IDF Frontend - idf.py

The idf.py command-line tool provides a front-end for easily managing your project builds, deployment and debugging, and more. It manages several tools, for example:

  • CMake, which configures the project to be built

  • Ninja which builds the project

  • esptool.py for flashing the target.

The getting started guide contains a brief introduction to how to set up idf.py to configure, build, and flash projects.

Important

idf.py should be run in an ESP-IDF “project” directory, i.e. one containing a CMakeLists.txt file. Older style projects with a Makefile will not work with idf.py.

Commands

Start a new project: create-project

idf.py create-project <project name>

This will create a new ESP-IDF project, additionally folder where the project will be created can be specified by the --path option.

Create a new component: create-component

This command creates a new component, which will have a minimum set of files necessary for building.

idf.py create-component <component name>

The -C option can be used to specify the directory the component will be created in. For more information about components see the build system page.

Select the Target Chip: set-target

ESP-IDF supports multiple targets (chips). A full list of supported targets in your version of ESP-IDF can be seen by running idf.py --list-targets.

This sets the current project target:

idf.py set-target <target>

Important

idf.py set-target will clear the build directory and re-generate the sdkconfig file from scratch. The old sdkconfig file will be saved as sdkconfig.old.

Note

The behavior of idf.py set-target command is equivalent to:

  1. clearing the build directory (idf.py fullclean)

  2. removing the sdkconfig file (mv sdkconfig sdkconfig.old)

  3. configuring the project with the new target (idf.py -DIDF_TARGET=esp32 reconfigure)

It is also possible to pass the desired IDF_TARGET as an environment variable (e.g. export IDF_TARGET=esp32s2) or as a CMake variable (e.g. -DIDF_TARGET=esp32s2 argument to CMake or idf.py). Setting the environment variable is a convenient method if you mostly work with one type of the chip.

To specify the _default_ value of IDF_TARGET for a given project, add CONFIG_IDF_TARGET value to sdkconfig.defaults. For example, CONFIG_IDF_TARGET="esp32s2". This value will be used if IDF_TARGET is not specified by other method: using an environment variable, CMake variable, or idf.py set-target command.

If the target has not been set by any of these methods, the build system will default to esp32 target.

Start the graphical configuration tool: menuconfig

idf.py menuconfig

Build the project: build

idf.py build

Running this command will build the project found in the current directory. This can involve multiple steps:

  • Create the build directory if needed. The sub-directory build is used to hold build output, although this can be changed with the -B option.

  • Run CMake as necessary to configure the project and generate build files for the main build tool.

  • Run the main build tool (Ninja or GNU Make). By default, the build tool is automatically detected but it can be explicitly set by passing the -G option to idf.py.

Building is incremental so if no source files or configuration has changed since the last build, nothing will be done.

Additionally, the command can be run with app, bootloader and partition-table arguments to build only the app, bootloader or partition table as applicable.

Remove the build output: clean

It is possible to remove the project build output files from the build directory by using:

idf.py clean

The project will be fully rebuilt on next build. Using this does not remove the CMake configuration output inside the build folder.

Delete the entire build contents: fullclean

idf.py fullclean

Running this command will delete the entire “build” directory contents. This includes all CMake configuration output. The next time the project is built, CMake will configure it from scratch. Note that this option recursively deletes all files in the build directory, so use with care. Project configuration is not deleted.

Flash the project: flash

Running the following command:

idf.py flash

will automatically build the project if necessary, and then flash it to the target. You can use -p and -b options to set serial port name and flasher baud rate, respectively.

Note

The environment variables ESPPORT and ESPBAUD can be used to set default values for the -p and -b options, respectively. Providing these options on the command line overrides the default.

Similarly to the build command, the command can be run with app, bootloader and partition-table arguments to flash only the app, bootloader or partition table as applicable.

Hints on how to resolve errors

idf.py will try to suggest hints on how to resolve errors. It works with a database of hints stored in tools/idf_py_actions/hints.yml and the hints will be printed if a match is found for the given error. idf.py menuconfig is not supported by automatic hints on resolving errors.

The --no-hints argument of idf.py can be used to turn the hints off in case they are not desired.

Important notes

Multiple idf.py commands can be combined into one. For example, idf.py -p COM4 clean flash monitor will clean the source tree, then build the project and flash it to the target before running the serial monitor.

The order of multiple idf.py commands on the same invocation is not important, they will automatically be executed in the correct order for everything to take effect (i.e. building before flashing, erasing before flashing, etc.).

For commands that are not known to idf.py an attempt to execute them as a build system target will be made.

The command idf.py supports shell autocompletion for bash, zsh and fish shells.

In order to make shell autocompletion supported, please make sure you have at least Python 3.5 and click 7.1 or newer (see also).

To enable autocompletion for idf.py use the export command (see this). Autocompletion is initiated by pressing the TAB key. Type idf.py - and press the TAB key to autocomplete options.

The autocomplete support for PowerShell is planned in the future.

Advanced Commands

Open the documentation: docs

Using the following command the documentation for the projects target and version will be opened in the browser:

idf.py docs

Show size: size

idf.py size

Will print app size information including occupied RAM and FLASH and section sizes.

idf.py size

Similarly, this will print the same information for each component used in the project.

idf.py size-files

Will print size information per source file in the project.

If you define variable -DOUTPUT_JSON=1 when running CMake (or idf.py), the output will be formatted as JSON not as human readable text. See idf.py-size for more information.

Reconfigure the project: reconfigure

idf.py reconfigure

This command re-runs CMake even if it doesn’t seem to need re-running. This isn’t necessary during normal usage, but can be useful after adding/removing files from the source tree, or when modifying CMake cache variables. For example, idf.py -DNAME='VALUE' reconfigure can be used to set variable NAME in CMake cache to value VALUE.

Clean the python byte code: python-clean

Generated python byte code can be deleted from the IDF directory using:

idf.py python-clean

The byte code may cause issues when switching between IDF and Python versions. It is advised to run this target after switching versions of Python.

Global Options

To list all available root level options, run idf.py --help. To list options that are specific for a subcommand, run idf.py <command> --help, for example idf.py monitor --help. Here is a list of some useful options:

  • -C <dir> allows overriding the project directory from the default current working directory.

  • -B <dir> allows overriding the build directory from the default build subdirectory of the project directory.

  • --ccache flag can be used to enable CCache when compiling source files, if the CCache tool is installed. This can dramatically reduce some build times.

Note that some older versions of CCache may exhibit bugs on some platforms, so if files are not rebuilt as expected then try disabling CCache and build again. CCache can be enabled by default by setting the IDF_CCACHE_ENABLE environment variable to a non-zero value.

  • -v flag causes both idf.py and the build system to produce verbose build output. This can be useful for debugging build problems.

  • --cmake-warn-uninitialized (or -w) will cause CMake to print uninitialized variable warnings found in the project directory only. This only controls CMake variable warnings inside CMake itself, not other types of build warnings. This option can also be set permanently by setting the IDF_CMAKE_WARN_UNINITIALIZED environment variable to a non-zero value.

  • --no-hints flag to disable hints on resolving errors and disable capturing output.

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