add CpuConfig per instance

Author: Federico Berti

src/main/java/m68k/cpu/Cpu.java

@@ -151,4 +151,8 @@ default int readMemoryWordSigned(int addr)
 	Instruction getInstructionFor(int opcode);
 	DisassembledOperand disassembleSrcEA(int address, int mode, int reg, Size sz);
 	DisassembledOperand disassembleDstEA(int address, int mode, int reg, Size sz);
+
+	default CpuConfig getConfig(){
+		return CpuConfig.DEFAULT_CONFIG;
+	}
 }

src/main/java/m68k/cpu/CpuConfig.java

@@ -0,0 +1,47 @@
+package m68k.cpu;
+
+import java.util.StringJoiner;
+
+/**
+ * Federico Berti
+ * <p>
+ * Copyright 2025
+ */
+public class CpuConfig {
+    public static final CpuConfig DEFAULT_CONFIG = new CpuConfig(false, false, false);
+    public final boolean emulateBrokenTasWrite;
+    public final boolean accurateDivTiming;
+
+    //TODO not working
+    public final boolean enablePrefetch;
+
+    public CpuConfig(boolean brokenTas, boolean divTiming, boolean enablePrefetch){
+        emulateBrokenTasWrite = brokenTas;
+        accurateDivTiming = divTiming;
+        this.enablePrefetch = enablePrefetch;
+    }
+
+    /**
+     * true -> hardware where write-back to *memory* doesn't work
+     */
+    public boolean emulateBrokenTasWrite(){
+       return emulateBrokenTasWrite;
+    }
+
+    public boolean accurateDivTiming() {
+        return accurateDivTiming;
+    }
+
+    public boolean enablePrefetch() {
+        return enablePrefetch;
+    }
+
+    @Override
+    public String toString() {
+        return new StringJoiner(", ", CpuConfig.class.getSimpleName() + "[", "]")
+                .add("emulateBrokenTasWrite=" + emulateBrokenTasWrite)
+                .add("accurateDivTiming=" + accurateDivTiming)
+                .add("enablePrefetch=" + enablePrefetch)
+                .toString();
+    }
+}

src/main/java/m68k/cpu/MC68000.java

@@ -1,6 +1,8 @@
 package m68k.cpu;
 
 import m68k.cpu.instructions.*;
+import m68k.util.LogHelper;
+import org.slf4j.Logger;
 
 /*
 //  M68k - Java Amiga MachineCore
@@ -28,44 +30,31 @@
 */
 public class MC68000 extends CpuCore implements InstructionSet
 {
-
-	public static final boolean ENABLE_PREFETCH = Boolean.valueOf(System.getProperty("68k.enable.prefetch", "false"));
-
-	static {
-		initProperties();
-	}
-
-	private static void initProperties() {
-		TAS.EMULATE_BROKEN_TAS = Boolean.valueOf(System.getProperty("68k.broken.tas", "false"));
-		if(TAS.EMULATE_BROKEN_TAS){
-			System.out.println("Emulating broken TAS instruction");
-		}
-		DIVU.ACCURATE_DIV_TIMING = Boolean.valueOf(System.getProperty("68k.accurate.div.timing", "false"));
-		if(DIVU.ACCURATE_DIV_TIMING){
-			System.out.println("Using accurate DIVU/S timing");
-		}
-		if(ENABLE_PREFETCH){
-			System.out.println("Enable prefetch");
-		}
-	}
-
+	private final static Logger LOG = LogHelper.getLogger(MC68000.class.getSimpleName());
 	protected final Instruction[] i_table;
 	protected final Instruction unknown;
 	protected int loaded_ops;
 
-	public MC68000()
-	{
+	protected final CpuConfig cpuConfig;
+
+	public MC68000() {
+		this(CpuConfig.DEFAULT_CONFIG);
+	}
+
+	public MC68000(CpuConfig c){
+		cpuConfig = c;
 		i_table = new Instruction[NUM_OPCODES];
 		unknown = new UNKNOWN(this);
 		for(int i = 0; i < NUM_OPCODES; i++)
 			i_table[i] = unknown;
 		loaded_ops = 0;
 		loadInstructionSet();
+		LOG.info("Using CpuConfig: {}", cpuConfig);
 	}
 
 	@Override
 	public int execute() {
-		if(ENABLE_PREFETCH){
+		if(cpuConfig.enablePrefetch){
 			return executePrefetch();
 		} else {
 			return executeNoPrefetch();
@@ -95,7 +84,7 @@ private int executeNoPrefetch() {
 
 	@Override
 	public int getPrefetchWord(){
-		return ENABLE_PREFETCH ? ir : readMemoryWord(reg_pc);
+		return cpuConfig.enablePrefetch ? ir : readMemoryWord(reg_pc);
 	}
 
 	protected void loadInstructionSet()
@@ -212,4 +201,9 @@ public Instruction getInstructionAt(int address)
 		int opcode = readMemoryWord(address);
 		return getInstructionFor(opcode);
 	}
+
+	@Override
+	public CpuConfig getConfig() {
+		return cpuConfig;
+	}
 }

src/main/java/m68k/cpu/instructions/DIVS.java

@@ -33,10 +33,12 @@
 public class DIVS implements InstructionHandler
 {
 	protected final Cpu cpu;
+	protected final boolean accurateDivTiming;
 
 	public DIVS(Cpu cpu)
 	{
 		this.cpu = cpu;
+		accurateDivTiming = cpu.getConfig().accurateDivTiming;
 	}
 
 	public void register(InstructionSet is)
@@ -120,7 +122,7 @@ protected final int divs(int opcode)
 				cpu.clrFlags((Cpu.V_FLAG | Cpu.C_FLAG));
 			}
 			//worst case but less than 10% difference between best and worst cases
-			time = DIVU.ACCURATE_DIV_TIMING ? getDivs68kCycles(d, s) : 158;
+			time = accurateDivTiming ? getDivs68kCycles(d, s) : 158;
 		}
 
 		return time + OperandTiming.getOperandTiming(op, Size.Word);

src/main/java/m68k/cpu/instructions/DIVU.java

@@ -30,13 +30,13 @@
 
 public class DIVU implements InstructionHandler
 {
-	public static boolean ACCURATE_DIV_TIMING;
-
 	protected final Cpu cpu;
+	protected final boolean accurateDivTiming;
 
 	public DIVU(Cpu cpu)
 	{
 		this.cpu = cpu;
+		accurateDivTiming = cpu.getConfig().accurateDivTiming;
 	}
 
 	public void register(InstructionSet is)
@@ -126,7 +126,7 @@ protected final int divu(int opcode)
 				cpu.clrFlags((Cpu.V_FLAG | Cpu.C_FLAG));
 			}
 			//worst case but less than 10% difference between best and worst cases
-			time = ACCURATE_DIV_TIMING ? getDivu68kCycles(dl, s) : 140;
+			time = accurateDivTiming ? getDivu68kCycles(dl, s) : 140;
 		}
 
 		return time + OperandTiming.getOperandTiming(op, Size.Word);

src/main/java/m68k/cpu/instructions/TAS.java

@@ -29,13 +29,13 @@
 //
 */
 public class TAS implements InstructionHandler {
-	//EMULATE_BROKEN_TAS -> hardware where write-back to *memory* doesn't work
-	public static boolean EMULATE_BROKEN_TAS;
 
 	protected final Cpu cpu;
+	protected final boolean emulateBrokenTasWrite;
 
 	public TAS(Cpu cpu) {
 		this.cpu = cpu;
+		emulateBrokenTasWrite = cpu.getConfig().emulateBrokenTasWrite;
 	}
 
 	public final void register(InstructionSet is)
@@ -90,7 +90,7 @@ protected synchronized final int tas(int opcode)
 		}
 		cpu.clrFlags(Cpu.C_FLAG | Cpu.V_FLAG);
 
-		boolean writeBack = !EMULATE_BROKEN_TAS || (EMULATE_BROKEN_TAS && op.isRegisterMode());
+		boolean writeBack = !emulateBrokenTasWrite || op.isRegisterMode();
 		if (writeBack) {
 			op.setByte(v | 0x80);
 		}

src/main/java/m68k/util/MC68000Helper.java

@@ -23,7 +23,6 @@
 import m68k.cpu.DisassembledInstruction;
 import m68k.cpu.Instruction;
 import m68k.cpu.MC68000;
-import m68k.cpu.instructions.TAS;
 import org.slf4j.Logger;
 
 import java.util.Arrays;
@@ -35,19 +34,14 @@ public class MC68000Helper {
     private final static Logger LOG = LogHelper.getLogger(MC68000Helper.class.getSimpleName());
 
     public static final boolean STOP_ON_EXCEPTION;
-    public static final boolean GENESIS_TAS_BROKEN;
     public static final boolean M68K_DEBUG;
     public final static int OVERCLOCK_FACTOR;
 
     static {
         STOP_ON_EXCEPTION =
                 Boolean.parseBoolean(System.getProperty("68k.stop.on.exception", "false"));
-        GENESIS_TAS_BROKEN = Boolean.parseBoolean(System.getProperty("68k.broken.tas", "true"));
         M68K_DEBUG = Boolean.parseBoolean(System.getProperty("68k.debug", "false"));
         OVERCLOCK_FACTOR = Integer.parseInt(System.getProperty("68k.overclock.factor", "0"));
-        if (GENESIS_TAS_BROKEN != TAS.EMULATE_BROKEN_TAS) {
-            LOG.info("Overriding 68k TAS broken setting: {}", GENESIS_TAS_BROKEN);
-        }
         if (M68K_DEBUG) {
             LOG.info("68k debug mode: true");
         }

src/test/java/m68k/cpu/instructions/TasTest.java

@@ -1,6 +1,7 @@
 package m68k.cpu.instructions;
 
 import m68k.cpu.Cpu;
+import m68k.cpu.CpuConfig;
 import m68k.cpu.MC68000;
 import m68k.memory.AddressSpace;
 import m68k.memory.MemorySpace;
@@ -19,12 +20,17 @@ public class TasTest {
 
     AddressSpace bus;
     Cpu cpu;
+    static CpuConfig tasBroken = new CpuConfig(true, false, false);
 
     @BeforeEach public void setUp() {
+        setUp(CpuConfig.DEFAULT_CONFIG);
+    }
+
+    private void setUp(CpuConfig cpuConfig) {
         //create 1kb of memory for the cpu
         bus = new MemorySpace(1);
 
-        cpu = new MC68000();
+        cpu = new MC68000(cpuConfig);
         cpu.setAddressSpace(bus);
         cpu.reset();
         cpu.setAddrRegisterLong(7, 0x200);
@@ -34,7 +40,6 @@ public class TasTest {
     // 0100 1010 1100 0000
     @Test
     public void testTasRegOk() {
-        TAS.EMULATE_BROKEN_TAS = false;
         bus.writeWord(4, 0x4AC0);    //TAS D0
         cpu.setPC(4);
         cpu.setDataRegisterLong(0, 0);
@@ -45,7 +50,7 @@ public void testTasRegOk() {
     }
 
     @Test public void testTasRegBroken() {
-        TAS.EMULATE_BROKEN_TAS = true;
+        setUp(tasBroken);
         bus.writeWord(4, 0x4AC0);    //TAS D0
         cpu.setPC(4);
         cpu.setDataRegisterLong(0, 0);
@@ -56,7 +61,6 @@ public void testTasRegOk() {
     }
 
     @Test public void testTasMemOk() {
-        TAS.EMULATE_BROKEN_TAS = false;
         int val = 0x20;
         int memAddr = 100;
         bus.writeWord(4, 0x4AD0);    //TAS (A0)
@@ -71,7 +75,7 @@ public void testTasRegOk() {
     }
 
     @Test public void testTasMemBroken() {
-        TAS.EMULATE_BROKEN_TAS = true;
+        setUp(tasBroken);
         bus.writeWord(4, 0x4AD0);    //TAS (A0)
         bus.writeByte(100, 0x20);
         cpu.setPC(4);

src/test/java/miggy/cpu/instructions/TASTest.java

@@ -1,24 +1,15 @@
 package miggy.cpu.instructions;
 
-import m68k.cpu.instructions.TAS;
 import miggy.BasicSetup;
 import miggy.SystemModel;
 import miggy.SystemModel.CpuFlag;
-import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 
 import static m68k.util.TestCpuUtil.*;
 
 // $Revision: 21 $
 public class TASTest extends BasicSetup {
 
-    @Override
-    @BeforeEach
-    protected void setUp() {
-        super.setUp();
-        TAS.EMULATE_BROKEN_TAS = false;
-    }
-
     @Test public void testSet() {
         setInstructionAtPC(0x4ac0);    //tas d0
         SystemModel.CPU.setDataRegister(0, 0x87654381);