Index: sys/conf/options.amd64
===================================================================
--- sys/conf/options.amd64
+++ sys/conf/options.amd64
@@ -61,3 +61,6 @@
 
 # EFI Runtime services support
 EFIRT			opt_efirt.h
+
+# Don't create a "legacy" PCI bridge if none is found.
+NO_LEGACY_PCIB		opt_cpu.h
Index: sys/conf/options.i386
===================================================================
--- sys/conf/options.i386
+++ sys/conf/options.i386
@@ -105,3 +105,6 @@
 
 # options for the Intel C600 SAS driver (isci)
 ISCI_LOGGING	opt_isci.h
+
+# Don't create a "legacy" PCI bridge if none is found.
+NO_LEGACY_PCIB		opt_cpu.h
Index: sys/x86/pci/pci_bus.c
===================================================================
--- sys/x86/pci/pci_bus.c
+++ sys/x86/pci/pci_bus.c
@@ -488,11 +488,13 @@
 	 * Note that pci_cfgregopen() thinks we have PCI devices..
 	 */
 	if (!found) {
+#ifndef NO_LEGACY_PCIB
 		if (bootverbose)
 			printf(
 	"legacy_pcib_identify: no bridge found, adding pcib0 anyway\n");
 		child = BUS_ADD_CHILD(parent, 100, "pcib", 0);
 		legacy_set_pcibus(child, 0);
+#endif
 	}
 }