--- src/VBox/Additions/bsdsunix/vboxvfs/Makefile.kmk.orig	2020-08-17 13:23:45.000000000 +1000
+++ src/VBox/Additions/bsdsunix/vboxvfs/Makefile.kmk	2020-08-23 02:08:09.229996000 +1000
@@ -0,0 +1,68 @@
+# $Id: Makefile.kmk $
+## @file
+# Sub-Makefile for the BSDSUniX Shared folder kernel module.
+#
+
+#
+# Copyright (C) 2007-2017 Oracle Corporation
+#
+# This file is part of VirtualBox Open Source Edition (OSE), as
+# available from http://www.virtualbox.org. This file is free software;
+# you can redistribute it and/or modify it under the terms of the GNU
+# General Public License (GPL) as published by the Free Software
+# Foundation, in version 2 as it comes in the "COPYING" file of the
+# VirtualBox OSE distribution. VirtualBox OSE is distributed in the
+# hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
+#
+
+SUB_DEPTH = ../../../../..
+include $(KBUILD_PATH)/subheader.kmk
+
+ifneq ($(KBUILD_HOST),bsdsunix)
+$(error "The BSDSUniX guest additions can only be built on BSDSUniX!")
+endif
+
+#
+# vboxvfs - The Shared Folder Driver
+#
+SYSMODS.bsdsunix      += vboxvfs
+vboxvfs_TEMPLATE      = VBOXGUESTR0
+vboxvfs_DEFS          = VBOX_WITH_HGCM
+vboxvfs_INCS          = \
+        . \
+       $(vboxvfs_0_OUTDIR)
+vboxvfs_SOURCES       = \
+	vboxvfs_vfsops.c \
+	vboxvfs_vnops.c \
+	vboxvfs_prov.c
+vboxvfs_LIBS          = \
+	$(VBOX_LIB_VBGL_R0) \
+	$(VBOX_LIB_IPRT_GUEST_R0)
+vboxvfs_DEPS          = \
+	$(vboxvfs_0_OUTDIR)/vnode_if.h \
+	$(vboxvfs_0_OUTDIR)/vnode_if_newproto.h \
+	$(vboxvfs_0_OUTDIR)/vnode_if_typedef.h
+vboxvfs_CLEAN        += $(vboxvfs_DEPS)
+
+VBOX_AWK := /usr/bin/awk
+
+$$(vboxvfs_0_OUTDIR):
+	$(QUIET)$(MKDIR) -p $(vboxvfs_0_OUTDIR)
+
+$$(vboxvfs_0_OUTDIR)/vnode_if.h: $$(vboxvfs_0_OUTDIR) $(VBOX_BSDSUNIX_SRC)/kern/vnode_if.src
+	$(call MSG_TOOL,awk,VBoxGuest,$<,$@)
+	$(QUIET)$(VBOX_AWK) -f $(VBOX_BSDSUNIX_SRC)/tools/vnode_if.awk $(VBOX_BSDSUNIX_SRC)/kern/vnode_if.src -h
+	$(QUIET)$(MV) vnode_if.h $(vboxvfs_0_OUTDIR)/vnode_if.h
+
+$$(vboxvfs_0_OUTDIR)/vnode_if_newproto.h: $$(vboxvfs_0_OUTDIR) $(VBOX_BSDSUNIX_SRC)/kern/vnode_if.src
+	$(call MSG_TOOL,awk,VBoxGuest,$<,$@)
+	$(QUIET)$(VBOX_AWK) -f $(VBOX_BSDSUNIX_SRC)/tools/vnode_if.awk $(VBOX_BSDSUNIX_SRC)/kern/vnode_if.src -p
+	$(QUIET)$(MV) vnode_if_newproto.h $(vboxvfs_0_OUTDIR)/vnode_if_newproto.h
+
+$$(vboxvfs_0_OUTDIR)/vnode_if_typedef.h: $$(vboxvfs_0_OUTDIR) $(VBOX_BSDSUNIX_SRC)/kern/vnode_if.src
+	$(call MSG_TOOL,awk,VBoxGuest,$<,$@)
+	$(QUIET)$(VBOX_AWK) -f $(VBOX_BSDSUNIX_SRC)/tools/vnode_if.awk $(VBOX_BSDSUNIX_SRC)/kern/vnode_if.src -q
+	$(QUIET)$(MV) vnode_if_typedef.h $(vboxvfs_0_OUTDIR)/vnode_if_typedef.h
+
+include $(FILE_KBUILD_SUB_FOOTER)
+