32x: uninitialised hInt vector should read 0 (tp)

src/main/java/s32x/bus/S32xBus.java

@@ -267,7 +267,7 @@ private int readHIntVector(int address, Size size) {
             if (verboseMd) LOG.info("HINT vector read, rv {}, address: {}, {} {}", DmaFifo68k.rv,
                     th(address), th(res), size);
         } else {
-            res = bios68k.readBuffer(address, size);
+            res = 0;
         }
         return res;
     }

src/test/java/s32x/HIntVectorRomTest.java

@@ -0,0 +1,46 @@
+package s32x;
+
+import omegadrive.util.Size;
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import s32x.dict.S32xDict;
+import s32x.util.MarsLauncherHelper;
+
+import static s32x.MarsRegTestUtil.*;
+import static s32x.util.S32xUtil.CpuDeviceAccess.M68K;
+
+/**
+ * Federico Berti
+ * <p>
+ * Copyright 2023
+ */
+public class HIntVectorRomTest {
+
+    private MarsLauncherHelper.Sh2LaunchContext lc;
+
+    @BeforeEach
+    public void before() {
+        lc = createTestInstance();
+    }
+
+    //testpico expects 0x70 to be 0 when the hintvector is not set, ie. it is not reading the data stored in the bios.
+    @Test
+    public void testVector() {
+        int addr = S32xDict.M68K_START_HINT_VECTOR_WRITEABLE;
+        //defaults to 0
+        checkAden(lc, 0);
+        //enable 32x, RV = 1
+        MarsRegTestUtil.setAdenMdSide(lc, 1);
+        setRv(lc, 1);
+        int res = readBus(lc, M68K, addr, Size.LONG);
+        Assertions.assertEquals(0, res);
+        int vector = 0xAABBCCDD;
+        writeBus(lc, M68K, addr, vector, Size.LONG);
+        res = readBus(lc, M68K, addr, Size.LONG);
+        Assertions.assertEquals(vector, res);
+        writeBus(lc, M68K, addr, 0, Size.LONG);
+        res = readBus(lc, M68K, addr, Size.LONG);
+        Assertions.assertEquals(0, res);
+    }
+}