/******************************************************************************
* \name KdpReceiveBuffer
* \brief Receives data from the KD port and fills a buffer.
* \param Buffer Pointer to a buffer that receives the data.
* \param Size Size of data to receive in bytes.
* \return KDP_PACKET_RECEIVED if successful.
* KDP_PACKET_TIMEOUT if the receice timed out.
*/
KDP_STATUS
NTAPI
KdpReceiveBuffer(
OUT PVOID Buffer,
IN ULONG Size)
{
PUCHAR ByteBuffer = Buffer;
UCHAR Byte;
KDP_STATUS Status;
while (Size-- > 0)
{
/* Try to get a byte from the port */
Status = KdpReceiveByte(&Byte);
if (Status != KDP_PACKET_RECEIVED)
return Status;
*ByteBuffer++ = Byte;
}
return KDP_PACKET_RECEIVED;
}
/******************************************************************************
* \name KdpReceiveBuffer
* \brief Recieves data from the KD port and fills a buffer.
* \param Buffer Pointer to a buffer that receives the data.
* \param Size Size of data to receive in bytes.
* \return KDP_PACKET_RECEIVED if successful.
* KDP_PACKET_TIMEOUT if the receice timed out.
*/
KDP_STATUS
NTAPI
KdpReceiveBuffer(
OUT PVOID Buffer,
IN ULONG Size)
{
ULONG i;
PUCHAR ByteBuffer = Buffer;
KDP_STATUS Status;
for (i = 0; i < Size; i++)
{
/* Try to get a byte from the port */
Status = KdpReceiveByte(&ByteBuffer[i]);
if (Status != KDP_PACKET_RECEIVED)
{
return Status;
}
}
return KDP_PACKET_RECEIVED;
}
/******************************************************************************
* \name KdpReceivePacketLeader
* \brief Recieves a packet leadr from the KD port.
* \param PacketLeader Pointer to an ULONG that receives the packet leader.
* \return KDP_PACKET_RECEIVED if successful.
* KDP_PACKET_TIMEOUT if the receive timed out.
* KDP_PACKET_RESEND if a breakin byte was detected.
*/
KDP_STATUS
NTAPI
KdpReceivePacketLeader(
OUT PULONG PacketLeader)
{
UCHAR Index = 0, Byte, Buffer[4];
KDP_STATUS KdStatus;
/* Set first character to 0 */
Buffer[0] = 0;
do
{
/* Receive a single byte */
KdStatus = KdpReceiveByte(&Byte);
/* Check for timeout */
if (KdStatus == KDP_PACKET_TIMEOUT)
{
/* Check if we already got a breakin byte */
if (Buffer[0] == BREAKIN_PACKET_BYTE)
{
return KDP_PACKET_RESEND;
}
/* Report timeout */
return KDP_PACKET_TIMEOUT;
}
/* Check if we received a byte */
if (KdStatus == KDP_PACKET_RECEIVED)
{
/* Check if this is a valid packet leader byte */
if (Byte == PACKET_LEADER_BYTE ||
Byte == CONTROL_PACKET_LEADER_BYTE)
{
/* Check if we match the first byte */
if (Byte != Buffer[0])
{
/* No, this is the new byte 0! */
Index = 0;
}
/* Store the byte in the buffer */
Buffer[Index] = Byte;
/* Continue with next byte */
Index++;
continue;
}
/* Check for breakin byte */
if (Byte == BREAKIN_PACKET_BYTE)
{
KDDBGPRINT("BREAKIN_PACKET_BYTE\n");
Index = 0;
Buffer[0] = Byte;
continue;
}
}
/* Restart */
Index = 0;
Buffer[0] = 0;
}
while (Index < 4);
/* Enable the debugger */
KdDebuggerNotPresent = FALSE;
SharedUserData->KdDebuggerEnabled |= 0x00000002;
/* Return the received packet leader */
*PacketLeader = *(PULONG)Buffer;
return KDP_PACKET_RECEIVED;
}
KDSTATUS
NTAPI
gdb_receive_packet(_Inout_ PKD_CONTEXT KdContext)
{
char* ByteBuffer = gdb_input;
UCHAR Byte;
KDSTATUS Status;
CHAR CheckSum = 0, ReceivedCheckSum;
do
{
Status = KdpReceiveByte(&Byte);
if (Status != KdPacketReceived)
return Status;
if (Byte == 0x03)
{
KdContext->KdpControlCPending = TRUE;
return KdPacketNeedsResend;
}
} while (Byte != '$');
while (TRUE)
{
/* Try to get a byte from the port */
Status = KdpReceiveByte(&Byte);
if (Status != KdPacketReceived)
return Status;
if (Byte == '#')
{
*ByteBuffer = '\0';
break;
}
*ByteBuffer++ = Byte;
CheckSum += (CHAR)Byte;
}
/* Get Check sum (two bytes) */
Status = KdpReceiveByte(&Byte);
if (Status != KdPacketReceived)
goto end;
ReceivedCheckSum = hex_value(Byte) << 4;
Status = KdpReceiveByte(&Byte);
if (Status != KdPacketReceived)
goto end;
ReceivedCheckSum += hex_value(Byte);
end:
if (ReceivedCheckSum != CheckSum)
{
/* Do not acknowledge to GDB */
KdpSendByte('-');
return KdPacketNeedsResend;
}
/* Acknowledge */
KdpSendByte('+');
return KdPacketReceived;
}
KDSTATUS
NTAPI
gdb_receive_packet(_Inout_ PKD_CONTEXT KdContext)
{
UCHAR* ByteBuffer = (UCHAR*)gdb_input;
UCHAR Byte;
KDSTATUS Status;
CHAR CheckSum = 0, ReceivedCheckSum;
do
{
Status = KdpReceiveByte(&Byte);
if (Status != KdPacketReceived)
return Status;
if (Byte == 0x03)
{
KDDBGPRINT("BREAK!");
KdContext->KdpControlCPending = TRUE;
return KdPacketNeedsResend;
}
} while (Byte != '$');
while (TRUE)
{
/* Try to get a byte from the port */
Status = KdpReceiveByte(&Byte);
if (Status != KdPacketReceived)
return Status;
if (Byte == '#')
{
*ByteBuffer = '\0';
break;
}
CheckSum += (CHAR)Byte;
/* See if we should escape */
if (Byte == 0x7d)
{
Status = KdpReceiveByte(&Byte);
if (Status != KdPacketReceived)
return Status;
CheckSum += (CHAR)Byte;
Byte ^= 0x20;
}
*ByteBuffer++ = Byte;
}
/* Get Check sum (two bytes) */
Status = KdpReceiveByte(&Byte);
if (Status != KdPacketReceived)
goto end;
ReceivedCheckSum = hex_value(Byte) << 4;
Status = KdpReceiveByte(&Byte);
if (Status != KdPacketReceived)
goto end;
ReceivedCheckSum += hex_value(Byte);
end:
if (ReceivedCheckSum != CheckSum)
{
/* Do not acknowledge to GDB */
KDDBGPRINT("Check sums don't match!");
KdpSendByte('-');
return KdPacketNeedsResend;
}
/* Acknowledge */
KdpSendByte('+');
return KdPacketReceived;
}
