Custom Targets¶

PIO allows you to declare unlimited number of the custom targets. There are a lot of use cases for them:

Pre/Post processing based on a dependent sources (other target, source file, etc.)
Command launcher with own arguments
Launch command with custom options declared in “platformio.ini” (Project Configuration File)
Python callback as a target (use the power of Python interpreter and PIO Build API).

A custom target can be processed using pio run --target option and you can list them via pio run --list-targets command.

Build System API¶

Import("env")

env.AddCustomTarget(
    name,
    dependencies,
    actions,
    title=None,
    description=None,
    always_build=True
)

AddCustomTarget arguments:

name: A name of target. ASCII chars (a-z, 0-9, _, -) are recommended. Good names are “gen_headers”, “program_bitstream”, etc.
dependencies: A list of dependencies that should be built BEFORE target will be launched. It is possible pass multiple dependencies as a Python list ["dep1", dep_target_2]. If a target does not have dependencies, None should be passed.
actions: A list of actions to call on a target. It is possible to pass multiple actions as a Python list ["python --version", my_calback].
title: A title of a target. It will be printed when using PIO Core (CLI) or PIO IDE. We recommend to keep a title very short, 1-2 words.
description: The same as a title argument but allows you to provide detailed explanation what target does.
always_build: If there are declared dependencies and they are already built, this target will not be called if always_build=False. A default value is always_build=True and means always building/calling target.

Examples¶

Command shortcut¶

Create a custom node target (alias) which will print a NodeJS version

platformio.ini:

[env:myenv]
platform = ...
...
extra_scripts = extra_script.py

extra_script.py:

Import("env")

# Single action/command per 1 target
env.AddCustomTarget("sysenv", None, 'python -c "import os; print(os.environ)"')

# Multiple actions
env.AddCustomTarget(
    name="pioenv",
    dependencies=None,
    actions=[
        "pio --version",
        "python --version"
    ],
    title="Core Env",
    description="Show PIO Core and Python versions"
)

Now, run pio run --target sysenv or pio run -t pioenv (short version).

Dependent target¶

Sometimes you need to run a command which depends on another target (file, firmware, etc). Let’s create an ota target and declare command which will depend on a project firmware. If a build process successes, declared command will be run.

platformio.ini:

[env:myenv]
platform = ...
...
extra_scripts = extra_script.py

extra_script.py:

Import("env")

env.AddCustomTarget(
    "ota",
    "$BUILD_DIR/${PROGNAME}.elf",
    "ota_script --firmware-path $SOURCE"
)

Now, run pio run -t ota.

Target with options¶

Let’s create a simple ping target and process it with pio run --target ping command:

platformio.ini:

[env:env_custom_target]
platform = ...
...
extra_scripts = extra_script.py
custom_ping_host = google.com

extra_script.py:

Import("env")

host = env.GetProjectOption("custom_ping_host")

def mytarget_callback(*args, **kwargs):
    print("Hello PIO!")
    env.Execute("ping " + host)


env.AddCustomTarget("ping", None, mytarget_callback)