diff --git a/board/linker_template_gnu.ld b/board/linker_template_gnu.ld
index f1f4c8c72..7195fdccf 100644
--- a/board/linker_template_gnu.ld
+++ b/board/linker_template_gnu.ld
@@ -78,15 +78,8 @@ SECTIONS
 		_f_sdata = .;
 		__SDATA_BEGIN__ = .;
 		*(.sdata .sdata.* .gnu.linkonce.s.*)
-		_e_sdata = .;
-		_e_data = .;
-	} > REGION_RAM AT > REGION_ROM
-
-	.bss (NOLOAD) : ALIGN(8)
-	{
 		PROVIDE (__sbss_start = .);
 		PROVIDE (___sbss_start = .);
-		_f_bss = .;
 		_f_sbss = .;
 		*(.dynsbss)
 		*(.sbss .sbss.* .gnu.linkonce.sb.*)
@@ -94,7 +87,13 @@ SECTIONS
 		_e_sbss = .;
 		PROVIDE (__sbss_end = .);
 		PROVIDE (___sbss_end = .);
+		_e_sdata = .;
+		_e_data = .;
+	} > REGION_RAM AT > REGION_ROM
 
+	.bss (NOLOAD) : ALIGN(8)
+	{
+		_f_bss = .;
 		*(.dynbss)
 		*(.bss .bss.* .gnu.linkonce.b.*)
 		*(COMMON)
diff --git a/board/linker_template_mw.ld b/board/linker_template_mw.ld
index e63571e54..bb63b6556 100644
--- a/board/linker_template_mw.ld
+++ b/board/linker_template_mw.ld
@@ -69,6 +69,7 @@ SECTIONS {
 			_f_data = .;
 			_f_sdata = .;
 			*(.sdata)
+			*(.sbss)
 			_e_sdata = .;
 			*(TYPE data)
 		}
diff --git a/example/baremetal/openthread/cli/mbedtls-config.h b/example/baremetal/openthread/cli/mbedtls-config.h
index 0b9693bd5..a6ceb5dba 100644
--- a/example/baremetal/openthread/cli/mbedtls-config.h
+++ b/example/baremetal/openthread/cli/mbedtls-config.h
@@ -33,6 +33,7 @@
 #include <openthread/config.h>
 #include <openthread/platform/logging.h>
 #include <openthread/platform/memory.h>
+#include <stdio.h>
 
 #if defined(_WIN32)
 #include <stdarg.h>
@@ -189,7 +190,7 @@ __inline int windows_kernel_snprintf(char * s, size_t n, const char * format, ..
 //#define MBEDTLS_PLATFORM_TIME_ALT
 //#define MBEDTLS_PLATFORM_FPRINTF_ALT
 //#define MBEDTLS_PLATFORM_PRINTF_ALT
-//#define MBEDTLS_PLATFORM_SNPRINTF_ALT
+#define MBEDTLS_PLATFORM_SNPRINTF_ALT
 //#define MBEDTLS_PLATFORM_NV_SEED_ALT
 
 /**
@@ -2557,7 +2558,7 @@ __inline int windows_kernel_snprintf(char * s, size_t n, const char * format, ..
 //#define MBEDTLS_PLATFORM_STD_FPRINTF      fprintf /**< Default fprintf to use, can be undefined */
 //#define MBEDTLS_PLATFORM_STD_PRINTF        printf /**< Default printf to use, can be undefined */
 /* Note: your snprintf must correclty zero-terminate the buffer! */
-//#define MBEDTLS_PLATFORM_STD_SNPRINTF    snprintf /**< Default snprintf to use, can be undefined */
+#define MBEDTLS_PLATFORM_STD_SNPRINTF    snprintf /**< Default snprintf to use, can be undefined */
 //#define MBEDTLS_PLATFORM_STD_EXIT_SUCCESS       0 /**< Default exit value to use, can be undefined */
 //#define MBEDTLS_PLATFORM_STD_EXIT_FAILURE       1 /**< Default exit value to use, can be undefined */
 //#define MBEDTLS_PLATFORM_STD_NV_SEED_READ   mbedtls_platform_std_nv_seed_read /**< Default nv_seed_read function to use, can be undefined */
diff --git a/example/baremetal/openthread/ncp/mbedtls-config.h b/example/baremetal/openthread/ncp/mbedtls-config.h
index 0b9693bd5..a6ceb5dba 100644
--- a/example/baremetal/openthread/ncp/mbedtls-config.h
+++ b/example/baremetal/openthread/ncp/mbedtls-config.h
@@ -33,6 +33,7 @@
 #include <openthread/config.h>
 #include <openthread/platform/logging.h>
 #include <openthread/platform/memory.h>
+#include <stdio.h>
 
 #if defined(_WIN32)
 #include <stdarg.h>
@@ -189,7 +190,7 @@ __inline int windows_kernel_snprintf(char * s, size_t n, const char * format, ..
 //#define MBEDTLS_PLATFORM_TIME_ALT
 //#define MBEDTLS_PLATFORM_FPRINTF_ALT
 //#define MBEDTLS_PLATFORM_PRINTF_ALT
-//#define MBEDTLS_PLATFORM_SNPRINTF_ALT
+#define MBEDTLS_PLATFORM_SNPRINTF_ALT
 //#define MBEDTLS_PLATFORM_NV_SEED_ALT
 
 /**
@@ -2557,7 +2558,7 @@ __inline int windows_kernel_snprintf(char * s, size_t n, const char * format, ..
 //#define MBEDTLS_PLATFORM_STD_FPRINTF      fprintf /**< Default fprintf to use, can be undefined */
 //#define MBEDTLS_PLATFORM_STD_PRINTF        printf /**< Default printf to use, can be undefined */
 /* Note: your snprintf must correclty zero-terminate the buffer! */
-//#define MBEDTLS_PLATFORM_STD_SNPRINTF    snprintf /**< Default snprintf to use, can be undefined */
+#define MBEDTLS_PLATFORM_STD_SNPRINTF    snprintf /**< Default snprintf to use, can be undefined */
 //#define MBEDTLS_PLATFORM_STD_EXIT_SUCCESS       0 /**< Default exit value to use, can be undefined */
 //#define MBEDTLS_PLATFORM_STD_EXIT_FAILURE       1 /**< Default exit value to use, can be undefined */
 //#define MBEDTLS_PLATFORM_STD_NV_SEED_READ   mbedtls_platform_std_nv_seed_read /**< Default nv_seed_read function to use, can be undefined */
diff --git a/example/baremetal/secureshield/secret_normal/README.rst b/example/baremetal/secureshield/secret_normal/README.rst
index 32687f07a..663fa6ba2 100644
--- a/example/baremetal/secureshield/secret_normal/README.rst
+++ b/example/baremetal/secureshield/secret_normal/README.rst
@@ -43,7 +43,7 @@ For nSIM, the commands to run this example are as follows:
 .. code-block:: console
 
     $ cd <embarc_root>/example/baremetal/secureshield/secret_normal
-    $ gmake BOARD=nsim BD_VER=1506 CUR_CORE=arcemsecureshield TOOLCHAIN=mw run
+    $ gmake BOARD=nsim BD_VER=10 CUR_CORE=arcsem TOOLCHAIN=mw run
 
 For EMSK 2.2, the commands to run this example are as follows:
 
diff --git a/example/baremetal/secureshield/secret_normal/makefile b/example/baremetal/secureshield/secret_normal/makefile
index 15339c48d..f15c78f7a 100644
--- a/example/baremetal/secureshield/secret_normal/makefile
+++ b/example/baremetal/secureshield/secret_normal/makefile
@@ -9,7 +9,9 @@ BOARD ?= nsim
 
 CUR_CORE ?= arcsem
 
-APPL_DEFINES  = -DLIB_SECURESHIELD_OVERRIDES -DNTSHELL_USE_CMDS_PERIPHERAL=0 -DNTSHELL_USE_CMDS_ARC=0
+# secureshield doesn't support stack check now
+APPL_DEFINES  = -DLIB_SECURESHIELD_OVERRIDES -DNTSHELL_USE_CMDS_PERIPHERAL=0\
+				-DNTSHELL_USE_CMDS_ARC=0 -DARC_FEATURE_STACK_CHECK=0
 
 #
 # root dir of embARC
diff --git a/example/baremetal/secureshield/secret_secure/README.rst b/example/baremetal/secureshield/secret_secure/README.rst
index 853a53424..ec9bc51a7 100644
--- a/example/baremetal/secureshield/secret_secure/README.rst
+++ b/example/baremetal/secureshield/secret_secure/README.rst
@@ -42,7 +42,7 @@ For nSIM, the commands to run this example are as follows:
 .. code-block:: console
 
     $ cd <embarc_root>/example/baremetal/secureshield/secret_secure
-    $ gmake BOARD=nsim BD_VER=1506 CUR_CORE=arcemsecureshield TOOLCHAIN=mw run
+    $ gmake BOARD=nsim BD_VER=10 CUR_CORE=arcsem TOOLCHAIN=mw run
 
 For EMSK 2.2, the commands to run this example are as follows:
 
diff --git a/example/baremetal/secureshield/secret_secure/makefile b/example/baremetal/secureshield/secret_secure/makefile
index fbceb093e..c6f1c08fc 100644
--- a/example/baremetal/secureshield/secret_secure/makefile
+++ b/example/baremetal/secureshield/secret_secure/makefile
@@ -9,7 +9,9 @@ BOARD ?= nsim
 
 CUR_CORE ?= arcsem
 
-APPL_DEFINES  = -DLIB_SECURESHIELD_OVERRIDES -DNTSHELL_USE_CMDS_PERIPHERAL=0 -DNTSHELL_USE_CMDS_ARC=0
+# secureshield doesn't support stack check now
+APPL_DEFINES  = -DLIB_SECURESHIELD_OVERRIDES -DNTSHELL_USE_CMDS_PERIPHERAL=0\
+				-DNTSHELL_USE_CMDS_ARC=0 -DARC_FEATURE_STACK_CHECK=0
 
 #
 # root dir of embARC
diff --git a/example/baremetal/secureshield/secret_secure_sid/README.rst b/example/baremetal/secureshield/secret_secure_sid/README.rst
index f97cc1212..4dcf2381c 100644
--- a/example/baremetal/secureshield/secret_secure_sid/README.rst
+++ b/example/baremetal/secureshield/secret_secure_sid/README.rst
@@ -44,7 +44,7 @@ For nSIM, the commands to run this example are as follows:
 .. code-block:: console
 
     $ cd <embarc_root>/example/baremetal/secureshield/secret_secure_sid
-    $ gmake BOARD=nsim BD_VER=1506 CUR_CORE=arcemsecureshield TOOLCHAIN=mw run
+    $ gmake BOARD=nsim BD_VER=10 CUR_CORE=arcsem TOOLCHAIN=mw run
 
 For EMSK 2.3, the commands to run this example are as follows:
 
diff --git a/example/baremetal/secureshield/secret_secure_sid/makefile b/example/baremetal/secureshield/secret_secure_sid/makefile
index 7b6fd434e..dd6cbddf3 100644
--- a/example/baremetal/secureshield/secret_secure_sid/makefile
+++ b/example/baremetal/secureshield/secret_secure_sid/makefile
@@ -10,7 +10,9 @@ BOARD ?= nsim
 
 CUR_CORE = arcsem
 
-APPL_DEFINES  = -DNTSHELL_USE_CMDS_PERIPHERAL=0 -DNTSHELL_USE_CMDS_ARC=0
+# secureshield doesn't support stack check now
+APPL_DEFINES  = -DNTSHELL_USE_CMDS_PERIPHERAL=0 -DNTSHELL_USE_CMDS_ARC=0\
+				-DARC_FEATURE_STACK_CHECK=0
 
 #
 # root dir of embARC
diff --git a/example/baremetal/secureshield/test_case/README.rst b/example/baremetal/secureshield/test_case/README.rst
index 64ca23416..f1bb4612b 100644
--- a/example/baremetal/secureshield/test_case/README.rst
+++ b/example/baremetal/secureshield/test_case/README.rst
@@ -34,7 +34,7 @@ It is supported by nSIM. The commands to run this example are as follows:
 .. code-block:: console
 
     $ cd <embarc_root>/example/baremetal/secureshield/test_case
-    $ gmake BOARD=nsim BD_VER=1506 CUR_CORE=arcemsecureshield TOOLCHAIN=mw run
+    $ gmake BOARD=nsim BD_VER=10 CUR_CORE=arcsem TOOLCHAIN=mw run
 
 Sample Output
 =============
diff --git a/example/baremetal/secureshield/test_case/makefile b/example/baremetal/secureshield/test_case/makefile
index a8ce53a10..35f8d30a2 100644
--- a/example/baremetal/secureshield/test_case/makefile
+++ b/example/baremetal/secureshield/test_case/makefile
@@ -9,7 +9,9 @@ BOARD ?= nsim
 
 CUR_CORE ?= arcsem
 
-APPL_DEFINES  = -DLIB_SECURESHIELD_OVERRIDES -DNTSHELL_USE_CMDS_PERIPHERAL=0 -DNTSHELL_USE_CMDS_ARC=0
+# secureshield doesn't support stack check now
+APPL_DEFINES  = -DLIB_SECURESHIELD_OVERRIDES -DNTSHELL_USE_CMDS_PERIPHERAL=0\
+				-DNTSHELL_USE_CMDS_ARC=0 -DARC_FEATURE_STACK_CHECK=0
 
 #
 # root dir of embARC
diff --git a/example/fatfs_test/main.c b/example/fatfs_test/main.c
new file mode 100644
index 000000000..5a92142f2
--- /dev/null
+++ b/example/fatfs_test/main.c
@@ -0,0 +1,103 @@
+/* ------------------------------------------
+ * Copyright (c) 2017, Synopsys, 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.
+
+ * 3) Neither the name of the Synopsys, Inc., nor the names of its contributors may
+ * be used to endorse or promote products derived from this software without
+ * specific prior done permission.
+
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 COPYRIGHT HOLDER 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 "embARC.h"
+#include "embARC_debug.h"
+
+#define DATA_SIZE  8192
+static FIL file;
+
+uint8_t data_write[DATA_SIZE];
+uint8_t data_read[DATA_SIZE];
+
+
+/**
+ * \brief	Test hardware board without any peripheral
+ */
+int main(void)
+{
+	uint8_t res;
+	uint32_t i;
+	uint32_t rw_counter;
+	uint32_t done;
+	uint8_t *buf;
+
+	EMBARC_PRINTF("test start\r\n");
+
+	for (i = 0; i < DATA_SIZE; i++) {
+		data_write[i] = 'a' + i % 26;
+	}
+
+	res = f_open(&file, "test1.txt", FA_WRITE | FA_CREATE_ALWAYS);
+
+	if (res) {
+		EMBARC_PRINTF("file open err\r\n");
+		while (1);
+	}
+
+	rw_counter = DATA_SIZE;
+	buf = data_write;
+
+	while (rw_counter) {
+		res = f_write(&file, buf, rw_counter, &done);
+
+		if (res) {
+			EMBARC_PRINTF("file write error :%d\r\n", res);
+			while (1);
+		}
+		rw_counter -= done;
+		buf += done;
+		EMBARC_PRINTF("%d bytes are written\r\n", done);
+	}
+	f_close(&file);
+
+	res = f_open(&file, "test1.txt", FA_READ | FA_OPEN_EXISTING);
+
+	if (res) {
+		EMBARC_PRINTF("file open err\r\n");
+		while (1);
+	}
+
+	rw_counter = DATA_SIZE;
+	buf = data_read;
+
+	while (rw_counter) {
+		res = f_read(&file, buf, rw_counter, &done);
+
+		if (res) {
+			EMBARC_PRINTF("file read error :%d\r\n", res);
+			while (1);
+		}
+		rw_counter -= done;
+		buf += done;
+		EMBARC_PRINTF("%d bytes are read\r\n", done);
+	}
+
+	while (1);
+}
diff --git a/example/fatfs_test/makefile b/example/fatfs_test/makefile
new file mode 100644
index 000000000..2bb854ab3
--- /dev/null
+++ b/example/fatfs_test/makefile
@@ -0,0 +1,24 @@
+# Application name
+APPL ?= fatfs_test
+
+BOARD = iotdk
+#
+# root dir of embARC
+#
+EMBARC_ROOT = ../..
+
+MID_SEL = common fatfs
+
+# application source dirs
+APPL_CSRC_DIR = .
+APPL_ASMSRC_DIR = .
+
+# application include dirs
+APPL_INC_DIR = .
+
+# include current project makefile
+COMMON_COMPILE_PREREQUISITES += makefile
+
+### Options above must be added before include options.mk ###
+# include key embARC build system makefile
+include $(EMBARC_ROOT)/options/options.mk
\ No newline at end of file
diff --git a/example/freertos/kernel_secure/README.rst b/example/freertos/kernel_secure/README.rst
index 97ffdc39c..4e4f767cb 100644
--- a/example/freertos/kernel_secure/README.rst
+++ b/example/freertos/kernel_secure/README.rst
@@ -28,12 +28,21 @@ Detailed Description
   - Re-configure the EMSK 2.3 board to EM7D configuration.
   - run the following commands
 
+For nSIM, the commands to run this example are as follows:
+
+.. code-block:: console
+
+    $ cd <embarc_root>/example/freertos/kernel_secure
+    $ gmake BOARD=nsim BD_VER=10 CUR_CORE=arcsem TOOLCHAIN=mw run
+
+For EMSK 2.3, the commands to run this example are as follows:
+
 .. code-block:: console
 
     $ cd <embarc_root>/example/freertos/kernel_secure
     $ make BOARD=emsk BD_VER=23 CUR_CORE=arcem7d TOOLCHAIN=gnu run
 
-.. note:: This example is only valid for arc processors with SecureShield feature (Currently, emsk 2.3 arcem7d)
+.. note:: This example is only valid for arc processors with SecureShield feature (Currently, emsk 2.3 arcem7d and nsim arcsem)
 
 
 Sample Output
diff --git a/example/freertos/kernel_secure/makefile b/example/freertos/kernel_secure/makefile
index 4878943c1..74aebcd74 100644
--- a/example/freertos/kernel_secure/makefile
+++ b/example/freertos/kernel_secure/makefile
@@ -20,6 +20,9 @@ EMBARC_ROOT = ../../..
 LIB_SEL = secureshield
 MID_SEL = common
 
+# secureshield doesn't support stack check now
+APPL_DEFINES  = -DARC_FEATURE_STACK_CHECK=0
+
 # application source dirs
 APPL_CSRC_DIR = .
 APPL_ASMSRC_DIR = .
diff --git a/example/freertos/sec/mbedtls/dtls/client/README.rst b/example/freertos/sec/mbedtls/dtls/client/README.rst
index 34fcb6797..7d853776e 100644
--- a/example/freertos/sec/mbedtls/dtls/client/README.rst
+++ b/example/freertos/sec/mbedtls/dtls/client/README.rst
@@ -18,7 +18,6 @@ Detailed Description
 * Extra Required Peripherals
 
     - Digilent PMOD WIFI(MRF24WG0MA)
-    - SD Card to store certification file, key file
 
 .. note::
    EMSDP has board WiFi module, no need to use PMOD WiFI.
@@ -39,16 +38,84 @@ Buidling and Running
 
 2. In pc node or mbedtls dtls_server node, run the server application to listen.
 
-3. Copy the ``tests`` dir in ``middleware/mbedtls`` into the SD card of secure server node, it will load CA file and key file.
+3. Change SERVER_NAME and SERVER_ADDR in dtls_client.c to the dtls_server node's IP address. And build this application again.
 
-4. Change SERVER_NAME and SERVER_ADDR in dtls_client.c to the dtls_server node's IP address. And build this application again.
-
-5. When initialization finished and network connected, run **main** in ntshell, it will try to do dtls communication.
+4. When initialization finished and network connected, run **main** in ntshell, it will try to do dtls communication.
 
 Sample Output
 =============
 
 .. code-block:: console
 
-
+	-----------------------------------------------------------
+	 ____                                _ ____
+	|  _ \ _____      _____ _ __ ___  __| | __ ) _   _
+	| |_) / _ \ \ /\ / / _ \ '__/ _ \/ _` |  _ \| | | |
+	|  __/ (_) \ V  V /  __/ | |  __/ (_| | |_) | |_| |
+	|_|   \___/ \_/\_/ \___|_|  \___|\__,_|____/ \__, |
+	                                             |___/
+	                     _       _    ____   ____
+	       ___ _ __ ___ | |__   / \  |  _ \ / ___|
+	      / _ \ '_ ` _ \| '_ \ / _ \ | |_) | |
+	     |  __/ | | | | | |_) / ___ \|  _ <| |___
+	      \___|_| |_| |_|_.__/_/   \_\_| \_\\____|
+	------------------------------------------------------------
+
+	embARC Build Time: Jan 23 2019, 10:57:51
+	Compiler Version: Metaware, 4.2.1 Compatible Clang 6.0.1 (branches/release_60)
+	FatFS initialized successfully!
+	Start Init LWIP
+	ntshell command info(Information) was registered!
+	ntshell command main(Call main function) was registered!
+	ntshell command ls(List information about files) was registered!
+	ntshell command cd(Change the working directory) was registered!
+	ntshell command rm(Remove the file or the folder) was registered!
+	ntshell command mkdir(Create the directory) was registered!
+	ntshell command cat(Output file contents) was registered!
+	ntshell command cp(Copy source to destination) was registered!
+	ntshell command mv(Rename file or move file) was registered!
+	ntshell command pwd(Print the current working directory) was registered!
+	ntshell command cls(Clear the console output) was registered!
+	ntshell command touch(Create a file) was registered!
+	ntshell command ymodem(Ymodem file transfer protocol) was registered!
+	ntshell command disk(Operate the storge device) was registered!
+	ntshell command load(Load .bin/.hex file from SD card to ram at specified address) was registered!
+	ntshell command go(Run the program at the specified address) was registered!
+	NTShell Task StartUp
+	COM1>RS9113 MAC ADDRESS:00-00-00-00-00-00
+
+	Now trying to connect to WIFI hotspot, please wait about 30s!
+	RS9113 MAC ADDRESS:88-da-1a-0b-5e-4c
+	Link is UP!
+
+	Now start get ip address using DHCP, Please wait about 30s!
+
+	-----WIFI IP ADDRESS INFO-----
+	ipaddr 192.168.137.46 netmask 255.255.255.0 gw 192.168.137.1
+	dns server 0 :192.168.137.1
+	dns server 1 :0.0.0.0
+	-----------------------------------
+	WiFi connected
+	Please run NT-Shell command(main) to start your application.
+	main command may required some arguments, please refer to example's document.
+	main
+
+	. Seeding the random number generator... ok
+	. Loading the CA root certificate ... ok (0 skipped)
+	. Connecting to udp/192.168.43.252/4433... ok
+	. Setting up the DTLS structure... ok
+	. Performing the SSL/TLS handshake... ok
+	. Verifying peer X.509 certificate... failed
+	! The certificate Common Name (CN) does not match with the expected CN
+	! The certificate is signed with an unacceptable hash.
+
+	> Write to server: 9 bytes written
+
+	Echo this
+
+	< Read from server: 9 bytes read
+
+	Echo this
+
+	. Closing the connection... done
 
diff --git a/example/freertos/sec/mbedtls/dtls/server/README.rst b/example/freertos/sec/mbedtls/dtls/server/README.rst
index 61c66bb83..6e301e677 100644
--- a/example/freertos/sec/mbedtls/dtls/server/README.rst
+++ b/example/freertos/sec/mbedtls/dtls/server/README.rst
@@ -17,7 +17,6 @@ Detailed Description
 * Extra Required Peripherals
 
     - Digilent PMOD WIFI(MRF24WG0MA)
-    - SD Card to store certification file, key file
 
 .. note::
    EMSDP has board WiFi module, no need to use PMOD WiFI.
@@ -37,14 +36,95 @@ Buidling and Running
    cd <embarc_root>/middleware/mbedtls
    sh apply_embarc_patch.sh
 
+2. When initialization finished and network connected, run **main** in ntshell, it will try to do dtls communication.
 
-2. Copy the ``tests`` dir in ``middleware/mbedtls`` into the SD card of secure server node, it will load CA file and key file.
-
-3. When initialization finished and network connected, run **main** in ntshell, it will try to do dtls communication.
-
-4. In pc node or mbedtls dtls_client node, run the client application to connect to the server node.
+3. In pc node or mbedtls dtls_client node, run the client application to connect to the server node.
 
 Sample Output
 =============
 
-.. code-block:: console
\ No newline at end of file
+.. code-block:: console
+
+	-----------------------------------------------------------
+	 ____                                _ ____
+	|  _ \ _____      _____ _ __ ___  __| | __ ) _   _
+	| |_) / _ \ \ /\ / / _ \ '__/ _ \/ _` |  _ \| | | |
+	|  __/ (_) \ V  V /  __/ | |  __/ (_| | |_) | |_| |
+	|_|   \___/ \_/\_/ \___|_|  \___|\__,_|____/ \__, |
+	                                             |___/
+	                     _       _    ____   ____
+	       ___ _ __ ___ | |__   / \  |  _ \ / ___|
+	      / _ \ '_ ` _ \| '_ \ / _ \ | |_) | |
+	     |  __/ | | | | | |_) / ___ \|  _ <| |___
+	      \___|_| |_| |_|_.__/_/   \_\_| \_\\____|
+	------------------------------------------------------------
+
+	embARC Build Time: Jan 23 2019, 11:21:59
+	Compiler Version: Metaware, 4.2.1 Compatible Clang 6.0.1 (branches/release_60)
+	FatFS initialized successfully!
+	Start Init LWIP
+	ntshell command info(Information) was registered!
+	ntshell command main(Call main function) was registered!
+	ntshell command ls(List information about files) was registered!
+	ntshell command cd(Change the working directory) was registered!
+	ntshell command rm(Remove the file or the folder) was registered!
+	ntshell command mkdir(Create the directory) was registered!
+	ntshell command cat(Output file contents) was registered!
+	ntshell command cp(Copy source to destination) was registered!
+	ntshell command mv(Rename file or move file) was registered!
+	ntshell command pwd(Print the current working directory) was registered!
+	ntshell command cls(Clear the console output) was registered!
+	ntshell command touch(Create a file) was registered!
+	ntshell command ymodem(Ymodem file transfer protocol) was registered!
+	ntshell command disk(Operate the storge device) was registered!
+	ntshell command load(Load .bin/.hex file from SD card to ram at specified address) was registered!
+	ntshell command go(Run the program at the specified address) was registered!
+	ntshell command spirw(Read/Write the image in spi flash for updating bootloader/application image) was registered!
+	ntshell command mload(Update firmware, read or write MCS file in the SPI flash) was registered!
+	NTShell Task StartUp
+	COM1>
+	Now trying to connect to WIFI hotspot, please wait about 30s!
+	MRF24G Device Information As Follows:
+	Device Type:2, ROM Ver:31, Patch Ver:7
+	Connection Profile ID:1
+	WF INIT SUCCESSFULL!
+	MRF24G MAC ADDRESS:00-1e-c0-0e-71-ac
+	WF_EVENT_CONNECTION_SUCCESSFUL
+	Link is UP!
+
+	Now start get ip address using DHCP, Please wait about 30s!
+
+	-----WIFI IP ADDRESS INFO-----
+	ipaddr 192.168.137.39 netmask 255.255.255.0 gw 192.168.137.1
+	dns server 0 :192.168.137.1
+	dns server 1 :0.0.0.0
+	-----------------------------------
+	WiFi connected
+	Please run NT-Shell command(main) to start your application.
+	main command may required some arguments, please refer to example's document.
+	main
+
+	. Loading the server cert. and key... ok
+	. Bind on udp/*/4433 ... ok
+	. Seeding the random number generator... ok
+	. Setting up the DTLS data... ok
+	. Waiting for a remote connection ... ok
+	. Performing the DTLS handshake... hello verification requested
+	. Waiting for a remote connection ... ok
+	. Performing the DTLS handshake... ok
+	< Read from client: 9 bytes read
+
+	Echo this
+
+	> Write to client: 9 bytes written
+
+	Echo this
+
+	. Closing the connection... done
+	. Waiting for a remote connection ... ok
+	. Performing the DTLS handshake... failed
+	! mbedtls_ssl_handshake returned -0x7900
+
+	Last error was: -30976 - SSL - Processing of the ClientHello handshake message failed
+
+	. Waiting for a remote connection ...
\ No newline at end of file
diff --git a/example/freertos/sec/mbedtls/ssl/client2/README.rst b/example/freertos/sec/mbedtls/ssl/client2/README.rst
index 936375954..5e26746ed 100644
--- a/example/freertos/sec/mbedtls/ssl/client2/README.rst
+++ b/example/freertos/sec/mbedtls/ssl/client2/README.rst
@@ -7,7 +7,7 @@ FreeRTOS mbed SSL Example: SSL Client
 Overview
 ********
 
-This example takes reference from mbedtls **ssL_client2 ** to test ssl client functionality.
+This example takes reference from mbedtls **ssL_client2** to test ssl client functionality.
 
 
 Detailed Description
@@ -18,7 +18,6 @@ Detailed Description
 * Extra Required Peripherals
 
     - Digilent PMOD WIFI(MRF24WG0MA)
-    - SD Card to store certification file, key file
 
 .. note::
    EMSDP has board WiFi module, no need to use PMOD WiFI.
@@ -43,10 +42,7 @@ commands
 
 2. In pc node or mbedtls ssl server node, run the server application to listen.
 
-3. Copy the ``tests`` dir in ``middleware/mbedtls`` into the SD card of secure
-server node, it will load CA file and key file.
-
-4. Here the mbedtls ssl server node's ip address is 192.168.43.76, we can get
+3. Here the mbedtls ssl server node's ip address is 192.168.43.76, we can get
 it from console output of uart. When initialization finished and network
 connected, run **main server_addr=192.168.43.76 auth_mode=optional** in
 ntshell, it will try to do ssl communication.
@@ -54,4 +50,98 @@ ntshell, it will try to do ssl communication.
 Sample Output
 =============
 
-.. code-block:: console
\ No newline at end of file
+.. code-block:: console
+
+	-----------------------------------------------------------
+	 ____                                _ ____
+	|  _ \ _____      _____ _ __ ___  __| | __ ) _   _
+	| |_) / _ \ \ /\ / / _ \ '__/ _ \/ _` |  _ \| | | |
+	|  __/ (_) \ V  V /  __/ | |  __/ (_| | |_) | |_| |
+	|_|   \___/ \_/\_/ \___|_|  \___|\__,_|____/ \__, |
+	                                             |___/
+	                     _       _    ____   ____
+	       ___ _ __ ___ | |__   / \  |  _ \ / ___|
+	      / _ \ '_ ` _ \| '_ \ / _ \ | |_) | |
+	     |  __/ | | | | | |_) / ___ \|  _ <| |___
+	      \___|_| |_| |_|_.__/_/   \_\_| \_\\____|
+	------------------------------------------------------------
+
+	embARC Build Time: Jan 23 2019, 11:38:25
+	Compiler Version: Metaware, 4.2.1 Compatible Clang 6.0.1 (branches/release_60)
+	FatFS initialized successfully!
+	Start Init LWIP
+	ntshell command info(Information) was registered!
+	ntshell command main(Call main function) was registered!
+	ntshell command ls(List information about files) was registered!
+	ntshell command cd(Change the working directory) was registered!
+	ntshell command rm(Remove the file or the folder) was registered!
+	ntshell command mkdir(Create the directory) was registered!
+	ntshell command cat(Output file contents) was registered!
+	ntshell command cp(Copy source to destination) was registered!
+	ntshell command mv(Rename file or move file) was registered!
+	ntshell command pwd(Print the current working directory) was registered!
+	ntshell command cls(Clear the console output) was registered!
+	ntshell command touch(Create a file) was registered!
+	ntshell command ymodem(Ymodem file transfer protocol) was registered!
+	ntshell command disk(Operate the storge device) was registered!
+	ntshell command load(Load .bin/.hex file from SD card to ram at specified address) was registered!
+	ntshell command go(Run the program at the specified address) was registered!
+	NTShell Task StartUp
+	COM1>RS9113 MAC ADDRESS:00-00-00-00-00-00
+
+	Now trying to connect to WIFI hotspot, please wait about 30s!
+	RS9113 MAC ADDRESS:88-da-1a-0b-5e-4c
+	Link is UP!
+
+	Now start get ip address using DHCP, Please wait about 30s!
+
+	-----WIFI IP ADDRESS INFO-----
+	ipaddr 192.168.137.46 netmask 255.255.255.0 gw 192.168.137.1
+	dns server 0 :192.168.137.1
+	dns server 1 :0.0.0.0
+	-----------------------------------
+	WiFi connected
+	Please run NT-Shell command(main) to start your application.
+	main command may required some arguments, please refer to example's document.
+	main server_addr=192.168.137.39 auth_mode=optional
+
+	. Seeding the random number generator... ok
+	. Loading the CA root certificate ... ok (0 skipped)
+	. Loading the client cert. and key... ok
+	. Connecting to tcp/192.168.137.39/4433... ok
+	. Setting up the SSL/TLS structure... ok
+	. Performing the SSL/TLS handshake... ok
+		[ Protocol is TLSv1.2 ]
+		[ Ciphersuite is TLS-ECDHE-ECDSA-WITH-AES-256-GCM-SHA384 ]
+		[ Record expansion is 29 ]
+		[ Maximum fragment length is 16384 ]
+	. Verifying peer X.509 certificate... failed
+	! The certificate validity has expired
+	! The certificate Common Name (CN) does not match with the expected CN
+	! The certificate validity starts in the future
+
+	. Peer certificate information    ...
+		cert. version     : 3
+		serial number     : 09
+		issuer name       : C=NL, O=PolarSSL, CN=Polarssl Test EC CA
+		subject name      : C=NL, O=PolarSSL, CN=localhost
+		issued  on        : 2013-09-24 15:52:04
+		expires on        : 2023-09-22 15:52:04
+		signed using      : ECDSA with SHA256
+		EC key size       : 256 bits
+		basic constraints : CA=false
+
+	> Write to server: 34 bytes written in 1 fragments
+
+	GET / HTTP/1.0
+	Extra-header:
+
+
+	< Read from server: 152 bytes read
+
+	HTTP/1.0 200 OK
+	Content-Type: text/html
+
+	<h2>mbed TLS Test Server</h2>
+	<p>Successful connection using: TLS-ECDHE-ECDSA-WITH-AES-256-GCM-SHA384</p>
+	. Closing the connection... done
diff --git a/example/freertos/sec/mbedtls/ssl/server2/README.rst b/example/freertos/sec/mbedtls/ssl/server2/README.rst
index 7403e5205..95fe8b181 100644
--- a/example/freertos/sec/mbedtls/ssl/server2/README.rst
+++ b/example/freertos/sec/mbedtls/ssl/server2/README.rst
@@ -7,7 +7,7 @@ FreeRTOS mbed SSL Example: SSL Server
 Overview
 ********
 
-This example takes reference from mbedtls **ssl_server2 ** to test ssl server
+This example takes reference from mbedtls **ssl_server2** to test ssl server
 functionality.
 
 
@@ -19,7 +19,6 @@ Detailed Description
 * Extra Required Peripherals
 
     - Digilent PMOD WIFI(MRF24WG0MA)
-    - SD Card to store certification file, key file
 
 .. note::
    EMSDP has board WiFi module, no need to use PMOD WiFI.
@@ -42,12 +41,100 @@ commands
    cd <embarc_root>/middleware/mbedtls
    sh apply_embarc_patch.sh
 
-2. Copy the ``tests`` dir in ``middleware/mbedtls`` into the SD card of secure
-server node, it will load CA file and key file.
-
-3. When initialization finished and network connected, run **main auth_mode=optional** in ntshell, it will wait for ssl client to connect to it.
+2. When initialization finished and network connected, run **main auth_mode=optional** in ntshell, it will wait for ssl client to connect to it.
 
 Sample Output
 =============
 
-.. code-block:: console
\ No newline at end of file
+.. code-block:: console
+
+	-----------------------------------------------------------
+	 ____                                _ ____
+	|  _ \ _____      _____ _ __ ___  __| | __ ) _   _
+	| |_) / _ \ \ /\ / / _ \ '__/ _ \/ _` |  _ \| | | |
+	|  __/ (_) \ V  V /  __/ | |  __/ (_| | |_) | |_| |
+	|_|   \___/ \_/\_/ \___|_|  \___|\__,_|____/ \__, |
+	                                             |___/
+	                     _       _    ____   ____
+	       ___ _ __ ___ | |__   / \  |  _ \ / ___|
+	      / _ \ '_ ` _ \| '_ \ / _ \ | |_) | |
+	     |  __/ | | | | | |_) / ___ \|  _ <| |___
+	      \___|_| |_| |_|_.__/_/   \_\_| \_\\____|
+	------------------------------------------------------------
+
+	embARC Build Time: Jan 23 2019, 11:35:42
+	Compiler Version: Metaware, 4.2.1 Compatible Clang 6.0.1 (branches/release_60)
+	FatFS initialized successfully!
+	Start Init LWIP
+	ntshell command info(Information) was registered!
+	ntshell command main(Call main function) was registered!
+	ntshell command ls(List information about files) was registered!
+	ntshell command cd(Change the working directory) was registered!
+	ntshell command rm(Remove the file or the folder) was registered!
+	ntshell command mkdir(Create the directory) was registered!
+	ntshell command cat(Output file contents) was registered!
+	ntshell command cp(Copy source to destination) was registered!
+	ntshell command mv(Rename file or move file) was registered!
+	ntshell command pwd(Print the current working directory) was registered!
+	ntshell command cls(Clear the console output) was registered!
+	ntshell command touch(Create a file) was registered!
+	ntshell command ymodem(Ymodem file transfer protocol) was registered!
+	ntshell command disk(Operate the storge device) was registered!
+	ntshell command load(Load .bin/.hex file from SD card to ram at specified address) was registered!
+	ntshell command go(Run the program at the specified address) was registered!
+	ntshell command spirw(Read/Write the image in spi flash for updating bootloader/application image) was registered!
+	ntshell command mload(Update firmware, read or write MCS file in the SPI flash) was registered!
+	NTShell Task StartUp
+	COM1>
+	Now trying to connect to WIFI hotspot, please wait about 30s!
+	MRF24G Device Information As Follows:
+	Device Type:2, ROM Ver:31, Patch Ver:7
+	Connection Profile ID:1
+	WF INIT SUCCESSFULL!
+	MRF24G MAC ADDRESS:00-1e-c0-0e-71-ac
+	WF_EVENT_CONNECTION_FAILED
+	WF_EVENT_CONNECTION_SUCCESSFUL
+	Link is UP!
+
+	Now start get ip address using DHCP, Please wait about 30s!
+
+	-----WIFI IP ADDRESS INFO-----
+	ipaddr 192.168.137.39 netmask 255.255.255.0 gw 192.168.137.1
+	dns server 0 :192.168.137.1
+	dns server 1 :0.0.0.0
+	-----------------------------------
+	WiFi connected
+	Please run NT-Shell command(main) to start your application.
+	main command may required some arguments, please refer to example's document.
+	main
+
+	. Seeding the random number generator... ok
+	. Loading the CA root certificate ... ok (0 skipped)
+	. Loading the server cert. and key... ok
+	. Bind on tcp://*:4433/ ... ok
+	. Setting up the SSL/TLS structure... ok
+	. Waiting for a remote connection ... ok
+	. Performing the SSL/TLS handshake... ok
+		[ Protocol is TLSv1.2 ]
+		[ Ciphersuite is TLS-ECDHE-ECDSA-WITH-AES-256-GCM-SHA384 ]
+		[ Record expansion is 29 ]
+		[ Maximum fragment length is 16384 ]
+	. Verifying peer X.509 certificate... failed
+	! Certificate verification was skipped
+
+	< Read from client: 34 bytes read
+
+	GET / HTTP/1.0
+	Extra-header:
+
+
+	> Write to client: 152 bytes written in 1 fragments
+
+	HTTP/1.0 200 OK
+	Content-Type: text/html
+
+	<h2>mbed TLS Test Server</h2>
+	<p>Successful connection using: TLS-ECDHE-ECDSA-WITH-AES-256-GCM-SHA384</p>
+
+	. Closing the connection... done
+	. Waiting for a remote connection ...
diff --git a/example/freertos/stack_check/FreeRTOSConfig.h b/example/freertos/stack_check/FreeRTOSConfig.h
new file mode 100644
index 000000000..77c7b88bb
--- /dev/null
+++ b/example/freertos/stack_check/FreeRTOSConfig.h
@@ -0,0 +1,113 @@
+/*
+    FreeRTOS V8.0.0 - Copyright (C) 2014 Real Time Engineers Ltd.
+    All rights reserved
+
+    VISIT http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION.
+
+    ***************************************************************************
+     *                                                                       *
+     *    FreeRTOS provides completely free yet professionally developed,    *
+     *    robust, strictly quality controlled, supported, and cross          *
+     *    platform software that has become a de facto standard.             *
+     *                                                                       *
+     *    Help yourself get started quickly and support the FreeRTOS         *
+     *    project by purchasing a FreeRTOS tutorial book, reference          *
+     *    manual, or both from: http://www.FreeRTOS.org/Documentation        *
+     *                                                                       *
+     *    Thank you!                                                         *
+     *                                                                       *
+    ***************************************************************************
+
+    This file is part of the FreeRTOS distribution.
+
+    FreeRTOS is free software; you can redistribute it and/or modify it under
+    the terms of the GNU General Public License (version 2) as published by the
+    Free Software Foundation >>!AND MODIFIED BY!<< the FreeRTOS exception.
+
+    >>! NOTE: The modification to the GPL is included to allow you to distribute
+    >>! a combined work that includes FreeRTOS without being obliged to provide
+    >>! the source code for proprietary components outside of the FreeRTOS
+    >>! kernel.
+
+    FreeRTOS is distributed in the hope that it will be useful, but WITHOUT ANY
+    WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+    FOR A PARTICULAR PURPOSE.  Full license text is available from the following
+    link: http://www.freertos.org/a00114.html
+
+    1 tab == 4 spaces!
+
+    ***************************************************************************
+     *                                                                       *
+     *    Having a problem?  Start by reading the FAQ "My application does   *
+     *    not run, what could be wrong?"                                     *
+     *                                                                       *
+     *    http://www.FreeRTOS.org/FAQHelp.html                               *
+     *                                                                       *
+    ***************************************************************************
+
+    http://www.FreeRTOS.org - Documentation, books, training, latest versions,
+    license and Real Time Engineers Ltd. contact details.
+
+    http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products,
+    including FreeRTOS+Trace - an indispensable productivity tool, a DOS
+    compatible FAT file system, and our tiny thread aware UDP/IP stack.
+
+    http://www.OpenRTOS.com - Real Time Engineers ltd license FreeRTOS to High
+    Integrity Systems to sell under the OpenRTOS brand.  Low cost OpenRTOS
+    licenses offer ticketed support, indemnification and middleware.
+
+    http://www.SafeRTOS.com - High Integrity Systems also provide a safety
+    engineered and independently SIL3 certified version for use in safety and
+    mission critical applications that require provable dependability.
+
+    1 tab == 4 spaces!
+*/
+
+#ifndef FREERTOS_CONFIG_H
+#define FREERTOS_CONFIG_H
+
+#include <stdio.h>
+/*-----------------------------------------------------------
+ * Application specific definitions.
+ *
+ * These definitions should be adjusted for your particular hardware and
+ * application requirements.
+ *
+ * THESE PARAMETERS ARE DESCRIBED WITHIN THE 'CONFIGURATION' SECTION OF THE
+ * FreeRTOS API DOCUMENTATION AVAILABLE ON THE FreeRTOS.org WEB SITE.
+ *
+ * See http://www.freertos.org/a00110.html.
+ *----------------------------------------------------------*/
+
+#define configUSE_PREEMPTION                    1
+#define configUSE_IDLE_HOOK                     0
+#define configUSE_TICK_HOOK                     0
+#define configCPU_CLOCK_HZ                      ( ( unsigned long ) BOARD_CPU_CLOCK )
+#define configTICK_RATE_HZ                      ( ( TickType_t ) 1000 )
+#define configMAX_PRIORITIES                    ( 4 )
+#define configMINIMAL_STACK_SIZE                ( ( unsigned short ) 104 )
+#define configTOTAL_HEAP_SIZE                   ( ( size_t ) ( 18 * 1024 ) )
+#define configMAX_TASK_NAME_LEN                 ( 10 )
+#define configUSE_TRACE_FACILITY                0
+#define configUSE_16_BIT_TICKS                  0
+#define configIDLE_SHOULD_YIELD                 1
+#define configUSE_MUTEXES                       1
+
+/* Co-routine definitions. */
+#define configUSE_CO_ROUTINES                   0
+#define configMAX_CO_ROUTINE_PRIORITIES         ( 2 )
+
+
+/* Set the following definitions to 1 to include the API function, or zero
+to exclude the API function. */
+
+#define INCLUDE_vTaskPrioritySet                1
+#define INCLUDE_uxTaskPriorityGet               1
+#define INCLUDE_vTaskDelete                     1
+#define INCLUDE_vTaskCleanUpResources           0
+#define INCLUDE_vTaskSuspend                    1
+#define INCLUDE_vTaskDelayUntil                 1
+#define INCLUDE_vTaskDelay                      1
+#define INCLUDE_xTaskGetCurrentTaskHandle       1
+
+#endif /* FREERTOS_CONFIG_H */
\ No newline at end of file
diff --git a/example/freertos/stack_check/main.c b/example/freertos/stack_check/main.c
new file mode 100644
index 000000000..971ad4c11
--- /dev/null
+++ b/example/freertos/stack_check/main.c
@@ -0,0 +1,435 @@
+/* ------------------------------------------
+ * Copyright (c) 2017, Synopsys, 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.
+
+ * 3) Neither the name of the Synopsys, Inc., nor the names of its contributors may
+ * be used to endorse or promote products derived from this software without
+ * specific prior written permission.
+
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 COPYRIGHT HOLDER 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.
+ *
+--------------------------------------------- */
+
+/**
+ * \defgroup	EMBARC_APP_FREERTOS_KERNEL	embARC FreeRTOS Kernel Example
+ * \ingroup	EMBARC_APPS_TOTAL
+ * \ingroup	EMBARC_APPS_OS_FREERTOS
+ * \brief	embARC Example for testing FreeRTOS task switch and interrupt/exception handling
+ *
+ * \details
+ * ### Extra Required Tools
+ *
+ * ### Extra Required Peripherals
+ *
+ * ### Design Concept
+ *     This example is designed to show the functionality of FreeRTOS.
+ *
+ * ### Usage Manual
+ *     Test case for show how FreeRTOS is working by task switching and interrupt/exception processing.
+ *     ![ScreenShot of freertos-demo under freertos](pic/images/example/emsk/emsk_freertos_demo.jpg)
+ *
+ * ### Extra Comments
+ *
+ */
+
+/**
+ * \file
+ * \ingroup	EMBARC_APP_FREERTOS_KERNEL
+ * \brief	main source file of the freertos demo
+ */
+
+/**
+ * \addtogroup	EMBARC_APP_FREERTOS_KERNEL
+ * @{
+ */
+
+#include "embARC.h"
+#include "embARC_debug.h"
+#include <stdlib.h>
+
+static void task1(void *par);
+static void task2(void *par);
+static void trap_exception(void *p_excinf);
+static void soft_interrupt(void *p_excinf);
+
+#ifdef INTNO_I2C0
+	#define SWI_INTNO		INTNO_I2C0
+#else
+	#define SWI_INTNO		20
+#endif
+
+#define TSK_PRIOR_HI		(configMAX_PRIORITIES-1)
+#define TSK_PRIOR_LO		(configMAX_PRIORITIES-2)
+
+// Task IDs
+static TaskHandle_t task1_handle = NULL;
+static TaskHandle_t task2_handle = NULL;
+
+// Mutex IDs
+static SemaphoreHandle_t mux1_id;
+
+// Semaphores
+static SemaphoreHandle_t sem1_id;
+
+// Events
+static EventGroupHandle_t evt1_cb;
+#define EVENT_WAIT_BITS		0x00000001
+
+// Queues
+static QueueHandle_t dtq1_id;
+
+// Local parameters
+static volatile unsigned int start = 0;
+static unsigned int perf_id = 0xFF;
+
+//#define ENABLE_DETAILED_RESULT_OUTPUT
+
+// Change this macro if you want to run more or less times
+#define MAX_SAMPLES		200
+
+#define TASK_DELAY_MS		2
+
+typedef struct _sample {
+	unsigned int t_measure;
+	unsigned int t_t2_t1;
+	unsigned int t_int_t1;
+	unsigned int t_t1_t2;
+	unsigned int t_t1_int;
+	unsigned int t_int_nest;
+	unsigned int t_nest_int;
+	unsigned int t_mux_rls;
+	unsigned int t_sem_snd;
+	unsigned int t_evt_snd;
+	unsigned int t_dtq_wri;
+} sample;
+
+
+static sample x;
+static sample x_aver = {0};
+
+static sample sample_array[MAX_SAMPLES];
+static int sample_count = 0;
+
+/** performance timer initialization */
+static void perf_init(unsigned int id)
+{
+	if (timer_start(id, TIMER_CTRL_NH, 0xFFFFFFFF) < 0) {
+		EMBARC_PRINTF("perf timer init failed\r\n");
+
+		while (1);
+	}
+
+	perf_id = id;
+}
+
+/** performance timer start */
+static void perf_start(void)
+{
+	if (timer_current(perf_id, (void *)(&start)) < 0) {
+		start = 0;
+	}
+}
+
+/** performance timer end, and return the time passed */
+static unsigned int perf_end(void)
+{
+	unsigned int end = 0;
+
+	if (timer_current(perf_id, (void *)(&end)) < 0) {
+		return 0;
+	}
+
+	if (start < end) {
+		return (end - start);
+	} else {
+		return (0xFFFFFFFF - start + end);
+	}
+}
+
+/**
+ * \brief  call FreeRTOS API, create and start tasks
+ */
+int main(void)
+{
+	EMBARC_PRINTF("Benchmark CPU Frequency: %d Hz\r\n", BOARD_CPU_CLOCK);
+	EMBARC_PRINTF("Benchmark will run %d times, please wait about %d ms\r\n", MAX_SAMPLES, (TASK_DELAY_MS*MAX_SAMPLES));
+
+	// Register interrupts
+	int_handler_install(SWI_INTNO, (EXC_HANDLER)soft_interrupt);
+	//int_pri_set(SWI_INTNO, INT_PRI_MIN);
+	int_enable(SWI_INTNO);
+
+	exc_handler_install(EXC_NO_TRAP, trap_exception); /*!< install the exception handler */
+
+	vTaskSuspendAll();
+
+	// Create Tasks
+	if (xTaskCreate(task1, "task1", 128, (void *)1, TSK_PRIOR_LO, &task1_handle)
+	    != pdPASS) {	/*!< FreeRTOS xTaskCreate() API function */
+		EMBARC_PRINTF("create task1 error\r\n");
+		return -1;
+	}
+
+	if (xTaskCreate(task2, "task2", 128, (void *)2, TSK_PRIOR_HI, &task2_handle)
+	    != pdPASS) {	/*!< FreeRTOS xTaskCreate() API function */
+		EMBARC_PRINTF("create task2 error\r\n");
+		return -1;
+	}
+
+	// Create Mutex
+	mux1_id = xSemaphoreCreateMutex();
+
+	// Create Semaphores
+	sem1_id = xSemaphoreCreateBinary();
+	xSemaphoreGive(sem1_id);
+
+	// Create Events
+	evt1_cb = xEventGroupCreate();
+
+	// Create Queues
+	dtq1_id = xQueueCreate(1, sizeof(uint32_t));
+
+	xTaskResumeAll();
+
+	vTaskSuspend(NULL);
+	vTaskSuspend(NULL);
+
+	return 0;
+}
+
+
+/**
+ * \brief  task1 in FreeRTOS
+ * \details Call vTaskDelayUntil() to execute task1 with a fixed period 1 second.
+ * \param[in] *par
+ */
+static void task1(void *par)
+{
+	uint32_t queue_data = 1;
+	TickType_t xLastExecutionTime;
+	volatile uint32_t data[32];
+	xLastExecutionTime = xTaskGetTickCount(); /*!< initialize current tick */
+
+	for (queue_data = 1; queue_data < 32; queue_data++) {
+		data[queue_data] = queue_data;
+	}
+	while (1) {
+		//// 1-E: Task2 --> Task1
+		x.t_t2_t1 = perf_end();
+		//// 2-S: Task1 --> Int
+		perf_start();
+		_arc_aux_write(AUX_IRQ_HINT, SWI_INTNO); /*!< activate soft_interrupt */
+		//// 5-E: Int --> Task1
+		x.t_int_t1 = perf_end();
+
+		// task delay, to control benchmark run speed
+		vTaskDelayUntil( &xLastExecutionTime, TASK_DELAY_MS);
+		// Task 1 acquire mutex first
+		xSemaphoreTake(mux1_id, portMAX_DELAY);
+		// Task 1 acquire semaphore first
+		xSemaphoreTake(sem1_id, portMAX_DELAY);
+
+		//// 6-S: Task1 --> Task2
+		perf_start();
+		vTaskResume(task2_handle);
+
+		//// 8-S: Mutex Release -> Mutex Acquire
+		perf_start();
+		// Task 1 release mutex, task 2 acquire it
+		xSemaphoreGive(mux1_id);
+
+		//// 9-S: Sem Post -> Sem Acquire
+		perf_start();
+		// Task 1 post sem, task 2 acquire it
+		xSemaphoreGive(sem1_id);
+
+		//// 10-S: Event Write -> Event Read
+		perf_start();
+		// Task 1 write event, task 2 read it
+		xEventGroupSetBits(evt1_cb, EVENT_WAIT_BITS);
+
+		//// 11-S: Queue Write -> Queue Read
+		perf_start();
+		// Task 1 write queue, task 2 read it
+		xQueueSend(dtq1_id, (void *)(&queue_data),  portMAX_DELAY);
+		queue_data ++;
+	}
+
+}
+
+/**
+ * \brief  task2 in FreeRTOS
+ * \details Print information in task2 and suspend task2.
+ * \param[in] *par
+ */
+static void task2(void *par)
+{
+	//volatile uint32_t * ptr;
+	static uint32_t perf_times = 0;
+	uint32_t queue_data = 0;
+	perf_init(TIMER_1);
+
+	//ptr = &queue_data;
+
+	//ptr += 16;
+
+	//*ptr = 10;
+
+	while (1) {
+		//// 1-S: Task2 --> Task1
+		perf_start();
+		vTaskSuspend(task2_handle); /*!< suspend task2 */
+		//// 6-E: Task1 --> Task2
+		x.t_t1_t2 = perf_end();
+		//// 7-S: Benchmark extra cost
+		perf_start();
+		//// 7-E: Benchmark extra cost
+		x.t_measure = perf_end();
+
+		// Task 2 wait for task 1 release mutex
+		xSemaphoreTake(mux1_id, portMAX_DELAY);
+		//// 8-E: Mutex Release -> Mutex Acquire
+		x.t_mux_rls = perf_end();
+		xSemaphoreGive(mux1_id);
+
+		// Task 2 wait for task 1 release sem
+		xSemaphoreTake(sem1_id, portMAX_DELAY);
+		//// 9-E: Sem Post -> Sem Acquire
+		x.t_sem_snd = perf_end();
+		xSemaphoreGive(sem1_id);
+
+		// Task 2 wait for task 1 set event
+		xEventGroupWaitBits(evt1_cb, EVENT_WAIT_BITS, pdTRUE, pdFALSE, portMAX_DELAY);
+
+		//// 10-E: Event Write -> Event Read
+		x.t_evt_snd = perf_end();
+
+		// Task 2 read queue
+		xQueueReceive(dtq1_id, (void *)(&queue_data), portMAX_DELAY);
+		//// 11-E: Queue Write -> Queue Read
+		x.t_dtq_wri = perf_end();
+
+		if (perf_times) {
+			if (sample_count < MAX_SAMPLES) {
+				sample_array[sample_count] = x;
+			} else {
+				/* Suspend task 1 */
+				vTaskSuspend(task1_handle);
+
+				for (int i = 0; i < MAX_SAMPLES; i ++) {
+					x_aver.t_measure += sample_array[i].t_measure;
+					x_aver.t_t2_t1 += sample_array[i].t_t2_t1;
+					x_aver.t_int_t1 += sample_array[i].t_int_t1;
+					x_aver.t_t1_t2 += sample_array[i].t_t1_t2;
+					x_aver.t_t1_int += sample_array[i].t_t1_int;
+					x_aver.t_int_nest += sample_array[i].t_int_nest;
+					x_aver.t_nest_int += sample_array[i].t_nest_int;
+					x_aver.t_mux_rls += sample_array[i].t_mux_rls;
+					x_aver.t_sem_snd += sample_array[i].t_sem_snd;
+					x_aver.t_evt_snd += sample_array[i].t_evt_snd;
+					x_aver.t_dtq_wri += sample_array[i].t_dtq_wri;
+				}
+
+				x_aver.t_measure /= MAX_SAMPLES;
+				x_aver.t_t2_t1 /= MAX_SAMPLES;
+				x_aver.t_int_t1 /= MAX_SAMPLES;
+				x_aver.t_t1_t2 /= MAX_SAMPLES;
+				x_aver.t_t1_int /= MAX_SAMPLES;
+				x_aver.t_int_nest /= MAX_SAMPLES;
+				x_aver.t_nest_int /= MAX_SAMPLES;
+				x_aver.t_mux_rls /= MAX_SAMPLES;
+				x_aver.t_sem_snd /= MAX_SAMPLES;
+				x_aver.t_evt_snd /= MAX_SAMPLES;
+				x_aver.t_dtq_wri /= MAX_SAMPLES;
+
+				EMBARC_PRINTF("\r\n");
+				EMBARC_PRINTF("Average benchmark result list as follows:\r\n");
+				EMBARC_PRINTF("extra measurement cost : %d cycles\r\n", x_aver.t_measure);
+				EMBARC_PRINTF("task2     ->  task1    : %d cycles\r\n", x_aver.t_t2_t1);
+				EMBARC_PRINTF("task1     ->  int      : %d cycles\r\n", x_aver.t_t1_int);
+				EMBARC_PRINTF("int       ->  nest int : %d cycles\r\n", x_aver.t_int_nest);
+				EMBARC_PRINTF("nest int  ->  int      : %d cycles\r\n", x_aver.t_nest_int);
+				EMBARC_PRINTF("int       ->  task1    : %d cycles\r\n", x_aver.t_int_t1);
+				EMBARC_PRINTF("task1     ->  task2    : %d cycles\r\n", x_aver.t_t1_t2);
+				EMBARC_PRINTF("mux: tsk1 ->  tsk2     : %d cycles\r\n", x_aver.t_mux_rls);
+				EMBARC_PRINTF("sem: tsk1 ->  tsk2     : %d cycles\r\n", x_aver.t_sem_snd);
+				EMBARC_PRINTF("evt: tsk1 ->  tsk2     : %d cycles\r\n", x_aver.t_evt_snd);
+				EMBARC_PRINTF("dtq: tsk1 ->  tsk2     : %d cycles\r\n", x_aver.t_dtq_wri);
+				EMBARC_PRINTF("\r\n");
+
+#ifdef ENABLE_DETAILED_RESULT_OUTPUT
+				EMBARC_PRINTF("Detailed benchmark result table list as follows:\r\n");
+				EMBARC_PRINTF("t_measure t_t2_t1 t_t1_int t_int_nest t_nest_int t_int_t1 t_t1_t2 t_mux_rls t_sem_snd t_evt_snd t_dtq_wri\r\n");
+
+				for (int i = 0; i < MAX_SAMPLES; i ++) {
+					EMBARC_PRINTF("%d\t%d\t%d\t%d\t%d\t%d\t%d\t%d\t%d\t%d\t%d\r\n", \
+					              sample_array[i].t_measure, sample_array[i].t_t2_t1, \
+					              sample_array[i].t_t1_int, sample_array[i].t_int_nest, \
+					              sample_array[i].t_nest_int, sample_array[i].t_int_t1, \
+					              sample_array[i].t_t1_t2, sample_array[i].t_mux_rls, \
+					              sample_array[i].t_sem_snd, sample_array[i].t_evt_snd, \
+					              sample_array[i].t_dtq_wri);
+				}
+
+#endif
+				exit(0); /* Exit benchmark application */
+			}
+
+			sample_count ++;
+		}
+
+		perf_times ++;
+	}
+}
+
+/**
+ * \brief  trap exception
+ * \details Call xTaskResumeFromISR() to resume task2 that can be called from within ISR.
+ * If resuming the task2 should result in a context switch, call vPortYieldFromIsr() to generate task switch request.
+ * \param[in] *p_excinf
+ */
+static void trap_exception(void *p_excinf)
+{
+	//// 3-E: Int --> Nest Int
+	x.t_int_nest = perf_end();
+	//// 4-S: Nest Int --> Int
+	perf_start();
+}
+
+/**
+ * \brief  soft interrupt
+ * \details Call trap_s instruction to raise the exception.
+ * \param[in] *p_excinf
+ */
+static void soft_interrupt(void *p_exinf)
+{
+	//// 2-E: Task1 --> Int
+	x.t_t1_int = perf_end();
+	//// 3-S: Int --> Nest Int
+	perf_start();
+	Asm("trap_s 1");
+	//// 4-E: Nest Int --> Int
+	x.t_nest_int = perf_end();
+	//// 5-S: Int --> Task1
+	perf_start();
+}
+
+/** @} */
diff --git a/example/freertos/stack_check/makefile b/example/freertos/stack_check/makefile
new file mode 100644
index 000000000..b9797aedf
--- /dev/null
+++ b/example/freertos/stack_check/makefile
@@ -0,0 +1,26 @@
+# Application name
+APPL ?= freertos_kernel
+
+# Selected OS
+OS_SEL ?= freertos
+
+#
+# root dir of embARC
+#
+EMBARC_ROOT = ../../..
+
+MID_SEL = common
+
+# application source dirs
+APPL_CSRC_DIR = .
+APPL_ASMSRC_DIR = .
+
+# application include dirs
+APPL_INC_DIR = .
+
+# include current project makefile
+COMMON_COMPILE_PREREQUISITES += makefile
+
+### Options above must be added before include options.mk ###
+# include key embARC build system makefile
+include $(EMBARC_ROOT)/options/options.mk
diff --git a/library/secureshield/board/secureshield_normal_template_gnu.ld b/library/secureshield/board/secureshield_normal_template_gnu.ld
index 2a6ce7db3..65b5b3933 100644
--- a/library/secureshield/board/secureshield_normal_template_gnu.ld
+++ b/library/secureshield/board/secureshield_normal_template_gnu.ld
@@ -176,6 +176,15 @@ SECTIONS
 		_f_sdata = .;
 		__SDATA_BEGIN__ = .;
 		*(BACKGROUND_RAM_OBJS_LIST .sdata BACKGROUND_RAM_OBJS_LIST .sdata.* BACKGROUND_RAM_OBJS_LIST .gnu.linkonce.s.*)
+		PROVIDE (__sbss_start = .);
+		PROVIDE (___sbss_start = .);
+		_f_sbss = .;
+		*(BACKGROUND_RAM_OBJS_LIST .dynsbss)
+		*(BACKGROUND_RAM_OBJS_LIST .sbss BACKGROUND_RAM_OBJS_LIST .sbss.*  BACKGROUND_RAM_OBJS_LIST .gnu.linkonce.sb.*)
+		*(BACKGROUND_RAM_OBJS_LIST .scommon)
+		_e_sbss = .;
+		PROVIDE (__sbss_end = .);
+		PROVIDE (___sbss_end = .);
 		_e_sdata = .;
 		_e_data = .;
 		_e_data_background_container = .;
@@ -185,16 +194,7 @@ SECTIONS
 	.bss (NOLOAD) : ALIGN(4)
 	{
 		_f_bss_background_container = .;
-		PROVIDE (__sbss_start = .);
-		PROVIDE (___sbss_start = .);
 		_f_bss = .;
-		_f_sbss = .;
-		*(BACKGROUND_RAM_OBJS_LIST .dynsbss)
-		*(BACKGROUND_RAM_OBJS_LIST .sbss BACKGROUND_RAM_OBJS_LIST .sbss.*  BACKGROUND_RAM_OBJS_LIST .gnu.linkonce.sb.*)
-		*(BACKGROUND_RAM_OBJS_LIST .scommon)
-		_e_sbss = .;
-		PROVIDE (__sbss_end = .);
-		PROVIDE (___sbss_end = .);
 		*(BACKGROUND_RAM_OBJS_LIST .dynbss)
 		*(BACKGROUND_RAM_OBJS_LIST .bss BACKGROUND_RAM_OBJS_LIST .bss.* BACKGROUND_RAM_OBJS_LIST .gnu.linkonce.b.*)
 		*( COMMON)
diff --git a/library/secureshield/board/secureshield_normal_template_mw.ld b/library/secureshield/board/secureshield_normal_template_mw.ld
index 6c2f0063b..ac492a245 100644
--- a/library/secureshield/board/secureshield_normal_template_mw.ld
+++ b/library/secureshield/board/secureshield_normal_template_mw.ld
@@ -151,6 +151,7 @@ SECTIONS {
 			_f_data = .;
 			_f_sdata = .;
 			*(.sdata)
+			*(.sbss)
 			_e_sdata = .;
 			*(TYPE data)
 		}
diff --git a/library/secureshield/board/secureshield_secure_template_gnu.ld b/library/secureshield/board/secureshield_secure_template_gnu.ld
index b6e91e5ac..fc55e7434 100644
--- a/library/secureshield/board/secureshield_secure_template_gnu.ld
+++ b/library/secureshield/board/secureshield_secure_template_gnu.ld
@@ -56,14 +56,8 @@ SECTIONS {
 		_f_sdata = .;
 		__SDATA_BEGIN__ = .;
 		*(.sdata .sdata.* .gnu.linkonce.s.*)
-		_e_sdata = .;
-		_e_data = .;
-	} > SECURE_RAM AT > SECURE_ROM
-
-	.bss (NOLOAD) : ALIGN(4) {
 		PROVIDE (__sbss_start = .);
 		PROVIDE (___sbss_start = .);
-		_f_bss = .;
 		_f_sbss = .;
 		*(.dynsbss)
 		*(.sbss .sbss.* .gnu.linkonce.sb.*)
@@ -71,7 +65,12 @@ SECTIONS {
 		_e_sbss = .;
 		PROVIDE (__sbss_end = .);
 		PROVIDE (___sbss_end = .);
+		_e_sdata = .;
+		_e_data = .;
+	} > SECURE_RAM AT > SECURE_ROM
 
+	.bss (NOLOAD) : ALIGN(4) {
+		_f_bss = .;
 		*(.dynbss)
 		*(.bss .bss.* .gnu.linkonce.b.*)
 		*(COMMON)
diff --git a/library/secureshield/board/secureshield_secure_template_mw.ld b/library/secureshield/board/secureshield_secure_template_mw.ld
index 2d2c2d376..92a65e2b1 100644
--- a/library/secureshield/board/secureshield_secure_template_mw.ld
+++ b/library/secureshield/board/secureshield_secure_template_mw.ld
@@ -47,6 +47,7 @@ SECTIONS {
 			_f_data = .;
 			_f_sdata = .;
 			*(.sdata)
+			*(.sbss)
 			_e_sdata = .;
 			*(TYPE data)
 		}