README.md - third_party/github/FreeRTOS/FreeRTOS-Kernel - Git at Google


            
            [![CMock Unit Tests](https://github.com/FreeRTOS/FreeRTOS-Kernel/actions/workflows/unit-tests.yml/badge.svg?branch=main&event=push)](https://github.com/FreeRTOS/FreeRTOS-Kernel/actions/workflows/unit-tests.yml?query=branch%3Amain+event%3Apush+workflow%3A%22CMock+Unit+Tests%22++)

            
            [![codecov](https://app.codecov.io/gh/FreeRTOS/FreeRTOS-Kernel/badge.svg?branch=main)](https://codecov.io/gh/FreeRTOS/FreeRTOS-Kernel)


            ## Getting started


            This repository contains FreeRTOS kernel source/header files and kernel

            
            ports only. This repository is referenced as a submodule in

            
            [FreeRTOS/FreeRTOS](https://github.com/FreeRTOS/FreeRTOS)

            
            repository, which contains pre-configured demo application projects under

            
            ```FreeRTOS/Demo``` directory.


            The easiest way to use FreeRTOS is to start with one of the pre-configured demo

            
            application projects.  That way you will have the correct FreeRTOS source files

            
            included, and the correct include paths configured. Once a demo application is

            
            building and executing you can remove the demo application files, and start to

            
            add in your own application source files.  See the

            
            [FreeRTOS Kernel Quick Start Guide](https://www.freertos.org/Documentation/01-FreeRTOS-quick-start/01-Beginners-guide/02-Quick-start-guide)

            
            for detailed instructions and other useful links.


            Additionally, for FreeRTOS kernel feature information refer to the

            
            [Developer Documentation](https://www.freertos.org/Documentation/02-Kernel/02-Kernel-features/00-Developer-docs),

            
            and [API Reference](https://www.freertos.org/Documentation/02-Kernel/04-API-references/01-Task-creation/00-TaskHandle).


            Also for contributing and creating a Pull Request please refer to

            
            [the instructions here](.github/CONTRIBUTING.md#contributing-via-pull-request).


            **FreeRTOS-Kernel V11.1.0

            
            [source code](https://github.com/FreeRTOS/FreeRTOS-Kernel/tree/V11.1.0) is part

            
            of the

            
            [FreeRTOS 202406.00 LTS](https://github.com/FreeRTOS/FreeRTOS-LTS/tree/202406-LTS)

            
            release.**


            ### Getting help


            If you have any questions or need assistance troubleshooting your FreeRTOS project,

            
            we have an active community that can help on the

            
            [FreeRTOS Community Support Forum](https://forums.freertos.org).


            ## To consume FreeRTOS-Kernel


            ### Consume with CMake


            If using CMake, it is recommended to use this repository using FetchContent.

            
            Add the following into your project's main or a subdirectory's `CMakeLists.txt`:


            - Define the source and version/tag you want to use:


            ```cmake

            
            FetchContent_Declare( freertos_kernel

            
              GIT_REPOSITORY https://github.com/FreeRTOS/FreeRTOS-Kernel.git

            
              GIT_TAG        main #Note: Best practice to use specific git-hash or tagged version

            
            )

            
            ```


            In case you prefer to add it as a git submodule, do:


            ```bash

            
            git submodule add https://github.com/FreeRTOS/FreeRTOS-Kernel.git <path of the submodule>

            
            git submodule update --init

            
            ```


            - Add a freertos_config library (typically an INTERFACE library) The following assumes the directory structure:

            
              - `include/FreeRTOSConfig.h`


            ```cmake

            
            add_library(freertos_config INTERFACE)


            target_include_directories(freertos_config SYSTEM

            
            INTERFACE

            
                include

            
            )


            target_compile_definitions(freertos_config

            
              INTERFACE

            
                projCOVERAGE_TEST=0

            
            )

            
            ```


            In case you installed FreeRTOS-Kernel as a submodule, you will have to add it as a subdirectory:


            ```cmake

            
            add_subdirectory(${FREERTOS_PATH})

            
            ```


            - Configure the FreeRTOS-Kernel and make it available

            
              - this particular example supports a native and cross-compiled build option.


            ```cmake

            
            set( FREERTOS_HEAP "4" CACHE STRING "" FORCE)

            
            # Select the native compile PORT

            
            set( FREERTOS_PORT "GCC_POSIX" CACHE STRING "" FORCE)

            
            # Select the cross-compile PORT

            
            if (CMAKE_CROSSCOMPILING)

            
              set(FREERTOS_PORT "GCC_ARM_CA9" CACHE STRING "" FORCE)

            
            endif()


            FetchContent_MakeAvailable(freertos_kernel)

            
            ```


            - In case of cross compilation, you should also add the following to `freertos_config`:


            ```cmake

            
            target_compile_definitions(freertos_config INTERFACE ${definitions})

            
            target_compile_options(freertos_config INTERFACE ${options})

            
            ```


            ### Consuming stand-alone - Cloning this repository


            To clone using HTTPS:


            ```

            
            git clone https://github.com/FreeRTOS/FreeRTOS-Kernel.git

            
            ```


            Using SSH:


            ```

            
            git clone git@github.com:FreeRTOS/FreeRTOS-Kernel.git

            
            ```


            ## Repository structure


            - The root of this repository contains the three files that are common to

            
            every port - list.c, queue.c and tasks.c.  The kernel is contained within these

            
            three files.  croutine.c implements the optional co-routine functionality - which

            
            is normally only used on very memory limited systems.


            - The ```./portable``` directory contains the files that are specific to a particular microcontroller and/or compiler.

            
            See the readme file in the ```./portable``` directory for more information.


            - The ```./include``` directory contains the real time kernel header files.


            - The ```./examples/template_configuration``` directory contains a sample `FreeRTOSConfig.h` to help jumpstart a new project.

            
            See the [FreeRTOSConfig.h](examples/template_configuration/FreeRTOSConfig.h) file for instructions.


            ### Code Formatting


            FreeRTOS files are formatted using the

            
            "[uncrustify](https://github.com/uncrustify/uncrustify)" tool.

            
            The configuration file used by uncrustify can be found in the

            
            [FreeRTOS/CI-CD-GitHub-Actions's](https://github.com/FreeRTOS/CI-CD-Github-Actions)

            
            [uncrustify.cfg](https://github.com/FreeRTOS/CI-CD-Github-Actions/tree/main/formatting)

            
            file.


            ### Line Endings


            File checked into the FreeRTOS-Kernel repository use unix-style LF line endings

            
            for the best compatibility with git.


            For optimal compatibility with Microsoft Windows tools, it is best to enable

            
            the git autocrlf feature. You can enable this setting for the current

            
            repository using the following command:


            ```

            
            git config core.autocrlf true

            
            ```


            ### Git History Optimizations


            Some commits in this repository perform large refactors which touch many lines

            
            and lead to unwanted behavior when using the `git blame` command. You can

            
            configure git to ignore the list of large refactor commits in this repository

            
            with the following command:


            ```

            
            git config blame.ignoreRevsFile .git-blame-ignore-revs

            
            ```


            ### Spelling and Formatting


            We recommend using [Visual Studio Code](https://code.visualstudio.com),

            
            commonly referred to as VSCode, when working on the FreeRTOS-Kernel.

            
            The FreeRTOS-Kernel also uses [cSpell](https://cspell.org/) as part of its

            
            spelling check. The config file for which can be found at [cspell.config.yaml](cspell.config.yaml)

            
            There is additionally a

            
            [cSpell plugin for VSCode](https://marketplace.visualstudio.com/items?itemName=streetsidesoftware.code-spell-checker)

            
            that can be used as well.

            
            *[.cSpellWords.txt](.github/.cSpellWords.txt)* contains words that are not

            
            traditionally found in an English dictionary. It is used by the spellchecker

            
            to verify the various jargon, variable names, and other odd words used in the

            
            FreeRTOS code base are correct. If your pull request fails to pass the spelling

            
            and you believe this is a mistake, then add the word to

            
            *[.cSpellWords.txt](.github/.cSpellWords.txt)*. When adding a word please

            
            then sort the list, which can be done by running the bash command:

            
            `sort -u .cSpellWords.txt -o .cSpellWords.txt`

            
            Note that only the FreeRTOS-Kernel Source Files, [include](include),

            
            [portable/MemMang](portable/MemMang), and [portable/Common](portable/Common)

            
            files are checked for proper spelling, and formatting at this time.


            ## Third Party Tools

            
            Visit [this link](.github/third_party_tools.md) for detailed information about

            
            third-party tools with FreeRTOS support.
	[![CMock Unit Tests](https://github.com/FreeRTOS/FreeRTOS-Kernel/actions/workflows/unit-tests.yml/badge.svg?branch=main&event=push)](https://github.com/FreeRTOS/FreeRTOS-Kernel/actions/workflows/unit-tests.yml?query=branch%3Amain+event%3Apush+workflow%3A%22CMock+Unit+Tests%22++)
	[![codecov](https://app.codecov.io/gh/FreeRTOS/FreeRTOS-Kernel/badge.svg?branch=main)](https://codecov.io/gh/FreeRTOS/FreeRTOS-Kernel)

	## Getting started

	This repository contains FreeRTOS kernel source/header files and kernel
	ports only. This repository is referenced as a submodule in
	[FreeRTOS/FreeRTOS](https://github.com/FreeRTOS/FreeRTOS)
	repository, which contains pre-configured demo application projects under
	```FreeRTOS/Demo``` directory.

	The easiest way to use FreeRTOS is to start with one of the pre-configured demo
	application projects. That way you will have the correct FreeRTOS source files
	included, and the correct include paths configured. Once a demo application is
	building and executing you can remove the demo application files, and start to
	add in your own application source files. See the
	[FreeRTOS Kernel Quick Start Guide](https://www.freertos.org/Documentation/01-FreeRTOS-quick-start/01-Beginners-guide/02-Quick-start-guide)
	for detailed instructions and other useful links.

	Additionally, for FreeRTOS kernel feature information refer to the
	[Developer Documentation](https://www.freertos.org/Documentation/02-Kernel/02-Kernel-features/00-Developer-docs),
	and [API Reference](https://www.freertos.org/Documentation/02-Kernel/04-API-references/01-Task-creation/00-TaskHandle).

	Also for contributing and creating a Pull Request please refer to
	[the instructions here](.github/CONTRIBUTING.md#contributing-via-pull-request).

	**FreeRTOS-Kernel V11.1.0
	[source code](https://github.com/FreeRTOS/FreeRTOS-Kernel/tree/V11.1.0) is part
	of the
	[FreeRTOS 202406.00 LTS](https://github.com/FreeRTOS/FreeRTOS-LTS/tree/202406-LTS)
	release.**

	### Getting help

	If you have any questions or need assistance troubleshooting your FreeRTOS project,
	we have an active community that can help on the
	[FreeRTOS Community Support Forum](https://forums.freertos.org).

	## To consume FreeRTOS-Kernel

	### Consume with CMake

	If using CMake, it is recommended to use this repository using FetchContent.
	Add the following into your project's main or a subdirectory's `CMakeLists.txt`:

	- Define the source and version/tag you want to use:

	```cmake
	FetchContent_Declare( freertos_kernel
	GIT_REPOSITORY https://github.com/FreeRTOS/FreeRTOS-Kernel.git
	GIT_TAG main #Note: Best practice to use specific git-hash or tagged version
	)
	```

	In case you prefer to add it as a git submodule, do:

	```bash
	git submodule add https://github.com/FreeRTOS/FreeRTOS-Kernel.git <path of the submodule>
	git submodule update --init
	```

	- Add a freertos_config library (typically an INTERFACE library) The following assumes the directory structure:
	- `include/FreeRTOSConfig.h`

	```cmake
	add_library(freertos_config INTERFACE)

	target_include_directories(freertos_config SYSTEM
	INTERFACE
	include
	)

	target_compile_definitions(freertos_config
	INTERFACE
	projCOVERAGE_TEST=0
	)
	```

	In case you installed FreeRTOS-Kernel as a submodule, you will have to add it as a subdirectory:

	```cmake
	add_subdirectory(${FREERTOS_PATH})
	```

	- Configure the FreeRTOS-Kernel and make it available
	- this particular example supports a native and cross-compiled build option.

	```cmake
	set( FREERTOS_HEAP "4" CACHE STRING "" FORCE)
	# Select the native compile PORT
	set( FREERTOS_PORT "GCC_POSIX" CACHE STRING "" FORCE)
	# Select the cross-compile PORT
	if (CMAKE_CROSSCOMPILING)
	set(FREERTOS_PORT "GCC_ARM_CA9" CACHE STRING "" FORCE)
	endif()

	FetchContent_MakeAvailable(freertos_kernel)
	```

	- In case of cross compilation, you should also add the following to `freertos_config`:

	```cmake
	target_compile_definitions(freertos_config INTERFACE ${definitions})
	target_compile_options(freertos_config INTERFACE ${options})
	```

	### Consuming stand-alone - Cloning this repository

	To clone using HTTPS:

	```
	git clone https://github.com/FreeRTOS/FreeRTOS-Kernel.git
	```

	Using SSH:

	```
	git clone git@github.com:FreeRTOS/FreeRTOS-Kernel.git
	```

	## Repository structure

	- The root of this repository contains the three files that are common to
	every port - list.c, queue.c and tasks.c. The kernel is contained within these
	three files. croutine.c implements the optional co-routine functionality - which
	is normally only used on very memory limited systems.

	- The ```./portable``` directory contains the files that are specific to a particular microcontroller and/or compiler.
	See the readme file in the ```./portable``` directory for more information.

	- The ```./include``` directory contains the real time kernel header files.

	- The ```./examples/template_configuration``` directory contains a sample `FreeRTOSConfig.h` to help jumpstart a new project.
	See the [FreeRTOSConfig.h](examples/template_configuration/FreeRTOSConfig.h) file for instructions.

	### Code Formatting

	FreeRTOS files are formatted using the
	"[uncrustify](https://github.com/uncrustify/uncrustify)" tool.
	The configuration file used by uncrustify can be found in the
	[FreeRTOS/CI-CD-GitHub-Actions's](https://github.com/FreeRTOS/CI-CD-Github-Actions)
	[uncrustify.cfg](https://github.com/FreeRTOS/CI-CD-Github-Actions/tree/main/formatting)
	file.

	### Line Endings

	File checked into the FreeRTOS-Kernel repository use unix-style LF line endings
	for the best compatibility with git.

	For optimal compatibility with Microsoft Windows tools, it is best to enable
	the git autocrlf feature. You can enable this setting for the current
	repository using the following command:

	```
	git config core.autocrlf true
	```

	### Git History Optimizations

	Some commits in this repository perform large refactors which touch many lines
	and lead to unwanted behavior when using the `git blame` command. You can
	configure git to ignore the list of large refactor commits in this repository
	with the following command:

	```
	git config blame.ignoreRevsFile .git-blame-ignore-revs
	```

	### Spelling and Formatting

	We recommend using [Visual Studio Code](https://code.visualstudio.com),
	commonly referred to as VSCode, when working on the FreeRTOS-Kernel.
	The FreeRTOS-Kernel also uses [cSpell](https://cspell.org/) as part of its
	spelling check. The config file for which can be found at [cspell.config.yaml](cspell.config.yaml)
	There is additionally a
	[cSpell plugin for VSCode](https://marketplace.visualstudio.com/items?itemName=streetsidesoftware.code-spell-checker)
	that can be used as well.
	[.cSpellWords.txt](.github/.cSpellWords.txt) contains words that are not
	traditionally found in an English dictionary. It is used by the spellchecker
	to verify the various jargon, variable names, and other odd words used in the
	FreeRTOS code base are correct. If your pull request fails to pass the spelling
	and you believe this is a mistake, then add the word to
	[.cSpellWords.txt](.github/.cSpellWords.txt). When adding a word please
	then sort the list, which can be done by running the bash command:
	`sort -u .cSpellWords.txt -o .cSpellWords.txt`
	Note that only the FreeRTOS-Kernel Source Files, [include](include),
	[portable/MemMang](portable/MemMang), and [portable/Common](portable/Common)
	files are checked for proper spelling, and formatting at this time.

	## Third Party Tools
	Visit [this link](.github/third_party_tools.md) for detailed information about
	third-party tools with FreeRTOS support.