Index: include/stddef.h
===================================================================
--- include/stddef.h
+++ include/stddef.h
@@ -72,7 +72,9 @@
 #endif
 #endif
 
+#ifndef offsetof
 #define	offsetof(type, field)	__offsetof(type, field)
+#endif /* offsetof */
 
 #if __EXT1_VISIBLE
 /* ISO/IEC 9899:2011 K.3.3.2 */
Index: stand/defs.mk
===================================================================
--- stand/defs.mk
+++ stand/defs.mk
@@ -55,6 +55,7 @@
 
 # Standard options:
 CFLAGS+=	-nostdinc
+CFLAGS+=	${CFLAGS_EARLY.${.IMPSRC:T}} ${CFLAGS_EARLY.${.TARGET:T}}
 .if ${MACHINE_ARCH} == "amd64" && ${DO32:U0} == 1
 CFLAGS+=	-I${BOOTOBJ}/libsa32
 .else
Index: stand/libsa/zfs/Makefile.inc
===================================================================
--- stand/libsa/zfs/Makefile.inc
+++ stand/libsa/zfs/Makefile.inc
@@ -1,15 +1,31 @@
 # $FreeBSD$
 
 .PATH:		${ZFSSRC}
-SRCS+=		zfs.c nvlist.c skein.c skein_block.c list.c
+SRCS+=		zfs.c nvlist.c skein.c skein_block.c list.c zstd_shim.c zstd.c
 .PATH:		${SYSDIR}/crypto/skein
-.PATH:		${SYSDIR}/cddl/contrib/opensolaris/uts/common/os
+.PATH:		${SYSDIR}/contrib/openzfs/module/os/freebsd/spl
+.PATH:		${SYSDIR}/contrib/openzfs/module/zstd/lib
 
 CFLAGS+=	-I${LDRSRC}
 CFLAGS+=	-I${SYSDIR}/cddl/boot/zfs
-CFLAGS+=	-I${SYSDIR}/cddl/contrib/opensolaris/uts/common
 CFLAGS+=	-I${SYSDIR}/crypto/skein
 
+ZFS_EARLY=	-I${SRCTOP}/sys/contrib/openzfs/include/os/freebsd	\
+		-I${SRCTOP}/sys/contrib/openzfs/include/os/freebsd/spl \
+		-I${SRCTOP}/sys/contrib/openzfs/include/os/freebsd/zfs
+
+CFLAGS_EARLY.list.c+=	${ZFS_EARLY}
+CFLAGS_EARLY.zstd_shim.c+= ${ZFS_EARLY}
+
+# Can't use the early flags because there's two conflicting definitions of boolean_t in
+# the zfs code that need to be unified.
+CFLAGS.nvlist.c+= -I${SRCTOP}/sys/contrib/openzfs/include/os/freebsd/spl
+CFLAGS.zfs.c+=	-I${SRCTOP}/sys/contrib/openzfs/include/os/freebsd/spl
+
+
+CFLAGS.zstd_shim.c+= -DIN_BASE \
+		 -I${SRCTOP}/sys/contrib/openzfs/include \
+
 # Do not unroll skein loops, reduce code size
 CFLAGS.skein_block.c+=	-DSKEIN_LOOP=111
 CFLAGS.zfs.c+=	-I${SRCTOP}/sys/cddl/contrib/opensolaris/common/lz4
Index: stand/libsa/zfs/zfsimpl.c
===================================================================
--- stand/libsa/zfs/zfsimpl.c
+++ stand/libsa/zfs/zfsimpl.c
@@ -40,6 +40,7 @@
 #include "zfsimpl.h"
 #include "zfssubr.c"
 
+extern int zstd_init(void);
 
 struct zfsmount {
 	const spa_t	*spa;
@@ -110,6 +111,7 @@
  */
 static const char *features_for_read[] = {
 	"org.illumos:lz4_compress",
+	"org.freebsd:zstd_compress",
 	"com.delphix:hole_birth",
 	"com.delphix:extensible_dataset",
 	"com.delphix:embedded_data",
@@ -169,6 +171,7 @@
 	dnode_cache_buf = malloc(SPA_MAXBLOCKSIZE);
 
 	zfs_init_crc();
+	zstd_init();
 }
 
 static int
Index: stand/libsa/zfs/zstd_shim.c
===================================================================
--- /dev/null
+++ stand/libsa/zfs/zstd_shim.c
@@ -0,0 +1,77 @@
+/* From src/sys: */
+
+/*
+ * define hearder guards that we need to turn off in this environment...
+ */
+#define _SYS_MALLOC_H_ 1
+
+#include <sys/ccompile.h>
+#include <sys/types.h>
+#include <sys/param.h>
+#include <sys/debug.h>
+#include <sys/proc.h>
+#include <sys/time.h>
+#include <sys/mutex.h>
+#include <sys/byteorder.h>
+
+typedef int krw_t;
+u_int cpu_feature;
+
+#define M_WAITOK 0
+#define M_ZERO 0
+#define M_NOWAIT 0
+#define MALLOC_DECLARE(x)
+#define KM_SLEEP 0
+
+extern void Free(void *p, char *file, int line);
+extern void *Malloc(size_t bytes, char *file, int line);
+#define zfs_kmem_free(p, size) Free(p, __FILE__, __LINE__)
+#define zfs_kmem_alloc(size, flags) Malloc((size), __FILE__, __LINE__) 
+#define kmem_zalloc(size, flags) Malloc((size), __FILE__, __LINE__) 
+#define kmem_free(p, size) Free(p, __FILE__, __LINE__)
+
+int mp_ncpus = 1;
+volatile time_t time_second = 1;
+
+#if 0
+typedef struct { 
+	void *ks_data;
+} kstat_t;
+typedef struct {
+	const char *n;
+	union { uint64_t ui64; } value;
+} kstat_named_t;
+kstat_t __kst;
+#define KSTAT_DATA_UINT64 .value.ui64 = 0
+#define kstat_create(a, b, c, d, e, f, g) &__kst
+#define kstat_install(k)
+#define kstat_delete(k)
+#else
+#endif
+
+typedef int boolean_t;
+
+#define sx_xlock(s) (1)
+#define sx_try_xlock(s) (1)
+#define sx_xunlock(s) (1)
+#define SX_DUPOK 0
+#define SX_NEW 0
+#define SX_NOWITNESS 0
+
+
+void
+sx_init_flags(struct sx *sx, const char *description, int opts)
+{
+
+}
+
+void
+sx_destroy(struct sx *sx)
+{
+
+}
+
+#include <contrib/openzfs/module/zstd/zfs_zstd.c>
+
+uintptr_t *__start_set_pcpu;
+uintptr_t *__stop_set_pcpu;
Index: sys/cddl/boot/zfs/zfsimpl.h
===================================================================
--- sys/cddl/boot/zfs/zfsimpl.h
+++ sys/cddl/boot/zfs/zfsimpl.h
@@ -611,9 +611,63 @@
 	ZIO_COMPRESS_GZIP_9,
 	ZIO_COMPRESS_ZLE,
 	ZIO_COMPRESS_LZ4,
+	ZIO_COMPRESS_ZSTD,
 	ZIO_COMPRESS_FUNCTIONS
 };
 
+enum zio_zstd_levels {
+	ZIO_ZSTD_LEVEL_INHERIT = 0,
+	ZIO_ZSTD_LEVEL_1,
+#define	ZIO_ZSTD_LEVEL_MIN	ZIO_ZSTD_LEVEL_1
+	ZIO_ZSTD_LEVEL_2,
+	ZIO_ZSTD_LEVEL_3,
+#define	ZIO_ZSTD_LEVEL_DEFAULT	ZIO_ZSTD_LEVEL_3
+	ZIO_ZSTD_LEVEL_4,
+	ZIO_ZSTD_LEVEL_5,
+	ZIO_ZSTD_LEVEL_6,
+	ZIO_ZSTD_LEVEL_7,
+	ZIO_ZSTD_LEVEL_8,
+	ZIO_ZSTD_LEVEL_9,
+	ZIO_ZSTD_LEVEL_10,
+	ZIO_ZSTD_LEVEL_11,
+	ZIO_ZSTD_LEVEL_12,
+	ZIO_ZSTD_LEVEL_13,
+	ZIO_ZSTD_LEVEL_14,
+	ZIO_ZSTD_LEVEL_15,
+	ZIO_ZSTD_LEVEL_16,
+	ZIO_ZSTD_LEVEL_17,
+	ZIO_ZSTD_LEVEL_18,
+	ZIO_ZSTD_LEVEL_19,
+#define	ZIO_ZSTD_LEVEL_MAX	ZIO_ZSTD_LEVEL_19
+	ZIO_ZSTD_LEVEL_RESERVE = 101, /* Leave room for new positive levels */
+	ZIO_ZSTD_LEVEL_FAST, /* Fast levels are negative */
+	ZIO_ZSTD_LEVEL_FAST_1,
+#define	ZIO_ZSTD_LEVEL_FAST_DEFAULT	ZIO_ZSTD_LEVEL_FAST_1
+	ZIO_ZSTD_LEVEL_FAST_2,
+	ZIO_ZSTD_LEVEL_FAST_3,
+	ZIO_ZSTD_LEVEL_FAST_4,
+	ZIO_ZSTD_LEVEL_FAST_5,
+	ZIO_ZSTD_LEVEL_FAST_6,
+	ZIO_ZSTD_LEVEL_FAST_7,
+	ZIO_ZSTD_LEVEL_FAST_8,
+	ZIO_ZSTD_LEVEL_FAST_9,
+	ZIO_ZSTD_LEVEL_FAST_10,
+	ZIO_ZSTD_LEVEL_FAST_20,
+	ZIO_ZSTD_LEVEL_FAST_30,
+	ZIO_ZSTD_LEVEL_FAST_40,
+	ZIO_ZSTD_LEVEL_FAST_50,
+	ZIO_ZSTD_LEVEL_FAST_60,
+	ZIO_ZSTD_LEVEL_FAST_70,
+	ZIO_ZSTD_LEVEL_FAST_80,
+	ZIO_ZSTD_LEVEL_FAST_90,
+	ZIO_ZSTD_LEVEL_FAST_100,
+	ZIO_ZSTD_LEVEL_FAST_500,
+	ZIO_ZSTD_LEVEL_FAST_1000,
+#define	ZIO_ZSTD_LEVEL_FAST_MAX	ZIO_ZSTD_LEVEL_FAST_1000
+	ZIO_ZSTD_LEVEL_AUTO = 251, /* Reserved for future use */
+	ZIO_ZSTD_LEVEL_LEVELS
+};
+
 #define	ZIO_COMPRESS_ON_VALUE	ZIO_COMPRESS_LZJB
 #define	ZIO_COMPRESS_DEFAULT	ZIO_COMPRESS_OFF
 
Index: sys/cddl/boot/zfs/zfssubr.c
===================================================================
--- sys/cddl/boot/zfs/zfssubr.c
+++ sys/cddl/boot/zfs/zfssubr.c
@@ -107,6 +107,10 @@
 #include "sha256.c"
 #include "skein_zfs.c"
 
+extern int zfs_zstd_decompress(void *s_start, void *d_start, size_t s_len,
+    size_t d_len, int n);
+
+
 static zio_checksum_info_t zio_checksum_table[ZIO_CHECKSUM_FUNCTIONS] = {
 	{{NULL, NULL}, NULL, NULL, 0, "inherit"},
 	{{NULL, NULL}, NULL, NULL, 0, "on"},
@@ -181,6 +185,7 @@
 	{NULL,			NULL,			9,	"gzip-9"},
 	{NULL,			zle_decompress,		64,	"zle"},
 	{NULL,			lz4_decompress,		0,	"lz4"},
+	{NULL,			zfs_zstd_decompress, ZIO_ZSTD_LEVEL_DEFAULT, "zstd"}
 };
 
 static void
Index: sys/cddl/contrib/opensolaris/uts/common/os/list.c
===================================================================
--- sys/cddl/contrib/opensolaris/uts/common/os/list.c
+++ /dev/null
@@ -1,243 +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 2008 Sun Microsystems, Inc.  All rights reserved.
- * Use is subject to license terms.
- */
-
-/*
- * Generic doubly-linked list implementation
- */
-
-#include <sys/list.h>
-#include <sys/list_impl.h>
-#include <sys/types.h>
-#include <sys/sysmacros.h>
-#include <sys/debug.h>
-
-#define	list_d2l(a, obj) ((list_node_t *)(((char *)obj) + (a)->list_offset))
-#define	list_object(a, node) ((void *)(((char *)node) - (a)->list_offset))
-#define	list_empty(a) ((a)->list_head.list_next == &(a)->list_head)
-
-#define	list_insert_after_node(list, node, object) {	\
-	list_node_t *lnew = list_d2l(list, object);	\
-	lnew->list_prev = (node);			\
-	lnew->list_next = (node)->list_next;		\
-	(node)->list_next->list_prev = lnew;		\
-	(node)->list_next = lnew;			\
-}
-
-#define	list_insert_before_node(list, node, object) {	\
-	list_node_t *lnew = list_d2l(list, object);	\
-	lnew->list_next = (node);			\
-	lnew->list_prev = (node)->list_prev;		\
-	(node)->list_prev->list_next = lnew;		\
-	(node)->list_prev = lnew;			\
-}
-
-#define	list_remove_node(node)					\
-	(node)->list_prev->list_next = (node)->list_next;	\
-	(node)->list_next->list_prev = (node)->list_prev;	\
-	(node)->list_next = (node)->list_prev = NULL
-
-void
-list_create(list_t *list, size_t size, size_t offset)
-{
-	ASSERT(list);
-	ASSERT(size > 0);
-	ASSERT(size >= offset + sizeof (list_node_t));
-
-	list->list_size = size;
-	list->list_offset = offset;
-	list->list_head.list_next = list->list_head.list_prev =
-	    &list->list_head;
-}
-
-void
-list_destroy(list_t *list)
-{
-	list_node_t *node = &list->list_head;
-
-	ASSERT(list);
-	ASSERT(list->list_head.list_next == node);
-	ASSERT(list->list_head.list_prev == node);
-
-	node->list_next = node->list_prev = NULL;
-}
-
-void
-list_insert_after(list_t *list, void *object, void *nobject)
-{
-	if (object == NULL) {
-		list_insert_head(list, nobject);
-	} else {
-		list_node_t *lold = list_d2l(list, object);
-		list_insert_after_node(list, lold, nobject);
-	}
-}
-
-void
-list_insert_before(list_t *list, void *object, void *nobject)
-{
-	if (object == NULL) {
-		list_insert_tail(list, nobject);
-	} else {
-		list_node_t *lold = list_d2l(list, object);
-		list_insert_before_node(list, lold, nobject);
-	}
-}
-
-void
-list_insert_head(list_t *list, void *object)
-{
-	list_node_t *lold = &list->list_head;
-	list_insert_after_node(list, lold, object);
-}
-
-void
-list_insert_tail(list_t *list, void *object)
-{
-	list_node_t *lold = &list->list_head;
-	list_insert_before_node(list, lold, object);
-}
-
-void
-list_remove(list_t *list, void *object)
-{
-	list_node_t *lold = list_d2l(list, object);
-	ASSERT(!list_empty(list));
-	ASSERT(lold->list_next != NULL);
-	list_remove_node(lold);
-}
-
-void *
-list_remove_head(list_t *list)
-{
-	list_node_t *head = list->list_head.list_next;
-	if (head == &list->list_head)
-		return (NULL);
-	list_remove_node(head);
-	return (list_object(list, head));
-}
-
-void *
-list_remove_tail(list_t *list)
-{
-	list_node_t *tail = list->list_head.list_prev;
-	if (tail == &list->list_head)
-		return (NULL);
-	list_remove_node(tail);
-	return (list_object(list, tail));
-}
-
-void *
-list_head(list_t *list)
-{
-	if (list_empty(list))
-		return (NULL);
-	return (list_object(list, list->list_head.list_next));
-}
-
-void *
-list_tail(list_t *list)
-{
-	if (list_empty(list))
-		return (NULL);
-	return (list_object(list, list->list_head.list_prev));
-}
-
-void *
-list_next(list_t *list, void *object)
-{
-	list_node_t *node = list_d2l(list, object);
-
-	if (node->list_next != &list->list_head)
-		return (list_object(list, node->list_next));
-
-	return (NULL);
-}
-
-void *
-list_prev(list_t *list, void *object)
-{
-	list_node_t *node = list_d2l(list, object);
-
-	if (node->list_prev != &list->list_head)
-		return (list_object(list, node->list_prev));
-
-	return (NULL);
-}
-
-/*
- *  Insert src list after dst list. Empty src list thereafter.
- */
-void
-list_move_tail(list_t *dst, list_t *src)
-{
-	list_node_t *dstnode = &dst->list_head;
-	list_node_t *srcnode = &src->list_head;
-
-	ASSERT(dst->list_size == src->list_size);
-	ASSERT(dst->list_offset == src->list_offset);
-
-	if (list_empty(src))
-		return;
-
-	dstnode->list_prev->list_next = srcnode->list_next;
-	srcnode->list_next->list_prev = dstnode->list_prev;
-	dstnode->list_prev = srcnode->list_prev;
-	srcnode->list_prev->list_next = dstnode;
-
-	/* empty src list */
-	srcnode->list_next = srcnode->list_prev = srcnode;
-}
-
-void
-list_link_replace(list_node_t *lold, list_node_t *lnew)
-{
-	ASSERT(list_link_active(lold));
-	ASSERT(!list_link_active(lnew));
-
-	lnew->list_next = lold->list_next;
-	lnew->list_prev = lold->list_prev;
-	lold->list_prev->list_next = lnew;
-	lold->list_next->list_prev = lnew;
-	lold->list_next = lold->list_prev = NULL;
-}
-
-void
-list_link_init(list_node_t *link)
-{
-	link->list_next = NULL;
-	link->list_prev = NULL;
-}
-
-int
-list_link_active(list_node_t *link)
-{
-	return (link->list_next != NULL);
-}
-
-int
-list_is_empty(list_t *list)
-{
-	return (list_empty(list));
-}
Index: sys/contrib/openzfs/include/os/freebsd/linux/compiler.h
===================================================================
--- sys/contrib/openzfs/include/os/freebsd/linux/compiler.h
+++ sys/contrib/openzfs/include/os/freebsd/linux/compiler.h
@@ -68,7 +68,7 @@
 #define	noinline			__noinline
 #define	____cacheline_aligned		__aligned(CACHE_LINE_SIZE)
 
-#ifndef _KERNEL
+#if !defined(_KERNEL) && !defined(_STANDALONE)
 #define	likely(x)			__builtin_expect(!!(x), 1)
 #define	unlikely(x)			__builtin_expect(!!(x), 0)
 #endif
Index: sys/contrib/openzfs/include/os/freebsd/spl/rpc/xdr.h
===================================================================
--- sys/contrib/openzfs/include/os/freebsd/spl/rpc/xdr.h
+++ sys/contrib/openzfs/include/os/freebsd/spl/rpc/xdr.h
@@ -33,7 +33,7 @@
 #include <rpc/types.h>
 #include_next <rpc/xdr.h>
 
-#ifndef _KERNEL
+#if !defined(_KERNEL) && !defined(_STANDALONE)
 
 #include <assert.h>
 
@@ -66,6 +66,6 @@
 	    xdrmem_control((xdrs), (req), (op)) :			\
 	    (*(xdrs)->x_ops->x_control)(xdrs, req, op))
 
-#endif	/* !_KERNEL */
+#endif	/* !_KERNEL && !_STANDALONE */
 
 #endif	/* !_OPENSOLARIS_RPC_XDR_H_ */
Index: sys/contrib/openzfs/include/os/freebsd/spl/sys/atomic.h
===================================================================
--- sys/contrib/openzfs/include/os/freebsd/spl/sys/atomic.h
+++ sys/contrib/openzfs/include/os/freebsd/spl/sys/atomic.h
@@ -34,7 +34,7 @@
 
 #define	atomic_sub_64	atomic_subtract_64
 
-#if defined(__i386__) && (defined(_KERNEL) || defined(KLD_MODULE))
+#if defined(__i386__) && (defined(_KERNEL) || defined(KLD_MODULE) || defined(_STANDALONE))
 #define	I386_HAVE_ATOMIC64
 #endif
 
Index: sys/contrib/openzfs/include/os/freebsd/spl/sys/byteorder.h
===================================================================
--- sys/contrib/openzfs/include/os/freebsd/spl/sys/byteorder.h
+++ sys/contrib/openzfs/include/os/freebsd/spl/sys/byteorder.h
@@ -80,6 +80,7 @@
 #define	BE_64(x)	BSWAP_64(x)
 #endif
 
+#if !defined(_STANDALONE)
 #if BYTE_ORDER == _BIG_ENDIAN
 #define	htonll(x)	BMASK_64(x)
 #define	ntohll(x)	BMASK_64(x)
@@ -101,6 +102,7 @@
 #define	ntohll(x)	BSWAP_64(x)
 #endif
 #endif
+#endif
 
 #define	BE_IN32(xa)	htonl(*((uint32_t *)(void *)(xa)))
 
Index: sys/contrib/openzfs/include/os/freebsd/spl/sys/ccompile.h
===================================================================
--- sys/contrib/openzfs/include/os/freebsd/spl/sys/ccompile.h
+++ sys/contrib/openzfs/include/os/freebsd/spl/sys/ccompile.h
@@ -113,7 +113,7 @@
 #define	__VPRINTFLIKE(__n)	__sun_attr__((__VPRINTFLIKE__(__n)))
 #define	__KPRINTFLIKE(__n)	__sun_attr__((__KPRINTFLIKE__(__n)))
 #define	__KVPRINTFLIKE(__n)	__sun_attr__((__KVPRINTFLIKE__(__n)))
-#ifdef _KERNEL
+#if	defined(_KERNEL) || defined(_STANDALONE)
 #define	__NORETURN		__sun_attr__((__noreturn__))
 #endif
 #define	__CONST			__sun_attr__((__const__))
@@ -174,7 +174,7 @@
 #define	__exit
 #endif
 
-#ifdef _KERNEL
+#if defined(_KERNEL) || defined(_STANDALONE)
 #define	param_set_charp(a, b) (0)
 #define	ATTR_UID AT_UID
 #define	ATTR_GID AT_GID
Index: sys/contrib/openzfs/include/os/freebsd/spl/sys/cmn_err.h
===================================================================
--- sys/contrib/openzfs/include/os/freebsd/spl/sys/cmn_err.h
+++ sys/contrib/openzfs/include/os/freebsd/spl/sys/cmn_err.h
@@ -52,42 +52,33 @@
 /*PRINTFLIKE2*/
 extern void cmn_err(int, const char *, ...)
     __KPRINTFLIKE(2);
-#pragma rarely_called(cmn_err)
 
 extern void vzcmn_err(zoneid_t, int, const char *, __va_list)
     __KVPRINTFLIKE(3);
-#pragma rarely_called(vzcmn_err)
 
 extern void vcmn_err(int, const char *, __va_list)
     __KVPRINTFLIKE(2);
-#pragma rarely_called(vcmn_err)
 
 /*PRINTFLIKE3*/
 extern void zcmn_err(zoneid_t, int, const char *, ...)
     __KPRINTFLIKE(3);
-#pragma rarely_called(zcmn_err)
 
 extern void vzprintf(zoneid_t, const char *, __va_list)
     __KVPRINTFLIKE(2);
-#pragma rarely_called(vzprintf)
 
 /*PRINTFLIKE2*/
 extern void zprintf(zoneid_t, const char *, ...)
     __KPRINTFLIKE(2);
-#pragma rarely_called(zprintf)
 
 extern void vuprintf(const char *, __va_list)
     __KVPRINTFLIKE(1);
-#pragma rarely_called(vuprintf)
 
 /*PRINTFLIKE1*/
 extern void panic(const char *, ...)
     __KPRINTFLIKE(1) __NORETURN;
-#pragma rarely_called(panic)
 
 extern void vpanic(const char *, __va_list)
     __KVPRINTFLIKE(1) __NORETURN;
-#pragma rarely_called(vpanic)
 
 #endif /* !_ASM */
 
Index: sys/contrib/openzfs/include/os/freebsd/spl/sys/condvar.h
===================================================================
--- sys/contrib/openzfs/include/os/freebsd/spl/sys/condvar.h
+++ sys/contrib/openzfs/include/os/freebsd/spl/sys/condvar.h
@@ -36,6 +36,7 @@
 #include <sys/spl_condvar.h>
 #include <sys/mutex.h>
 #include <sys/time.h>
+#include <sys/errno.h>
 
 /*
  * cv_timedwait() is similar to cv_wait() except that it additionally expects
Index: sys/contrib/openzfs/include/os/freebsd/spl/sys/kmem.h
===================================================================
--- sys/contrib/openzfs/include/os/freebsd/spl/sys/kmem.h
+++ sys/contrib/openzfs/include/os/freebsd/spl/sys/kmem.h
@@ -29,6 +29,7 @@
 #ifndef _OPENSOLARIS_SYS_KMEM_H_
 #define	_OPENSOLARIS_SYS_KMEM_H_
 
+#ifdef _KERNEL
 #include <sys/param.h>
 #include <sys/malloc.h>
 #include <sys/vmem.h>
@@ -93,5 +94,5 @@
 	zfs_kmem_alloc((size), (kmflags) | M_ZERO)
 #define	kmem_free(buf, size)		zfs_kmem_free((buf), (size))
 
-
+#endif
 #endif	/* _OPENSOLARIS_SYS_KMEM_H_ */
Index: sys/contrib/openzfs/include/os/freebsd/spl/sys/kstat.h
===================================================================
--- sys/contrib/openzfs/include/os/freebsd/spl/sys/kstat.h
+++ sys/contrib/openzfs/include/os/freebsd/spl/sys/kstat.h
@@ -121,7 +121,6 @@
 	size_t		ks_raw_bufsize;		/* size of raw ops buffer */
 	struct sysctl_ctx_list ks_sysctl_ctx;
 	struct sysctl_oid *ks_sysctl_root;
-
 };
 
 typedef struct kstat_named_s {
Index: sys/contrib/openzfs/include/os/freebsd/spl/sys/proc.h
===================================================================
--- sys/contrib/openzfs/include/os/freebsd/spl/sys/proc.h
+++ sys/contrib/openzfs/include/os/freebsd/spl/sys/proc.h
@@ -41,7 +41,7 @@
 #include <sys/kmem.h>
 #include <sys/malloc.h>
 
-
+#ifdef _KERNEL
 #define	CPU		curcpu
 #define	minclsyspri	PRIBIO
 #define	defclsyspri minclsyspri
@@ -111,4 +111,5 @@
 	return (p == curproc);
 }
 
+#endif
 #endif	/* _OPENSOLARIS_SYS_PROC_H_ */
Index: sys/contrib/openzfs/include/sys/zfs_context.h
===================================================================
--- sys/contrib/openzfs/include/sys/zfs_context.h
+++ sys/contrib/openzfs/include/sys/zfs_context.h
@@ -32,7 +32,7 @@
 extern "C" {
 #endif
 
-#ifdef __KERNEL__
+#if defined(__KERNEL__) || defined(_STANDALONE)
 #include <sys/note.h>
 #include <sys/types.h>
 #include <sys/atomic.h>
Index: sys/contrib/openzfs/include/sys/zio_compress.h
===================================================================
--- sys/contrib/openzfs/include/sys/zio_compress.h
+++ sys/contrib/openzfs/include/sys/zio_compress.h
@@ -30,7 +30,9 @@
 #ifndef _SYS_ZIO_COMPRESS_H
 #define	_SYS_ZIO_COMPRESS_H
 
+#if !defined(_STANDALONE)
 #include <sys/abd.h>
+#endif
 
 #ifdef	__cplusplus
 extern "C" {
@@ -134,6 +136,7 @@
 typedef int zio_getlevel_func_t(void *src, size_t s_len, uint8_t *level);
 
 
+#if !defined(_STANDALONE)
 /*
  * Common signature for all zio decompress functions using an ABD as input.
  * This is helpful if you have both compressed ARC and scatter ABDs enabled,
@@ -141,6 +144,8 @@
  */
 typedef int zio_decompress_abd_func_t(abd_t *src, void *dst,
     size_t s_len, size_t d_len, int);
+#endif
+
 /*
  * Information about each compression function.
  */
@@ -183,10 +188,12 @@
 /*
  * Compress and decompress data if necessary.
  */
+#if !defined(_STANDALONE)
 extern size_t zio_compress_data(enum zio_compress c, abd_t *src, void *dst,
     size_t s_len, uint8_t level);
 extern int zio_decompress_data(enum zio_compress c, abd_t *src, void *dst,
     size_t s_len, size_t d_len, uint8_t *level);
+#endif
 extern int zio_decompress_data_buf(enum zio_compress c, void *src, void *dst,
     size_t s_len, size_t d_len, uint8_t *level);
 extern int zio_compress_to_feature(enum zio_compress comp);
Index: sys/contrib/openzfs/lib/libspl/include/os/freebsd/sys/param.h
===================================================================
--- sys/contrib/openzfs/lib/libspl/include/os/freebsd/sys/param.h
+++ sys/contrib/openzfs/lib/libspl/include/os/freebsd/sys/param.h
@@ -45,9 +45,9 @@
  */
 #define	MAXNAMELEN	256
 
-#ifndef IN_BASE
-#define	UID_NOBODY	60001		/* user ID no body */
-#define	GID_NOBODY	UID_NOBODY
+#ifdef IN_BASE
+#define	UID_NOBODY	65534		/* user ID no body */
+#define	GID_NOBODY	65534
 #endif
 #define	UID_NOACCESS	60002		/* user ID no access */
 
Index: sys/contrib/openzfs/module/os/freebsd/spl/list.c
===================================================================
--- sys/contrib/openzfs/module/os/freebsd/spl/list.c
+++ sys/contrib/openzfs/module/os/freebsd/spl/list.c
@@ -27,10 +27,11 @@
  * Generic doubly-linked list implementation
  */
 
+#include <sys/types.h>
+#include <sys/param.h>
 #include <sys/list.h>
 #include <sys/list_impl.h>
 #include <sys/types.h>
-#include <sys/sysmacros.h>
 #include <sys/debug.h>
 
 #define	list_d2l(a, obj) ((list_node_t *)(((char *)obj) + (a)->list_offset))
Index: sys/contrib/openzfs/module/zstd/zfs_zstd.c
===================================================================
--- sys/contrib/openzfs/module/zstd/zfs_zstd.c
+++ sys/contrib/openzfs/module/zstd/zfs_zstd.c
@@ -41,15 +41,20 @@
 
 #include <sys/param.h>
 #include <sys/sysmacros.h>
+#if !defined(_STANDALONE)
 #include <sys/zfs_context.h>
 #include <sys/zio_compress.h>
 #include <sys/spa.h>
+#else
+#include <sys/zio_compress.h>
+#endif
 #include <sys/zstd/zstd.h>
 
 #define	ZSTD_STATIC_LINKING_ONLY
 #include "lib/zstd.h"
 #include "lib/zstd_errors.h"
 
+#if !defined(_STANDALONE)
 kstat_t *zstd_ksp = NULL;
 
 typedef struct zstd_stats {
@@ -75,6 +80,10 @@
 	{ "compress_failed",		KSTAT_DATA_UINT64 },
 	{ "decompress_failed",		KSTAT_DATA_UINT64 },
 };
+#else
+#undef ZSTDSTAT_BUMP
+#define ZSTDSTAT_BUMP(x)
+#endif
 
 /* Enums describing the allocator type specified by kmem_type in zstd_kmem */
 enum zstd_kmem_type {
@@ -695,6 +704,7 @@
 	pool_count = (boot_ncpus * 4);
 	zstd_meminit();
 
+#if !defined(_STANDALONE)
 	/* Initialize kstat */
 	zstd_ksp = kstat_create("zfs", 0, "zstd", "misc",
 	    KSTAT_TYPE_NAMED, sizeof (zstd_stats) / sizeof (kstat_named_t),
@@ -703,6 +713,7 @@
 		zstd_ksp->ks_data = &zstd_stats;
 		kstat_install(zstd_ksp);
 	}
+#endif
 
 	return (0);
 }
@@ -710,12 +721,13 @@
 extern void __exit
 zstd_fini(void)
 {
+#if !defined(_STANDALONE)
 	/* Deinitialize kstat */
 	if (zstd_ksp != NULL) {
 		kstat_delete(zstd_ksp);
 		zstd_ksp = NULL;
 	}
-
+#endif
 	/* Release fallback memory */
 	vmem_free(zstd_dctx_fallback.mem, zstd_dctx_fallback.mem_size);
 	mutex_destroy(&zstd_dctx_fallback.barrier);
Index: sys/sys/errno.h
===================================================================
--- sys/sys/errno.h
+++ sys/sys/errno.h
@@ -187,7 +187,7 @@
 #define	ELAST		97		/* Must be equal largest errno */
 #endif /* _POSIX_SOURCE */
 
-#if defined(_KERNEL) || defined(_WANT_KERNEL_ERRNO)
+#if defined(_KERNEL) || defined(_WANT_KERNEL_ERRNO) || defined(_STANDALONE)
 /* pseudo-errors returned inside kernel to modify return to process */
 #define	ERESTART	(-1)		/* restart syscall */
 #define	EJUSTRETURN	(-2)		/* don't modify regs, just return */
Index: sys/sys/systm.h
===================================================================
--- sys/sys/systm.h
+++ sys/sys/systm.h
@@ -139,7 +139,6 @@
 #include <sys/param.h>		/* MAXCPU */
 #include <sys/pcpu.h>		/* curthread */
 #include <sys/kpilite.h>
-#endif
 
 /*
  * Helpful macros for quickly coming up with assertions with informative
@@ -632,4 +631,5 @@
 
 __NULLABILITY_PRAGMA_POP
 
+#endif
 #endif /* !_SYS_SYSTM_H_ */
Index: sys/sys/time.h
===================================================================
--- sys/sys/time.h
+++ sys/sys/time.h
@@ -393,7 +393,7 @@
 		}							\
 	} while (0)
 
-#ifdef _KERNEL
+#if defined(_KERNEL) || defined(_STANDALONE)
 
 /* Operations on timevals. */
 
@@ -492,7 +492,7 @@
 #define	CPUCLOCK_WHICH_TID	1
 #endif
 
-#ifdef _KERNEL
+#if defined(_KERNEL) || defined(_STANDALONE)
 
 /*
  * Kernel to clock driver interface.
@@ -600,7 +600,7 @@
 	(((sbt2) >= sbt_timethreshold) ?				\
 	    ((*(sbt) = getsbinuptime()), 1) : ((*(sbt) = sbinuptime()), 0))
 
-#else /* !_KERNEL */
+#else /* !_KERNEL && !_STANDALONE */
 #include <time.h>
 
 #include <sys/cdefs.h>
Index: sys/sys/types.h
===================================================================
--- sys/sys/types.h
+++ sys/sys/types.h
@@ -270,7 +270,7 @@
 
 typedef __rman_res_t    rman_res_t;
 
-#ifdef _KERNEL
+#if	defined(_KERNEL)
 typedef	int		boolean_t;
 typedef	struct device	*device_t;
 typedef	__intfptr_t	intfptr_t;
@@ -292,6 +292,10 @@
 typedef	char		vm_memattr_t;	/* memory attribute codes */
 typedef	struct vm_page	*vm_page_t;
 
+#define offsetof(type, field) __offsetof(type, field)
+#endif /* _KERNEL */
+
+#if	defined(_KERNEL) || defined(_STANDALONE)
 #if !defined(__bool_true_false_are_defined) && !defined(__cplusplus)
 #define	__bool_true_false_are_defined	1
 #define	false	0
@@ -301,10 +305,7 @@
 #endif
 typedef	_Bool	bool;
 #endif /* !__bool_true_false_are_defined && !__cplusplus */
-
-#define offsetof(type, field) __offsetof(type, field)
-
-#endif /* _KERNEL */
+#endif /* KERNEL || _STANDALONE */
 
 /*
  * The following are all things that really shouldn't exist in this header,