystemContext.SystemContextIa32->Dr3 = Address;\r
    Dr7.Bits.G3                          = 0;\r
    Dr7.Bits.RW3                         = 0;\r
    Dr7.Bits.LEN3                        = 0;\r
  } else {\r
    return EFI_INVALID_PARAMETER;\r
  }\r
\r
  // Update DR7 register so appropriate Gn, RWn and LENn bits can be turned off.\r
  SystemContext.SystemContextIa32->Dr7 = Dr7.UintN;\r
\r
  return EFI_SUCCESS;\r
}\r
\r
/**\r
  ‘Z1, [addr], [length]’\r
  ‘Z2, [addr], [length]’\r
  ‘Z3, [addr], [length]’\r
  ‘Z4, [addr], [length]’\r
\r
  Insert hardware breakpoint/watchpoint at address addr of size length\r
\r
  @param SystemContext  Register content at time of the exception\r
  @param *PacketData    Pointer to the Payload data for the packet\r
\r
**/\r
VOID\r
EFIAPI\r
InsertBreakPoint (\r
  IN  EFI_SYSTEM_CONTEXT  SystemContext,\r
  IN  CHAR8               *PacketData\r
  )\r
{\r
  UINTN       Type;\r
  UINTN       Address;\r
  UINTN       Length;\r
  UINTN       Register;\r
  EFI_STATUS  Status;\r
  BREAK_TYPE  BreakType = NotSupported;\r
  UINTN       ErrorCode;\r
\r
  ErrorCode = ParseBreakpointPacket (PacketData, &Type, &Address, &Length);\r
  if (ErrorCode > 0) {\r
    SendError ((UINT8)ErrorCode);\r
    return;\r
  }\r
\r
  switch (Type) {\r
    case 0:      // Software breakpoint\r
      BreakType = SoftwareBreakpoint;\r
      break;\r
\r
    case 1:      // Hardware breakpoint\r
      BreakType = InstructionExecution;\r
      break;\r
\r
    case 2:      // Write watchpoint\r
      BreakType = DataWrite;\r
      break;\r
\r
    case 3:      // Read watchpoint\r
      BreakType = DataRead;\r
      break;\r
\r
    case 4:      // Access watchpoint\r
      BreakType = DataReadWrite;\r
      break;\r
\r
    default:\r
      Print ((CHAR16 *)L"Insert breakpoint default: %x\n", Type);\r
      SendError (GDB_EINVALIDBRKPOINTTYPE);\r
      return;\r
  }\r
\r
  // Find next free debug register\r
  Status = FindNextFreeDebugRegister (SystemContext, &Register);\r
  if (EFI_ERROR (Status)) {\r
    Print ((CHAR16 *)L"No space left on device\n");\r
    SendError (GDB_ENOSPACE);\r
    return;\r
  }\r
\r
  // Write Address, length data at particular DR register\r
  Status = EnableDebugRegister (SystemContext, Register, Address, Length, (UINTN)BreakType);\r
  if (EFI_ERROR (Status)) {\r
    if (Status == EFI_UNSUPPORTED) {\r
      Print ((CHAR16 *)L"Not supported\n");\r
      SendNotSupported ();\r
      return;\r
    }\r
\r
    Print ((CHAR16 *)L"Invalid argument\n");\r
    SendError (GDB_EINVALIDARG);\r
    return;\r
  }\r
\r
  SendSuccess ();\r
}\r
\r
/**\r
  ‘z1, [addr], [length]’\r
  ‘z2, [addr], [length]’\r
  ‘z3, [addr], [length]’\r
  ‘z4, [addr], [length]’\r
\r
  Remove hardware breakpoint/watchpoint at address addr of size length\r
\r
  @param *PacketData    Pointer to the Payload data for the packet\r
\r
**/\r
VOID\r
EFIAPI\r
RemoveBreakPoint (\r
  IN  EFI_SYSTEM_CONTEXT  SystemContext,\r
  IN  CHAR8               *PacketData\r
  )\r
{\r
  UINTN       Type;\r
  UINTN       Address;\r
  UINTN       Length;\r
  UINTN       Register;\r
  BREAK_TYPE  BreakType = NotSupported;\r
  EFI_STATUS  Status;\r
  UINTN       ErrorCode;\r
\r
  // Parse breakpoint packet data\r
  ErrorCode = ParseBreakpointPacket (PacketData, &Type, &Address, &Length);\r
  if (ErrorCode > 0) {\r
    SendError ((UINT8)ErrorCode);\r
    return;\r
  }\r
\r
  switch (Type) {\r
    case 0:      // Software breakpoint\r
      BreakType = SoftwareBreakpoint;\r
      break;\r
\r
    case 1:      // Hardware breakpoint\r
      BreakType = InstructionExecution;\r
      break;\r
\r
    case 2:      // Write watchpoint\r
      BreakType = DataWrite;\r
      break;\r
\r
    case 3:      // Read watchpoint\r
      BreakType = DataRead;\r
      break;\r
\r
    case 4:      // Access watchpoint\r
      BreakType = DataReadWrite;\r
      break;\r
\r
    default:\r
      SendError (GDB_EINVALIDBRKPOINTTYPE);\r
      return;\r
  }\r
\r
  // Find matching debug register\r
  Status = FindMatchingDebugRegister (SystemContext, Address, Length, (UINTN)BreakType, &Register);\r
  if (EFI_ERROR (Status)) {\r
    if (Status == EFI_UNSUPPORTED) {\r
      Print ((CHAR16 *)L"Not supported.\n");\r
      SendNotSupported ();\r
      return;\r
    }\r
\r
    Print ((CHAR16 *)L"No matching register found.\n");\r
    SendError (GDB_ENOSPACE);\r
    return;\r
  }\r
\r
  // Remove breakpoint\r
  Status = DisableDebugRegister (SystemContext, Register);\r
  if (EFI_ERROR (Status)) {\r
    Print ((CHAR16 *)L"Invalid argument.\n");\r
    SendError (GDB_EINVALIDARG);\r
    return;\r
  }\r
\r
  SendSuccess ();\r
}\r
\r
VOID\r
InitializeProcessor (\r
  VOID\r
  )\r
{\r
}\r
\r
BOOLEAN\r
ValidateAddress (\r
  IN  VOID  *Address\r
  )\r
{\r
  return TRUE;\r
}\r
\r
BOOLEAN\r
ValidateException (\r
  IN  EFI_EXCEPTION_TYPE     ExceptionType,\r
  IN OUT EFI_SYSTEM_CONTEXT  SystemContext\r
  )\r
{\r
  return TRUE;\r
}\r