Index: head/sys/arm64/arm64/mp_machdep.c
===================================================================
--- head/sys/arm64/arm64/mp_machdep.c
+++ head/sys/arm64/arm64/mp_machdep.c
@@ -638,10 +638,11 @@
 void
 cpu_mp_setmaxid(void)
 {
-#if defined(DEV_ACPI) || defined(FDT)
 	int cores;
-#endif
 
+	mp_ncpus = 1;
+	mp_maxid = 0;
+
 	switch(arm64_bus_method) {
 #ifdef DEV_ACPI
 	case ARM64_BUS_ACPI:
@@ -653,7 +654,6 @@
 				    cores);
 			mp_ncpus = cores;
 			mp_maxid = cores - 1;
-			return;
 		}
 		break;
 #endif
@@ -667,18 +667,21 @@
 				    cores);
 			mp_ncpus = cores;
 			mp_maxid = cores - 1;
-			return;
 		}
 		break;
 #endif
 	default:
+		if (bootverbose)
+			printf("No CPU data, limiting to 1 core\n");
 		break;
 	}
 
-	if (bootverbose)
-		printf("No CPU data, limiting to 1 core\n");
-	mp_ncpus = 1;
-	mp_maxid = 0;
+	if (TUNABLE_INT_FETCH("hw.ncpu", &cores)) {
+		if (cores > 0 && cores < mp_ncpus) {
+			mp_ncpus = cores;
+			mp_maxid = cores - 1;
+		}
+	}
 }
 
 /*