[mirror_edk2.git] / EmbeddedPkg / GdbStub / Arm / 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
  This program and the accompanying materials\r
  are licensed and made available under the terms and conditions of the BSD License\r
  which accompanies this distribution.  The full text of the license may be found at\r
  http://opensource.org/licenses/bsd-license.php\r
\r
  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,\r
  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r
\r
**/\r
\r
#include <GdbStubInternal.h>\r
#include <Library/CacheMaintenanceLib.h>\r
#include <Library/PrintLib.h>\r
\r
//\r
// Array of exception types that need to be hooked by the debugger\r
// (efi, gdb) //efi number\r
//\r
EFI_EXCEPTION_TYPE_ENTRY gExceptionType[] = {\r
  { EXCEPT_ARM_SOFTWARE_INTERRUPT,  GDB_SIGTRAP }\r
//  { EXCEPT_ARM_UNDEFINED_INSTRUCTION, GDB_SIGTRAP },\r
//  { EXCEPT_ARM_PREFETCH_ABORT,        GDB_SIGTRAP },\r
//  { EXCEPT_ARM_DATA_ABORT,            GDB_SIGEMT  },\r
//  { EXCEPT_ARM_RESERVED,              GDB_SIGILL  }\r
};\r
\r
// Shut up some annoying RVCT warnings\r
#ifdef __CC_ARM\r
#pragma diag_suppress 1296\r
#endif\r
\r
UINTN gRegisterOffsets[] = {\r
  OFFSET_OF(EFI_SYSTEM_CONTEXT_ARM, R0),\r
  OFFSET_OF(EFI_SYSTEM_CONTEXT_ARM, R1),\r
  OFFSET_OF(EFI_SYSTEM_CONTEXT_ARM, R2),\r
  OFFSET_OF(EFI_SYSTEM_CONTEXT_ARM, R3),\r
  OFFSET_OF(EFI_SYSTEM_CONTEXT_ARM, R4),\r
  OFFSET_OF(EFI_SYSTEM_CONTEXT_ARM, R5),\r
  OFFSET_OF(EFI_SYSTEM_CONTEXT_ARM, R6),\r
  OFFSET_OF(EFI_SYSTEM_CONTEXT_ARM, R7),\r
  OFFSET_OF(EFI_SYSTEM_CONTEXT_ARM, R8),\r
  OFFSET_OF(EFI_SYSTEM_CONTEXT_ARM, R9),\r
  OFFSET_OF(EFI_SYSTEM_CONTEXT_ARM, R10),\r
  OFFSET_OF(EFI_SYSTEM_CONTEXT_ARM, R11),\r
  OFFSET_OF(EFI_SYSTEM_CONTEXT_ARM, R12),\r
  OFFSET_OF(EFI_SYSTEM_CONTEXT_ARM, SP),\r
  OFFSET_OF(EFI_SYSTEM_CONTEXT_ARM, LR),\r
  OFFSET_OF(EFI_SYSTEM_CONTEXT_ARM, PC),\r
  0x00000F01,                               // f0\r
  0x00000F02,\r
  0x00000F03,\r
  0x00000F11,                               // f1\r
  0x00000F12,\r
  0x00000F13,\r
  0x00000F21,                               // f2\r
  0x00000F22,\r
  0x00000F23,\r
  0x00000F31,                               // f3\r
  0x00000F32,\r
  0x00000F33,\r
  0x00000F41,                               // f4\r
  0x00000F42,\r
  0x00000F43,\r
  0x00000F51,                               // f5\r
  0x00000F52,\r
  0x00000F53,\r
  0x00000F61,                               // f6\r
  0x00000F62,\r
  0x00000F63,\r
  0x00000F71,                               // f7\r
  0x00000F72,\r
  0x00000F73,\r
  0x00000FFF,                               // fps\r
  OFFSET_OF(EFI_SYSTEM_CONTEXT_ARM, CPSR)\r
};\r
\r
// restore warnings for RVCT\r
#ifdef __CC_ARM\r
#pragma diag_default 1296\r
#endif\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
/**\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
/**\r
 Check to see if the ISA is supported.\r
 ISA = Instruction Set Architecture\r
\r
 @retval TRUE if Isa is supported\r
\r
**/\r
BOOLEAN\r
CheckIsa (\r
  IN  EFI_INSTRUCTION_SET_ARCHITECTURE  Isa\r
  )\r
{\r
  if (Isa == IsaArm) {\r
    return TRUE;\r
  } else {\r
    return FALSE;\r
  }\r
}\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 ARM 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
  ASSERT(gRegisterOffsets[RegNumber] < 0xF00);\r
  TempPtr = ((UINT8 *)SystemContext.SystemContextArm) + gRegisterOffsets[RegNumber];\r
  return (UINT32 *)TempPtr;\r
}\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
  CHAR8 Char;\r
\r
  if (gRegisterOffsets[RegNumber] > 0xF00) {\r
    AsciiSPrint (OutBufPtr, 9, "00000000");\r
    OutBufPtr += 8;\r
    return OutBufPtr;\r
  }\r
\r
  RegSize = 0;\r
  while (RegSize < 32) {\r
    Char = mHexToStr[(UINT8)((*FindPointerToRegister (SystemContext, RegNumber) >> (RegSize+4)) & 0xf)];\r
    if ((Char >= 'A') && (Char <= 'F')) {\r
      Char = Char - 'A' + 'a';\r
    }\r
    *OutBufPtr++ = Char;\r
\r
    Char = mHexToStr[(UINT8)((*FindPointerToRegister (SystemContext, RegNumber) >> RegSize) & 0xf)];\r
    if ((Char >= 'A') && (Char <= 'F')) {\r
      Char = Char - 'A' + 'a';\r
    }\r
    *OutBufPtr++ = Char;\r
\r
    RegSize = RegSize + 8;\r
  }\r
  return OutBufPtr;\r
}\r
\r
\r
/**\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[9]; // 1 reg=8 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 >= 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
\r
/**\r
 Reads the general registers into an output buffer  and sends it as a packet\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   Index;\r
  CHAR8   *OutBuffer;\r
  CHAR8   *OutBufPtr;\r
  UINTN   RegisterCount = MaxRegisterCount ();\r
\r
  // It is not safe to allocate pool here....\r
  OutBuffer = AllocatePool ((RegisterCount * 8) + 1); // 8 bytes per register in string format plus a null to terminate\r
  OutBufPtr = OutBuffer;\r
  for (Index = 0; Index < RegisterCount; Index++) {\r
    OutBufPtr = BasicReadRegister (SystemContext, Index, OutBufPtr);\r
  }\r
\r
  *OutBufPtr = '\0';\r
  SendPacket (OutBuffer);\r
  FreePool (OutBuffer);\r
}\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 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
  UINT32 NewValue; // the new value of the RegNumber-th Register\r
\r
  if (gRegisterOffsets[RegNumber] > 0xF00) {\r
    return InBufPtr + 8;\r
  }\r
\r
  NewValue = 0;\r
  RegSize = 0;\r
  while (RegSize < 32) {\r
    TempValue = HexCharToInt (*InBufPtr++);\r
\r
    if ((INTN)TempValue < 0) {\r
      SendError (GDB_EBADMEMDATA);\r
      return NULL;\r
    }\r
\r
    NewValue += (TempValue << (RegSize+4));\r
    TempValue = HexCharToInt (*InBufPtr++);\r
\r
    if ((INTN)TempValue < 0) {\r
      SendError (GDB_EBADMEMDATA);\r
      return NULL;\r
    }\r
\r
    NewValue += (TempValue << RegSize);\r
    RegSize = RegSize + 8;\r
  }\r
  *(FindPointerToRegister (SystemContext, RegNumber)) = NewValue;\r
  return InBufPtr;\r
}\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
 @param   SystemContext   Register content at time of the exception\r
 @param   InBuffer      Ponter to the input buffer received from gdb server\r
 **/\r
VOID\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
  *RegNumBufPtr = '\0';\r
  RegNumber = AsciiStrHexToUintn (RegNumBuffer);\r
\r
  // check if this is a valid Register Number\r
  if (RegNumber >= MaxRegisterCount ()) {\r
    SendError (GDB_EINVALIDREGNUM);\r
    return;\r
  }\r
  InBufPtr++;  // skips the '=' character\r
  BasicWriteRegister (SystemContext, RegNumber, InBufPtr);\r
  SendSuccess();\r
}\r
\r
\r
/** ‘G XX...’\r
 Writes the new values received into the input buffer to the general registers\r
 @param   SystemContext       Register content at time of the exception\r
 @param   InBuffer          Pointer to the input buffer received from gdb server\r
 **/\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
  UINTN  MinLength;\r
  UINTN  RegisterCount = MaxRegisterCount ();\r
\r
  MinLength = (RegisterCount * 8) + 1;  // 'G' plus the registers in ASCII format\r
\r
  if (AsciiStrLen (InBuffer) < MinLength) {\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 < RegisterCount; i++) {\r
    InBufPtr = BasicWriteRegister (SystemContext, i, InBufPtr);\r
  }\r
\r
  SendSuccess ();\r
}\r
\r
// What about Thumb?\r
// Use SWI 0xdbdbdb as the debug instruction\r
#define GDB_ARM_BKPT    0xefdbdbdb\r
\r
BOOLEAN mSingleStepActive = FALSE;\r
UINT32  mSingleStepPC;\r
UINT32  mSingleStepData;\r
UINTN   mSingleStepDataSize;\r
\r
typedef struct {\r
  LIST_ENTRY  Link;\r
  UINT64      Signature;\r
  UINT32      Address;\r
  UINT32      Instruction;\r
} ARM_SOFTWARE_BREAKPOINT;\r
\r
#define ARM_SOFTWARE_BREAKPOINT_SIGNATURE     SIGNATURE_64('A', 'R', 'M', 'B', 'R', 'K', 'P', 'T')\r
#define ARM_SOFTWARE_BREAKPOINT_FROM_LINK(a)  CR(a, ARM_SOFTWARE_BREAKPOINT, Link, ARM_SOFTWARE_BREAKPOINT_SIGNATURE)\r
\r
LIST_ENTRY  BreakpointList;\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
  if (mSingleStepActive) {\r
    // Currently don't support nesting\r
    return;\r
  }\r
  mSingleStepActive = TRUE;\r
\r
  mSingleStepPC = SystemContext.SystemContextArm->PC;\r
\r
  mSingleStepDataSize = sizeof (UINT32);\r
  mSingleStepData = (*(UINT32 *)mSingleStepPC);\r
  *(UINT32 *)mSingleStepPC = GDB_ARM_BKPT;\r
  if (*(UINT32 *)mSingleStepPC != GDB_ARM_BKPT) {\r
    // For some reason our breakpoint did not take\r
    mSingleStepActive = FALSE;\r
  }\r
\r
  InvalidateInstructionCacheRange ((VOID *)mSingleStepPC, mSingleStepDataSize);\r
  //DEBUG((EFI_D_ERROR, "AddSingleStep at 0x%08x (was: 0x%08x is:0x%08x)\n", SystemContext.SystemContextArm->PC, mSingleStepData, *(UINT32 *)mSingleStepPC));\r
}\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
  if (!mSingleStepActive) {\r
    return;\r
  }\r
\r
  if (mSingleStepDataSize == sizeof (UINT16)) {\r
    *(UINT16 *)mSingleStepPC = (UINT16)mSingleStepData;\r
  } else {\r
    //DEBUG((EFI_D_ERROR, "RemoveSingleStep at 0x%08x (was: 0x%08x is:0x%08x)\n", SystemContext.SystemContextArm->PC, *(UINT32 *)mSingleStepPC, mSingleStepData));\r
    *(UINT32 *)mSingleStepPC = mSingleStepData;\r
  }\r
  InvalidateInstructionCacheRange ((VOID *)mSingleStepPC, mSingleStepDataSize);\r
  mSingleStepActive = FALSE;\r
}\r
\r
\r
\r
/**\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.SystemContextArm->PC = AsciiStrHexToUintn (&PacketData[1]);\r
  }\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
  SendNotSupported ();\r
}\r
\r
UINTN\r
GetBreakpointDataAddress (\r
  IN  EFI_SYSTEM_CONTEXT  SystemContext,\r
  IN  UINTN               BreakpointNumber\r
  )\r
{\r
  return 0;\r
}\r
\r
UINTN\r
GetBreakpointDetected (\r
  IN  EFI_SYSTEM_CONTEXT  SystemContext\r
  )\r
{\r
  return 0;\r
}\r
\r
BREAK_TYPE\r
GetBreakpointType (\r
  IN  EFI_SYSTEM_CONTEXT  SystemContext,\r
  IN  UINTN               BreakpointNumber\r
  )\r
{\r
  return NotSupported;\r
}\r
\r
ARM_SOFTWARE_BREAKPOINT *\r
SearchBreakpointList (\r
  IN  UINT32  Address\r
  )\r
{\r
  LIST_ENTRY              *Current;\r
  ARM_SOFTWARE_BREAKPOINT *Breakpoint;\r
\r
  Current = GetFirstNode (&BreakpointList);\r
  while (!IsNull (&BreakpointList, Current)) {\r
    Breakpoint = ARM_SOFTWARE_BREAKPOINT_FROM_LINK(Current);\r
\r
    if (Address == Breakpoint->Address) {\r
      return Breakpoint;\r
    }\r
\r
    Current = GetNextNode (&BreakpointList, Current);\r
  }\r
\r
  return NULL;\r
}\r
\r
VOID\r
SetBreakpoint (\r
  IN UINT32 Address\r
  )\r
{\r
  ARM_SOFTWARE_BREAKPOINT *Breakpoint;\r
\r
  Breakpoint = SearchBreakpointList (Address);\r
\r
  if (Breakpoint != NULL) {\r
    return;\r
  }\r
\r
  // create and fill breakpoint structure\r
  Breakpoint = AllocatePool (sizeof(ARM_SOFTWARE_BREAKPOINT));\r
\r
  Breakpoint->Signature   = ARM_SOFTWARE_BREAKPOINT_SIGNATURE;\r
  Breakpoint->Address     = Address;\r
  Breakpoint->Instruction = *(UINT32 *)Address;\r
\r
  // Add it to the list\r
  InsertTailList (&BreakpointList, &Breakpoint->Link);\r
\r
  // Insert the software breakpoint\r
  *(UINT32 *)Address = GDB_ARM_BKPT;\r
  InvalidateInstructionCacheRange ((VOID *)Address, 4);\r
\r
  //DEBUG((EFI_D_ERROR, "SetBreakpoint at 0x%08x (was: 0x%08x is:0x%08x)\n", Address, Breakpoint->Instruction, *(UINT32 *)Address));\r
}\r
\r
VOID\r
ClearBreakpoint (\r
  IN UINT32 Address\r
  )\r
{\r
  ARM_SOFTWARE_BREAKPOINT *Breakpoint;\r
\r
  Breakpoint = SearchBreakpointList (Address);\r
\r
  if (Breakpoint == NULL) {\r
    return;\r
  }\r
\r
  // Add it to the list\r
  RemoveEntryList (&Breakpoint->Link);\r
\r
  // Restore the original instruction\r
  *(UINT32 *)Address = Breakpoint->Instruction;\r
  InvalidateInstructionCacheRange ((VOID *)Address, 4);\r
\r
  //DEBUG((EFI_D_ERROR, "ClearBreakpoint at 0x%08x (was: 0x%08x is:0x%08x)\n", Address, GDB_ARM_BKPT, *(UINT32 *)Address));\r
\r
  FreePool (Breakpoint);\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 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
      break;\r
\r
    default  :\r
      DEBUG((EFI_D_ERROR, "Insert breakpoint default: %x\n", Type));\r
      SendError (GDB_EINVALIDBRKPOINTTYPE);\r
      return;\r
  }\r
\r
  SetBreakpoint (Address);\r
\r
  SendSuccess ();\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      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
      break;\r
\r
    default:\r
      SendError (GDB_EINVALIDBRKPOINTTYPE);\r
      return;\r
  }\r
\r
  ClearBreakpoint (Address);\r
\r
  SendSuccess ();\r
}\r
\r
VOID\r
InitializeProcessor (\r
  VOID\r
  )\r
{\r
  // Initialize breakpoint list\r
  InitializeListHead (&BreakpointList);\r
}\r
\r
BOOLEAN\r
ValidateAddress (\r
  IN  VOID  *Address\r
  )\r
{\r
  if ((UINT32)Address < 0x80000000) {\r
    return FALSE;\r
  } else {\r
    return TRUE;\r
  }\r
}\r
\r
BOOLEAN\r
ValidateException (\r
  IN  EFI_EXCEPTION_TYPE    ExceptionType,\r
  IN OUT EFI_SYSTEM_CONTEXT SystemContext\r
  )\r
{\r
  UINT32  ExceptionAddress;\r
  UINT32  Instruction;\r
\r
  // Is it a debugger SWI?\r
  ExceptionAddress = SystemContext.SystemContextArm->PC -= 4;\r
  Instruction      = *(UINT32 *)ExceptionAddress;\r
  if (Instruction != GDB_ARM_BKPT) {\r
    return FALSE;\r
  }\r
\r
  // Special for SWI-based exception handling.  SWI sets up the context\r
  // to return to the instruction following the SWI instruction - NOT what we want\r
  // for a debugger!\r
  SystemContext.SystemContextArm->PC = ExceptionAddress;\r
\r
  return TRUE;\r
}\r
\r