The case of ARM CM4 & cxd32xx @NuttX12.4.0

Step1 : Add the SoC

Create the SoC directory.

 touch arch/arm/include/cxd32xx
 touch arch/arm/src/cxd32xx

Modify "arch/arm/Kconfig" to register the SoC directory.

Add "Kconfig" and "Make.defs" for the SoC directory.

 touch arch/arm/src/cxd32xx/Kconfig
 touch arch/arm/src/cxd32xx/Make.defs

For details about these files, see apache/nuttx/pull/12441

Step2 : Add the Board

There are two ways about adding the Board directory. The one is in-of-tree, another one is out-of-tree. For details see [[/guide](]{.title-ref}/guide.md)s/customboards`. And if you wanted to add own apps, see [[/guide](]{.title-ref}/guide.md)s/customapps`.

This time, the way of out-of-tree is selected. The directory structure is following :

apps/
nuttx/
out-of-tree/cxd32xx_boards

Create the board : cb2sdb2 as the board of cxd32xx.

 touch out-of-tree/cxd32xx_boards/cb2sdb2/configs/nsh
 touch out-of-tree/cxd32xx_boards/cb2sdb2/include
 touch out-of-tree/cxd32xx_boards/cb2sdb2/scripts
 touch out-of-tree/cxd32xx_boards/cb2sdb2/src

Add "Kconfig", "defconfig", "Make.defs" and "Makefile".

 touch out-of-tree/cxd32xx_boards/cb2sdb2/Kconfig
 touch out-of-tree/cxd32xx_boards/cb2sdb2/configs/nsh/defconfig
 touch out-of-tree/cxd32xx_boards/cb2sdb2/scripts/Make.defs
 touch out-of-tree/cxd32xx_boards/cb2sdb2/src/Makefile

For details about these files, see out-of-tree{.interpreted-text role="ref"}.

Step3 : Configure

Now you can do configure by following commands. It is important to confirm these commands are working.

 cd nuttx
 ./tools/configure.sh -l ../out-of-tree/cxd32xx_boards/cb2sdb2/configs/nsh

And you can do menuconfig by following command.

 make menuconfig

And you can do distclean by following command.

 make distclean

Step4 : Compile

Try to build with the implementation of Step1-2, you would face the error as following if you implemented only directory / Kconfig / Make.defs / Makefile / defconfig about Step1-2.

 make
Create version.h
LN: platform/board to /home/lassdk/workdir/nuttx1/apps/platform/dummy
In file included from /home/lassdk/workdir/nuttx1/nuttx/include/nuttx/irq.h:37:0,
                 from /home/lassdk/workdir/nuttx1/nuttx/include/nuttx/sched.h:40,
                 from /home/lassdk/workdir/nuttx1/nuttx/include/nuttx/arch.h:87,
                 from ./clock/clock_initialize.c:37:
/home/lassdk/workdir/nuttx1/nuttx/include/arch/irq.h:43:27: 
fatal error: arch/chip/irq.h: No such file or directory
compilation terminated.
ERROR: arm-none-eabi-gcc failed: 1
       command: arm-none-eabi-gcc -MT ./clock_initialize.o  -M '-Wstrict-prototypes'
        '-Wno-attributes' '-Wno-unknown-pragmas' '-Wno-psabi' '-Os'
         '-fno-strict-aliasing' '-fomit-frame-pointer' '-fno-common' '-Wall'
         '-Wshadow' '-Wundef' 
         '-ffunction-sections' '-fdata-sections' '-mlittle-endian' 
         '-march=armv7e-m' '-mtune=cortex-m4' 
          '-mfpu=fpv4-sp-d16' '-mfloat-abi=hard' '-mthumb' '-Wa,-mthumb' 
          '-Wa,-mimplicit-it=always' '-isystem' 
          '/home/lassdk/workdir/nuttx1/nuttx/include'
           '-D__NuttX__' '-DNDEBUG' '-D__KERNEL__' '-pipe' '-I' 
           '/home/lassdk/workdir/nuttx1/nuttx/sched' ./clock/clock_initialize.c
make[2]: *** [/home/lassdk/workdir/nuttx1/nuttx/tools/Config.mk:230: 
clock_initialize.ddc] Error 1
make[1]: *** [Makefile:71: .depend] Error 2
make: *** [tools/Unix.mk:619: pass2dep] Error 2

Try to add "irq.h" with referring to cxd56xx and retry to build. This time, the build system will teach that you have to implement "chip.h" as following.

 make
CC:  clock/clock_initialize.c In file included from
 /home/lassdk/workdir/nuttx2/nuttx/include/arch/armv7-m/irq.h:37:0,
                 from /home/lassdk/workdir/nuttx2/nuttx/include/arch/irq.h:56,
                 from /home/lassdk/workdir/nuttx2/nuttx/include/nuttx/irq.h:37,
                 from /home/lassdk/workdir/nuttx2/nuttx/include/nuttx/sched.h:40,
                 from /home/lassdk/workdir/nuttx2/nuttx/include/nuttx/arch.h:87,
                 from clock/clock_initialize.c:37:
/home/lassdk/workdir/nuttx2/nuttx/include/arch/armv7-m/nvicpri.h:28:28
 fatal error: arch/chip/chip.h: No such file or directory
compilation terminated.
make[1]: *** [Makefile:61: clock_initialize.o] Error 1
make: *** [tools/LibTargets.mk:65: sched/libsched.a] Error 2

Continue this try and error until pass the Compiling.

Step5 : Link

After the pass of Compiling, you will get following error. To resolve this error, you have to implement the linker script.

 make
make[1]: *** No rule to make target 
'/home/lassdk/workdir/nuttx1/nuttx/../cxd32xx_boards/cb2sdb2/scripts/cb2sdb2.ld', 
needed by '/home/lassdk/workdir/nuttx1/nuttx/../cxd32xx_boards/cb2sdb2/scripts/cb2sdb2.ld.tmp'.
  Stop.
make: *** [tools/Unix.mk:545: nuttx] Error 2

Try to add the linker script with referring to some board(cxd56xx, lpc43xx, etc) or out-of-tree and retry to build, the build system will teach that you have to implement some symbols as following.

 make
CPP:  /home/lassdk/workdir/nuttx1/nuttx/../cxd32xx_boards/cb2sdb2/scripts/cb2sdb2.ld->
 /home/lassdk/workdir/nuttx1/nuttx/../boarLD: nuttx
arm-none-eabi-ld: warning: cannot find entry symbol __start; defaulting to 24011000
/home/lassdk/workdir/nuttx1/nuttx/staging/libarch.a(arm_vectors.o):(.vectors+0x4): 
undefined reference to `__start'
/home/lassdk/workdir/nuttx1/nuttx/staging/libarch.a(arm_doirq.o): In function `arm_doirq':
arm_doirq.c:(.text.arm_doirq+0x12): undefined reference to `arm_ack_irq'
/home/lassdk/workdir/nuttx1/nuttx/staging/libdrivers.a(syslog_channel.o): 
In function `syslog_default_putc':
syslog_channel.c:(.text.syslog_default_putc+0x2): undefined reference to `up_putc'
/home/lassdk/workdir/nuttx1/nuttx/staging/libarch.a(arm_nputs.o): In function `up_nputs':
arm_nputs.c:(.text.up_nputs+0x10): undefined reference to `up_putc'
make[1]: *** [Makefile:197: nuttx] Error 1
make: *** [tools/Unix.mk:545: nuttx] Error 2

Step6 : Implement

There are some implementation items, major items are below listed. To pass the Linking, try to implement these symbols.

+-----------------+------------------------+--------------------------------------------------------------------+ | Category | Item | Comment | +-----------------+------------------------+--------------------------------------------------------------------+ | SoC directory | entory point : __start | apache/nuttx/pull/12441 |

• +------------------------+ + | | Serial Driver | | + +------------------------+ + | | IDLE task stack | | + +------------------------+ + | | INTC | | + +------------------------+ + | | Timer | | +-----------------+------------------------+------------------------------------------------+-------------------+ | Board directory | board_app_initialize | [[/application](]{.title-ref}/application.md)s/nsh/customizing` + +------------------------+------------------------------------------------+ | | sched/Kconfig :BOARD<EARLY/LATE>_INITIALIZE| | +-----------------+------------------------+------------------------------------------------+-------------------+

If got the pass of Linking, you would see following result.

 make
Create version.h
LN: platform/board to /home/lassdk/workdir/nuttx2/apps/platform/dummy
Register: nsh
Register: sh
CPP:  /home/lassdk/workdir/nuttx2/nuttx/../boards/cb2sdb2/scripts/cb2sdb2.ld->
 /home/lassdk/workdir/nuttx2/nuttx/../boarLD: nuttx

Step7 : Verify

To execute and debug on the evaluation board, add following configurations.

CONFIG_RAW_BINARY=y
CONFIG_DEBUG_SYMBOLS=y

If your implementations were good, you would see following logs.

NuttShell (NSH) NuttX-12.4.0
nsh>
nsh>
nsh>

After confirming to boot NuttShell(NSH), try to execute "apps/testing/ostest". The "apps/testing/ostest" needs following configurations.

CONFIG_BUILTIN=y
CONFIG_NSH_BUILTIN_APPS=y
CONFIG_SCHED_WAITPID=y
CONFIG_TESTING_OSTEST=y

And one more test is recommended to check the timer implementation whether the kernel could count the time accurately or not. I checked it by following code. About the function : cxd32_timerget(), see apache/nuttx/pull/12441

extern uint32_t cxd32_timerget(void);

  {
    uint32_t pre;
    uint32_t post;

    pre = cxd32_timerget();
    sleep(1);
    post = cxd32_timerget();
    printf("pre:%lu post:%lu expect:1sec\n", pre, post);

    pre = cxd32_timerget();
    sleep(10);
    post = cxd32_timerget();
    printf("pre:%lu post:%lu expect:10sec\n", pre, post);
  }

Appendix : out-of-tree code

diff --git a/cxd32xx_apps/Make.defs b/cxd32xx_apps/Make.defs
new file mode 100644
index 0000000..2d6b86e
--- /dev/null
+++ b/cxd32xx_apps/Make.defs
@@ -0,0 +1 @@
+include (wildcard (APPDIR)/cxd32xx_apps/*/Make.defs)
diff --git a/cxd32xx_apps/Makefile b/cxd32xx_apps/Makefile
new file mode 100644
index 0000000..e451b29
--- /dev/null
+++ b/cxd32xx_apps/Makefile
@@ -0,0 +1,3 @@
+MENUDESC = "cxd32xx_apps"
+
+include (APPDIR)/Directory.mk
diff --git a/cxd32xx_apps/hello/Kconfig b/cxd32xx_apps/hello/Kconfig
new file mode 100644
index 0000000..7f0b41e
--- /dev/null
+++ b/cxd32xx_apps/hello/Kconfig
@@ -0,0 +1,29 @@
+#
+# For a description of the syntax of this configuration file,
+# see the file kconfig-language.txt in the NuttX tools repository.
+#
+
+config CXD32XX_APPS_HELLO
+    tristate "CXD32XX Hello App"
+    default n
+    ---help---
+        Enable the CXD32XX Hello App
+
+if CXD32XX_APPS_HELLO
+
+config CXD32XX_APPS_HELLO_PROGNAME
+    string "Program name"
+    default "hello"
+    ---help---
+        This is the name of the program that will be used when the NSH ELF
+        program is installed.
+
+config CXD32XX_APPS_HELLO_PRIORITY
+    int "CXD32XX Hello task priority"
+    default 100
+
+config CXD32XX_APPS_HELLO_STACKSIZE
+    int "CXD32XX Hello stack size"
+    default DEFAULT_TASK_STACKSIZE
+
+endif
diff --git a/cxd32xx_apps/hello/Make.defs b/cxd32xx_apps/hello/Make.defs
new file mode 100644
index 0000000..730329a
--- /dev/null
+++ b/cxd32xx_apps/hello/Make.defs
@@ -0,0 +1,3 @@
+ifneq ((CONFIG_CXD32XX_APPS_HELLO),)
+CONFIGURED_APPS += (APPDIR)/cxd32xx_apps/hello
+endif
diff --git a/cxd32xx_apps/hello/Makefile b/cxd32xx_apps/hello/Makefile
new file mode 100644
index 0000000..b3438e1
--- /dev/null
+++ b/cxd32xx_apps/hello/Makefile
@@ -0,0 +1,14 @@
+include (APPDIR)/Make.defs
+
+# Custom Hello built-in application info
+
+PROGNAME = (CONFIG_CXD32XX_APPS_HELLO_PROGNAME)
+PRIORITY = (CONFIG_CXD32XX_APPS_HELLO_PRIORITY)
+STACKSIZE = (CONFIG_CXD32XX_APPS_HELLO_STACKSIZE)
+MODULE = (CONFIG_CXD32XX_APPS_HELLO)
+
+# Custom Hello
+
+MAINSRC = hello.c
+
+include (APPDIR)/Application.mk
diff --git a/cxd32xx_apps/hello/hello.c b/cxd32xx_apps/hello/hello.c
new file mode 100644
index 0000000..b14a762
--- /dev/null
+++ b/cxd32xx_apps/hello/hello.c
@@ -0,0 +1,24 @@
+/****************************************************************************
+ * cxd32xx_apps/hello/hello.c
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+#include <stdio.h>
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * hello_main
+ ****************************************************************************/
+
+int main(int argc, FAR char *argv[])
+{
+  printf("Hello, World!!\n");
+  return 0;
+}
diff --git a/cxd32xx_apps/time/Kconfig b/cxd32xx_apps/time/Kconfig
new file mode 100644
index 0000000..64e7591
--- /dev/null
+++ b/cxd32xx_apps/time/Kconfig
@@ -0,0 +1,28 @@
+#
+# For a description of the syntax of this configuration file,
+# see the file kconfig-language.txt in the NuttX tools repository.
+#
+
+config CXD32XX_APPS_TIME
+    tristate "CXD32XX Time App"
+    default n
+    ---help---
+        Enable the CXD32XX Time App
+
+if CXD32XX_APPS_HELLO
+
+config CXD32XX_APPS_TIME_PROGNAME
+    string "Program name"
+    default "time"
+    ---help---
+        This apps measures the elapsed time of sleep system call to confirm the timer implementation.
+
+config CXD32XX_APPS_TIME_PRIORITY
+    int "CXD32XX Time task priority"
+    default 100
+
+config CXD32XX_APPS_TIME_STACKSIZE
+    int "CXD32XX Time stack size"
+    default DEFAULT_TASK_STACKSIZE
+
+endif
diff --git a/cxd32xx_apps/time/Make.defs b/cxd32xx_apps/time/Make.defs
new file mode 100644
index 0000000..cdfb4cc
--- /dev/null
+++ b/cxd32xx_apps/time/Make.defs
@@ -0,0 +1,3 @@
+ifneq ((CONFIG_CXD32XX_APPS_TIME),)
+CONFIGURED_APPS += (APPDIR)/cxd32xx_apps/time
+endif
diff --git a/cxd32xx_apps/time/Makefile b/cxd32xx_apps/time/Makefile
new file mode 100644
index 0000000..94c9007
--- /dev/null
+++ b/cxd32xx_apps/time/Makefile
@@ -0,0 +1,14 @@
+include (APPDIR)/Make.defs
+
+# Custom Hello built-in application info
+
+PROGNAME = (CONFIG_CXD32XX_APPS_TIME_PROGNAME)
+PRIORITY = (CONFIG_CXD32XX_APPS_TIME_PRIORITY)
+STACKSIZE = (CONFIG_CXD32XX_APPS_TIME_STACKSIZE)
+MODULE = (CONFIG_CXD32XX_APPS_TIME)
+
+# Custom Hello
+
+MAINSRC = time.c
+
+include (APPDIR)/Application.mk
diff --git a/cxd32xx_apps/time/time.c b/cxd32xx_apps/time/time.c
new file mode 100644
index 0000000..9775ef2
--- /dev/null
+++ b/cxd32xx_apps/time/time.c
@@ -0,0 +1,41 @@
+/****************************************************************************
+ * cxd32xx_apps/time/time.c
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+#include <stdio.h>
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+extern uint32_t cxd32_timerget(void);
+
+/****************************************************************************
+ * hello_main
+ ****************************************************************************/
+
+int main(int argc, FAR char *argv[])
+{
+  uint32_t pre;
+  uint32_t post;
+
+  printf("measures the elapsed time of sleep system call to confirm \
+  the timer implementation.\n");
+
+  pre = cxd32_timerget();
+  sleep(1);
+  post = cxd32_timerget();
+  printf("pre:%lu post:%lu expect:1sec\n", pre, post);
+
+  pre = cxd32_timerget();
+  sleep(10);
+  post = cxd32_timerget();
+  printf("pre:%lu post:%lu expect:10sec\n", pre, post);
+
+  return 0;
+}
diff --git a/cxd32xx_boards/cb2sdb2/Kconfig b/cxd32xx_boards/cb2sdb2/Kconfig
new file mode 100644
index 0000000..f72f3c0
--- /dev/null
+++ b/cxd32xx_boards/cb2sdb2/Kconfig
@@ -0,0 +1,4 @@
+#
+# For a description of the syntax of this configuration file,
+# see the file kconfig-language.txt in the NuttX tools repository.
+#
diff --git a/cxd32xx_boards/cb2sdb2/configs/nsh/defconfig b/cxd32xx_boards/cb2sdb2/configs/nsh/defconfig
new file mode 100644
index 0000000..1d4c3e2
--- /dev/null
+++ b/cxd32xx_boards/cb2sdb2/configs/nsh/defconfig
@@ -0,0 +1,38 @@
+#
+# This file is autogenerated: PLEASE DO NOT EDIT IT.
+#
+# You can use "make menuconfig" to make any modifications to the installed .config file.
+# You can then do "make savedefconfig" to generate a new defconfig file that includes your
+# modifications.
+#
+CONFIG_ARCH="arm"
+CONFIG_ARCH_CORTEXM4=y
+CONFIG_ARCH_FPU=y
+CONFIG_ARCH_CHIP="cxd32xx"
+CONFIG_ARCH_CHIP_CXD32XX=y
+CONFIG_ARCH_BOARD_CUSTOM=y
+CONFIG_ARCH_BOARD_CUSTOM_DIR="../out-of-tree/cxd32xx_boards/cb2sdb2"
+CONFIG_ARCH_BOARD_CUSTOM_DIR_RELPATH=y
+CONFIG_ARCH_BOARD_CUSTOM_NAME="cb2sdb2"
+CONFIG_INIT_ENTRYPOINT="nsh_main"
+CONFIG_UART0_SERIAL_CONSOLE=y
+CONFIG_SYSTEM_NSH=y
+CONFIG_RAM_START=0x00800000
+CONFIG_RAM_SIZE=244736
+CONFIG_ARCH_RAMVECTORS=y
+CONFIG_RAW_BINARY=y
+CONFIG_DEBUG_SYMBOLS=y
+CONFIG_UART_PL011=y
+CONFIG_UART0_PL011=y
+CONFIG_UART0_BASE=0x42104000
+CONFIG_UART0_IRQ=89
+CONFIG_UART0_CLK_FREQ=32000000
+CONFIG_UART_PL011_PLATFORMIF=y
+CONFIG_BUILTIN=y
+CONFIG_NSH_BUILTIN_APPS=y
+CONFIG_SCHED_WAITPID=y
+CONFIG_TESTING_OSTEST=y
+CONFIG_FS_PROCFS=y
+CONFIG_STACK_COLORATION=y
+CONFIG_CXD32XX_APPS_HELLO=y
+CONFIG_CXD32XX_APPS_TIME=y
diff --git a/cxd32xx_boards/cb2sdb2/include/board.h b/cxd32xx_boards/cb2sdb2/include/board.h
new file mode 100644
index 0000000..eae687e
--- /dev/null
+++ b/cxd32xx_boards/cb2sdb2/include/board.h
@@ -0,0 +1,54 @@
+/****************************************************************************
+ * cxd32xx_boards/cb2sdb2/include/board.h
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.  The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+#ifndef __CXD32XX_BOARDS_CB2SDB2_INCLUDE_BOARD_H
+#define __CXD32XX_BOARDS_CB2SDB2_INCLUDE_BOARD_H
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+#include <nuttx/irq.h>
+#include <sys/boardctl.h>
+#include <stdbool.h>
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Types
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Function Prototypes
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: cxd32_boardinitialize
+ *
+ * Description:
+ *
+ ****************************************************************************/
+
+void cxd32_boardinitialize(void);
+
+#endif /* __CXD32XX_BOARDS_CB2SDB2_INCLUDE_BOARD_H */
diff --git a/cxd32xx_boards/cb2sdb2/scripts/Make.defs b/cxd32xx_boards/cb2sdb2/scripts/Make.defs
new file mode 100644
index 0000000..4986d69
--- /dev/null
+++ b/cxd32xx_boards/cb2sdb2/scripts/Make.defs
@@ -0,0 +1,40 @@
+############################################################################
+# cxd32xx_boards/cb2sdb2/scripts/Make.defs
+#
+# Licensed to the Apache Software Foundation (ASF) under one or more
+# contributor license agreements.  See the NOTICE file distributed with
+# this work for additional information regarding copyright ownership.  The
+# ASF licenses this file to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance with the
+# License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
+# License for the specific language governing permissions and limitations
+# under the License.
+#
+############################################################################
+
+include (TOPDIR)/.config
+include (TOPDIR)/tools/Config.mk
+include (TOPDIR)/arch/arm/src/armv7-m/Toolchain.defs
+
+LDSCRIPT = cb2sdb2.ld
+
+ARCHSCRIPT += (BOARD_DIR)(DELIM)scripts(DELIM)(LDSCRIPT)
+
+ARCHPICFLAGS = -fpic -msingle-pic-base -mpic-register=r10
+
+CFLAGS := (ARCHCFLAGS) (ARCHOPTIMIZATION) (ARCHCPUFLAGS) (ARCHINCLUDES) (ARCHDEFINES) (EXTRAFLAGS) -pipe
+CPICFLAGS = (ARCHPICFLAGS) (CFLAGS)
+CXXFLAGS := (ARCHCXXFLAGS) (ARCHOPTIMIZATION) (ARCHCPUFLAGS) (ARCHXXINCLUDES) (ARCHDEFINES) (EXTRAFLAGS) -pipe
+CXXPICFLAGS = (ARCHPICFLAGS) (CXXFLAGS)
+CPPFLAGS := (ARCHINCLUDES) (ARCHDEFINES) (EXTRAFLAGS)
+AFLAGS := (CFLAGS) -D__ASSEMBLY__
+
+NXFLATLDFLAGS1 = -r -d -warn-common
+NXFLATLDFLAGS2 = (NXFLATLDFLAGS1) -T(TOPDIR)/binfmt/libnxflat/gnu-nxflat-pcrel.ld -no-check-sections
+LDNXFLATFLAGS = -e main -s 2048
diff --git a/cxd32xx_boards/cb2sdb2/scripts/cb2sdb2.ld b/cxd32xx_boards/cb2sdb2/scripts/cb2sdb2.ld
new file mode 100644
index 0000000..34ac8ac
--- /dev/null
+++ b/cxd32xx_boards/cb2sdb2/scripts/cb2sdb2.ld
@@ -0,0 +1,99 @@
+/****************************************************************************
+ * cxd32xx_boards/cb2sdb2/scripts/cb2sdb2.ld
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.  The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+INCLUDE ../../../../out-of-tree/cxd32xx_boards/cb2sdb2/scripts/memmap.ld
+
+OUTPUT_ARCH(arm)
+ENTRY(__start)         /* Treat __start as the anchor for dead code stripping */
+EXTERN(_vectors)       /* Force the vectors to be included in the output */
+SECTIONS
+{
+    .text : {
+        _stext = ABSOLUTE(.);
+        *(.entry)
+        *(.vectors)
+        *(.text .text.*)
+        *(.fixup)
+        *(.gnu.warning)
+        *(.rodata .rodata.*)
+        *(.gnu.linkonce.t.*)
+        *(.glue_7)
+        *(.glue_7t)
+        *(.got)
+        *(.gcc_except_table)
+        *(.gnu.linkonce.r.*)
+        _etext = ABSOLUTE(.);
+    } > flash_Cached
+
+    .init_section : {
+        _sinit = ABSOLUTE(.);
+        KEEP(*(SORT_BY_INIT_PRIORITY(.init_array.*) SORT_BY_INIT_PRIORITY(.ctors.*)))
+        KEEP(*(.init_array .ctors))
+        _einit = ABSOLUTE(.);
+    } > flash_Cached
+
+    .ARM.extab : {
+        *(.ARM.extab*)
+    } > flash_Cached
+
+    __exidx_start = ABSOLUTE(.);
+    .ARM.exidx : {
+        *(.ARM.exidx*)
+    } > flash_Cached
+    __exidx_end = ABSOLUTE(.);
+
+    _eronly = ABSOLUTE(.);
+
+    .data : {
+        _sdata = ABSOLUTE(.);
+        *(.data .data.*)
+        *(.gnu.linkonce.d.*)
+        CONSTRUCTORS
+        . = ALIGN(4);
+        _edata = ABSOLUTE(.);
+    } > sram AT > flash_Cached
+
+    .ram_vectors : {
+        *(.ram_vectors)
+    } > sram
+
+    .bss : {            /* BSS              */
+        _sbss = ABSOLUTE(.);
+        *(.bss .bss.*)
+        *(.gnu.linkonce.b.*)
+        *(COMMON)
+        . = ALIGN(4);
+        _ebss = ABSOLUTE(.);
+    } > sram
+
+    /* Stabs debugging sections.    */
+    .stab 0 : { *(.stab) }
+    .stabstr 0 : { *(.stabstr) }
+    .stab.excl 0 : { *(.stab.excl) }
+    .stab.exclstr 0 : { *(.stab.exclstr) }
+    .stab.index 0 : { *(.stab.index) }
+    .stab.indexstr 0 : { *(.stab.indexstr) }
+    .comment 0 : { *(.comment) }
+    .debug_abbrev 0 : { *(.debug_abbrev) }
+    .debug_info 0 : { *(.debug_info) }
+    .debug_line 0 : { *(.debug_line) }
+    .debug_pubnames 0 : { *(.debug_pubnames) }
+    .debug_aranges 0 : { *(.debug_aranges) }
+}
diff --git a/cxd32xx_boards/cb2sdb2/scripts/memmap.ld b/cxd32xx_boards/cb2sdb2/scripts/memmap.ld
new file mode 100644
index 0000000..848f336
--- /dev/null
+++ b/cxd32xx_boards/cb2sdb2/scripts/memmap.ld
@@ -0,0 +1,13 @@
+/****************************************************************************
+ * Automatically generated file; DO NOT EDIT.
+ ****************************************************************************/
+
+MEMORY
+{
+  sram              (rwx) : ORIGIN = 0x00800000, LENGTH = 0x0003BC00
+  sram_erw          (rw)  : ORIGIN = 0x0083BC00, LENGTH = 0x00001000
+  sram_frw          (rw)  : ORIGIN = 0x0083CC00, LENGTH = 0x00002000
+  sram_prt          (rw)  : ORIGIN = 0x0083EC00, LENGTH = 0x00001000
+  sram_lib          (rwx) : ORIGIN = 0x0083FC00, LENGTH = 0x00000400
+  flash_Cached      (rx)  : ORIGIN = 0x24010000, LENGTH = 0x0013F000
+}
diff --git a/cxd32xx_boards/cb2sdb2/src/Makefile b/cxd32xx_boards/cb2sdb2/src/Makefile
new file mode 100644
index 0000000..f8b1cd8
--- /dev/null
+++ b/cxd32xx_boards/cb2sdb2/src/Makefile
@@ -0,0 +1,25 @@
+############################################################################
+# cxd32xx_boards/cb2sdb2/src/Makefile
+#
+# Licensed to the Apache Software Foundation (ASF) under one or more
+# contributor license agreements.  See the NOTICE file distributed with
+# this work for additional information regarding copyright ownership.  The
+# ASF licenses this file to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance with the
+# License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
+# License for the specific language governing permissions and limitations
+# under the License.
+#
+############################################################################
+
+include (TOPDIR)/Make.defs
+
+CSRCS += cxd32_appinit.c cxd32_boot.c
+
+include (TOPDIR)/boards/Board.mk
diff --git a/cxd32xx_boards/cb2sdb2/src/cxd32_appinit.c b/cxd32xx_boards/cb2sdb2/src/cxd32_appinit.c
new file mode 100644
index 0000000..c1bef5f
--- /dev/null
+++ b/cxd32xx_boards/cb2sdb2/src/cxd32_appinit.c
@@ -0,0 +1,90 @@
+/****************************************************************************
+ * cxd32xx_boards/cb2sdb2/src/cxd32_appinit.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.  The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+#include <nuttx/compiler.h>
+
+#include <sys/types.h>
+#include <nuttx/board.h>
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: board_app_initialize
+ *
+ * Description:
+ *   Perform application specific initialization.  This function is never
+ *   called directly from application code, but only indirectly via the
+ *   (non-standard) boardctl() interface using the command BOARDIOC_INIT.
+ *
+ * Input Parameters:
+ *   arg - The boardctl() argument is passed to the board_app_initialize()
+ *         implementation without modification.  The argument has no
+ *         meaning to NuttX; the meaning of the argument is a contract
+ *         between the board-specific initialization logic and the
+ *         matching application logic.  The value could be such things as a
+ *         mode enumeration value, a set of DIP switch switch settings, a
+ *         pointer to configuration data read from a file or serial FLASH,
+ *         or whatever you would like to do with it.  Every implementation
+ *         should accept zero/NULL as a default configuration.
+ *
+ * Returned Value:
+ *   Zero (OK) is returned on success; a negated errno value is returned on
+ *   any failure to indicate the nature of the failure.
+ *
+ ****************************************************************************/
+
+int board_app_initialize(uintptr_t arg)
+{
+  /* XXX : it will be implemented later */
+
+  return OK;
+}
+
+/****************************************************************************
+ * Name: board_late_initialize
+ *
+ * Description:
+ *   If CONFIG_BOARD_LATE_INITIALIZE is selected, then an additional
+ *   initialization call will be performed in the boot-up sequence to a
+ *   function called board_late_initialize().  board_late_initialize()
+ *   will be called immediately after up_initialize() is called and just
+ *   before the initial application is started.  This additional
+ *   initialization phase may be used, for example, to initialize board-
+ *   specific device drivers.
+ *
+ ****************************************************************************/
+
+#ifdef CONFIG_BOARD_LATE_INITIALIZE
+void weak_function board_late_initialize(void)
+{
+  /* XXX : it will be implemented later */
+}
+#endif
diff --git a/cxd32xx_boards/cb2sdb2/src/cxd32_boot.c b/cxd32xx_boards/cb2sdb2/src/cxd32_boot.c
new file mode 100644
index 0000000..edf4328
--- /dev/null
+++ b/cxd32xx_boards/cb2sdb2/src/cxd32_boot.c
@@ -0,0 +1,56 @@
+/****************************************************************************
+ * cxd32xx_boards/cb2sdb2/src/cxd32_boot.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.  The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <debug.h>
+
+#include <nuttx/board.h>
+#include <arch/board/board.h>
+
+#include "arm_internal.h"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: cxd32_boardinitialize
+ *
+ * Description:
+ *
+ ****************************************************************************/
+
+void cxd32_boardinitialize(void)
+{
+  /* XXX : it will be implemented later */
+}