I'm trying to write my own CMake build system for the STM32F407 on Windows. Below is my CMakeLists.txt:
cmake_minimum_required(VERSION 3.0)project(test_1 LANGUAGES C)#Set the path if arm-none-eabi's bin folder is not added in the SYSTEM path environment variableset(CMAKE_TOOLCHAIN_FILE "toolchain_stm32f407.cmake")set_property(SOURCE startup_stm32f407xx.s PROPERTY LANGUAGE C)set(INCLUDE_DIRECTORIES ./inc)include_directories(${INCLUDE_DIRECTORIES})set(SOURCE_FILES ./src/main.c)add_executable(${CMAKE_PROJECT_NAME}.elf ${SOURCE_FILES})add_custom_target(TARGET ${CMAKE_PROJECT_NAME}.elf POST_BUILD COMMAND ${CMAKE_SIZE} --format=berkeley "${CMAKE_PROJECT_NAME}.elf")I have 2 toolchain files. One works properly and another one gives me an error.Erroneous toolchain file:
set(CMAKE_SYSTEM_NAME Generic)set(CMAKE_SYSTEM_PROCESSOR ARM)option(LINUX OFF)#Set the path if arm-none-eabi's bin folder is not added in the SYSTEM path environment variableif(LINUX) set(ARM_TOOLCHAIN_PATH "./gcc-arm-none-eabi-9-2019-q4-major/bin")else(LINUX) set(ARM_TOOLCHAIN_PATH "D:/gcc-arm-none-eabi-7-2018-q2-update/bin") set(EXE ".exe")endif(LINUX)set(LINKER_PATH "./STM32F407VGTx_FLASH.ld")option(DEBUG ON)set(CMAKE_C_COMPILER_WORKS ON)set(CMAKE_CXX_COMPILER_WORKS ON)set(CMAKE_C_COMPILER ${ARM_TOOLCHAIN_PATH}/arm-none-eabi-gcc${EXE})set(CMAKE_CXX_COMPILER ${ARM_TOOLCHAIN_PATH}/arm-none-eabi-g++.exe${EXE})set(CMAKE_ASM_COMPILER ${ARM_TOOLCHAIN_PATH}/arm-none-eabi-as.exe${EXE})set(CMAKE_OBJCOPY ${ARM_TOOLCHAIN_PATH}/arm-none-eabi-objcopy${EXE})if(DEBUG) set(DEBUG_FLAG "-g")endif(DEBUG)set(COMMON_FLAGS "-mthumb -mfloat-abi=hard -mfpu=fpv4-sp-d16 -mthumb-interwork ${DEBUG_FLAG} \ -mcpu=cortex-m4 -march=armv7e-m \ -Wall -fdata-sections -ffunction-section")#Should these flags be added?: -Wall -Wextra -Wimplicit-function-declaration -Wredundant-decls -Wstrict-prototypes#-Wundef -Wshadowset(CMAKE_C_FLAGS "${COMMON_FLAGS} -std=gnu99 --specs=nosys.specs") set(CMAKE_CXX_FLAGS "${COMMON_FLAGS} -std=c++11 --specs=nosys.specs")set(CMAKE_EXE_LINKER_FLAGS "${COMMON_FLAGS} -Wl,-map=linker.map -Wl,--gc-sections" CACHE INTERNAL "")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)Error:
>cmake -H. -B_build -DCMAKE_TOOLCHAIN_FILE:PATH="toolchain_stm32f407.cmake"-- The C compiler identification is unknownCMake Error at CMakeLists.txt:3 (project): The CMAKE_C_COMPILER: D:/gcc-arm-none-eabi-7-2018-q2-update/bin/arm-none-eabi-gcc.exe is not a full path and was not found in the PATH. Tell CMake where to find the compiler by setting either the environment variable "CC" or the CMake cache entry CMAKE_C_COMPILER to the full path to the compiler, or to the compiler name if it is in the PATH.-- Configuring incomplete, errors occurred!Properly working toolchain:(Got the toolchain file from this question:Link)
set(CMAKE_SYSTEM_NAME Generic)set(CMAKE_SYSTEM_PROCESSOR arm)set(CMAKE_C_COMPILER "arm-none-eabi-gcc.exe")set(CMAKE_CXX_COMPILER "arm-none-eabi-g++.exe")set(CMAKE_EXE_LINKER_FLAGS "--specs=nosys.specs" CACHE INTERNAL "")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)My questions are:
- I'm unable to understand what is lacking in the erroneous toolchain file which is causing that error.
- In CMakeLists.txt, I have set CMAKE_TOOLCHAIN_FILE to the toolchain file. But the toolchain file is not detected unless I pass it as a CLI option using "-DCMAKE_TOOLCHAIN_FILE:PATH=". What is causing this?
- Why does only CMAKE_EXE_LINKER_FLAGS need to be cached?
Thanks