Index: stand/efi/include/efizfs.h
===================================================================
--- stand/efi/include/efizfs.h
+++ stand/efi/include/efizfs.h
@@ -40,13 +40,15 @@
 	STAILQ_ENTRY(zfsinfo) zi_link;
 	EFI_HANDLE zi_handle;
         uint64_t zi_pool_guid;
+        uint64_t zi_vdev_guid;
 } zfsinfo_t;
 
 extern uint64_t pool_guid;
+extern uint64_t primary_vdev_guid;
 
 void efi_zfs_probe(void);
 EFI_HANDLE efizfs_get_handle_by_guid(uint64_t);
-bool efizfs_get_guid_by_handle(EFI_HANDLE, uint64_t *);
+bool efizfs_get_guid_by_handle(EFI_HANDLE, uint64_t *, uint64_t *);
 zfsinfo_list_t *efizfs_get_zfsinfo_list(void);
 void efizfs_set_preferred(EFI_HANDLE);
 
Index: stand/efi/libefi/efizfs.c
===================================================================
--- stand/efi/libefi/efizfs.c
+++ stand/efi/libefi/efizfs.c
@@ -44,6 +44,7 @@
 static zfsinfo_list_t zfsinfo;
 
 uint64_t pool_guid;
+uint64_t primary_vdev_guid;
 
 static EFI_HANDLE preferred;
 
@@ -73,7 +74,8 @@
 }
 
 bool
-efizfs_get_guid_by_handle(EFI_HANDLE handle, uint64_t *guid)
+efizfs_get_guid_by_handle(EFI_HANDLE handle, uint64_t *guid,
+		    uint64_t *vdev_guid)
 {
 	zfsinfo_t *zi;
 
@@ -82,6 +84,8 @@
 	STAILQ_FOREACH(zi, &zfsinfo, zi_link) {
 		if (zi->zi_handle == handle) {
 			*guid = zi->zi_pool_guid;
+			if (vdev_guid != NULL)
+				*vdev_guid = zi->zi_vdev_guid;
 			return (true);
 		}
 	}
@@ -89,13 +93,14 @@
 }
 
 static void
-insert_zfs(EFI_HANDLE handle, uint64_t guid)
+insert_zfs(EFI_HANDLE handle, uint64_t guid, uint64_t vdev_guid)
 {
         zfsinfo_t *zi;
 
         zi = malloc(sizeof(zfsinfo_t));
         zi->zi_handle = handle;
         zi->zi_pool_guid = guid;
+        zi->zi_vdev_guid = vdev_guid;
         STAILQ_INSERT_TAIL(&zfsinfo, zi, zi_link);
 }
 
@@ -105,7 +110,7 @@
 	pdinfo_list_t *hdi;
 	pdinfo_t *hd, *pd = NULL;
 	char devname[SPECNAMELEN + 1];
-        uint64_t guid;
+        uint64_t guid, vdev_guid;
 
 	hdi = efiblk_get_pdinfo_list(&efipart_hddev);
 	STAILQ_INIT(&zfsinfo);
@@ -120,10 +125,12 @@
 		STAILQ_FOREACH(pd, &hd->pd_part, pd_link) {
 			snprintf(devname, sizeof(devname), "%s%dp%d:",
 			    efipart_hddev.dv_name, hd->pd_unit, pd->pd_unit);
-			if (zfs_probe_dev(devname, &guid) == 0) {
-				insert_zfs(pd->pd_handle, guid);
-				if (pd->pd_handle == preferred)
+			if (zfs_probe_dev(devname, &guid, &vdev_guid) == 0) {
+				insert_zfs(pd->pd_handle, guid, vdev_guid);
+				if (pd->pd_handle == preferred) {
 					pool_guid = guid;
+					primary_vdev_guid = vdev_guid;
+				}
 			}
 
 		}
Index: stand/efi/loader/main.c
===================================================================
--- stand/efi/loader/main.c
+++ stand/efi/loader/main.c
@@ -260,9 +260,10 @@
 static bool
 try_as_currdev(pdinfo_t *hd, pdinfo_t *pp)
 {
-	uint64_t guid;
 
 #ifdef EFI_ZFS_BOOT
+	uint64_t guid, vdev_guid;
+
 	/*
 	 * If there's a zpool on this device, try it as a ZFS
 	 * filesystem, which has somewhat different setup than all
@@ -270,8 +271,12 @@
 	 * This all stems from ZFS being both a device (zpool) and
 	 * a filesystem, plus the boot env feature.
 	 */
-	if (efizfs_get_guid_by_handle(pp->pd_handle, &guid))
-		return (probe_zfs_currdev(guid));
+	if (efizfs_get_guid_by_handle(pp->pd_handle, &guid, &vdev_guid))
+		if (probe_zfs_currdev(guid)) {
+			pool_guid = guid;
+			primary_vdev_guid = vdev_guid;
+			return (true);
+		}
 #endif
 	/*
 	 * All other filesystems just need the pdinfo
@@ -505,6 +510,12 @@
 		printf("Trying ZFS pool\n");
 		if (probe_zfs_currdev(pool_guid))
 			return (0);
+		/*
+		 * Invalidate the pool information because it failed a currdev
+		 * probe, likely due to the sanity check.
+		 */
+		pool_guid = 0;
+		primary_vdev_guid = 0;
 	}
 #endif /* EFI_ZFS_BOOT */
 
@@ -973,6 +984,8 @@
 		if (!interactive_interrupt("Failed to find bootable partition"))
 			return (EFI_NOT_FOUND);
 
+	if (pool_guid != 0)
+		zfs_set_bootcfg_env(pool_guid, primary_vdev_guid);
 	efi_init_environment();
 
 #if !defined(__arm__)
Index: stand/i386/loader/main.c
===================================================================
--- stand/i386/loader/main.c
+++ stand/i386/loader/main.c
@@ -258,9 +258,6 @@
 extract_currdev(void)
 {
     struct i386_devdesc		new_currdev;
-#ifdef LOADER_ZFS_SUPPORT
-    char			buf[20];
-#endif
     int				biosdev = -1;
 
     /* Assume we are booting from a BIOS disk by default */
@@ -291,10 +288,7 @@
 	    new_currdev.d_kind.zfs.pool_guid = zargs->pool;
 	    new_currdev.d_kind.zfs.root_guid = zargs->root;
 	    if (zargs->size >= sizeof(*zargs) && zargs->primary_vdev != 0) {
-		sprintf(buf, "%llu", zargs->primary_pool);
-		setenv("vfs.zfs.boot.primary_pool", buf, 1);
-		sprintf(buf, "%llu", zargs->primary_vdev);
-		setenv("vfs.zfs.boot.primary_vdev", buf, 1);
+		zfs_set_bootcfg_env(zargs->primary_pool, zargs->primary_vdev);
 	    }
 	} else {
 	    /* old style zfsboot block */
@@ -409,7 +403,7 @@
     for (dev.dd.d_unit = 0; bd_unit2bios(&dev) >= 0; dev.dd.d_unit++) {
 	snprintf(devname, sizeof(devname), "%s%d:", bioshd.dv_name,
 	    dev.dd.d_unit);
-	zfs_probe_dev(devname, NULL);
+	zfs_probe_dev(devname, NULL, NULL);
     }
 }
 #endif
Index: stand/libsa/zfs/libzfs.h
===================================================================
--- stand/libsa/zfs/libzfs.h
+++ stand/libsa/zfs/libzfs.h
@@ -47,13 +47,15 @@
 int	zfs_parsedev(struct zfs_devdesc *dev, const char *devspec,
 		     const char **path);
 char	*zfs_fmtdev(void *vdev);
-int	zfs_probe_dev(const char *devname, uint64_t *pool_guid);
+int	zfs_probe_dev(const char *devname, uint64_t *pool_guid,
+		    uint64_t *vdev_guid);
 int	zfs_list(const char *name);
 uint64_t ldi_get_size(void *);
 void	init_zfs_bootenv(const char *currdev);
 int	zfs_bootenv(const char *name);
 int	zfs_belist_add(const char *name, uint64_t __unused);
 int	zfs_set_env(void);
+void	zfs_set_bootcfg_env(uint64_t pool_guid, uint64_t vdev_guid);
 
 extern struct devsw zfs_dev;
 extern struct fs_ops zfs_fsops;
Index: stand/libsa/zfs/zfs.c
===================================================================
--- stand/libsa/zfs/zfs.c
+++ stand/libsa/zfs/zfs.c
@@ -38,6 +38,7 @@
 #include <sys/param.h>
 #include <sys/time.h>
 #include <sys/queue.h>
+#include <machine/_inttypes.h>
 #include <disk.h>
 #include <part.h>
 #include <stddef.h>
@@ -449,6 +450,7 @@
 	int		fd;
 	const char	*devname;
 	uint64_t	*pool_guid;
+	uint64_t	*vdev_guid;
 	u_int		secsz;
 };
 
@@ -463,15 +465,23 @@
 }
 
 static int
-zfs_probe(int fd, uint64_t *pool_guid)
+zfs_probe(int fd, uint64_t *pool_guid, uint64_t *vdev_guid)
 {
 	spa_t *spa;
+	vdev_t *vdev;
 	int ret;
 
 	spa = NULL;
 	ret = vdev_probe(vdev_read, (void *)(uintptr_t)fd, &spa);
-	if (ret == 0 && pool_guid != NULL)
-		*pool_guid = spa->spa_guid;
+	if (ret == 0) {
+		if (pool_guid != NULL)
+			*pool_guid = spa->spa_guid;
+		if (vdev_guid != NULL) {
+			vdev = spa_get_primary_vdev(spa);
+			if (vdev != NULL)
+				*vdev_guid = vdev->v_guid;
+		}
+	}
 	return (ret);
 }
 
@@ -496,13 +506,14 @@
 	pa.fd = open(devname, O_RDONLY);
 	if (pa.fd == -1)
 		return (0);
-	ret = zfs_probe(pa.fd, ppa->pool_guid);
+	ret = zfs_probe(pa.fd, ppa->pool_guid, ppa->vdev_guid);
 	if (ret == 0)
 		return (0);
 	/* Do we have BSD label here? */
 	if (part->type == PART_FREEBSD) {
 		pa.devname = devname;
 		pa.pool_guid = ppa->pool_guid;
+		pa.vdev_guid = ppa->vdev_guid;
 		pa.secsz = ppa->secsz;
 		table = ptable_open(&pa, part->end - part->start + 1,
 		    ppa->secsz, zfs_diskread);
@@ -516,7 +527,7 @@
 }
 
 int
-zfs_probe_dev(const char *devname, uint64_t *pool_guid)
+zfs_probe_dev(const char *devname, uint64_t *pool_guid, uint64_t *vdev_guid)
 {
 	struct disk_devdesc *dev;
 	struct ptable *table;
@@ -526,6 +537,8 @@
 
 	if (pool_guid)
 		*pool_guid = 0;
+	if (vdev_guid)
+		*vdev_guid = 0;
 	pa.fd = open(devname, O_RDONLY);
 	if (pa.fd == -1)
 		return (ENXIO);
@@ -540,7 +553,7 @@
 
 		free(dev);
 		if (partition != -1 && slice != -1) {
-			ret = zfs_probe(pa.fd, pool_guid);
+			ret = zfs_probe(pa.fd, pool_guid, vdev_guid);
 			if (ret == 0)
 				return (0);
 		}
@@ -553,6 +566,7 @@
 	if (ret == 0) {
 		pa.devname = devname;
 		pa.pool_guid = pool_guid;
+		pa.vdev_guid = vdev_guid;
 		table = ptable_open(&pa, mediasz / pa.secsz, pa.secsz,
 		    zfs_diskread);
 		if (table != NULL) {
@@ -940,6 +954,7 @@
 	return (0);
 }
 
+
 int
 zfs_set_env(void)
 {
@@ -1015,3 +1030,14 @@
 
 	return (rv);
 }
+
+void
+zfs_set_bootcfg_env(uint64_t pool_guid, uint64_t vdev_guid)
+{
+	char buf[20];
+
+	sprintf(buf, "%"PRIu64, pool_guid);
+	setenv("vfs.zfs.boot.primary_pool", buf, 1);
+	sprintf(buf, "%"PRIu64, vdev_guid);
+	setenv("vfs.zfs.boot.primary_vdev", buf, 1);
+}
Index: stand/libsa/zfs/zfsimpl.c
===================================================================
--- stand/libsa/zfs/zfsimpl.c
+++ stand/libsa/zfs/zfsimpl.c
@@ -719,7 +719,6 @@
 	return (0);
 }
 
-#ifdef BOOT2
 static spa_t *
 spa_get_primary(void)
 {
@@ -745,7 +744,6 @@
 		vdev = kid;
 	return (vdev);
 }
-#endif
 
 static spa_t *
 spa_create(uint64_t guid, const char *name)
Index: stand/sparc64/loader/main.c
===================================================================
--- stand/sparc64/loader/main.c
+++ stand/sparc64/loader/main.c
@@ -794,7 +794,7 @@
 				guidp = &guid;
 			else
 				guidp = NULL;
-			if (zfs_probe_dev(devname, guidp) == ENXIO)
+			if (zfs_probe_dev(devname, guidp, NULL) == ENXIO)
 				break;
 		}
 	}
Index: stand/userboot/userboot/main.c
===================================================================
--- stand/userboot/userboot/main.c
+++ stand/userboot/userboot/main.c
@@ -278,7 +278,7 @@
 	for (unit = 0; unit < userboot_disk_maxunit; unit++) {
 		sprintf(devname, "disk%d:", unit);
 		pool_guid = 0;
-		zfs_probe_dev(devname, &pool_guid);
+		zfs_probe_dev(devname, &pool_guid, NULL);
 		if (pool_guid != 0)
 			userboot_zfs_found = 1;
 	}