implements halt using WFI if hartid!=0 and multicore

env/riscv_vp/init.c

@@ -103,7 +103,10 @@ void __attribute__((weak)) _init() {
     while(i < NUM_INTERRUPTS) {
         localISR[i++] = default_handler;
     }
-
+#endif
+#if defined(NUM_HARTS) && NUM_HARTS > 1
+    for(int i = 1; i < NUM_HARTS; ++i)
+        set_aclint_msip(aclint, i, 1);
 #endif
 }