285 lines
7.9 KiB
ReStructuredText
285 lines
7.9 KiB
ReStructuredText
.. include:: /substitutions.rst
|
|
.. _cpp_cmake:
|
|
|
|
C++ Example using CMake
|
|
=======================
|
|
|
|
In some situations, developers intend to implement software using the NuttX platform in
|
|
a previously set hardware and configuration where it is not possible or allowed to make
|
|
changes. In such situations, less contact with the operating source tree is better, where
|
|
it is only used for the application.
|
|
|
|
Some approaches are possible to do that today:
|
|
|
|
* https://cwiki.apache.org/confluence/display/NUTTX/Building+NuttX+with+Applications+Outside+of+the+Source+Tree
|
|
* https://www.programmersought.com/article/61604062421/
|
|
|
|
We have been seen the increase of the use of C++ language in embedded systems application. And
|
|
CMake (https://www.cmake.org) is the preferred build system used to build C++ projects. NuttX
|
|
support C++ based projects.
|
|
|
|
Using the 'build as a library' procedure of NuttX, it is possible to build NuttX
|
|
applications using C++ language and also the cmake build tool.
|
|
|
|
This document will show how to reimplement the hellocpp project using this cmake.
|
|
|
|
Preparation
|
|
-----------
|
|
|
|
#. Base NuttX compilation changes
|
|
|
|
For this example, load the configuration 'stm32f4discovery:testlibcxx' for building
|
|
|
|
.. code-block:: console
|
|
|
|
$ cd nuttx
|
|
$ ./tools/configure.sh stm32f4discovery:testlibcxx
|
|
|
|
In menuconfig, the main points to be changed on a typical NuttX configuration are the following:
|
|
|
|
* Set RTOS Features -> Tasks and Scheduling -> Application entry point to 'hellocpp_main'
|
|
|
|
* Build NuttX and generate the export
|
|
|
|
.. code-block:: console
|
|
|
|
$ make export
|
|
|
|
Creating the project
|
|
--------------------
|
|
|
|
#. Create your project file structure
|
|
|
|
The project structure is organized as follow:
|
|
|
|
.. code-block:: console
|
|
|
|
hellocpp/
|
|
hellocpp/CMakeLists.txt
|
|
hellocpp/cmake/stm32f4discovery.cmake
|
|
hellocpp/nuttx-export-10.0.1/
|
|
hellocpp/src/CMakeLists.txt
|
|
hellocpp/src/main.cpp
|
|
hellocpp/src/HelloWorld.h
|
|
hellocpp/src/HelloWorld.cpp
|
|
|
|
The directory 'nuttx-export-10.0.1' is the unzipped content from the file created during
|
|
make export procedure done before.
|
|
|
|
#. File contents
|
|
|
|
* hellocpp/CMakeLists.txt
|
|
|
|
.. code-block:: cmake
|
|
|
|
cmake_minimum_required(VERSION 3.2...3.15)
|
|
|
|
project(HelloCpp
|
|
VERSION 1.0
|
|
DESCRIPTION "Hello world C++ NuttX"
|
|
)
|
|
|
|
set(CMAKE_CXX_STANDARD 17)
|
|
set(CMAKE_CXX_STANDARD_REQUIRED ON)
|
|
# set(CMAKE_CXX_EXTENSIONS OFF)
|
|
set(CMAKE_C_STANDARD 99)
|
|
|
|
set(NUTTX_PATH "${CMAKE_SOURCE_DIR}/nuttx-export-10.0.1")
|
|
|
|
include(cmake/stm32f4discovery.cmake)
|
|
|
|
set(AC_COMMON_FLAGS "${AC_COMMON_FLAGS} -fno-builtin -Wall -Wshadow -Wundef -fno-strict-aliasing -fno-strength-reduce -fomit-frame-pointer -Os")
|
|
set(AC_COMMON_FLAGS "${AC_COMMON_FLAGS} -D_DEBUG -D_LIBCPP_BUILD_STATIC -D_LIBCPP_NO_EXCEPTIONS ")
|
|
set(AC_COMMON_FLAGS "${AC_COMMON_FLAGS} -fno-exceptions -fcheck-new -fno-rtti -pedantic ")
|
|
set(AC_COMMON_FLAGS "${AC_COMMON_FLAGS} -nostdinc++")
|
|
|
|
set(AC_DEFINES "${AC_DEFINES} -DCONFIG_WCHAR_BUILTIN")
|
|
|
|
include_directories(
|
|
src
|
|
${NUTTX_PATH}/include
|
|
${NUTTX_PATH}/include/libcxx
|
|
${NUTTX_PATH}/arch/chip
|
|
)
|
|
|
|
set(EXE_NAME hellocpp)
|
|
|
|
set(CMAKE_CXX_FLAGS "${AC_HW_FLAGS} ${AC_DEFINES} ${AC_COMMON_FLAGS} ${AC_CXX_EXTRA_FLAGS}")
|
|
if (PARAM_DEBUG)
|
|
set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -g")
|
|
endif()
|
|
|
|
set(CMAKE_SKIP_RPATH ON)
|
|
set(CMAKE_CXX_LINK_EXECUTABLE "${CMAKE_LINKER} ${AC_LINKER_FLAGS} -o ${EXE_NAME}.elf <OBJECTS> <LINK_LIBRARIES>")
|
|
|
|
set(BUILD_SHARED_LIBS OFF)
|
|
|
|
add_subdirectory(src)
|
|
|
|
* hellocpp/cmake/stm32f4discovery.cmake
|
|
|
|
.. code-block:: cmake
|
|
|
|
set(CMAKE_SYSTEM_NAME Generic)
|
|
set(CMAKE_SYSTEM_PROCESSOR arm)
|
|
|
|
set(MCU_LINKER_SCRIPT "${NUTTX_PATH}/scripts/ld.script")
|
|
|
|
set(COMPILER_PREFIX arm-none-eabi-)
|
|
|
|
# cmake-format: off
|
|
set(CMAKE_C_COMPILER ${COMPILER_PREFIX}gcc)
|
|
set(CMAKE_CXX_COMPILER ${COMPILER_PREFIX}g++)
|
|
set(CMAKE_AR ${COMPILER_PREFIX}ar)
|
|
set(CMAKE_RANLIB ${COMPILER_PREFIX}ranlib)
|
|
set(CMAKE_LINKER ${COMPILER_PREFIX}ld)
|
|
set(CMAKE_ASM_COMPILER ${COMPILER_PREFIX}gcc)
|
|
set(CMAKE_OBJCOPY ${COMPILER_PREFIX}objcopy)
|
|
set(CMAKE_OBJDUMP ${COMPILER_PREFIX}objdump)
|
|
set(CMAKE_SIZE ${COMPILER_PREFIX}size)
|
|
|
|
set(CMAKE_FIND_ROOT_PATH_MODE_PROGRAM NEVER)
|
|
set(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY)
|
|
set(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY)
|
|
set(CMAKE_FIND_ROOT_PATH_MODE_PACKAGE ONLY)
|
|
|
|
set(CMAKE_TRY_COMPILE_TARGET_TYPE STATIC_LIBRARY)
|
|
|
|
set(AC_HW_FLAGS "-mcpu=cortex-m4 -mthumb -mfloat-abi=soft ")
|
|
set(AC_HW_FLAGS "${AC_HW_FLAGS} -isystem ${NUTTX_PATH}/include")
|
|
set(AC_HW_FLAGS "${AC_HW_FLAGS} -pipe -D__NuttX__")
|
|
|
|
set(AC_LINKER_FLAGS "--entry=__start -nostartfiles -nodefaultlibs -T${MCU_LINKER_SCRIPT}")
|
|
|
|
* hellocpp/src/CMakeLists.txt
|
|
|
|
.. code-block:: cmake
|
|
|
|
set(HEADER_FILES
|
|
HelloWorld.h
|
|
)
|
|
|
|
set(SOURCE_FILES
|
|
HelloWorld.cpp
|
|
)
|
|
|
|
link_directories(${EXE_NAME} ${NUTTX_PATH}/libs)
|
|
|
|
add_executable(${EXE_NAME} ${SOURCE_FILES} main.cpp ${HEADER_FILES})
|
|
|
|
add_custom_command(
|
|
TARGET ${EXE_NAME}
|
|
POST_BUILD
|
|
COMMAND ${CMAKE_OBJCOPY} ARGS -S -O binary ${CMAKE_BINARY_DIR}/${EXE_NAME}.elf ${CMAKE_BINARY_DIR}/${EXE_NAME}.bin
|
|
)
|
|
|
|
target_link_libraries(${EXE_NAME} --start-group)
|
|
|
|
target_link_libraries(${EXE_NAME} sched)
|
|
target_link_libraries(${EXE_NAME} drivers)
|
|
target_link_libraries(${EXE_NAME} boards)
|
|
target_link_libraries(${EXE_NAME} c)
|
|
target_link_libraries(${EXE_NAME} mm)
|
|
target_link_libraries(${EXE_NAME} arch)
|
|
target_link_libraries(${EXE_NAME} xx)
|
|
target_link_libraries(${EXE_NAME} apps)
|
|
target_link_libraries(${EXE_NAME} fs)
|
|
target_link_libraries(${EXE_NAME} binfmt)
|
|
target_link_libraries(${EXE_NAME} board)
|
|
target_link_libraries(${EXE_NAME} gcc)
|
|
target_link_libraries(${EXE_NAME} supc++)
|
|
|
|
target_link_libraries(${EXE_NAME} --end-group)
|
|
|
|
* hellocpp/src/main.cpp
|
|
|
|
.. code-block:: c++
|
|
|
|
#include "HelloWorld.h"
|
|
#include <nuttx/config.h>
|
|
|
|
extern "C"
|
|
{
|
|
int hellocpp_main(void)
|
|
{
|
|
|
|
CHelloWorld *pHelloWorld = new CHelloWorld();
|
|
pHelloWorld->HelloWorld();
|
|
|
|
CHelloWorld helloWorld;
|
|
helloWorld.HelloWorld();
|
|
|
|
delete pHelloWorld;
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
* hellocpp/src/HelloWorld.h
|
|
|
|
.. code-block:: c++
|
|
|
|
#ifndef HELLOWORLD_H_
|
|
#define HELLOWORLD_H_
|
|
|
|
#include "nuttx/config.h"
|
|
|
|
class CHelloWorld
|
|
{
|
|
public:
|
|
CHelloWorld();
|
|
~CHelloWorld();
|
|
bool HelloWorld(void);
|
|
private:
|
|
int mSecret;
|
|
};
|
|
|
|
#endif
|
|
|
|
* hellocpp/src/HelloWorld.cpp
|
|
|
|
.. code-block:: c++
|
|
|
|
#include <cstdio>
|
|
#include <string>
|
|
|
|
#include "HelloWorld.h"
|
|
|
|
CHelloWorld::CHelloWorld() {
|
|
mSecret = 42;
|
|
std::printf("Constructor: mSecret=%d\n",mSecret);
|
|
}
|
|
|
|
CHelloWorld::~CHelloWorld() {
|
|
|
|
}
|
|
|
|
bool CHelloWorld::HelloWorld(void) {
|
|
std::printf("HelloWorld: mSecret=%d\n",mSecret);
|
|
|
|
std::string sentence = "Hello";
|
|
std::printf("TEST=%s\n",sentence.c_str());
|
|
|
|
if (mSecret == 42) {
|
|
std::printf("CHelloWorld: HelloWorld: Hello, world!\n");
|
|
return true;
|
|
}
|
|
else {
|
|
std::printf("CHelloWorld: HelloWorld: CONSTRUCTION FAILED!\n");
|
|
return false;
|
|
}
|
|
}
|
|
|
|
Building
|
|
--------
|
|
|
|
To launch build, you use the cmake procedure:
|
|
|
|
.. code-block:: console
|
|
|
|
$ mkdir build
|
|
$ cd build
|
|
$ cmake ..
|
|
$ make
|
|
|
|
And finally a bin file will be created to be loaded on the board.
|