第一个APP

配置与编译

在nuttx中的tool路径下

./configure.sh stm32f4stm32f4discovery/nsh #这个配置看个人情况
cd ..
make

编写Make.defs、Kconfig、Makefile文件

在apps/README.txt中有明确以上三个文件主要的格式

Example Built-In Application

An example application skeleton can be found under the examples/hello
sub-directory. This example shows how a builtin application can be added
to the project. One must:

1. Create sub-directory as: progname
2. In this directory there should be:

• A Make.defs file that would be included by the apps/Makefile
• A Kconfig file that would be used by the configuration tool (see the file kconfig-language.txt in the NuttX tools repository). This Kconfig file should be included by the apps/Kconfig file
• A Makefile, and
• The application source code.

3. The application source code should provide the entry point:
   main()
4. Set the requirements in the file: Makefile, specially the lines:
   PROGNAME = progname
   PRIORITY = SCHED_PRIORITY_DEFAULT
   STACKSIZE = 768
   ASRCS = asm source file list as a.asm b.asm ...
   CSRCS = C source file list as foo1.c foo2.c ..
5. The Make.defs file should include a line like:
   ifneq ($(CONFIG_PROGNAME),)
   CONFIGURED_APPS += progname
   endif

注：Kconfig的语法可能需要同学去找tools/kconfig-language.txt看看

举例

我在自己的电脑上新建了一个app，其路径为apps/examples/test_20200206，并新建Make.defs、Kconfig、Makefile、hello_test.c、hello_test.h。
Make.defs内容为：

ifneq ($(CONFIG_EXAMPLES_TEST_20200206),)
CONFIGURED_APPS += $(APPDIR)/examples/test_20200206
endif

Kconfig内容为：

config EXAMPLES_TEST_20200206
        bool "test_program"
        default n
        ---help---
                Enable the test example, written by WL

Makefile内容为：

-include $(TOPDIR)/Make.defs#不可删除

PROGNAME  = test_20200206
PRIORITY  = SCHED_PRIORITY_DEFAULT
STACKSIZE = 748
ASRCS = 
CSRCS = hello_test.c

include $(APPDIR)/Application.mk#不可删除

hello_test.c内容为：

#include <nuttx/config.h>
#include <stdio.h>
int test_20200206_main(int argc, FAR char * argv[])
{
    printf("first nuttx program!\n");
    return 0;
}

进入nuttx目录下：

make menuconfig

配置界面

选择Application Configuration中的Examples下新增的App，保存退出后，直接编译，生成nuttx，运行nuttx，需要输入用户名和密码，均为默认值，username=admin password=Administrator。在nsh中运行刚刚加入的app。

nsh> test_20200206
first nuttx program!
Segmentation fault: 11

注意：出现了个段错误，直觉stack size可能比较小，我就把Makefile中的stack size=748改为2048，再次运行没有任何错误。

参考材料

1、Godenfreemans的《NuttX的学习笔记
》
2、nuttx/Document；
3、nuttx/README.txt；
4、tools/kconfig-language.txt