Index: usr.sbin/mpsutil/Makefile
===================================================================
--- usr.sbin/mpsutil/Makefile	(revision 347510)
+++ usr.sbin/mpsutil/Makefile	(working copy)
@@ -1,7 +1,7 @@
 # $FreeBSD$
 
 PROG=	mpsutil
-SRCS=	mps_cmd.c mps_debug.c mps_flash.c mps_show.c mpsutil.c
+SRCS=	mps_cmd.c mps_debug.c mps_flash.c mps_show.c mps_slot.c mpsutil.c
 MAN=	mpsutil.8
 
 WARNS?= 3
Index: usr.sbin/mpsutil/mps_cmd.c
===================================================================
--- usr.sbin/mpsutil/mps_cmd.c	(revision 347510)
+++ usr.sbin/mpsutil/mps_cmd.c	(working copy)
@@ -283,6 +283,29 @@ mps_map_btdh(int fd, uint16_t *devhandle, uint16_t
 }
 
 int
+mps_set_slot_status(int fd, U16 handle, U16 slot, U32 status)
+{
+	MPI2_SEP_REQUEST req;
+	MPI2_SEP_REPLY reply;
+
+	bzero(&req, sizeof(req));
+	req.Function = MPI2_FUNCTION_SCSI_ENCLOSURE_PROCESSOR;
+	req.Action = MPI2_SEP_REQ_ACTION_WRITE_STATUS;
+	req.Flags = MPI2_SEP_REQ_FLAGS_ENCLOSURE_SLOT_ADDRESS;
+	req.EnclosureHandle = handle;
+	req.Slot = slot;
+	req.SlotStatus = status;
+
+	if (mps_pass_command(fd, &req, sizeof(req), &reply, sizeof(reply),
+	    NULL, 0, NULL, 0, 30) != 0)
+		return (errno);
+
+	if (!IOC_STATUS_SUCCESS(reply.IOCStatus))
+		return (EIO);
+	return (0);
+}
+
+int
 mps_read_config_page_header(int fd, U8 PageType, U8 PageNumber, U32 PageAddress,
     MPI2_CONFIG_PAGE_HEADER *header, U16 *IOCStatus)
 {
Index: usr.sbin/mpsutil/mps_slot.c
===================================================================
--- usr.sbin/mpsutil/mps_slot.c	(nonexistent)
+++ usr.sbin/mpsutil/mps_slot.c	(working copy)
@@ -0,0 +1,112 @@
+/*-
+ * Copyright (c) 2019 Andriy Gapon <avg@FreeBSD.org>
+ *
+ * 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 AND CONTRIBUTORS ``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 OR CONTRIBUTORS 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>
+__RCSID("$FreeBSD$");
+
+#include <sys/stat.h>
+#include <sys/param.h>
+#include <sys/mman.h>
+
+#include <errno.h>
+#include <err.h>
+#include <fcntl.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "mpsutil.h"
+
+MPS_TABLE(top, slot);
+
+static int
+slot_set(int argc, char **argv)
+{
+	char *endptr;
+	unsigned long ux;
+	long x;
+	int error;
+	int fd;
+	U32 status;
+	U16 handle;
+	U16 slot;
+
+	if (argc != 5) {
+		warnx("Incorrect number of arguments");
+		return (EINVAL);
+	}
+
+	if (strcmp(argv[1], "status") != 0) {
+		warnx("Invalid argument '%s', expecting 'status'",
+		    argv[1]);
+		return (EINVAL);
+	}
+
+	errno = 0;
+	x = strtol(argv[2], &endptr, 0);
+	if (*endptr != '\0' || errno != 0 || x < 0 || x > UINT16_MAX) {
+		warnx("Invalid enclosure handle argument '%s'", argv[2]);
+		return (EINVAL);
+	}
+	handle = x;
+
+	errno = 0;
+	x = strtol(argv[3], &endptr, 0);
+	if (*endptr != '\0' || errno != 0 || x < 0 || x > UINT16_MAX) {
+		warnx("Invalid slot argument '%s'", argv[3]);
+		return (EINVAL);
+	}
+	slot = x;
+
+	errno = 0;
+	ux = strtoul(argv[4], &endptr, 0);
+	if (*endptr != '\0' || errno != 0 || ux > UINT32_MAX) {
+		warnx("Invalid status argument '%s'", argv[4]);
+		return (EINVAL);
+	}
+	status = ux;
+
+	fd = mps_open(mps_unit);
+	if (fd < 0) {
+		error = errno;
+		warn("mps_open");
+		return (error);
+	}
+
+	if (mps_set_slot_status(fd, handle, slot, status) != 0) {
+		warnx("Failed to set status");
+		close(fd);
+		return (1);
+	}
+
+	close(fd);
+	printf("Successfully set slot status\n");
+	return (0);
+}
+
+MPS_COMMAND(slot, set, slot_set, "status <enclosure handle> <slot number> "
+    "<status>", "Set status of the slot in the directly attached enclosure");

Index: usr.sbin/mpsutil/mpsutil.h
===================================================================
--- usr.sbin/mpsutil/mpsutil.h	(revision 347510)
+++ usr.sbin/mpsutil/mpsutil.h	(working copy)
@@ -128,6 +128,7 @@ int	mps_map_btdh(int fd, uint16_t *devhandle, uint
 const char *mps_ioc_status(U16 IOCStatus);
 int	mps_firmware_send(int fd, unsigned char *buf, uint32_t len, bool bios);
 int	mps_firmware_get(int fd, unsigned char **buf, bool bios);
+int	mps_set_slot_status(int fd, U16 handle, U16 slot, U32 status);
 
 static __inline void *
 mps_read_man_page(int fd, U8 PageNumber, U16 *IOCStatus)