diff --git a/usr/src/boot/sys/boot/efi/include/efi.h b/usr/src/boot/sys/boot/efi/include/efi.h
index 6815446a2605..b844d16010cd 100644
--- a/usr/src/boot/sys/boot/efi/include/efi.h
+++ b/usr/src/boot/sys/boot/efi/include/efi.h
@@ -61,4 +61,9 @@ Revision History
 #include "efipoint.h"
 #include "efiuga.h"
 
+/*
+ * illumos UUID
+ */
+#define	ILLUMOS_BOOT_VAR_GUID \
+	{ 0x8B54B311, 0x7163, 0x40d3, {0xA6, 0x7B, 0xE7, 0xB2, 0x95, 0x1B, 0x3D, 0x56} }
 #endif
diff --git a/usr/src/boot/sys/boot/efi/include/efilib.h b/usr/src/boot/sys/boot/efi/include/efilib.h
index e6fd4ee8abb7..d477bf6f1b9f 100644
--- a/usr/src/boot/sys/boot/efi/include/efilib.h
+++ b/usr/src/boot/sys/boot/efi/include/efilib.h
@@ -1,4 +1,4 @@
-/*-
+/*
  * Copyright (c) 2000 Doug Rabson
  * Copyright (c) 2006 Marcel Moolenaar
  * All rights reserved.
@@ -106,6 +106,17 @@ int wcscmp(CHAR16 *, CHAR16 *);
 void cpy8to16(const char *, CHAR16 *, size_t);
 void cpy16to8(const CHAR16 *, char *, size_t);
 
+/*
+ * Routines for interacting with EFI's env vars in a more unix-like
+ * way than the standard APIs. In addition, convenience routines for
+ * the loader setting / getting illumos specific variables.
+ */
+
+EFI_STATUS efi_illumos_getenv(const char *v, void *data, size_t *len);
+EFI_STATUS efi_getenv(EFI_GUID *g, const char *v, void *data, size_t *len);
+EFI_STATUS efi_global_getenv(const char *v, void *data, size_t *len);
+EFI_STATUS efi_setenv_illumos_wcs(const char *varname, CHAR16 *valstr);
+
 /* guids and names */
 bool efi_guid_to_str(const EFI_GUID *, char **);
 bool efi_str_to_guid(const char *, EFI_GUID *);
diff --git a/usr/src/boot/sys/boot/efi/libefi/Makefile b/usr/src/boot/sys/boot/efi/libefi/Makefile
index b8b4c5e6d653..0886f0f352d3 100644
--- a/usr/src/boot/sys/boot/efi/libefi/Makefile
+++ b/usr/src/boot/sys/boot/efi/libefi/Makefile
@@ -30,6 +30,7 @@ SRCS=	delay.c \
 	efi_console.c \
 	efi_driver_utils.c \
 	efichar.c \
+	efienv.c \
 	efinet.c \
 	efipart.c \
 	efizfs.c \
diff --git a/usr/src/boot/sys/boot/efi/libefi/efienv.c b/usr/src/boot/sys/boot/efi/libefi/efienv.c
new file mode 100644
index 000000000000..253d525c1ac0
--- /dev/null
+++ b/usr/src/boot/sys/boot/efi/libefi/efienv.c
@@ -0,0 +1,85 @@
+/*
+ * Copyright (c) 2018 Netflix, Inc.
+ * All rights reserved.
+ *
+ * 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>
+
+#include <stand.h>
+#include <efi.h>
+#include <efichar.h>
+#include <efilib.h>
+
+static EFI_GUID illumosBootVarGUID = ILLUMOS_BOOT_VAR_GUID;
+static EFI_GUID GlobalBootVarGUID = EFI_GLOBAL_VARIABLE;
+
+EFI_STATUS
+efi_getenv(EFI_GUID *g, const char *v, void *data, size_t *len)
+{
+	size_t ul;
+	CHAR16 *uv;
+	UINT32 attr;
+	UINTN dl;
+	EFI_STATUS rv;
+
+	uv = NULL;
+	if (utf8_to_ucs2(v, &uv, &ul) != 0)
+		return (EFI_OUT_OF_RESOURCES);
+	dl = *len;
+	rv = RS->GetVariable(uv, g, &attr, &dl, data);
+	if (rv == EFI_SUCCESS)
+		*len = dl;
+	free(uv);
+	return (rv);
+}
+
+EFI_STATUS
+efi_global_getenv(const char *v, void *data, size_t *len)
+{
+
+	return (efi_getenv(&GlobalBootVarGUID, v, data, len));
+}
+
+EFI_STATUS
+efi_illumos_getenv(const char *v, void *data, size_t *len)
+{
+
+	return (efi_getenv(&illumosBootVarGUID, v, data, len));
+}
+
+EFI_STATUS
+efi_setenv_illumos_wcs(const char *varname, CHAR16 *valstr)
+{
+	CHAR16 *var = NULL;
+	size_t len;
+	EFI_STATUS rv;
+
+	if (utf8_to_ucs2(varname, &var, &len) != 0)
+		return (EFI_OUT_OF_RESOURCES);
+	rv = RS->SetVariable(var, &illumosBootVarGUID,
+	    EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_RUNTIME_ACCESS,
+	    (ucs2len(valstr) + 1) * sizeof (CHAR16), valstr);
+	free(var);
+	return (rv);
+}
diff --git a/usr/src/boot/sys/boot/efi/libefi/env.c b/usr/src/boot/sys/boot/efi/libefi/env.c
index 663d343bf374..c43e4b118b03 100644
--- a/usr/src/boot/sys/boot/efi/libefi/env.c
+++ b/usr/src/boot/sys/boot/efi/libefi/env.c
@@ -28,6 +28,7 @@
 #include <stand.h>
 #include <string.h>
 #include <efi.h>
+#include <efichar.h>
 #include <efilib.h>
 #include <efigpt.h>	/* Partition GUIDS */
 #include <Guid/MemoryTypeInformation.h>
@@ -46,6 +47,7 @@ static struct efi_uuid_mapping {
 	EFI_GUID efi_guid;
 } efi_uuid_mapping[] = {
 	{ .efi_guid_name = "global", .efi_guid = EFI_GLOBAL_VARIABLE },
+	{ .efi_guid_name = "illumos", .efi_guid = ILLUMOS_BOOT_VAR_GUID },
 	/* EFI Systab entry names. */
 	{ .efi_guid_name = "MPS Table", .efi_guid = MPS_TABLE_GUID },
 	{ .efi_guid_name = "ACPI Table", .efi_guid = ACPI_TABLE_GUID },
@@ -102,12 +104,12 @@ static struct efi_uuid_mapping {
 	{ .efi_guid_name = "loaded image device path",
 	    .efi_guid = EFI_LOADED_IMAGE_DEVICE_PATH_PROTOCOL_GUID },
 	{ .efi_guid_name = "ISA io", .efi_guid = EFI_ISA_IO_PROTOCOL_GUID },
-        { .efi_guid_name = "IDE controller init",
+	{ .efi_guid_name = "IDE controller init",
 	    .efi_guid = EFI_IDE_CONTROLLER_INIT_PROTOCOL_GUID },
-        { .efi_guid_name = "ISA ACPI", .efi_guid = EFI_ISA_ACPI_PROTOCOL_GUID },
-        { .efi_guid_name = "PCI", .efi_guid = EFI_PCI_IO_PROTOCOL_GUID },
-        { .efi_guid_name = "PCI root", .efi_guid = EFI_PCI_ROOT_IO_GUID },
-        { .efi_guid_name = "PCI enumeration",
+	{ .efi_guid_name = "ISA ACPI", .efi_guid = EFI_ISA_ACPI_PROTOCOL_GUID },
+	{ .efi_guid_name = "PCI", .efi_guid = EFI_PCI_IO_PROTOCOL_GUID },
+	{ .efi_guid_name = "PCI root", .efi_guid = EFI_PCI_ROOT_IO_GUID },
+	{ .efi_guid_name = "PCI enumeration",
 	    .efi_guid = EFI_PCI_ENUMERATION_COMPLETE_GUID },
         { .efi_guid_name = "Driver diagnostics",
 	    .efi_guid = EFI_DRIVER_DIAGNOSTICS_PROTOCOL_GUID },
@@ -443,24 +445,43 @@ efi_print_mem_type(const CHAR16 *varnamearg, uint8_t *data, UINTN datasz)
 	return (CMD_OK);
 }
 
-/* Print global variables. */
+/*
+ * Print illumos variables.
+ * We have LoaderPath and LoaderDev as CHAR16 strings.
+ */
 static int
-efi_print_global(const CHAR16 *varnamearg, uint8_t *data, UINTN datasz)
+efi_print_illumos(const CHAR16 *varnamearg, uint8_t *data, UINTN datasz)
 {
-	int len;
 	int rv = -1;
-	char *var;
+	char *var = NULL;
+
+	if (ucs2_to_utf8(varnamearg, &var) != 0)
+		return (CMD_ERROR);
+
+	if (strcmp("LoaderPath", var) == 0 ||
+	    strcmp("LoaderDev", var) == 0) {
+		printf(" = ");
+		printf("%S", (CHAR16 *)data);
+
+		if (pager_output("\n"))
+			rv = CMD_WARN;
+		else
+			rv = CMD_OK;
+	}
 
-	for (len = 0; varnamearg[len] != 0; len++)
-		;
+	free(var);
+	return (rv);
+}
 
-	if (len == 0)
-		return (CMD_OK);
-	len++;
+/* Print global variables. */
+static int
+efi_print_global(const CHAR16 *varnamearg, uint8_t *data, UINTN datasz)
+{
+	int rv = -1;
+	char *var = NULL;
 
-	if ((var = malloc(len)) == NULL)
+	if (ucs2_to_utf8(varnamearg, &var) != 0)
 		return (CMD_ERROR);
-	cpy16to8(varnamearg, var, len);
 
 	if (strcmp("AuditMode", var) == 0) {
 		printf(" = ");
@@ -667,6 +688,8 @@ efi_print_var(CHAR16 *varnamearg, EFI_GUID *matchguid, int lflag)
 	if (lflag == 0) {
 		if (strcmp(str, "global") == 0)
 			rv = efi_print_global(varnamearg, data, datasz);
+		else if (strcmp(str, "illumos") == 0)
+			rv = efi_print_illumos(varnamearg, data, datasz);
 		else if (strcmp(str,
 		    EFI_MEMORY_TYPE_INFORMATION_VARIABLE_NAME) == 0)
 			rv = efi_print_mem_type(varnamearg, data, datasz);
diff --git a/usr/src/cmd/rcap/rcapd/Makefile b/usr/src/cmd/rcap/rcapd/Makefile
index 36d36882f98a..77f4d6812e78 100644
--- a/usr/src/cmd/rcap/rcapd/Makefile
+++ b/usr/src/cmd/rcap/rcapd/Makefile
@@ -19,45 +19,88 @@
 # CDDL HEADER END
 #
 #
-# Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
+# Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
 # Use is subject to license terms.
 #
 
-MANIFEST =	rcap.xml
+include ../../Makefile.cmd
+include ../../Makefile.cmd.64
 
-include		../../Makefile.cmd
+.KEEP_STATE:
+
+PROG				= rcapd
+ROOTUSRLIBRCAP			= $(ROOT)/usr/lib/rcap
+ROOTUSRLIBRCAPPROG		= $(ROOTUSRLIBRCAP)/$(PROG)
 
-ROOTMANIFESTDIR =	$(ROOTSVCSYSTEM)
+COMMON_DIR=	../common
 
+MANIFEST = rcap.xml
+ROOTMANIFESTDIR = $(ROOTSVCSYSTEM)
 $(ROOTSVCSYSTEM)/rcap.xml := FILEMODE = 0444
 
-.KEEP_STATE:
 
-SUBDIRS =		$(MACH)
-$(BUILD64)SUBDIRS +=	$(MACH64)
+SRCS =	rcapd_main.c \
+	rcapd_collection.c \
+	rcapd_collection_project.c \
+	rcapd_collection_zone.c \
+	rcapd_mapping.c \
+	rcapd_rfd.c \
+	rcapd_scanner.c \
+	rcapd_stat.c \
+	utils.c
+
+LINTSRCS = rcapd_main.c \
+	rcapd_collection.c \
+	rcapd_collection_project.c \
+	rcapd_collection_zone.c \
+	rcapd_mapping.c \
+	rcapd_rfd.c \
+	rcapd_scanner.c \
+	$(COMMON_DIR)/rcapd_stat.c \
+	$(COMMON_DIR)/utils.c
+
+$(NOT_RELEASE_BUILD)CPPFLAGS	+= -DDEBUG
+CPPFLAGS			+= -DDEBUG_MSG
+CPPFLAGS			+= -I$(COMMON_DIR)
+LDLIBS			+= -lkstat -lproc -lproject -lzonecfg -lumem -lscf
+LDLIBS			+= $(EXTRA_LDLIBS)
+
+LINTFLAGS64		+= -u
+
+OBJS =			$(SRCS:%.c=%.o) rcapd_conf.o
+
+POFILES =		$(OBJS:%.o=%.po)
+POFILE =		$(PROG).po
+
+CLOBBERFILES +=		$(POFILES) $(POFILE)
+
+include ../Makefile.com
+
+.NO_PARALLEL:
+.PARALLEL: $(OBJS)
 
-MSGSUBDIRS=		$(MACH)
+all: $(PROG)
 
-all := TARGET = all
-clean := TARGET = clean
-clobber := TARGET = clobber
-install := TARGET = install
-lint := TARGET = lint
-_msg := TARGET = _msg
+install: all $(ROOTUSRLIBRCAPPROG) $(ROOTUSRLIBRCAP) $(ROOTMANIFEST)
 
-include		Makefile.ins
+$(PROG): $(OBJS)
+	$(LINK.c) $(OBJS) -o $@ $(LDLIBS)
+	$(POST_PROCESS)
 
-all clean clobber lint: $(SUBDIRS)
+check: $(CHKMANIFEST)
 
-install:	all $(SUBDIRS) $(ROOTMANIFEST) $(ISAEXEC)
-	-$(RM) $(ROOTUSRLIBRCAPPROG)
-	$(LN) $(ISAEXEC) $(ROOTUSRLIBRCAPPROG)
+clean:
+	$(RM) $(OBJS)
+	$(RM) rcapd_conf.c
 
-check:		$(CHKMANIFEST)
+lint:
+	$(LINT.c) $(LINTSRCS) $(LDLIBS)
 
-_msg: $(MSGSUBDIRS)
+$(POFILE): $(POFILES)
+	$(RM) $@
+	$(CAT) $(POFILES) > $@
 
-$(SUBDIRS): FRC
-	@cd $@; pwd; VERSION='$(VERSION)' $(MAKE) $(TARGET)
+$(ROOTUSRLIBRCAP)/%: $(ROOTUSRLIBRCAP) %
+	$(INS.file)
 
-FRC:
+include ../../Makefile.targ
diff --git a/usr/src/cmd/rcap/rcapd/Makefile.ins b/usr/src/cmd/rcap/rcapd/Makefile.ins
deleted file mode 100644
index 97c85e98d8b0..000000000000
--- a/usr/src/cmd/rcap/rcapd/Makefile.ins
+++ /dev/null
@@ -1,34 +0,0 @@
-#
-# CDDL HEADER START
-#
-# The contents of this file are subject to the terms of the
-# Common Development and Distribution License (the "License").
-# You may not use this file except in compliance with the License.
-#
-# You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
-# or http://www.opensolaris.org/os/licensing.
-# See the License for the specific language governing permissions
-# and limitations under the License.
-#
-# When distributing Covered Code, include this CDDL HEADER in each
-# file and include the License file at usr/src/OPENSOLARIS.LICENSE.
-# If applicable, add the following below this CDDL HEADER, with the
-# fields enclosed by brackets "[]" replaced with your own identifying
-# information: Portions Copyright [yyyy] [name of copyright owner]
-#
-# CDDL HEADER END
-#
-#
-# Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
-# Use is subject to license terms.
-#
-# Copyright 2018 Toomas Soome <tsoome@me.com>
-#
-
-PROG				= rcapd
-ROOTUSRLIBRCAP			= $(ROOT)/usr/lib/rcap
-ROOTUSRLIBRCAP32		= $(ROOTUSRLIBRCAP)/$(MACH32)
-ROOTUSRLIBRCAP64		= $(ROOTUSRLIBRCAP)/$(MACH64)
-ROOTUSRLIBRCAPPROG		= $(ROOTUSRLIBRCAP)/$(PROG)
-ROOTUSRLIBRCAPPROG32		= $(ROOTUSRLIBRCAP32)/$(PROG)
-ROOTUSRLIBRCAPPROG64		= $(ROOTUSRLIBRCAP64)/$(PROG)
diff --git a/usr/src/cmd/rcap/rcapd/Makefile.rcapd b/usr/src/cmd/rcap/rcapd/Makefile.rcapd
deleted file mode 100644
index 975ff1388af4..000000000000
--- a/usr/src/cmd/rcap/rcapd/Makefile.rcapd
+++ /dev/null
@@ -1,106 +0,0 @@
-#
-# CDDL HEADER START
-#
-# The contents of this file are subject to the terms of the
-# Common Development and Distribution License (the "License").
-# You may not use this file except in compliance with the License.
-#
-# You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
-# or http://www.opensolaris.org/os/licensing.
-# See the License for the specific language governing permissions
-# and limitations under the License.
-#
-# When distributing Covered Code, include this CDDL HEADER in each
-# file and include the License file at usr/src/OPENSOLARIS.LICENSE.
-# If applicable, add the following below this CDDL HEADER, with the
-# fields enclosed by brackets "[]" replaced with your own identifying
-# information: Portions Copyright [yyyy] [name of copyright owner]
-#
-# CDDL HEADER END
-#
-#
-# Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
-# Use is subject to license terms.
-#
-
-.KEEP_STATE:
-.SUFFIXES:
-
-#
-# subdirs must define COMMON_DIR and include Makefile.com
-#
-
-# For PROG and ROOT* variables
-include	../Makefile.ins
-
-SRCS =	rcapd_main.c \
-	rcapd_collection.c \
-	rcapd_collection_project.c \
-	rcapd_collection_zone.c \
-	rcapd_mapping.c \
-	rcapd_rfd.c \
-	rcapd_scanner.c \
-	rcapd_stat.c \
-	utils.c
-
-LINTSRCS = ../rcapd_main.c \
-	../rcapd_collection.c \
-	../rcapd_collection_project.c \
-	../rcapd_collection_zone.c \
-	../rcapd_mapping.c \
-	../rcapd_rfd.c \
-	../rcapd_scanner.c \
-	$(COMMON_DIR)/rcapd_stat.c \
-	$(COMMON_DIR)/utils.c
-
-$(NOT_RELEASE_BUILD)CPPFLAGS	+= -DDEBUG
-CPPFLAGS			+= -DDEBUG_MSG
-CPPFLAGS			+= -I$(COMMON_DIR)
-LDLIBS				+= -lkstat -lproc -lproject -lzonecfg -lumem -lscf
-LDLIBS				+= $(EXTRA_LDLIBS)
-
-LINTFLAGS			+= -u
-LINTFLAGS64			+= -u
-
-OBJS =			$(SRCS:%.c=%.o) rcapd_conf.o
-
-POFILES =		$(OBJS:%.o=%.po)
-POFILE =		$(PROG).po
-
-CLOBBERFILES +=		$(POFILES) $(POFILE)
-
-.NO_PARALLEL:
-.PARALLEL: $(OBJS)
-
-all: $(PROG)
-
-$(PROG): $(OBJS)
-	$(LINK.c) $(OBJS) -o $@ $(LDLIBS)
-	$(POST_PROCESS)
-
-%.o: ../%.c
-	$(COMPILE.c) $<
-%.po: ../%.c
-	$(COMPILE.cpp) $< > $<.i
-	$(BUILD.po)
-
-
-clean:
-	$(RM) $(OBJS)
-	$(RM) rcapd_conf.c
-
-lint:
-	$(LINT.c) $(LINTSRCS) $(LDLIBS)
-
-$(POFILE): $(POFILES)
-	$(RM) $@
-	$(CAT) $(POFILES) > $@
-
-$(ROOTUSRLIBRCAP)/%: $(ROOTUSRLIBRCAP) %
-	$(INS.file)
-$(ROOTUSRLIBRCAP32)/%: $(ROOTUSRLIBRCAP32) %
-	$(INS.file)
-$(ROOTUSRLIBRCAP64)/%: $(ROOTUSRLIBRCAP64) %
-	$(INS.file)
-
-include ../../../Makefile.targ
diff --git a/usr/src/cmd/rcap/rcapd/amd64/Makefile b/usr/src/cmd/rcap/rcapd/amd64/Makefile
deleted file mode 100644
index 217cce4e2503..000000000000
--- a/usr/src/cmd/rcap/rcapd/amd64/Makefile
+++ /dev/null
@@ -1,33 +0,0 @@
-#
-# CDDL HEADER START
-#
-# The contents of this file are subject to the terms of the
-# Common Development and Distribution License, Version 1.0 only
-# (the "License").  You may not use this file except in compliance
-# with the License.
-#
-# You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
-# or http://www.opensolaris.org/os/licensing.
-# See the License for the specific language governing permissions
-# and limitations under the License.
-#
-# When distributing Covered Code, include this CDDL HEADER in each
-# file and include the License file at usr/src/OPENSOLARIS.LICENSE.
-# If applicable, add the following below this CDDL HEADER, with the
-# fields enclosed by brackets "[]" replaced with your own identifying
-# information: Portions Copyright [yyyy] [name of copyright owner]
-#
-# CDDL HEADER END
-#
-#
-# Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
-# Use is subject to license terms.
-#
-
-include ../../../Makefile.cmd
-include ../../../Makefile.cmd.64
-COMMON_DIR=	../../common	# for Makefile.com
-include ../Makefile.rcapd
-include ../../Makefile.com
-
-install: all $(ROOTUSRLIBRCAPPROG64) $(ROOTUSRLIBRCAP)
diff --git a/usr/src/cmd/rcap/rcapd/i386/Makefile b/usr/src/cmd/rcap/rcapd/i386/Makefile
deleted file mode 100644
index 1cb37d65f8db..000000000000
--- a/usr/src/cmd/rcap/rcapd/i386/Makefile
+++ /dev/null
@@ -1,32 +0,0 @@
-#
-# CDDL HEADER START
-#
-# The contents of this file are subject to the terms of the
-# Common Development and Distribution License, Version 1.0 only
-# (the "License").  You may not use this file except in compliance
-# with the License.
-#
-# You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
-# or http://www.opensolaris.org/os/licensing.
-# See the License for the specific language governing permissions
-# and limitations under the License.
-#
-# When distributing Covered Code, include this CDDL HEADER in each
-# file and include the License file at usr/src/OPENSOLARIS.LICENSE.
-# If applicable, add the following below this CDDL HEADER, with the
-# fields enclosed by brackets "[]" replaced with your own identifying
-# information: Portions Copyright [yyyy] [name of copyright owner]
-#
-# CDDL HEADER END
-#
-#
-# Copyright 2003 Sun Microsystems, Inc.  All rights reserved.
-# Use is subject to license terms.
-#
-
-include ../../../Makefile.cmd
-COMMON_DIR=	../../common	# for Makefile.com
-include ../Makefile.rcapd
-include ../../Makefile.com
-
-install: all $(ROOTUSRLIBRCAPPROG32) $(ROOTUSRLIBRCAP)
diff --git a/usr/src/cmd/rcap/rcapd/sparc/Makefile b/usr/src/cmd/rcap/rcapd/sparc/Makefile
deleted file mode 100644
index 1cb37d65f8db..000000000000
--- a/usr/src/cmd/rcap/rcapd/sparc/Makefile
+++ /dev/null
@@ -1,32 +0,0 @@
-#
-# CDDL HEADER START
-#
-# The contents of this file are subject to the terms of the
-# Common Development and Distribution License, Version 1.0 only
-# (the "License").  You may not use this file except in compliance
-# with the License.
-#
-# You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
-# or http://www.opensolaris.org/os/licensing.
-# See the License for the specific language governing permissions
-# and limitations under the License.
-#
-# When distributing Covered Code, include this CDDL HEADER in each
-# file and include the License file at usr/src/OPENSOLARIS.LICENSE.
-# If applicable, add the following below this CDDL HEADER, with the
-# fields enclosed by brackets "[]" replaced with your own identifying
-# information: Portions Copyright [yyyy] [name of copyright owner]
-#
-# CDDL HEADER END
-#
-#
-# Copyright 2003 Sun Microsystems, Inc.  All rights reserved.
-# Use is subject to license terms.
-#
-
-include ../../../Makefile.cmd
-COMMON_DIR=	../../common	# for Makefile.com
-include ../Makefile.rcapd
-include ../../Makefile.com
-
-install: all $(ROOTUSRLIBRCAPPROG32) $(ROOTUSRLIBRCAP)
diff --git a/usr/src/cmd/rcap/rcapd/sparcv9/Makefile b/usr/src/cmd/rcap/rcapd/sparcv9/Makefile
deleted file mode 100644
index aedc9bb79389..000000000000
--- a/usr/src/cmd/rcap/rcapd/sparcv9/Makefile
+++ /dev/null
@@ -1,33 +0,0 @@
-#
-# CDDL HEADER START
-#
-# The contents of this file are subject to the terms of the
-# Common Development and Distribution License, Version 1.0 only
-# (the "License").  You may not use this file except in compliance
-# with the License.
-#
-# You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
-# or http://www.opensolaris.org/os/licensing.
-# See the License for the specific language governing permissions
-# and limitations under the License.
-#
-# When distributing Covered Code, include this CDDL HEADER in each
-# file and include the License file at usr/src/OPENSOLARIS.LICENSE.
-# If applicable, add the following below this CDDL HEADER, with the
-# fields enclosed by brackets "[]" replaced with your own identifying
-# information: Portions Copyright [yyyy] [name of copyright owner]
-#
-# CDDL HEADER END
-#
-#
-# Copyright 2003 Sun Microsystems, Inc.  All rights reserved.
-# Use is subject to license terms.
-#
-
-include ../../../Makefile.cmd
-include ../../../Makefile.cmd.64
-COMMON_DIR=	../../common	# for Makefile.com
-include ../Makefile.rcapd
-include ../../Makefile.com
-
-install: all $(ROOTUSRLIBRCAPPROG64) $(ROOTUSRLIBRCAP)
diff --git a/usr/src/lib/fm/topo/libtopo/common/topo_hc.h b/usr/src/lib/fm/topo/libtopo/common/topo_hc.h
index 81492fad3fbd..8d4a4dd2a4cb 100644
--- a/usr/src/lib/fm/topo/libtopo/common/topo_hc.h
+++ b/usr/src/lib/fm/topo/libtopo/common/topo_hc.h
@@ -21,7 +21,7 @@
 
 /*
  * Copyright (c) 2006, 2010, Oracle and/or its affiliates. All rights reserved.
- * Copyright (c) 2017, Joyent, Inc.
+ * Copyright (c) 2018, Joyent, Inc.
  */
 
 #ifndef _TOPO_HC_H
@@ -101,6 +101,7 @@ extern "C" {
 #define	TOPO_PGROUP_IO		"io"
 #define	TOPO_IO_DEVTYPE		"devtype"
 #define	TOPO_IO_DRIVER		"driver"
+#define	TOPO_IO_INSTANCE	"instance"
 #define	TOPO_IO_MODULE		"module"
 #define	TOPO_IO_DEV		"dev"
 #define	TOPO_IO_DEVID		"devid"
diff --git a/usr/src/lib/fm/topo/modules/common/pcibus/did_props.c b/usr/src/lib/fm/topo/modules/common/pcibus/did_props.c
index 6d900c298981..e216dec9d1b9 100644
--- a/usr/src/lib/fm/topo/modules/common/pcibus/did_props.c
+++ b/usr/src/lib/fm/topo/modules/common/pcibus/did_props.c
@@ -54,6 +54,8 @@ static int DEVprop_set(tnode_t *, did_t *,
     const char *, const char *, const char *);
 static int DRIVERprop_set(tnode_t *, did_t *,
     const char *, const char *, const char *);
+static int INSTprop_set(tnode_t *, did_t *,
+    const char *, const char *, const char *);
 static int MODULEprop_set(tnode_t *, did_t *,
     const char *, const char *, const char *);
 static int EXCAP_set(tnode_t *, did_t *,
@@ -101,6 +103,7 @@ txprop_t Fn_common_props[] = {
 	{ DI_DEVTYPPROP, &io_pgroup, TOPO_IO_DEVTYPE, maybe_di_chars_copy },
 	{ DI_DEVIDPROP, &pci_pgroup, TOPO_PCI_DEVID, maybe_di_uint_to_str },
 	{ NULL, &io_pgroup, TOPO_IO_DRIVER, DRIVERprop_set },
+	{ NULL, &io_pgroup, TOPO_IO_INSTANCE, INSTprop_set },
 	{ NULL, &io_pgroup, TOPO_IO_MODULE, MODULEprop_set },
 	{ "serd_io_device_nonfatal_n", &io_pgroup, "serd_io_device_nonfatal_n",
 	    maybe_di_uint_to_dec_str },
@@ -172,6 +175,7 @@ txprop_t Dev_common_props[] = {
 txprop_t Bus_common_props[] = {
 	{ DI_DEVTYPPROP, &io_pgroup, TOPO_IO_DEVTYPE, maybe_di_chars_copy },
 	{ NULL, &io_pgroup, TOPO_IO_DRIVER, DRIVERprop_set },
+	{ NULL, &io_pgroup, TOPO_IO_INSTANCE, INSTprop_set },
 	{ NULL, &io_pgroup, TOPO_IO_MODULE, MODULEprop_set },
 	{ NULL, &protocol_pgroup, TOPO_PROP_LABEL, label_set },
 	{ NULL, &protocol_pgroup, TOPO_PROP_FRU, FRU_set },
@@ -182,6 +186,7 @@ txprop_t RC_common_props[] = {
 	{ NULL, &io_pgroup, TOPO_IO_DEV, DEVprop_set },
 	{ DI_DEVTYPPROP, &io_pgroup, TOPO_IO_DEVTYPE, maybe_di_chars_copy },
 	{ NULL, &io_pgroup, TOPO_IO_DRIVER, DRIVERprop_set },
+	{ NULL, &io_pgroup, TOPO_IO_INSTANCE, INSTprop_set },
 	{ NULL, &io_pgroup, TOPO_IO_MODULE, MODULEprop_set },
 	{ NULL, &pci_pgroup, TOPO_PCI_EXCAP, EXCAP_set },
 	{ NULL, &pci_pgroup, TOPO_PCI_BDF, BDF_set },
@@ -213,6 +218,7 @@ txprop_t IOB_common_props[] = {
 txprop_t HB_common_props[] = {
 	{ NULL, &io_pgroup, TOPO_IO_DEV, DEVprop_set },
 	{ NULL, &io_pgroup, TOPO_IO_DRIVER, DRIVERprop_set },
+	{ NULL, &io_pgroup, TOPO_IO_INSTANCE, INSTprop_set },
 	{ NULL, &io_pgroup, TOPO_IO_MODULE, MODULEprop_set },
 	{ NULL, &protocol_pgroup, TOPO_PROP_ASRU, ASRU_set },
 	/*
@@ -776,6 +782,22 @@ DRIVERprop_set(tnode_t *tn, did_t *pd,
 	return (0);
 }
 
+/*ARGSUSED*/
+static int
+INSTprop_set(tnode_t *tn, did_t *pd,
+    const char *dpnm, const char *tpgrp, const char *tpnm)
+{
+	int inst, err;
+
+	if ((inst = di_instance(did_dinode(pd))) == -1)
+		return (0);
+	if (topo_prop_set_uint32(tn,
+	    tpgrp, tpnm, TOPO_PROP_IMMUTABLE, inst, &err) < 0)
+		return (topo_mod_seterrno(did_mod(pd), err));
+
+	return (0);
+}
+
 /*ARGSUSED*/
 static int
 MODULEprop_set(tnode_t *tn, did_t *pd,
diff --git a/usr/src/pkg/manifests/service-resource-cap.mf b/usr/src/pkg/manifests/service-resource-cap.mf
index 49302f476e91..24e7396a7890 100644
--- a/usr/src/pkg/manifests/service-resource-cap.mf
+++ b/usr/src/pkg/manifests/service-resource-cap.mf
@@ -43,13 +43,11 @@ dir path=usr/share/man/man1
 dir path=usr/share/man/man1m
 file path=lib/svc/manifest/system/rcap.xml group=sys mode=0444
 file path=usr/bin/rcapstat mode=0555
-file path=usr/lib/rcap/$(ARCH32)/rcapd mode=0555
-file path=usr/lib/rcap/$(ARCH64)/rcapd mode=0555
+file path=usr/lib/rcap/rcapd mode=0555
 file path=usr/sbin/rcapadm mode=0555
 file path=usr/share/man/man1/rcapstat.1
 file path=usr/share/man/man1m/rcapadm.1m
 file path=usr/share/man/man1m/rcapd.1m
-hardlink path=usr/lib/rcap/rcapd target=../isaexec
 legacy pkg=SUNWrcapr desc="Solaris Resource Capping Daemon (Root)" \
     name="Solaris Resource Capping Daemon (Root)"
 legacy pkg=SUNWrcapu desc="Solaris Resource Capping Daemon (Usr)" \
diff --git a/usr/src/tools/ctf/cvt/ctfmerge.c b/usr/src/tools/ctf/cvt/ctfmerge.c
index 5706cceb1778..1d6d751d9957 100644
--- a/usr/src/tools/ctf/cvt/ctfmerge.c
+++ b/usr/src/tools/ctf/cvt/ctfmerge.c
@@ -504,9 +504,11 @@ worker_runphase2(workqueue_t *wq)
 /*
  * Main loop for worker threads.
  */
-static void
-worker_thread(workqueue_t *wq)
+static void *
+worker_thread(void *ptr)
 {
+	workqueue_t *wq = ptr;
+
 	worker_runphase1(wq);
 
 	debug(2, "%d: entering first barrier\n", pthread_self());
@@ -530,6 +532,7 @@ worker_thread(workqueue_t *wq)
 	debug(2, "%d: phase 1 complete\n", pthread_self());
 
 	worker_runphase2(wq);
+	return (NULL);
 }
 
 /*
@@ -692,7 +695,7 @@ start_threads(workqueue_t *wq)
 
 	for (i = 0; i < wq->wq_nthreads; i++) {
 		pthread_create(&wq->wq_thread[i], NULL,
-		    (void *(*)(void *))worker_thread, wq);
+		    worker_thread, wq);
 	}
 
 	sigset(SIGINT, handle_sig);
diff --git a/usr/src/tools/ctf/cvt/ctftools.h b/usr/src/tools/ctf/cvt/ctftools.h
index 708dfd82efd9..79746cba521c 100644
--- a/usr/src/tools/ctf/cvt/ctftools.h
+++ b/usr/src/tools/ctf/cvt/ctftools.h
@@ -58,11 +58,11 @@ extern "C" {
 #endif
 
 #ifndef MAX
-#define	MAX(a, b) 		((a) < (b) ? (b) : (a))
+#define	MAX(a, b)		((a) < (b) ? (b) : (a))
 #endif
 
 #ifndef MIN
-#define	MIN(a, b) 		((a) > (b) ? (b) : (a))
+#define	MIN(a, b)		((a) > (b) ? (b) : (a))
 #endif
 
 #define	TRUE	1
@@ -271,13 +271,13 @@ typedef enum iitype {
 typedef struct iidesc {
 	iitype_t	ii_type;
 	char		*ii_name;
-	tdesc_t 	*ii_dtype;
+	tdesc_t		*ii_dtype;
 	char		*ii_owner;	/* File that defined this node */
 	int		ii_flags;
 
 	/* Function arguments (if any) */
 	int		ii_nargs;
-	tdesc_t 	**ii_args;
+	tdesc_t		**ii_args;
 	int		ii_vargs;	/* Function uses varargs */
 } iidesc_t;
 
@@ -358,14 +358,15 @@ void iter_iidescs_by_name(tdata_t *, const char *,
 iidesc_t *iidesc_dup(iidesc_t *);
 iidesc_t *iidesc_dup_rename(iidesc_t *, char const *, char const *);
 void iidesc_add(hash_t *, iidesc_t *);
-void iidesc_free(iidesc_t *, void *);
+void iidesc_free(iidesc_t *);
+void iidesc_free_cb(void *, void *);
 int iidesc_count_type(void *, void *);
 void iidesc_stats(hash_t *);
 int iidesc_dump(iidesc_t *);
 
 /* input.c */
 typedef enum source_types {
-	SOURCE_NONE 	= 0,
+	SOURCE_NONE	= 0,
 	SOURCE_UNKNOWN	= 1,
 	SOURCE_C	= 2,
 	SOURCE_S	= 4
diff --git a/usr/src/tools/ctf/cvt/iidesc.c b/usr/src/tools/ctf/cvt/iidesc.c
index b6b9a0c7f235..0d75e3f852d0 100644
--- a/usr/src/tools/ctf/cvt/iidesc.c
+++ b/usr/src/tools/ctf/cvt/iidesc.c
@@ -23,8 +23,6 @@
  * Use is subject to license terms.
  */
 
-#pragma ident	"%Z%%M%	%I%	%E% SMI"
-
 /*
  * Routines for manipulating iidesc_t structures
  */
@@ -99,7 +97,7 @@ iidesc_add(hash_t *hash, iidesc_t *new)
 		bcopy(new, old, sizeof (*old));
 		bcopy(&tmp, new, sizeof (*new));
 
-		iidesc_free(new, NULL);
+		iidesc_free(new);
 		return;
 	}
 
@@ -151,17 +149,22 @@ iidesc_dup_rename(iidesc_t *src, char const *name, char const *owner)
 
 /*ARGSUSED*/
 void
-iidesc_free(iidesc_t *idp, void *private)
+iidesc_free_cb(void *ptr, void *private)
 {
-	if (idp->ii_name)
-		free(idp->ii_name);
-	if (idp->ii_nargs)
-		free(idp->ii_args);
-	if (idp->ii_owner)
-		free(idp->ii_owner);
+	iidesc_t *idp = ptr;
+
+	free(idp->ii_name);
+	free(idp->ii_args);
+	free(idp->ii_owner);
 	free(idp);
 }
 
+void
+iidesc_free(iidesc_t *idp)
+{
+	iidesc_free_cb(idp, NULL);
+}
+
 int
 iidesc_dump(iidesc_t *ii)
 {
diff --git a/usr/src/tools/ctf/cvt/st_parse.c b/usr/src/tools/ctf/cvt/st_parse.c
index 1530734a48c7..03facfd5cb0d 100644
--- a/usr/src/tools/ctf/cvt/st_parse.c
+++ b/usr/src/tools/ctf/cvt/st_parse.c
@@ -448,7 +448,7 @@ parse_stab(stab_t *stab, char *cp, iidesc_t **iidescp)
 	bzero(&resetbuf, sizeof (resetbuf));
 
 	if (rc < 0 || ii->ii_type == II_NOT) {
-		iidesc_free(ii, NULL);
+		iidesc_free(ii);
 		return (rc);
 	}
 
diff --git a/usr/src/tools/ctf/cvt/stabs.c b/usr/src/tools/ctf/cvt/stabs.c
index f7b3034c6406..53b456585992 100644
--- a/usr/src/tools/ctf/cvt/stabs.c
+++ b/usr/src/tools/ctf/cvt/stabs.c
@@ -23,8 +23,6 @@
  * Use is subject to license terms.
  */
 
-#pragma ident	"%Z%%M%	%I%	%E% SMI"
-
 /*
  * Routines used to read stabs data from a file, and to build a tdata structure
  * based on the interesting parts of that data.
@@ -331,7 +329,7 @@ stabs_read(tdata_t *td, Elf *elf, const char *file)
 		 */
 		if (scope && stab->n_type != N_PSYM) {
 			if (iidescp)
-				iidesc_free(iidescp, NULL);
+				iidesc_free(iidescp);
 			goto parse_loop_end;
 		}
 
@@ -356,7 +354,7 @@ stabs_read(tdata_t *td, Elf *elf, const char *file)
 
 		case II_PSYM:
 			fnarg_add(curfun, iidescp);
-			iidesc_free(iidescp, NULL);
+			iidesc_free(iidescp);
 			break;
 		default:
 			aborterr("invalid ii_type %d for stab type %d",
diff --git a/usr/src/tools/ctf/cvt/tdata.c b/usr/src/tools/ctf/cvt/tdata.c
index 295928586e13..ca71168bcfcd 100644
--- a/usr/src/tools/ctf/cvt/tdata.c
+++ b/usr/src/tools/ctf/cvt/tdata.c
@@ -246,22 +246,22 @@ static void (*free_cbs[])(tdesc_t *) = {
 };
 
 /*ARGSUSED1*/
-static int
-tdesc_free_cb(tdesc_t *tdp, void *private)
+static void
+tdesc_free_cb(void *ptr, void *private)
 {
+	tdesc_t *tdp = ptr;
+
 	if (tdp->t_name)
 		free(tdp->t_name);
 	if (free_cbs[tdp->t_type])
 		free_cbs[tdp->t_type](tdp);
 	free(tdp);
-
-	return (1);
 }
 
 void
 tdesc_free(tdesc_t *tdp)
 {
-	(void) tdesc_free_cb(tdp, NULL);
+	tdesc_free_cb(tdp, NULL);
 }
 
 static int
@@ -390,8 +390,8 @@ tdata_new(void)
 void
 tdata_free(tdata_t *td)
 {
-	hash_free(td->td_iihash, (void (*)())iidesc_free, NULL);
-	hash_free(td->td_layouthash, (void (*)())tdesc_free_cb, NULL);
+	hash_free(td->td_iihash, iidesc_free_cb, NULL);
+	hash_free(td->td_layouthash, tdesc_free_cb, NULL);
 	hash_free(td->td_idhash, NULL, NULL);
 	list_free(td->td_fwdlist, NULL, NULL);
 
diff --git a/usr/src/uts/common/io/ldterm.c b/usr/src/uts/common/io/ldterm.c
index 6c396db60164..1af97c86ea7f 100644
--- a/usr/src/uts/common/io/ldterm.c
+++ b/usr/src/uts/common/io/ldterm.c
@@ -22,6 +22,7 @@
  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
  * Use is subject to license terms.
  * Copyright (c) 2014, Joyent, Inc.  All rights reserved.
+ * Copyright 2018 OmniOS Community Edition (OmniOSce) Association.
  */
 
 /* Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T	*/
@@ -381,7 +382,7 @@ static struct streamtab ldtrinfo;
 static struct fmodsw fsw = {
 	"ldterm",
 	&ldtrinfo,
-	D_MTQPAIR | D_MP
+	D_MTQPAIR | D_MP | _D_SINGLE_INSTANCE
 };
 
 static struct modlstrmod modlstrmod = {
diff --git a/usr/src/uts/common/io/ptem.c b/usr/src/uts/common/io/ptem.c
index 481169daf3dc..e4dc15a3ac4f 100644
--- a/usr/src/uts/common/io/ptem.c
+++ b/usr/src/uts/common/io/ptem.c
@@ -26,6 +26,7 @@
 /*
  * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
  * Use is subject to license terms.
+ * Copyright 2018 OmniOS Community Edition (OmniOSce) Association.
  */
 
 /*
@@ -62,7 +63,7 @@ extern struct streamtab pteminfo;
 static struct fmodsw fsw = {
 	"ptem",
 	&pteminfo,
-	D_MTQPAIR | D_MP
+	D_MTQPAIR | D_MP | _D_SINGLE_INSTANCE
 };
 
 static struct modlstrmod modlstrmod = {
diff --git a/usr/src/uts/common/io/ttcompat.c b/usr/src/uts/common/io/ttcompat.c
index ab420c82e7e4..22b1442e50fa 100644
--- a/usr/src/uts/common/io/ttcompat.c
+++ b/usr/src/uts/common/io/ttcompat.c
@@ -21,6 +21,7 @@
 /*
  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
  * Use is subject to license terms.
+ * Copyright 2018 OmniOS Community Edition (OmniOSce) Association.
  */
 
 /*	Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T	*/
@@ -73,7 +74,7 @@ static struct streamtab ttcoinfo;
 static struct fmodsw fsw = {
 	"ttcompat",
 	&ttcoinfo,
-	D_MTQPAIR | D_MP
+	D_MTQPAIR | D_MP | _D_SINGLE_INSTANCE
 };
 
 /*
diff --git a/usr/src/uts/common/io/usb/clients/hid/hid.c b/usr/src/uts/common/io/usb/clients/hid/hid.c
index 249941d03c98..084fa7fedc4b 100644
--- a/usr/src/uts/common/io/usb/clients/hid/hid.c
+++ b/usr/src/uts/common/io/usb/clients/hid/hid.c
@@ -434,6 +434,7 @@ hid_attach(dev_info_t *dip, ddi_attach_cmd_t cmd)
 	mutex_enter(&hidp->hid_mutex);
 	if (usb_ep_xdescr_fill(USB_EP_XDESCR_CURRENT_VERSION, dip, ep_data,
 	    &hidp->hid_ep_intr_xdescr) != USB_SUCCESS) {
+		mutex_exit(&hidp->hid_mutex);
 
 		goto fail;
 	}
@@ -1072,11 +1073,11 @@ hid_wput(queue_t *q, mblk_t *mp)
 {
 	hid_state_t	*hidp = (hid_state_t *)q->q_ptr;
 	int		error = USB_SUCCESS;
-	struct iocblk 	*iocbp;
+	struct iocblk	*iocbp;
 	mblk_t		*datap;
 	int		direction;
 	struct copyresp *crp;
-	queue_t 	*tmpq;
+	queue_t		*tmpq;
 	int		flag;
 
 	USB_DPRINTF_L4(PRINT_MASK_ALL, hidp->hid_log_handle,
@@ -2576,7 +2577,7 @@ hid_send_async_ctrl_request(hid_default_pipe_arg_t *hid_default_pipe_arg,
 	}
 
 	ctrl_req->ctrl_bmRequestType	= request_type;
-	ctrl_req->ctrl_bRequest 	= (uint8_t)request_request;
+	ctrl_req->ctrl_bRequest		= (uint8_t)request_request;
 	ctrl_req->ctrl_wValue		= hid_request->hid_req_wValue;
 	ctrl_req->ctrl_wIndex		= request_index;
 	ctrl_req->ctrl_wLength		= hid_request->hid_req_wLength;
diff --git a/usr/src/uts/common/os/streamio.c b/usr/src/uts/common/os/streamio.c
index 62569eefed63..509a3cfd40c0 100644
--- a/usr/src/uts/common/os/streamio.c
+++ b/usr/src/uts/common/os/streamio.c
@@ -25,6 +25,7 @@
 /*
  * Copyright (c) 1988, 2010, Oracle and/or its affiliates. All rights reserved.
  * Copyright 2017 Joyent, Inc.
+ * Copyright 2018 OmniOS Community Edition (OmniOSce) Association.
  */
 
 #include <sys/types.h>
@@ -3783,6 +3784,30 @@ strioctl(struct vnode *vp, int cmd, intptr_t arg, int flag, int copyflag,
 		TRACE_2(TR_FAC_STREAMS_FR, TR_I_PUSH,
 		    "I_PUSH:fp %p stp %p", fp, stp);
 
+		/*
+		 * If the module is flagged as single-instance, then check
+		 * to see if the module is already pushed. If it is, return
+		 * as if the push was successful.
+		 */
+		if (fp->f_qflag & _QSINGLE_INSTANCE) {
+			queue_t *q;
+
+			claimstr(stp->sd_wrq);
+			for (q = stp->sd_wrq->q_next; q; q = q->q_next) {
+				if (q->q_flag & QREADR) {
+					q = NULL;
+					break;
+				}
+				if (strcmp(mname, Q2NAME(q)) == 0)
+					break;
+			}
+			releasestr(stp->sd_wrq);
+			if (q != NULL) {
+				fmodsw_rele(fp);
+				return (0);
+			}
+		}
+
 		if (error = strstartplumb(stp, flag, cmd)) {
 			fmodsw_rele(fp);
 			return (error);
diff --git a/usr/src/uts/common/os/strsubr.c b/usr/src/uts/common/os/strsubr.c
index 87e0c5511d85..8cc27df4ebf1 100644
--- a/usr/src/uts/common/os/strsubr.c
+++ b/usr/src/uts/common/os/strsubr.c
@@ -26,6 +26,7 @@
  * Copyright 2010 Sun Microsystems, Inc.  All rights reserved.
  * Use is subject to license terms.
  * Copyright (c) 2016 by Delphix. All rights reserved.
+ * Copyright 2018 OmniOS Community Edition (OmniOSce) Association.
  */
 
 #include <sys/types.h>
@@ -950,7 +951,7 @@ str_sendsig(vnode_t *vp, int event, uchar_t band, int error)
  */
 static void
 dosendsig(proc_t *proc, int events, int sevent, k_siginfo_t *info,
-	uchar_t band, int error)
+    uchar_t band, int error)
 {
 	ASSERT(MUTEX_HELD(&proc->p_lock));
 
@@ -2350,7 +2351,7 @@ mux_rmvedge(stdata_t *upstp, int muxid, str_stack_t *ss)
  */
 int
 devflg_to_qflag(struct streamtab *stp, uint32_t devflag, uint32_t *qflagp,
-	uint32_t *sqtypep)
+    uint32_t *sqtypep)
 {
 	uint32_t qflag = 0;
 	uint32_t sqtype = 0;
@@ -2464,6 +2465,17 @@ devflg_to_qflag(struct streamtab *stp, uint32_t devflag, uint32_t *qflagp,
 		qflag |= _QDIRECT;
 	}
 
+	/*
+	 * Private flag used to indicate that a streams module should only
+	 * be pushed once. The TTY streams modules have this flag since if
+	 * libc believes itself to be an xpg4 process then it will
+	 * automatically and unconditionally push them when a PTS device is
+	 * opened. If an application is not aware of this then without this
+	 * flag we would end up with duplicate modules.
+	 */
+	if (devflag & _D_SINGLE_INSTANCE)
+		qflag |= _QSINGLE_INSTANCE;
+
 	*qflagp = qflag;
 	*sqtypep = sqtype;
 	return (0);
@@ -8087,7 +8099,7 @@ strflushrq(vnode_t *vp, int flag)
 
 void
 strsetrputhooks(vnode_t *vp, uint_t flags,
-		msgfunc_t protofunc, msgfunc_t miscfunc)
+    msgfunc_t protofunc, msgfunc_t miscfunc)
 {
 	struct stdata *stp = vp->v_stream;
 
diff --git a/usr/src/uts/common/sys/conf.h b/usr/src/uts/common/sys/conf.h
index 7447db408f37..4bf3d5c7e30f 100644
--- a/usr/src/uts/common/sys/conf.h
+++ b/usr/src/uts/common/sys/conf.h
@@ -24,6 +24,7 @@
 /*
  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
  * Use is subject to license terms.
+ * Copyright 2018 OmniOS Community Edition (OmniOSce) Association.
  */
 
 #ifndef _SYS_CONF_H
@@ -221,6 +222,8 @@ extern int cdev_prop_op(dev_t, dev_info_t *, ddi_prop_op_t,
 
 #define	D_OPEN_RETURNS_EINTR	0x100000 /* EINTR expected from open(9E) */
 
+#define	_D_SINGLE_INSTANCE	0x200000 /* Module may only be pushed once */
+
 #endif /* !defined(_XPG4_2) || defined(__EXTENSIONS__) */
 
 #ifdef	__cplusplus
diff --git a/usr/src/uts/common/sys/stream.h b/usr/src/uts/common/sys/stream.h
index 4114e5b13e52..7a2f3c9305bc 100644
--- a/usr/src/uts/common/sys/stream.h
+++ b/usr/src/uts/common/sys/stream.h
@@ -21,6 +21,7 @@
 /*
  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
  * Use is subject to license terms.
+ * Copyright 2018 OmniOS Community Edition (OmniOSce) Association.
  */
 
 /*	Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T	*/
@@ -189,6 +190,8 @@ typedef struct queue {
 #define	_QASSOCIATED	0x10000000	/* queue is associated with a device */
 #define	_QDIRECT	0x20000000	/* Private; transport module uses */
 					/* direct interface to/from sockfs */
+#define	_QSINGLE_INSTANCE	0x40000000	/* Private; module may only */
+						/* be pushed once */
 
 /* queue sqflags (protected by SQLOCK). */
 #define	Q_SQQUEUED	0x01		/* Queue is in the syncq list */