--- /usr/share/initramfs-tools/hooks/fixrtc.orig	2018-01-10 20:10:30.161777606 +0100
+++ /usr/share/initramfs-tools/hooks/fixrtc	2018-01-10 20:13:51.581857236 +0100
@@ -18,6 +18,8 @@
         ;;
 esac

+test -e /dev/rtc || exit 0   # no RTC = nothing to fix here.
+
 . /usr/share/initramfs-tools/hook-functions

 # We use date, hwclock and dumpe2fs