-"root=/dev/nfs nfsroot=$(serverip):$(rootpath) " \
-"ip=$(ipaddr):$(serverip):$(gatewayip):$(subnetmask):$(hostname):eth0:off ;" \
+"root=/dev/nfs nfsroot=${serverip}:${rootpath} " \
+"ip=${ipaddr}:${serverip}:${gatewayip}:${subnetmask}:${hostname}:eth0:off ;" \