Index: etc/rc.initdiskless
===================================================================
--- etc/rc.initdiskless
+++ etc/rc.initdiskless
@@ -195,10 +195,27 @@
     to_umount="$b ${to_umount}"
 }
 
-# Create a generic memory disk (using tmpfs)
+# Attempt to load tmpfs, if it is not already available
+# tmpfs_status is empty if load_tmpfs has not been called,
+# 0 if tmpfs is available, and some other status code otherwise
+#
+tmpfs_status=""
+load_tmpfs() {
+    kldstat -q -m tmpfs || kldload -q tmpfs >/dev/null 2>&1
+    tmpfs_status=$?
+}
+
+# Create a generic memory disk
+# Use tmpfs, if available, otherwise fall back to using mfs
 #
 mount_md() {
-    mount -t tmpfs -o size=$(($1 * 512)) tmpfs $2
+    # Only try to load tmpfs once
+    ${tmpfs_status:+:} load_tmpfs
+    if [ $tmpfs_status -eq 0 ]; then
+	mount -t tmpfs -o size=$(($1 * 512)) tmpfs $2
+    else
+	/sbin/mdmfs -S -i 4096 -s $1 -M md $2
+    fi
 }
 
 # Create the memory filesystem if it has not already been created