/** @file
Processor specific parts of the 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.
**/
#include <GdbDebugAgent.h>
//
// Array of exception types that need to be hooked by the debugger
// {EFI mapping, GDB mapping}
//
EFI_EXCEPTION_TYPE_ENTRY gExceptionType[] = {
{ EXCEPT_IA32_DIVIDE_ERROR, GDB_SIGFPE },
{ EXCEPT_IA32_DEBUG, GDB_SIGTRAP },
{ EXCEPT_IA32_NMI, GDB_SIGEMT },
{ EXCEPT_IA32_BREAKPOINT, GDB_SIGTRAP },
{ EXCEPT_IA32_OVERFLOW, GDB_SIGSEGV },
{ EXCEPT_IA32_BOUND, GDB_SIGSEGV },
{ EXCEPT_IA32_INVALID_OPCODE, GDB_SIGILL },
{ EXCEPT_IA32_DOUBLE_FAULT, GDB_SIGEMT },
{ EXCEPT_IA32_STACK_FAULT, GDB_SIGSEGV },
{ EXCEPT_IA32_GP_FAULT, GDB_SIGSEGV },
{ EXCEPT_IA32_PAGE_FAULT, GDB_SIGSEGV },
{ EXCEPT_IA32_FP_ERROR, GDB_SIGEMT },
{ EXCEPT_IA32_ALIGNMENT_CHECK, GDB_SIGEMT },
{ EXCEPT_IA32_MACHINE_CHECK, GDB_SIGEMT }
};
// The offsets of registers SystemContext.
// The fields in the array are in the gdb ordering.
//
//16 regs
UINTN gRegisterOffsets[] = {
OFFSET_OF(EFI_SYSTEM_CONTEXT_IA32, Eax),
OFFSET_OF(EFI_SYSTEM_CONTEXT_IA32, Ecx),
OFFSET_OF(EFI_SYSTEM_CONTEXT_IA32, Edx),
OFFSET_OF(EFI_SYSTEM_CONTEXT_IA32, Ebx),
OFFSET_OF(EFI_SYSTEM_CONTEXT_IA32, Esp),
OFFSET_OF(EFI_SYSTEM_CONTEXT_IA32, Ebp),
OFFSET_OF(EFI_SYSTEM_CONTEXT_IA32, Esi),
OFFSET_OF(EFI_SYSTEM_CONTEXT_IA32, Edi),
OFFSET_OF(EFI_SYSTEM_CONTEXT_IA32, Eip),
OFFSET_OF(EFI_SYSTEM_CONTEXT_IA32, Eflags),
OFFSET_OF(EFI_SYSTEM_CONTEXT_IA32, Cs),
OFFSET_OF(EFI_SYSTEM_CONTEXT_IA32, Ss),
OFFSET_OF(EFI_SYSTEM_CONTEXT_IA32, Ds),
OFFSET_OF(EFI_SYSTEM_CONTEXT_IA32, Es),
OFFSET_OF(EFI_SYSTEM_CONTEXT_IA32, Fs),
OFFSET_OF(EFI_SYSTEM_CONTEXT_IA32, Gs)
};
//Debug only..
VOID
PrintReg (
IN EFI_SYSTEM_CONTEXT SystemContext
)
{
Print ((CHAR16 *)L"EAX: %x ", SystemContext.SystemContextIa32->Eax);
Print ((CHAR16 *)L"ECX: %x ", SystemContext.SystemContextIa32->Ecx);
Print ((CHAR16 *)L"EDX: %x ", SystemContext.SystemContextIa32->Edx);
Print ((CHAR16 *)L"EBX: %x ", SystemContext.SystemContextIa32->Ebx);
Print ((CHAR16 *)L"ESP: %x ", SystemContext.SystemContextIa32->Esp);
Print ((CHAR16 *)L"EBP: %x ", SystemContext.SystemContextIa32->Ebp);
Print ((CHAR16 *)L"ESI: %x ", SystemContext.SystemContextIa32->Esi);
Print ((CHAR16 *)L"EDI: %x ", SystemContext.SystemContextIa32->Edi);
Print ((CHAR16 *)L"EIP: %x\n", SystemContext.SystemContextIa32->Eip);
Print ((CHAR16 *)L"EFlags: %x\n", SystemContext.SystemContextIa32->Eflags);
}
//Debug only..
VOID
PrintDRreg (
IN EFI_SYSTEM_CONTEXT SystemContext
)
{
Print ((CHAR16 *)L"DR0: %x ", SystemContext.SystemContextIa32->Dr0);
Print ((CHAR16 *)L"DR1: %x ", SystemContext.SystemContextIa32->Dr1);
Print ((CHAR16 *)L"DR2: %x ", SystemContext.SystemContextIa32->Dr2);
Print ((CHAR16 *)L"DR3: %x ", SystemContext.SystemContextIa32->Dr3);
Print ((CHAR16 *)L"DR6: %x ", SystemContext.SystemContextIa32->Dr6);
Print ((CHAR16 *)L"DR7: %x\n", SystemContext.SystemContextIa32->Dr7);
}
/**
Return the number of entries in the gExceptionType[]
@retval UINTN, the number of entries in the gExceptionType[] array.
**/
UINTN
MaxEfiException (
VOID
)
{
return sizeof (gExceptionType)/sizeof (EFI_EXCEPTION_TYPE_ENTRY);
}
/**
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
)
{
return (BOOLEAN)(Isa == IsaIa32);
}
/**
This takes in the register number and the System Context, and returns a pointer to the RegNumber-th register in gdb ordering
It is, by default, set to find the register pointer of the IA32 member
@param SystemContext Register content at time of the exception
@param RegNumber The register to which we want to find a pointer
@retval the pointer to the RegNumber-th pointer
**/
UINTN *
FindPointerToRegister(
IN EFI_SYSTEM_CONTEXT SystemContext,
IN UINTN RegNumber
)
{
UINT8 *TempPtr;
TempPtr = ((UINT8 *)SystemContext.SystemContextIa32) + gRegisterOffsets[RegNumber];
return (UINTN *)TempPtr;
}
/**
Adds the RegNumber-th register's value to the output buffer, starting at the given OutBufPtr
@param SystemContext Register content at time of the exception
@param RegNumber the number of the register that we want to read
@param OutBufPtr pointer to the output buffer's end. the new data will be added from this point on.
@retval the pointer to the next character of the output buffer that is available to be written on.
**/
CHAR8 *
BasicReadRegister (
IN EFI_SYSTEM_CONTEXT SystemContext,
IN UINTN RegNumber,
IN CHAR8 *OutBufPtr
)
{
UINTN RegSize;
RegSize = 0;
while (RegSize < REG_SIZE) {
*OutBufPtr++ = mHexToStr[((*FindPointerToRegister(SystemContext, RegNumber) >> (RegSize+4)) & 0xf)];
*OutBufPtr++ = mHexToStr[((*FindPointerToRegister(SystemContext, RegNumber) >> RegSize) & 0xf)];
RegSize = RegSize + 8;
}
return OutBufPtr;
}
/** ‘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 Pointer to the input buffer received from gdb server
**/
VOID
EFIAPI
ReadNthRegister (
IN EFI_SYSTEM_CONTEXT SystemContext,
IN CHAR8 *InBuffer
)
{
UINTN RegNumber;
CHAR8 OutBuffer[9]; // 1 reg=8 hex chars, and the end '\0' (escape seq)
CHAR8 *OutBufPtr; // pointer to the output buffer
RegNumber = AsciiStrHexToUintn (&InBuffer[1]);
if ((RegNumber < 0) || (RegNumber >= sizeof (gRegisterOffsets)/sizeof (UINTN))) {
SendError (GDB_EINVALIDREGNUM);
return;
}
OutBufPtr = OutBuffer;
OutBufPtr = BasicReadRegister(SystemContext, RegNumber, OutBufPtr);
*OutBufPtr = '\0'; // the end of the buffer
SendPacket(OutBuffer);
}
/** ‘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
EFIAPI
ReadGeneralRegisters (
IN EFI_SYSTEM_CONTEXT SystemContext
)
{
UINTN i;
CHAR8 OutBuffer[129]; // 16 regs, 8 hex chars each, and the end '\0' (escape seq)
CHAR8 *OutBufPtr; // pointer to the output buffer
OutBufPtr = OutBuffer;
for(i = 0 ; i < sizeof (gRegisterOffsets)/sizeof (UINTN) ; i++) { // there are only 16 registers to read
OutBufPtr = BasicReadRegister(SystemContext, i, OutBufPtr);
}
*OutBufPtr = '\0'; // the end of the buffer
SendPacket(OutBuffer);
}
/**
Adds the RegNumber-th register's value to the output buffer, starting at the given OutBufPtr
@param SystemContext Register content at time of the exception
@param RegNumber the number of the register that we want to write
@param InBufPtr pointer to the output buffer. the new data will be extracted from the input buffer from this point on.
@retval the pointer to the next character of the input buffer that can be used
**/
CHAR8 *
BasicWriteRegister (
IN EFI_SYSTEM_CONTEXT SystemContext,
IN UINTN RegNumber,
IN CHAR8 *InBufPtr
)
{
UINTN RegSize;
UINTN TempValue; // the value transferred from a hex char
UINT32 NewValue; // the new value of the RegNumber-th Register
NewValue = 0;
RegSize = 0;
while (RegSize < REG_SIZE) {
TempValue = HexCharToInt(*InBufPtr++);
if (TempValue < 0) {
SendError (GDB_EBADMEMDATA);
return NULL;
}
NewValue += (TempValue << (RegSize+4));
TempValue = HexCharToInt(*InBufPtr++);
if (TempValue < 0) {
SendError (GDB_EBADMEMDATA);
return NULL;
}
NewValue += (TempValue << RegSize);
RegSize = RegSize + 8;
}
*(FindPointerToRegister(SystemContext, RegNumber)) = NewValue;
return InBufPtr;
}
/** ‘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 Ponter to the input buffer received from gdb server
**/
VOID
EFIAPI
WriteNthRegister (
IN EFI_SYSTEM_CONTEXT SystemContext,
IN CHAR8 *InBuffer
)
{
UINTN RegNumber;
CHAR8 RegNumBuffer[MAX_REG_NUM_BUF_SIZE]; // put the 'n..' part of the message into this array
CHAR8 *RegNumBufPtr;
CHAR8 *InBufPtr; // pointer to the input buffer
// find the register number to write
InBufPtr = &InBuffer[1];
RegNumBufPtr = RegNumBuffer;
while (*InBufPtr != '=') {
*RegNumBufPtr++ = *InBufPtr++;
}
*RegNumBufPtr = '\0';
RegNumber = AsciiStrHexToUintn (RegNumBuffer);
// check if this is a valid Register Number
if ((RegNumber < 0) || (RegNumber >= sizeof (gRegisterOffsets)/sizeof (UINTN))) {
SendError (GDB_EINVALIDREGNUM);
return;
}
InBufPtr++; // skips the '=' character
BasicWriteRegister (SystemContext, RegNumber, InBufPtr);
SendSuccess();
}
/** ‘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
EFIAPI
WriteGeneralRegisters (
IN EFI_SYSTEM_CONTEXT SystemContext,
IN CHAR8 *InBuffer
)
{
UINTN i;
CHAR8 *InBufPtr; /// pointer to the input buffer
// check to see if the buffer is the right size which is
// 1 (for 'G') + 16 (for 16 registers) * 8 ( for 8 hex chars each) = 129
if (AsciiStrLen(InBuffer) != 129) { // 16 regs, 8 hex chars each, and the end '\0' (escape seq)
//Bad message. Message is not the right length
SendError (GDB_EBADBUFSIZE);
return;
}
InBufPtr = &InBuffer[1];
// Read the new values for the registers from the input buffer to an array, NewValueArray.
// The values in the array are in the gdb ordering
for(i=0; i < sizeof (gRegisterOffsets)/sizeof (UINTN); i++) { // there are only 16 registers to write
InBufPtr = BasicWriteRegister(SystemContext, i, InBufPtr);
}
SendSuccess();
}
/** ‘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
**/
VOID
EFIAPI
ContinueAtAddress (
IN EFI_SYSTEM_CONTEXT SystemContext,
IN CHAR8 *PacketData
)
{
if (PacketData[1] != '\0') {
SystemContext.SystemContextIa32->Eip = AsciiStrHexToUintn (&PacketData[1]);
}
}
/** ‘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
**/
VOID
EFIAPI
SingleStep (
IN EFI_SYSTEM_CONTEXT SystemContext,
IN CHAR8 *PacketData
)
{
SendNotSupported();
}
/**
Returns breakpoint data address from DR0-DR3 based on the input breakpoint number
@param SystemContext Register content at time of the exception
@param BreakpointNumber Breakpoint number
@retval Address Data address from DR0-DR3 based on the breakpoint number.
**/
UINTN
GetBreakpointDataAddress (
IN EFI_SYSTEM_CONTEXT SystemContext,
IN UINTN BreakpointNumber
)
{
UINTN Address;
if (BreakpointNumber == 1) {
Address = SystemContext.SystemContextIa32->Dr0;
} else if (BreakpointNumber == 2) {
Address = SystemContext.SystemContextIa32->Dr1;
} else if (BreakpointNumber == 3) {
Address = SystemContext.SystemContextIa32->Dr2;
} else if (BreakpointNumber == 4) {
Address = SystemContext.SystemContextIa32->Dr3;
} else {
Address = 0;
}
return Address;
}
/**
Returns currently detected breakpoint value based on the register DR6 B0-B3 field.
If no breakpoint is detected then it returns 0.
@param SystemContext Register content at time of the exception
@retval {1-4} Currently detected breakpoint value
@retval 0 No breakpoint detected.
**/
UINTN
GetBreakpointDetected (
IN EFI_SYSTEM_CONTEXT SystemContext
)
{
IA32_DR6 Dr6;
UINTN BreakpointNumber;
Dr6.UintN = SystemContext.SystemContextIa32->Dr6;
if (Dr6.Bits.B0 == 1) {
BreakpointNumber = 1;
} else if (Dr6.Bits.B1 == 1) {
BreakpointNumber = 2;
} else if (Dr6.Bits.B2 == 1) {
BreakpointNumber = 3;
} else if (Dr6.Bits.B3 == 1) {
BreakpointNumber = 4;
} else {
BreakpointNumber = 0; //No breakpoint detected
}
return BreakpointNumber;
}
/**
Returns Breakpoint type (InstructionExecution, DataWrite, DataRead or DataReadWrite)
based on the Breakpoint number
@param SystemContext Register content at time of the exception
@param BreakpointNumber Breakpoint number
@retval BREAK_TYPE Breakpoint type value read from register DR7 RWn field
For unknown value, it returns NotSupported.
**/
BREAK_TYPE
GetBreakpointType (
IN EFI_SYSTEM_CONTEXT SystemContext,
IN UINTN BreakpointNumber
)
{
IA32_DR7 Dr7;
BREAK_TYPE Type = NotSupported; //Default is NotSupported type
Dr7.UintN = SystemContext.SystemContextIa32->Dr7;
if (BreakpointNumber == 1) {
Type = (BREAK_TYPE) Dr7.Bits.RW0;
} else if (BreakpointNumber == 2) {
Type = (BREAK_TYPE) Dr7.Bits.RW1;
} else if (BreakpointNumber == 3) {
Type = (BREAK_TYPE) Dr7.Bits.RW2;
} else if (BreakpointNumber == 4) {
Type = (BREAK_TYPE) Dr7.Bits.RW3;
}
return Type;
}
/**
Parses Length and returns the length which DR7 LENn field accepts.
For example: If we receive 1-Byte length then we should return 0.
Zero gets written to DR7 LENn field.
@param Length Breakpoint length in Bytes (1 byte, 2 byte, 4 byte)
@retval Length Appropriate converted values which DR7 LENn field accepts.
**/
UINTN
ConvertLengthData (
IN UINTN Length
)
{
if (Length == 1) { //1-Byte length
return 0;
} else if (Length == 2) { //2-Byte length
return 1;
} else if (Length == 4) { //4-Byte length
return 3;
} else { //Undefined or 8-byte length
return 2;
}
}
/**
Finds the next free debug register. If all the registers are occupied then
EFI_OUT_OF_RESOURCES is returned.
@param SystemContext Register content at time of the exception
@param Register Register value (0 - 3 for the first free debug register)
@retval EFI_STATUS Appropriate status value.
**/
EFI_STATUS
FindNextFreeDebugRegister (
IN EFI_SYSTEM_CONTEXT SystemContext,
OUT UINTN *Register
)
{
IA32_DR7 Dr7;
Dr7.UintN = SystemContext.SystemContextIa32->Dr7;
if (Dr7.Bits.G0 == 0) {
*Register = 0;
} else if (Dr7.Bits.G1 == 0) {
*Register = 1;
} else if (Dr7.Bits.G2 == 0) {
*Register = 2;
} else if (Dr7.Bits.G3 == 0) {
*Register = 3;
} else {
return EFI_OUT_OF_RESOURCES;
}
return EFI_SUCCESS;
}
/**
Enables the debug register. Writes Address value to appropriate DR0-3 register.
Sets LENn, Gn, RWn bits in DR7 register.
@param SystemContext Register content at time of the exception
@param Register Register value (0 - 3)
@param Address Breakpoint address value
@param Type Breakpoint type (Instruction, Data write, Data read
or write etc.)
@retval EFI_STATUS Appropriate status value.
**/
EFI_STATUS
EnableDebugRegister (
IN EFI_SYSTEM_CONTEXT SystemContext,
IN UINTN Register,
IN UINTN Address,
IN UINTN Length,
IN UINTN Type
)
{
IA32_DR7 Dr7;
//Convert length data
Length = ConvertLengthData (Length);
//For Instruction execution, length should be 0
//(Ref. Intel reference manual 18.2.4)
if ((Type == 0) && (Length != 0)) {
return EFI_INVALID_PARAMETER;
}
//Hardware doesn't support ReadWatch (z3 packet) type. GDB can handle
//software breakpoint. We should send empty packet in both these cases.
if ((Type == (BREAK_TYPE)DataRead) ||
(Type == (BREAK_TYPE)SoftwareBreakpoint)) {
return EFI_UNSUPPORTED;
}
//Read DR7 so appropriate Gn, RWn and LENn bits can be modified.
Dr7.UintN = SystemContext.SystemContextIa32->Dr7;
if (Register == 0) {
SystemContext.SystemContextIa32->Dr0 = Address;
Dr7.Bits.G0 = 1;
Dr7.Bits.RW0 = Type;
Dr7.Bits.LEN0 = Length;
} else if (Register == 1) {
SystemContext.SystemContextIa32->Dr1 = Address;
Dr7.Bits.G1 = 1;
Dr7.Bits.RW1 = Type;
Dr7.Bits.LEN1 = Length;
} else if (Register == 2) {
SystemContext.SystemContextIa32->Dr2 = Address;
Dr7.Bits.G2 = 1;
Dr7.Bits.RW2 = Type;
Dr7.Bits.LEN2 = Length;
} else if (Register == 3) {
SystemContext.SystemContextIa32->Dr3 = Address;
Dr7.Bits.G3 = 1;
Dr7.Bits.RW3 = Type;
Dr7.Bits.LEN3 = Length;
} else {
return EFI_INVALID_PARAMETER;
}
//Update Dr7 with appropriate Gn, RWn and LENn bits
SystemContext.SystemContextIa32->Dr7 = Dr7.UintN;
return EFI_SUCCESS;
}
/**
Returns register number 0 - 3 for the maching debug register.
This function compares incoming Address, Type, Length and
if there is a match then it returns the appropriate register number.
In case of mismatch, function returns EFI_NOT_FOUND message.
@param SystemContext Register content at time of the exception
@param Address Breakpoint address value
@param Length Breakpoint length value
@param Type Breakpoint type (Instruction, Data write,
Data read or write etc.)
@param Register Register value to be returned
@retval EFI_STATUS Appropriate status value.
**/
EFI_STATUS
FindMatchingDebugRegister (
IN EFI_SYSTEM_CONTEXT SystemContext,
IN UINTN Address,
IN UINTN Length,
IN UINTN Type,
OUT UINTN *Register
)
{
IA32_DR7 Dr7;
//Hardware doesn't support ReadWatch (z3 packet) type. GDB can handle
//software breakpoint. We should send empty packet in both these cases.
if ((Type == (BREAK_TYPE)DataRead) ||
(Type == (BREAK_TYPE)SoftwareBreakpoint)) {
return EFI_UNSUPPORTED;
}
//Convert length data
Length = ConvertLengthData(Length);
Dr7.UintN = SystemContext.SystemContextIa32->Dr7;
if ((Dr7.Bits.G0 == 1) &&
(Dr7.Bits.LEN0 == Length) &&
(Dr7.Bits.RW0 == Type) &&
(Address == SystemContext.SystemContextIa32->Dr0)) {
*Register = 0;
} else if ((Dr7.Bits.G1 == 1) &&
(Dr7.Bits.LEN1 == Length) &&
(Dr7.Bits.RW1 == Type) &&
(Address == SystemContext.SystemContextIa32->Dr1)) {
*Register = 1;
} else if ((Dr7.Bits.G2 == 1) &&
(Dr7.Bits.LEN2 == Length) &&
(Dr7.Bits.RW2 == Type) &&
(Address == SystemContext.SystemContextIa32->Dr2)) {
*Register = 2;
} else if ((Dr7.Bits.G3 == 1) &&
(Dr7.Bits.LEN3 == Length) &&
(Dr7.Bits.RW3 == Type) &&
(Address == SystemContext.SystemContextIa32->Dr3)) {
*Register = 3;
} else {
Print ((CHAR16 *)L"No match found..\n");
return EFI_NOT_FOUND;
}
return EFI_SUCCESS;
}
/**
Disables the particular debug register.
@param SystemContext Register content at time of the exception
@param Register Register to be disabled
@retval EFI_STATUS Appropriate status value.
**/
EFI_STATUS
DisableDebugRegister (
IN EFI_SYSTEM_CONTEXT SystemContext,
IN UINTN Register
)
{
IA32_DR7 Dr7;
UINTN Address = 0;
//Read DR7 register so appropriate Gn, RWn and LENn bits can be turned off.
Dr7.UintN = SystemContext.SystemContextIa32->Dr7;
if (Register == 0) {
SystemContext.SystemContextIa32->Dr0 = Address;
Dr7.Bits.G0 = 0;
Dr7.Bits.RW0 = 0;
Dr7.Bits.LEN0 = 0;
} else if (Register == 1) {
SystemContext.SystemContextIa32->Dr1 = Address;
Dr7.Bits.G1 = 0;
Dr7.Bits.RW1 = 0;
Dr7.Bits.LEN1 = 0;
} else if (Register == 2) {
SystemContext.SystemContextIa32->Dr2 = Address;
Dr7.Bits.G2 = 0;
Dr7.Bits.RW2 = 0;
Dr7.Bits.LEN2 = 0;
} else if (Register == 3) {
SystemContext.SystemContextIa32->Dr3 = Address;
Dr7.Bits.G3 = 0;
Dr7.Bits.RW3 = 0;
Dr7.Bits.LEN3 = 0;
} else {
return EFI_INVALID_PARAMETER;
}
//Update DR7 register so appropriate Gn, RWn and LENn bits can be turned off.
SystemContext.SystemContextIa32->Dr7 = Dr7.UintN;
return EFI_SUCCESS;
}
/**
‘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
)
{
UINTN Type;
UINTN Address;
UINTN Length;
UINTN Register;
EFI_STATUS Status;
BREAK_TYPE BreakType = NotSupported;
UINTN ErrorCode;
ErrorCode = ParseBreakpointPacket (PacketData, &Type, &Address, &Length);
if (ErrorCode > 0) {
SendError ((UINT8)ErrorCode);
return;
}
switch (Type) {
case 0: //Software breakpoint
BreakType = SoftwareBreakpoint;
break;
case 1: //Hardware breakpoint
BreakType = InstructionExecution;
break;
case 2: //Write watchpoint
BreakType = DataWrite;
break;
case 3: //Read watchpoint
BreakType = DataRead;
break;
case 4: //Access watchpoint
BreakType = DataReadWrite;
break;
default :
Print ((CHAR16 *)L"Insert breakpoint default: %x\n", Type);
SendError (GDB_EINVALIDBRKPOINTTYPE);
return;
}
// Find next free debug register
Status = FindNextFreeDebugRegister (SystemContext, &Register);
if (EFI_ERROR(Status)) {
Print ((CHAR16 *)L"No space left on device\n");
SendError (GDB_ENOSPACE);
return;
}
// Write Address, length data at particular DR register
Status = EnableDebugRegister (SystemContext, Register, Address, Length, (UINTN)BreakType);
if (EFI_ERROR(Status)) {
if (Status == EFI_UNSUPPORTED) {
SendNotSupported();
return;
}
SendError (GDB_EINVALIDARG);
return;
}
SendSuccess ();
}
/**
‘z1, [addr], [length]’
‘z2, [addr], [length]’
‘z3, [addr], [length]’
‘z4, [addr], [length]’
Remove hardware breakpoint/watchpoint at address addr of size length
@param *PacketData Pointer to the Payload data for the packet
**/
VOID
EFIAPI
RemoveBreakPoint (
IN EFI_SYSTEM_CONTEXT SystemContext,
IN CHAR8 *PacketData
)
{
UINTN Type;
UINTN Address;
UINTN Length;
UINTN Register;
BREAK_TYPE BreakType = NotSupported;
EFI_STATUS Status;
UINTN ErrorCode;
//Parse breakpoint packet data
ErrorCode = ParseBreakpointPacket (PacketData, &Type, &Address, &Length);
if (ErrorCode > 0) {
SendError ((UINT8)ErrorCode);
return;
}
switch (Type) {
case 0: //Software breakpoint
BreakType = SoftwareBreakpoint;
break;
case 1: //Hardware breakpoint
BreakType = InstructionExecution;
break;
case 2: //Write watchpoint
BreakType = DataWrite;
break;
case 3: //Read watchpoint
BreakType = DataRead;
break;
case 4: //Access watchpoint
BreakType = DataReadWrite;
break;
default :
SendError (GDB_EINVALIDBRKPOINTTYPE);
return;
}
//Find matching debug register
Status = FindMatchingDebugRegister (SystemContext, Address, Length, (UINTN)BreakType, &Register);
if (EFI_ERROR(Status)) {
if (Status == EFI_UNSUPPORTED) {
SendNotSupported();
return;
}
SendError (GDB_ENOSPACE);
return;
}
//Remove breakpoint
Status = DisableDebugRegister(SystemContext, Register);
if (EFI_ERROR(Status)) {
SendError (GDB_EINVALIDARG);
return;
}
SendSuccess ();
}
/**
Initialize debug agent.
This function is used to set up debug environment to support source level debugging.
If certain Debug Agent Library instance has to save some private data in the stack,
this function must work on the mode that doesn't return to the caller, then
the caller needs to wrap up all rest of logic after InitializeDebugAgent() into one
function and pass it into InitializeDebugAgent(). InitializeDebugAgent() is
responsible to invoke the passing-in function at the end of InitializeDebugAgent().
If the parameter Function is not NULL, Debug Agent Library instance will invoke it by
passing in the Context to be its parameter.
If Function() is NULL, Debug Agent Library instance will return after setup debug
environment.
@param[in] InitFlag Init flag is used to decide the initialize process.
@param[in] Context Context needed according to InitFlag; it was optional.
@param[in] Function Continue function called by debug agent library; it was
optional.
**/
VOID
EFIAPI
InitializeDebugAgent (
IN UINT32 InitFlag,
IN VOID *Context, OPTIONAL
IN DEBUG_AGENT_CONTINUE Function OPTIONAL
)
{
// BugBug: Add the code to build an GDT/IDT
if (Function != NULL) {
Function (Context);
}
}