diff --git a/Kconfig b/Kconfig
index c71394b1acd..77c73411dc9 100644
--- a/Kconfig
+++ b/Kconfig
@@ -281,6 +281,13 @@ config RRLOAD_BINARY
 		Create nuttx.rr in the rrload binary format used with
 		BSPs from www.ridgerun.com using the tools/mkimage.sh script.
 
+config CXD56_BINARY
+	bool "spk binary format"
+	default n
+	---help---
+		Create nuttx.spk binary format used on spresense board and boards
+		based on cxd56xx arch.
+
 config INTELHEX_BINARY
 	bool "Intel HEX binary format"
 	default n
diff --git a/configs/spresense/lcd/defconfig b/configs/spresense/lcd/defconfig
index 200848042ac..085629160a7 100644
--- a/configs/spresense/lcd/defconfig
+++ b/configs/spresense/lcd/defconfig
@@ -26,6 +26,7 @@ CONFIG_COMPOSITE_MSFT_OS_DESCRIPTORS=y
 CONFIG_COMPOSITE_PRODUCTID=0x0bc2
 CONFIG_COMPOSITE_VENDORID=0x054c
 CONFIG_COMPOSITE_VENDORSTR="Sony"
+CONFIG_CXD56_BINARY=y
 CONFIG_CXD56_DMAC_SPI4_RX=y
 CONFIG_CXD56_DMAC_SPI4_TX=y
 CONFIG_CXD56_I2C0=y
diff --git a/configs/spresense/mpy/defconfig b/configs/spresense/mpy/defconfig
index 74dc689357c..3b43d453568 100644
--- a/configs/spresense/mpy/defconfig
+++ b/configs/spresense/mpy/defconfig
@@ -19,6 +19,7 @@ CONFIG_BOARD_LOOPSPERMSEC=5434
 CONFIG_BOOT_RUNFROMISRAM=y
 CONFIG_BUILTIN=y
 CONFIG_CLOCK_MONOTONIC=y
+CONFIG_CXD56_BINARY=y
 CONFIG_CXD56_ADC=y
 CONFIG_CXD56_CISIF=y
 CONFIG_CXD56_HPADC0=y
diff --git a/configs/spresense/nsh/defconfig b/configs/spresense/nsh/defconfig
index f3264bf4cf7..00d1a5fa3da 100644
--- a/configs/spresense/nsh/defconfig
+++ b/configs/spresense/nsh/defconfig
@@ -17,6 +17,7 @@ CONFIG_BOARD_LOOPSPERMSEC=5434
 CONFIG_BOOT_RUNFROMISRAM=y
 CONFIG_BUILTIN=y
 CONFIG_CLOCK_MONOTONIC=y
+CONFIG_CXD56_BINARY=y
 CONFIG_CXD56_I2C0=y
 CONFIG_CXD56_I2C=y
 CONFIG_CXD56_SPI4=y
diff --git a/configs/spresense/rndis/defconfig b/configs/spresense/rndis/defconfig
index 2ebedc41744..0d30d533283 100644
--- a/configs/spresense/rndis/defconfig
+++ b/configs/spresense/rndis/defconfig
@@ -21,6 +21,7 @@ CONFIG_BOOT_RUNFROMISRAM=y
 CONFIG_BUILTIN=y
 CONFIG_CLOCK_MONOTONIC=y
 CONFIG_CODECS_HASH_MD5=y
+CONFIG_CXD56_BINARY=y
 CONFIG_CXD56_SDIO=y
 CONFIG_CXD56_USBDEV=y
 CONFIG_DEBUG_FULLOPT=y
diff --git a/configs/spresense/src/Makefile b/configs/spresense/src/Makefile
index a602db996a2..55ea240f8f6 100644
--- a/configs/spresense/src/Makefile
+++ b/configs/spresense/src/Makefile
@@ -39,6 +39,7 @@ DEPPATH = --dep-path .
 ASRCS =
 CSRCS =
 
+CSRCS += cxd56_main.c
 CSRCS += cxd56_boot.c
 CSRCS += cxd56_clock.c
 CSRCS += cxd56_bringup.c
diff --git a/configs/spresense/src/cxd56_main.c b/configs/spresense/src/cxd56_main.c
new file mode 100644
index 00000000000..0424e1edc9e
--- /dev/null
+++ b/configs/spresense/src/cxd56_main.c
@@ -0,0 +1,56 @@
+/****************************************************************************
+ * bsp/board/spresense/src/spresense_main.c
+ *
+ *   Copyright 2018 Sony Semiconductor Solutions Corporation
+ *
+ * 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 Sony Semiconductor Solutions Corporation 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 OWNER 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.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+#include <nuttx/compiler.h>
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/* This function is provided outside exported SDK, therefore here is defined
+ * as weak symbol to avoid link error.
+ */
+
+int nsh_main(int argc, char *argv[]);
+
+int weak_function spresense_main(int argc, char *argv[])
+{
+  return nsh_main(argc, argv);
+}
diff --git a/configs/spresense/usbmsc/defconfig b/configs/spresense/usbmsc/defconfig
index 0cfeff733bc..0d97b6c680c 100644
--- a/configs/spresense/usbmsc/defconfig
+++ b/configs/spresense/usbmsc/defconfig
@@ -26,6 +26,7 @@ CONFIG_COMPOSITE_MSFT_OS_DESCRIPTORS=y
 CONFIG_COMPOSITE_PRODUCTID=0x0bc2
 CONFIG_COMPOSITE_VENDORID=0x054c
 CONFIG_COMPOSITE_VENDORSTR="Sony"
+CONFIG_CXD56_BINARY=y
 CONFIG_CXD56_I2C0=y
 CONFIG_CXD56_I2C=y
 CONFIG_CXD56_SDIO=y
diff --git a/configs/spresense/usbnsh/defconfig b/configs/spresense/usbnsh/defconfig
index ef9926e7034..ddb4b5ac214 100644
--- a/configs/spresense/usbnsh/defconfig
+++ b/configs/spresense/usbnsh/defconfig
@@ -19,6 +19,7 @@ CONFIG_BOARD_LOOPSPERMSEC=5434
 CONFIG_BOOT_RUNFROMISRAM=y
 CONFIG_BUILTIN=y
 CONFIG_CLOCK_MONOTONIC=y
+CONFIG_CXD56_BINARY=y
 CONFIG_CXD56_I2C0=y
 CONFIG_CXD56_I2C=y
 CONFIG_CXD56_SDIO=y
diff --git a/configs/spresense/wifi/defconfig b/configs/spresense/wifi/defconfig
index 07e4caf7829..b3bfef0baa6 100644
--- a/configs/spresense/wifi/defconfig
+++ b/configs/spresense/wifi/defconfig
@@ -20,6 +20,7 @@ CONFIG_BOOT_RUNFROMISRAM=y
 CONFIG_BUILTIN=y
 CONFIG_CLOCK_MONOTONIC=y
 CONFIG_CODECS_HASH_MD5=y
+CONFIG_CXD56_BINARY=y
 CONFIG_CXD56_DMAC_SPI5_RX=y
 CONFIG_CXD56_DMAC_SPI5_TX=y
 CONFIG_CXD56_SDIO=y
diff --git a/tools/.gitignore b/tools/.gitignore
index 5c7facb0dba..a72cda1cfa9 100644
--- a/tools/.gitignore
+++ b/tools/.gitignore
@@ -20,3 +20,4 @@
 /*.dSYM
 /.k2h-body.dat
 /.k2h-apndx.dat
+/cxd56
\ No newline at end of file
diff --git a/tools/Makefile.unix b/tools/Makefile.unix
index 32442dae220..eb889627e9a 100644
--- a/tools/Makefile.unix
+++ b/tools/Makefile.unix
@@ -442,6 +442,18 @@ ifeq ($(CONFIG_RAW_BINARY),y)
 	@echo "CP: $(NUTTXNAME).bin"
 	$(Q) $(OBJCOPY) $(OBJCOPYARGS) -O binary $(BIN) $(NUTTXNAME).bin
 endif
+ifeq ($(CONFIG_CXD56_BINARY),y)
+	$(Q) if [ ! -f "tools/cxd56/mkspk" ] ; then \
+		echo ""; \
+		echo "Please run the following command to clone the needed tools"; \
+		echo "git clone https://github.com/sonydevworld/cxd56/ tools/cxd56"; \
+		echo ""; \
+		echo "run make again to create the nuttx.spk image."; \
+	else \
+		echo "Generating: $(NUTTXNAME).spk"; \
+		tools/cxd56/mkspk -c2 nuttx nuttx nuttx.spk; \
+	fi
+endif
 ifeq ($(CONFIG_UBOOT_UIMAGE),y)
 	@echo "MKIMAGE: uImage"
 	$(Q) mkimage -A $(CONFIG_ARCH) -O linux -C none -T kernel -a $(CONFIG_UIMAGE_LOAD_ADDRESS) \
diff --git a/tools/Makefile.win b/tools/Makefile.win
index 155e096e104..d6a5bce57e9 100644
--- a/tools/Makefile.win
+++ b/tools/Makefile.win
@@ -451,6 +451,18 @@ ifeq ($(CONFIG_RAW_BINARY),y)
 	@echo "CP: $(NUTTXNAME).bin"
 	$(Q) $(OBJCOPY) $(OBJCOPYARGS) -O binary $(BIN) $(NUTTXNAME).bin
 endif
+ifeq ($(CONFIG_CXD56_BINARY),y)
+	$(Q) if [ ! -f "tools/cxd56/mkspk.exe" ] ; then \
+		echo ""; \
+		echo "Please run the following command to clone the needed tools"; \
+		echo "git clone https://github.com/sonydevworld/cxd56/ tools\cxd56"; \
+		echo ""; \
+		echo "run make again to create the nuttx.spk image."; \
+	else \
+		echo "Generating: $(NUTTXNAME).spk"; \
+		tools\cxd56\mkspk.exe -c2 nuttx nuttx nuttx.spk; \
+	fi
+endif
 
 # $(BIN)
 #