diff --git a/sys/arm64/acpica/acpi_machdep.c b/sys/arm64/acpica/acpi_machdep.c
--- a/sys/arm64/acpica/acpi_machdep.c
+++ b/sys/arm64/acpica/acpi_machdep.c
@@ -194,6 +194,9 @@
 				break;
 			}
 		acpi_unmap_table(xsdt);
+	} else {
+		printf("ACPI: Unsupported RSDP version %d and XSDT %#llx\n",
+		    rsdp->Revision, rsdp->XsdtPhysicalAddress);
 	}
 	pmap_unmapbios((vm_offset_t)rsdp, sizeof(ACPI_TABLE_RSDP));