Index: contrib/elftoolchain/readelf/readelf.c
===================================================================
--- contrib/elftoolchain/readelf/readelf.c
+++ contrib/elftoolchain/readelf/readelf.c
@@ -1123,6 +1123,7 @@
 	case 1: return "NT_FREEBSD_ABI_TAG";
 	case 2: return "NT_FREEBSD_NOINIT_TAG";
 	case 3: return "NT_FREEBSD_ARCH_TAG";
+	case 4: return "NT_FREEBSD_FEATURE_CTL";
 	default: return (note_type_unknown(nt));
 	}
 }
Index: lib/csu/aarch64/crt1.c
===================================================================
--- lib/csu/aarch64/crt1.c
+++ lib/csu/aarch64/crt1.c
@@ -37,6 +37,7 @@
 #include "libc_private.h"
 #include "crtbrand.c"
 #include "ignore_init.c"
+#include "feature.c"
 
 #ifdef GCRT
 extern void _mcleanup(void);
Index: lib/csu/amd64/crt1.c
===================================================================
--- lib/csu/amd64/crt1.c
+++ lib/csu/amd64/crt1.c
@@ -34,6 +34,7 @@
 #include "libc_private.h"
 #include "crtbrand.c"
 #include "ignore_init.c"
+#include "feature.c"
 
 typedef void (*fptr)(void);
 
Index: lib/csu/arm/crt1.c
===================================================================
--- lib/csu/arm/crt1.c
+++ lib/csu/arm/crt1.c
@@ -51,6 +51,7 @@
 #include "libc_private.h"
 #include "crtbrand.c"
 #include "ignore_init.c"
+#include "feature.c"
 
 struct Struct_Obj_Entry;
 struct ps_strings;
Index: lib/csu/common/feature.c
===================================================================
--- /dev/null
+++ lib/csu/common/feature.c
@@ -0,0 +1,50 @@
+/*-
+ * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
+ *
+ * Copyright 2018 The FreeBSD Foundation.
+ *
+ * This software was developed by Ed Maste under the sponsorship of
+ * The FreeBSD Foundation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/param.h>
+#include <sys/elf_common.h>
+#include "notes.h"
+
+static const struct {
+	int32_t	namesz;
+	int32_t	descsz;
+	int32_t	type;
+	char	name[sizeof(NOTE_FREEBSD_VENDOR)];
+	uint32_t desc[1];
+} crt_feature_ctl __attribute__ ((section (NOTE_SECTION),
+    aligned(4))) __used = {
+	.namesz = sizeof(NOTE_FREEBSD_VENDOR),
+	.descsz = sizeof(uint32_t),
+	.type = NT_FREEBSD_FEATURE_CTL,
+	.name = NOTE_FREEBSD_VENDOR,
+	.desc = { 0 }
+};
Index: lib/csu/mips/crt1.c
===================================================================
--- lib/csu/mips/crt1.c
+++ lib/csu/mips/crt1.c
@@ -42,6 +42,7 @@
 #include "libc_private.h"
 #include "crtbrand.c"
 #include "ignore_init.c"
+#include "feature.c"
 
 struct Struct_Obj_Entry;
 struct ps_strings;
Index: lib/csu/powerpc/crt1.c
===================================================================
--- lib/csu/powerpc/crt1.c
+++ lib/csu/powerpc/crt1.c
@@ -49,6 +49,7 @@
 #include "libc_private.h"
 #include "crtbrand.c"
 #include "ignore_init.c"
+#include "feature.c"
 
 struct Struct_Obj_Entry;
 struct ps_strings;
Index: lib/csu/powerpc64/crt1.c
===================================================================
--- lib/csu/powerpc64/crt1.c
+++ lib/csu/powerpc64/crt1.c
@@ -49,6 +49,7 @@
 #include "libc_private.h"
 #include "crtbrand.c"
 #include "ignore_init.c"
+#include "feature.c"
 
 struct Struct_Obj_Entry;
 struct ps_strings;
Index: lib/csu/riscv/crt1.c
===================================================================
--- lib/csu/riscv/crt1.c
+++ lib/csu/riscv/crt1.c
@@ -41,6 +41,7 @@
 #include "libc_private.h"
 #include "crtbrand.c"
 #include "ignore_init.c"
+#include "feature.c"
 
 typedef void (*fptr)(void);
 
Index: lib/csu/sparc64/crt1.c
===================================================================
--- lib/csu/sparc64/crt1.c
+++ lib/csu/sparc64/crt1.c
@@ -40,6 +40,7 @@
 #include "libc_private.h"
 #include "crtbrand.c"
 #include "ignore_init.c"
+#include "feature.c"
 
 struct Struct_Obj_Entry;
 struct ps_strings;
Index: sys/sys/elf_common.h
===================================================================
--- sys/sys/elf_common.h
+++ sys/sys/elf_common.h
@@ -759,6 +759,7 @@
 #define	NT_FREEBSD_ABI_TAG	1
 #define	NT_FREEBSD_NOINIT_TAG	2
 #define	NT_FREEBSD_ARCH_TAG	3
+#define	NT_FREEBSD_FEATURE_CTL	4
 
 /* Values for n_type.  Used in core files. */
 #define	NT_PRSTATUS	1	/* Process status. */