package org.nanovm.transfer;
//
// NVMComm2, the NanoVM Communication Protocol
// Copyright (C) 2006 by Till Harbaum <Till@Harbaum.org>,
// Oliver Schulz <whisp@users.sf.net>
//
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 2 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
//
// Parts of this tool are based on public domain code written by Kimberley
// Burchett: http://www.kimbly.com/code/classfile/
//
import java.io.*;
class NVMComm2 {
// ASCII codes used during transmission
public static final int ASCII_DLE = 0x10;
public static final int ASCII_SYN = 0x16;
protected static final int NVC2_TIMEOUT_CHARS = 20; //!!8; // Input timout in units of byte transmission time
protected static final int NVC2_MIN_RESPONSE_SIZE = 5; // Minimum size of a message (without start byte)
protected static final int NVC2_MAX_MSG_LEN = 0x7F; // Maximum message length
protected static final int MAX_DATA_LEN = 16; // Maximum data length to use in message
protected InputStream m_inputStream;
protected OutputStream m_outputStream;
protected int m_ioSpeed;
protected int m_recvInputTimeout;
protected int m_lastMsgID;
public static final short CMD_NONE = 0xFF;
public static final short CMD_FOPEN = 0x70;
public static final short CMD_FCLOSE = 0x71;
public static final short CMD_RWFILE = 0x72;
public static final short CMD_RUNLVL = 0x7E;
public static final byte RUNLVL_HALT = 0x00;
public static final byte RUNLVL_CONF = 0x01;
public static final byte RUNLVL_VM = 0x03;
public static final byte RUNLVL_RESET = 0x06;
public static final byte RUNLVL_BOOT = 0x07;
// CCITT CRC-16, msb-first, int version
// 0 <= data <= 0xFF, 0 <= crc <= 0xFFFF
public static int crc16ccittUpdateMsbf(int data, int crc) {
crc = ((crc >> 8) & 0xFF) | ((crc << 8) & 0xFFFF);
crc ^= data;
crc ^= (crc & 0xFF) >> 4;
crc ^= ((crc << 8) << 4) & 0xFFFF;
crc ^= ((crc & 0xFF) << 4) << 1;
return crc;
}
// CCITT CRC-16, msb-first, byte/short version
public static short crc16ccittUpdateMsbf(byte data, short crc) {
return (short) crc16ccittUpdateMsbf(0xFF & (int) data, 0xFFFF & (int) crc);
}
// CCITT CRC-16, lsb-first, int version
// 0 <= data <= 0xFF, 0 <= crc <= 0xFFFF
public static int crc16ccittUpdateLsbf(int data, int crc) {
data ^= (crc & 0xFF);
data ^= (data << 4) & 0xFF;
crc = ((data << 8) & 0xFFFF) | (crc >> 8);
crc ^= (data >> 4);
crc ^= (data << 3) & 0xFFFF;
return crc;
}
// CCITT CRC-16, lsb-first, byte/short version
public static short crc16ccittUpdateLsbf(byte data, short crc) {
return (short) crc16ccittUpdateLsbf(0xFF & (int) data, 0xFFFF & (int) crc);
}
protected void put(int i) {
byte[] ioArray = new byte[1];
i &= 0xff;
ioArray[0] = (byte) i;
try {
m_outputStream.write(ioArray);
} catch (Exception e) {
System.out.println("Writing Error");
System.out.println(e.toString());
System.exit(-1);
}
}
public static class QueryMessage {
protected short m_address;
protected boolean m_read;
protected short m_command;
protected byte[] m_data;
public short getAddress() {
return m_address;
} // slave address, must be 0x01 for now
public boolean isRead() {
return m_read;
} // read or write
public short getCommand() {
return m_command;
} // 0x00 if empty mesage, 0x00 <= command <= 0xFF
public byte[] getData() {
return m_data;
} // data (only when write query)
public QueryMessage(short address, boolean read, short command,
byte[] data) {
m_address = address;
m_read = read;
m_command = command;
m_data = data;
}
}
public static class ResponseMessage {
public boolean m_error;
protected byte[] m_data;
public boolean isError() {
return m_error;
} // error Response / normal Resonse
public byte[] getData() {
return m_data;
} // response data or error info
public ResponseMessage(boolean isError, byte[] data) {
m_error = isError;
m_data = data;
}
}
protected static class CommBuffer {
protected byte[] m_data;
protected int m_fill;
int size() {
return m_data.length;
}
int fill() {
return m_fill;
}
int space() {
return size() - fill();
}
byte getData(int i) {
return m_data[i];
}
void pushBack(byte b) {
if (space() > 0) m_data[m_fill++] = b;
}
void popFront(int count) {
if (count >= m_fill) m_fill = 0;
else {
for (int i = 0; i < m_fill - count; ++i) m_data[i] = m_data[i + count];
m_fill -= count;
}
}
public CommBuffer(int maxSize) {
m_data = new byte[maxSize];
m_fill = 0;
}
}
public ResponseMessage receiveResponse(int messageId, CommBuffer buffer) {
final int NVC2_RECV_DROP = 0;
final int NVC2_RECV_SEARCH = 1;
final int NVC2_RECV_SYNCED = 2;
final int NVC2_RECV_DATA = 3;
int status = NVC2_RECV_SEARCH;
int neededInput = 0;
boolean commTimeout = false;
boolean errorMsg = false;
int msgLen = 0;
int recvId = 0;
// Minimum buffer size
if (buffer.space() < NVC2_MIN_RESPONSE_SIZE) return null;
// Don't give up while input available or while buffer might contain
// a complete message.
while ((!commTimeout) || (buffer.fill() >= NVC2_MIN_RESPONSE_SIZE)) {
// if not enough buffer space, drop currently tracked message
if (buffer.space() < neededInput) status = NVC2_RECV_DROP;
if (status == NVC2_RECV_DROP) {
// drop currently tracked message
neededInput = buffer.fill() < 1 ? 1 : 0;
status = NVC2_RECV_SEARCH;
}
// try to read necessary input from input stream
while ((neededInput > 0) && !commTimeout) {
// wait for input within timeout limits
boolean inputAvailable = false;
try {
for (int i = 0; (m_inputStream.available() == 0) && (i < m_recvInputTimeout); ++i)
Thread.currentThread().sleep(2); // sleep 2 ms}
inputAvailable = (m_inputStream.available() > 0);
} catch (Exception e) {
}
if (inputAvailable) {
// input available
byte[] data = new byte[1];
try {
m_inputStream.read(data);
} catch (Exception e) {
System.out.println("Reading Error");
System.out.println(e.toString());
System.exit(-1);
}
// System.out.print(" " + Integer.toHexString(0xFF & (int)data[0]) ); //!! DEBUG
buffer.pushBack(data[0]);
if (neededInput > 0) --neededInput;
} else {
// timeout
commTimeout = true;
}
}
// if not enough data after reading, drop currently tracked message
if (neededInput > 0) status = NVC2_RECV_DROP;
if (status == NVC2_RECV_SEARCH) {
// need at least 1 byte of input
neededInput = (buffer.fill() < 1) ? 1 : 0;
if (neededInput == 0) {
// search buffer for slave-message start-symbol
for (int i = 0; i < buffer.fill(); ++i) {
byte value = buffer.getData(0);
buffer.popFront(1);
if ((0xFF & (int) value) == ASCII_SYN) {
status = NVC2_RECV_SYNCED;
break;
}
}
}
}
if (status == NVC2_RECV_SYNCED) {
// need first 4 bytes of input
neededInput = (buffer.fill() < 4) ?
4 - buffer.fill() : 0;
if (neededInput == 0) {
int msgLenR;
// analyse message header
msgLen = (0xFF) & (int) buffer.getData(0);
int MsgLen2 = 0xFF & (int) buffer.getData(1);
int MsgLen2inv = 0xFF ^ MsgLen2;
if (msgLen != MsgLen2inv)
msgLenR = MsgLen2;
else {
// LEi instead of LEr, signifies error message
errorMsg = true;
msgLenR = MsgLen2inv;
}
recvId = 0xFF & (int) buffer.getData(2);
boolean slaveFlag = (recvId & 0x01) > 0;
recvId = (recvId >> 1) & 0x07;
if ((msgLen != msgLenR) || !slaveFlag) {
status = NVC2_RECV_DROP;
} else {
status = NVC2_RECV_DATA;
}
}
}
if (status == NVC2_RECV_DATA) {
// need complete message
neededInput = (buffer.fill() < msgLen + 2) ?
msgLen + 2 - buffer.fill() : 0;
if (neededInput == 0) {
// calculate CRC (FCS-16)
short crc = (short) 0xFFFF;
for (int i = 0; i < msgLen; ++i)
crc = crc16ccittUpdateLsbf(buffer.getData(i), crc);
crc ^= 0xFFFF;
short readCrc = (short) (
((0xFF & (int) buffer.getData(msgLen)) << 0)
| ((0xFF & (int) buffer.getData(msgLen + 1)) << 8)
);
if (crc != readCrc) {
// System.out.println("DEBUG: CRC error, was: "
// + Integer.toHexString(0xFFFF & (int)readCrc)
// + " should have been: "
// + Integer.toHexString(0xFFFF & (int)crc)
//);
// crc error
return new ResponseMessage(true, null);
} else {
if (recvId == messageId) {
// generate and return message
byte[] data = null;
if (msgLen > 3) {
data = new byte[msgLen - 3];
for (int i = 0; i < msgLen - 3; ++i)
data[i] = buffer.getData(i + 3);
}
return new ResponseMessage(errorMsg, data);
} else {
// wrong message number, drop message
status = NVC2_RECV_DROP;
}
}
}
}
}
return null;
}
public void sendQuery(int messageId, QueryMessage query) {
int dsize = (query.getData() == null) ? 0 : query.getData().length;
if (dsize >= NVC2_MAX_MSG_LEN - 5) return; // Can't fit data in response
boolean sendContent = query.getCommand() != CMD_NONE;
int msgLen = query.getCommand() == CMD_NONE ? 4 : dsize + 5;
// send DLE
put(ASCII_DLE);
// compose message
byte[] msg = new byte[msgLen + 2];
msg[0] = (byte) msgLen;
msg[1] = (byte) msgLen;
msg[2] = (byte) ((0x07 & messageId) << 1);
msg[3] = (byte) (((0xFF & (int) query.getAddress()) << 1) | (query.isRead() ? 1 : 0));
if (sendContent) {
msg[4] = (byte) query.getCommand();
for (int i = 0; i < dsize; ++i) msg[i + 5] = query.getData()[i];
}
// calculate and append CRC (FCS-16)
short crc = (short) 0xFFFF;
for (int i = 0; i < msgLen; ++i)
crc = crc16ccittUpdateLsbf(msg[i], crc);
crc ^= 0xFFFF;
msg[msgLen + 0] = (byte) (0xFF & (crc >> 0));
msg[msgLen + 1] = (byte) (0xFF & (crc >> 8));
// System.out.print("DEBUG: Sending query: ");
// System.out.print(" " + Integer.toHexString(0xFF & (int)ASCII_DLE));
// for (int i=0; i<msgLen+2; ++i) System.out.print(" " + Integer.toHexString(0xFF & (int)msg[i]));
// System.out.println("");
// send message
for (int i = 0; i < msgLen + 2; ++i) put(msg[i]);
}
public ResponseMessage executeQuery(short address, boolean read,
short command, byte[] data, int maxTries) {
final int recvBufferSize = 0xFF;
m_lastMsgID = 0x07 & (m_lastMsgID + 1);
int messageId = m_lastMsgID;
QueryMessage query = new QueryMessage(address, read, command, data);
CommBuffer buffer = new CommBuffer(recvBufferSize);
for (int i = 0; (maxTries == 0) || (i < maxTries); ++i) {
sendQuery(messageId, query);
// System.out.print("DEBUG: Receiving response:");
ResponseMessage response = receiveResponse(messageId, buffer);
// System.out.println("");
if (response != null) {
if (!response.isError()) {
// normal message
// System.out.println("DEBUG: Received normal response.");
return response;
} else {
// error message, try again if transmission error, else return
if ((response.getData() != null) && (response.getData().length > 0)) {
// System.out.println("DEBUG: Received error response with error code.");
return response;
} else {
// System.out.println("DEBUG: Received transmission error.");
}
}
} else {
// System.out.println("DEBUG: Received no valid response.");
// timeout, do nothing
}
}
// System.out.println("DEBUG: Communication timeout.");
return null;
}
public ResponseMessage executeQuery(short address, boolean read,
short command, byte data, int maxTries) {
byte[] dataArray = {data};
return executeQuery(address, read, command, dataArray, maxTries);
}
public NVMComm2(InputStream inputStream, OutputStream outputStream, int ioSpeed) {
m_inputStream = inputStream;
m_outputStream = outputStream;
m_ioSpeed = ioSpeed;
m_recvInputTimeout = NVC2_TIMEOUT_CHARS * (10000 / ioSpeed) + 1;
m_lastMsgID = 0;
}
}