Add copy checksum

src/main/java/com/romraider/maps/checksum/ChecksumCOPY.java

@@ -0,0 +1,73 @@
+/*
+ * RomRaider Open-Source Tuning, Logging and Reflashing
+ * Copyright (C) 2006-2020 RomRaider.com
+ *
+ * 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.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+package com.romraider.maps.checksum;
+import java.util.Map;
+import com.romraider.util.HexUtil;
+
+/**
+ * This class implements a copy "checksum", which can be useful for old Motronic ECUs
+ * It simply checks if an array of data is identical to a specified location and copies it over if necessary
+ */
+    public final class ChecksumCOPY implements ChecksumManager {
+    private static final String START = "start";
+    private static final String END = "end";
+    private static final String LOC = "loc";
+    private int start; // Start of checksum area
+    private int end; // End of area (inclusive)
+    private int loc; // Start of location where data is copied
+
+    @Override
+    public void configure(Map<String, String> vars) {
+    	if(start >= end) 
+    	{
+	        this.start = HexUtil.hexToInt(vars.get(START));
+	        this.end = HexUtil.hexToInt(vars.get(END));
+	        this.loc = HexUtil.hexToInt(vars.get(LOC));
+    	}
+    }
+    
+	@Override
+	public int getNumberOfChecksums() {
+		return 1;
+	}
+
+    @Override
+    public int validate(byte[] binData) {
+    	for(int i = 0; i <= start - end; i++)
+    	{
+    		if(binData[start + i] != binData[loc + i])
+    		{
+    			return 0;
+    		}
+    	}	
+    	return 1; 	
+    }
+
+    @Override
+    public int update(byte[] binData) {
+    	int updateNeeded = 1 - validate(binData);
+    	
+    	if(updateNeeded > 0)
+    	{
+    		System.arraycopy(binData, start, binData, loc, start + 1 - end);
+    	}
+    	return updateNeeded;
+    }
+}