Index: linux-2.6.21.7/drivers/serial/Makefile
===================================================================
--- linux-2.6.21.7.orig/drivers/serial/Makefile
+++ linux-2.6.21.7/drivers/serial/Makefile
@@ -5,6 +5,7 @@
 #
 
 obj-$(CONFIG_SERIAL_CORE) += serial_core.o
+obj-$(CONFIG_AMAZON_ASC_UART) += amazon_asc.o
 obj-$(CONFIG_SERIAL_21285) += 21285.o
 obj-$(CONFIG_SERIAL_8250) += 8250.o
 obj-$(CONFIG_SERIAL_8250_PNP) += 8250_pnp.o