--- src/VBox/Additions/common/VBoxGuest/Makefile.kmk.orig	2020-07-10 02:50:06.000000000 +1000
+++ src/VBox/Additions/common/VBoxGuest/Makefile.kmk	2020-08-23 02:14:29.678634000 +1000
@@ -31,12 +31,13 @@
 include $(PATH_SUB_CURRENT)/lib/Makefile.kmk
 
 
-if1of ($(KBUILD_TARGET), darwin freebsd haiku netbsd os2 solaris win)
+if1of ($(KBUILD_TARGET), darwin bsdsunix freebsd haiku netbsd os2 solaris win)
  #
  # VBoxGuest - The Guest Additions Driver.
  #
  SYSMODS += VBoxGuest
  VBoxGuest_TEMPLATE      = VBOXGUESTR0
+ VBoxGuest_NAME.bsdsunix = vboxguest
  VBoxGuest_NAME.freebsd  = vboxguest
  VBoxGuest_NAME.haiku    = vboxguest
  VBoxGuest_NAME.netbsd   = vboxguest
@@ -63,11 +64,13 @@
 	$(if $(VBOX_WITH_DPC_LATENCY_CHECKER),VBOX_WITH_DPC_LATENCY_CHECKER,)
  VBoxGuest_DEPS.solaris += $(VBOX_SVN_REV_KMK)
  VBoxGuest_DEPS.haiku   += $(VBOX_SVN_REV_HEADER)
+ VBoxGuest_DEPS.bsdsunix += $(VBOX_SVN_REV_HEADER)
  VBoxGuest_DEPS.freebsd += $(VBOX_SVN_REV_HEADER)
  VBoxGuest_DEPS.netbsd  += $(VBOX_SVN_REV_HEADER)
  VBoxGuest_DEPS.darwin  += $(VBOX_SVN_REV_HEADER)
  VBoxGuest_DEFS          = VBGL_VBOXGUEST VBOX_WITH_HGCM
  VBoxGuest_INCS          = .
+ VBoxGuest_INCS.bsdsunix  = $(VBoxGuest_0_OUTDIR) $(PATH_STAGE)/gen-sys-hdrs
  VBoxGuest_INCS.freebsd  = $(VBoxGuest_0_OUTDIR) $(PATH_STAGE)/gen-sys-hdrs
  VBoxGuest_INCS.netbsd   = $(VBoxGuest_0_OUTDIR) netbsd
  ifeq ($(KBUILD_HOST),solaris)
@@ -91,11 +94,14 @@
     VBoxGuest.cpp_SDKS   = $(VBOX_WINDDK_GST_WLH)
    endif
   endif # win
-  ifn1of ($(KBUILD_TARGET), linux freebsd netbsd solaris haiku)
+  ifn1of ($(KBUILD_TARGET), linux bsdsunix freebsd netbsd solaris haiku)
    VBoxGuest_SOURCES    = VBoxGuest-$(KBUILD_TARGET).cpp
   else
    VBoxGuest_SOURCES    = VBoxGuest-$(KBUILD_TARGET).c
    VBoxGuest_$(KBUILD_TARGET).c_DEPS = $(VBOX_SVN_REV_HEADER)
+   ifeq ($(KBUILD_TARGET),bsdsunix)
+    VBoxGuest-$(KBUILD_TARGET).c_CFLAGS = -Wno-sign-compare # /usr/src/sys/sys/vmmeter.h: In function 'vm_paging_needed'
+   endif
    ifeq ($(KBUILD_TARGET),freebsd)
     VBoxGuest-$(KBUILD_TARGET).c_CFLAGS = -Wno-sign-compare # /usr/src/sys/sys/vmmeter.h: In function 'vm_paging_needed'
    endif
@@ -110,6 +116,10 @@
   VBoxGuest_LIBS        += \
   	$(VBOX_LIB_VBGL_R0BASE) \
   	$(VBOX_LIB_IPRT_GUEST_R0)
+  VBoxGuest_ORDERDEPS.bsdsunix = \
+  	$(PATH_STAGE)/gen-sys-hdrs/pci_if.h \
+  	$(PATH_STAGE)/gen-sys-hdrs/bus_if.h \
+  	$(PATH_STAGE)/gen-sys-hdrs/device_if.h
   VBoxGuest_ORDERDEPS.freebsd = \
   	$(PATH_STAGE)/gen-sys-hdrs/pci_if.h \
   	$(PATH_STAGE)/gen-sys-hdrs/bus_if.h \
@@ -228,6 +238,19 @@
 
 endif # Linux
 
+ifeq ($(KBUILD_TARGET),bsdsunix)
+ #
+ # Install the source files and script(s).
+ #
+ include $(PATH_SUB_CURRENT)/bsdsunix/files_vboxguest
+ # sources and stuff.
+ INSTALLS += vboxguest-src
+ vboxguest-src_INST     = $(INST_ADDITIONS)src/vboxguest/
+ vboxguest-src_MODE     = a+r,u+w
+ vboxguest-src_SOURCES  = $(subst ",,$(FILES_VBOXGUEST_NOBIN))
+
+endif # BSDSUniX
+
 ifeq ($(KBUILD_TARGET),freebsd)
  #
  # Install the source files and script(s).