Index: boot/arch/sparc64/Makefile.inc
===================================================================
--- boot/arch/sparc64/Makefile.inc	(revision 6c34be69eef6e892de7663ec0a2bacb932d8c72d)
+++ boot/arch/sparc64/Makefile.inc	(revision 2a72d9fbcffe5d34ff500bcdfb95b61bec9bac9d)
@@ -41,5 +41,10 @@
 RD_DRVS_ESSENTIAL += \
 	platform/sun4u \
-	bus/pci/pciintel
+	bus/pci/pciintel \
+	bus/isa \
+	char/ns8250
+
+RD_DRV_CFG += \
+	bus/isa
 
 RD_SRVS_NON_ESSENTIAL +=