Use devtpmfs when avaible

defaults/initrd.scripts

@@ -307,8 +307,13 @@ run_shell() {
 }
 
 runmdev() {
-	# busybox udev replacement
-	mdev -s
+	# Use devtmpfs if enabled in kernel,
+	# else busybox udev replacement
+	if grep -qs devtmpfs /proc/filesystems ; then
+		mount -t devtmpfs devtmpfs /dev
+	else
+		mdev -s
+	fi
 }
 
 test_success() {

defaults/linuxrc

@@ -724,6 +724,8 @@ fi
 cd "${CHROOT}"
 mkdir "${CHROOT}/proc" "${CHROOT}/sys" 2>/dev/null
 echo -ne "${BOLD}.${NORMAL}"
+# If devtmpfs is mounted assume genkernel mounted it at /dev and try unmounting it
+grep -qs devtmpfs /proc/mounts && ( umount /dev || echo '*: Failed to unmount the devtmpfs /dev!' )
 umount /sys || echo '*: Failed to unmount the ramdisk /sys!'
 umount /proc || echo '*: Failed to unmount the ramdisk /proc!'
 echo -e "${BOLD}.${NORMAL}"