Index: Mk/Uses/elfctl.mk
===================================================================
--- /dev/null
+++ Mk/Uses/elfctl.mk
@@ -0,0 +1,27 @@
+# Change an ELF binary's feature control note
+#
+# Feature:	elfctl
+# Usage:	USES=elfctl
+# Valid ARGS:	none
+#
+# Variables
+#
+#   ELF_FEATURES=	path/to/file1:featurelist \
+#			path/to/file1:featurelist \
+			path/to/file2:featurelist
+#
+# The file paths listed in ELF_FEATURES are relative to ${PREFIX}.
+#
+
+.if !defined(_INCLUDE_USES_ELFCTL_MK)
+_INCLUDE_USES_ELFCTL_MK=	yes
+
+.if ! empty(ELF_FEATURES)
+_USES_install+=	620:elfctl-post-build
+elfctl-post-build:
+.for feat in ${ELF_FEATURES}
+	${ELFCTL} -i -e ${feat:C/.*://} ${STAGEDIR}${PREFIX}/${feat:C/:.*//}
+.endfor
+.endif
+
+.endif
Index: Mk/bsd.commands.mk
===================================================================
--- Mk/bsd.commands.mk
+++ Mk/bsd.commands.mk
@@ -34,6 +34,7 @@
 DIFF?=			/usr/bin/diff
 DIRNAME?=		/usr/bin/dirname
 EGREP?=			/usr/bin/egrep
+ELFCTL?=		/usr/bin/elfctl
 EXPR?=			/bin/expr
 FALSE?=			false	# Shell builtin
 FILE?=			/usr/bin/file