diff --git a/api/api.c b/api/api.c
index c5f6edb..1cdc72b 100644
--- a/api/api.c
+++ b/api/api.c
@@ -495,45 +495,47 @@ static int API_env_set(va_list ap)
  */
 static int API_env_enum(va_list ap)
 {
-	int i, n;
-	char *last, **next;
+	int i;
+	char *last, **next, *s;
+	ENTRY *match, search;
+	static char *buf;
 
 	last = (char *)va_arg(ap, u_int32_t);
 
 	if ((next = (char **)va_arg(ap, u_int32_t)) == NULL)
 		return API_EINVAL;
 
-	if (last == NULL)
-		/* start over */
-		*next = ((char *)env_get_addr(0));
-	else {
-		*next = last;
-
-		for (i = 0; env_get_char(i) != '\0'; i = n + 1) {
-			for (n = i; env_get_char(n) != '\0'; ++n) {
-				if (n >= CONFIG_ENV_SIZE) {
-					/* XXX shouldn't we set *next = NULL?? */
-					return 0;
-				}
-			}
-
-			if (envmatch((uchar *)last, i) < 0)
-				continue;
-
-			/* try to get next name */
-			i = n + 1;
-			if (env_get_char(i) == '\0') {
-				/* no more left */
-				*next = NULL;
-				return 0;
-			}
-
-			*next = ((char *)env_get_addr(i));
-			return 0;
+	/*
+	 * This leverages realloc's behavior of growing but never shrinking the
+	 * existing buffer.
+	 */
+	if (last == NULL) {
+		i = 0;
+		buf = realloc(buf, 512); /* Start with reasonable size buf. */
+	} else {
+		buf = realloc(buf, strlen(last) + 1);
+		strcpy(buf, last);
+		if ((s = strchr(buf, '=')) != NULL)
+		     *s = 0;
+		search.key = buf;
+		if ((i = hsearch_r(search, FIND, &match, &env_htab, 0)) == 0) {
+			i = API_EINVAL;
+			goto done;
 		}
 	}
 
+	/* hmatch on empty string is effectively "get next entry after i". */
+	if ((i = hmatch_r("", i, &match, &env_htab)) == 0)
+		goto done;
+	buf = realloc(buf, strlen(match->key) + strlen(match->data) + 2);
+	snprintf(buf, buflen, "%s=%s", match->key, match->data);
+	*next = buf;
 	return 0;
+done:
+	free(buf);
+	buf = NULL;
+	*next = NULL;
+	return i;
 }
 
 /*
diff --git a/api/api_storage.c b/api/api_storage.c
index b76b07d..89d071e 100644
--- a/api/api_storage.c
+++ b/api/api_storage.c
@@ -107,10 +107,13 @@ static int dev_stor_get(int type, int first, int *more, struct device_info *di)
 
 	if (first) {
 		di->cookie = (void *)get_dev(specs[type].name, 0);
-		if (di->cookie == NULL)
+		if (di->cookie == NULL) {
 			return 0;
-		else
+		} else {
 			found = 1;
+			if (specs[type].max_dev > 1)
+				*more = 1;
+		}
 
 	} else {
 		for (i = 0; i < specs[type].max_dev; i++)
@@ -146,7 +149,8 @@ static int dev_stor_get(int type, int first, int *more, struct device_info *di)
 			dd = (block_dev_desc_t *)di->cookie;
 			if (dd->type == DEV_TYPE_UNKNOWN) {
 				debugf("device instance exists, but is not active..");
-				found = 0;
+				di->di_stor.block_count = 0;
+				di->di_stor.block_size = 0;
 			} else {
 				di->di_stor.block_count = dd->lba;
 				di->di_stor.block_size = dd->blksz;
diff --git a/common/cmd_elf.c b/common/cmd_elf.c
index ab9c7e3..e5ad434 100644
--- a/common/cmd_elf.c
+++ b/common/cmd_elf.c
@@ -35,22 +35,12 @@ unsigned long do_bootelf_exec(ulong (*entry)(int, char * const[]),
 	unsigned long ret;
 
 	/*
-	 * QNX images require the data cache is disabled.
-	 * Data cache is already flushed, so just turn it off.
-	 */
-	int dcache = dcache_status();
-	if (dcache)
-		dcache_disable();
-
-	/*
-	 * pass address parameter as argv[0] (aka command name),
-	 * and all remaining args
+	 * FreeBSD wants the caches enabled while ubldr runs, and as of r276397
+	 * the kernel can tolerate being entered with internal (but not external
+	 * PL310) caches enabled on armv6/7 systems.  So don't disable caches
+	 * here, just launch the program directly.
 	 */
 	ret = entry(argc, argv);
-
-	if (dcache)
-		dcache_enable();
-
 	return ret;
 }
 
diff --git a/common/cmd_test.c b/common/cmd_test.c
index c93fe78..b0837de 100644
--- a/common/cmd_test.c
+++ b/common/cmd_test.c
@@ -65,9 +65,14 @@ static int do_test(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 	char * const *ap;
 	int i, op, left, adv, expr, last_expr, last_unop, last_binop;
 
-	/* args? */
-	if (argc < 3)
+	/*
+	 * If no args, that's bogus, return false.
+	 * If op is -z and no other args, answer is Yes, string is empty.
+	 */
+	if (argc < 2)
 		return 1;
+	else if (argc == 2)
+		return !(strcmp(argv[1], "-z") == 0);
 
 #ifdef DEBUG
 	{
diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c
index a26f3ce..8c14baf 100644
--- a/drivers/mmc/mmc.c
+++ b/drivers/mmc/mmc.c
@@ -20,6 +20,7 @@
 
 static struct list_head mmc_devices;
 static int cur_dev_num = -1;
+static int mmc_error_print_max = -1;
 
 __weak int board_mmc_getwp(struct mmc *mmc)
 {
@@ -1262,9 +1263,14 @@ void mmc_destroy(struct mmc *mmc)
 block_dev_desc_t *mmc_get_dev(int dev)
 {
 	struct mmc *mmc = find_mmc_device(dev);
-	if (!mmc || mmc_init(mmc))
+	if (!mmc)
 		return NULL;
 
+	/* If mmc_init fails, mmc->block_dev will be of type
+	 * DEV_TYPE_UNKNOWN with blksz and lba set to zero.
+	 */
+	mmc_init(mmc);
+
 	return &mmc->block_dev;
 }
 #endif
@@ -1298,7 +1304,7 @@ int mmc_start_init(struct mmc *mmc)
 	err = mmc_go_idle(mmc);
 
 	if (err)
-		return err;
+		goto done;
 
 	/* The internal partition reset to user partition(0) at every CMD0*/
 	mmc->part_num = 0;
@@ -1315,15 +1321,33 @@ int mmc_start_init(struct mmc *mmc)
 
 		if (err && err != IN_PROGRESS) {
 #if !defined(CONFIG_SPL_BUILD) || defined(CONFIG_SPL_LIBCOMMON_SUPPORT)
-			printf("Card did not respond to voltage select!\n");
+			if (mmc_error_print_max < 4) {
+				mmc_error_print_max++;
+				printf("Card did not respond to voltage select!\n");
+
+				if (mmc_error_print_max == 4) {
+					printf("Discarding further error messages\n");
+				}
+			}
 #endif
-			return UNUSABLE_ERR;
+//			return UNUSABLE_ERR;
+			goto done;
 		}
 	}
 
 	if (err == IN_PROGRESS)
 		mmc->init_in_progress = 1;
 
+done:
+	if (err) {
+		mmc->has_init = 0;
+		mmc->block_dev.type = DEV_TYPE_UNKNOWN;
+		mmc->block_dev.blksz = 0;
+		mmc->block_dev.lba = 0;
+	} else {
+		mmc->has_init = 1;
+	}
+
 	return err;
 }
 
diff --git a/drivers/net/rtl8169.c b/drivers/net/rtl8169.c
index 8183df3..758646a 100644
--- a/drivers/net/rtl8169.c
+++ b/drivers/net/rtl8169.c
@@ -610,12 +610,12 @@ static int rtl_send(struct eth_device *dev, void *packet, int length)
 		puts("tx timeout/error\n");
 		printf("%s elapsed time : %lu\n", __func__, currticks()-stime);
 #endif
-		ret = 0;
+		ret = -1;
 	} else {
 #ifdef DEBUG_RTL8169_TX
 		puts("tx done\n");
 #endif
-		ret = length;
+		ret = 0;
 	}
 	/* Delay to make net console (nc) work properly */
 	udelay(20);
diff --git a/include/configs/jetson-tk1.h b/include/configs/jetson-tk1.h
index 0fc15ba..59a137a 100644
--- a/include/configs/jetson-tk1.h
+++ b/include/configs/jetson-tk1.h
@@ -110,6 +110,9 @@
 #define CONFIG_CMD_NET
 #define CONFIG_CMD_DHCP
 
+/* API support for UBLDR */
+#define CONFIG_API
+
 #include "tegra-common-usb-gadget.h"
 #include "tegra-common-post.h"
 
diff --git a/include/configs/tegra-common.h b/include/configs/tegra-common.h
index 3f2121d..e799e7b 100644
--- a/include/configs/tegra-common.h
+++ b/include/configs/tegra-common.h
@@ -158,4 +158,9 @@
 #include <config_distro_defaults.h>
 #endif
 
+#ifndef CONFIG_SPL_BUILD
+#define CONFIG_SYS_DCACHE_OFF
+#define CONFIG_CMD_CACHE
+#endif
+
 #endif /* _TEGRA_COMMON_H_ */