This is the documentation for the latest (main) development branch of Zephyr. If you are looking for the documentation of previous releases, use the drop-down menu on the left and select the desired version.

Test Runner (Twister)

This script scans for the set of unit test applications in the git repository and attempts to execute them. By default, it tries to build each test case on boards marked as default in the board definition file.

The default options will build the majority of the tests on a defined set of boards and will run in an emulated environment if available for the architecture or configuration being tested.

In normal use, twister runs a limited set of kernel tests (inside an emulator). Because of its limited test execution coverage, twister cannot guarantee local changes will succeed in the full build environment, but it does sufficient testing by building samples and tests for different boards and different configurations to help keep the complete code tree buildable.

When using (at least) one -v option, twister’s console output shows for every test how the test is run (qemu, native_sim, etc.) or whether the binary was just built. There are a few reasons why twister only builds a test and doesn’t run it:

  • The test is marked as build_only: true in its .yaml configuration file.

  • The test configuration has defined a harness but you don’t have it or haven’t set it up.

  • The target device is not connected and not available for flashing

  • You or some higher level automation invoked twister with --build-only.

To run the script in the local tree, follow the steps below:

$ source
$ ./scripts/twister

If you have a system with a large number of cores and plenty of free storage space, you can build and run all possible tests using the following options:

$ ./scripts/twister --all --enable-slow

This will build for all available boards and run all applicable tests in a simulated (for example QEMU) environment.

If you want to run tests on one or more specific platforms, you can use the --platform option, it is a platform filter for testing, with this option, test suites will only be built/run on the platforms specified. This option also supports different revisions of one same board, you can use --platform board@revision to test on a specific revision.

The list of command line options supported by twister can be viewed using:

$ ./scripts/twister --help

Board Configuration

To build tests for a specific board and to execute some of the tests on real hardware or in an emulation environment such as QEMU a board configuration file is required which is generic enough to be used for other tasks that require a board inventory with details about the board and its configuration that is only available during build time otherwise.

The board metadata file is located in the board directory and is structured using the YAML markup language. The example below shows a board with a data required for best test coverage for this specific board:

identifier: frdm_k64f
name: NXP FRDM-K64F
type: mcu
arch: arm
  - zephyr
  - gnuarmemb
  - xtools
  - arduino_gpio
  - arduino_i2c
  - netif:eth
  - adc
  - i2c
  - nvs
  - spi
  - gpio
  - usb_device
  - watchdog
  - can
  - pwm
  default: true

A string that matches how the board is defined in the build system. This same string is used when building, for example when calling west build or cmake:

# with west
west build -b reel_board
# with cmake
cmake -DBOARD=reel_board ..

The actual name of the board as it appears in marketing material.


Type of the board or configuration, currently we support 2 types: mcu, qemu


Simulator used to simulate the platform, e.g. qemu.


Architecture of the board


The list of supported toolchains that can build this board. This should match one of the values used for ZEPHYR_TOOLCHAIN_VARIANT when building on the command line


Available RAM on the board (specified in KB). This is used to match testcase requirements. If not specified we default to 128KB.


Available FLASH on the board (specified in KB). This is used to match testcase requirements. If not specified we default to 512KB.


A list of features this board supports. This can be specified as a single word feature or as a variant of a feature class. For example:

  - pci

This indicates the board does support PCI. You can make a testcase build or run only on such boards, or:

  - netif:eth
  - sensor:bmi16

A testcase can both depend on ‘eth’ to only test ethernet or on ‘netif’ to run on any board with a networking interface.


testing relating keywords to provide best coverage for the features of this board.

default: [True|False]:

This is a default board, it will tested with the highest priority and is covered when invoking the simplified twister without any additional arguments.


Do not attempt to build (and therefore run) tests marked with this list of tags.


Only execute tests with this list of tags on a specific platform.

timeout_multiplier: <float> (default 1)

Multiply each test case timeout by specified ratio. This option allows to tune timeouts only for required platform. It can be useful in case naturally slow platform I.e.: HW board with power-efficient but slow CPU or simulation platform which can perform instruction accurate simulation but does it slowly.


A list of environment variables. Twister will check if all these environment variables are set, and otherwise skip this platform. This allows the user to define a platform which should be used, for example, only if some required software or hardware is present, and to signal that presence to twister using these environment variables.

Test Cases

Test cases are detected by the presence of a testcase.yaml or a sample.yaml files in the application’s project directory. This file may contain one or more entries in the test section each identifying a test scenario.

The name of each testcase needs to be unique in the context of the overall testsuite and has to follow basic rules:

  1. The format of the test identifier shall be a string without any spaces or special characters (allowed characters: alphanumeric and [_=]) consisting of multiple sections delimited with a dot (.).

  2. Each test identifier shall start with a section followed by a subsection separated by a dot. For example, a test that covers semaphores in the kernel shall start with kernel.semaphore.

  3. All test identifiers within a testcase.yaml file need to be unique. For example a testcase.yaml file covering semaphores in the kernel can have:

    • kernel.semaphore: For general semaphore tests

    • kernel.semaphore.stress: Stress testing semaphores in the kernel.

  4. Depending on the nature of the test, an identifier can consist of at least two sections:

    • Ztest tests: The individual testcases in the ztest testsuite will be concatenated to identifier in the testcase.yaml file generating unique identifiers for every testcase in the suite.

    • Standalone tests and samples: This type of test should at least have 3 sections in the test identifier in the testcase.yaml (or sample.yaml) file. The last section of the name shall signify the test itself.

Test cases are written using the YAML syntax and share the same structure as samples. The following is an example test with a few options that are explained in this document.

    build_only: true
    platform_allow: qemu_cortex_m3 qemu_x86
    tags: bluetooth
    build_only: true
    extra_args: CONF_FILE="prj_br.conf"
    filter: not CONFIG_DEBUG
    platform_exclude: up_squared
    platform_allow: qemu_cortex_m3 qemu_x86
    tags: bluetooth

A sample with tests will have the same structure with additional information related to the sample and what is being demonstrated:

  name: hello world
  description: Hello World sample, the simplest Zephyr application
    build_only: true
    tags: tests
    min_ram: 16
    build_only: true
    extra_args: CONF_FILE=prj_single.conf
    filter: not CONFIG_BT
    tags: tests
    min_ram: 16

The full canonical name for each test case is:<path to test case>/<test entry>

Each test block in the testcase meta data can define the following key/value pairs:

tags: <list of tags> (required)

A set of string tags for the testcase. Usually pertains to functional domains but can be anything. Command line invocations of this script can filter the set of tests to run based on tag.

skip: <True|False> (default False)

skip testcase unconditionally. This can be used for broken tests.

slow: <True|False> (default False)

Don’t run this test case unless --enable-slow or --enable-slow-only was passed in on the command line. Intended for time-consuming test cases that are only run under certain circumstances, like daily builds. These test cases are still compiled.

extra_args: <list of extra arguments>

Extra arguments to pass to Make when building or running the test case.

extra_configs: <list of extra configurations>

Extra configuration options to be merged with a master prj.conf when building or running the test case. For example:

  tags: drivers adc
    depends_on: adc

Using namespacing, it is possible to apply a configuration only to some hardware. Currently both architectures and platforms are supported:

  tags: drivers adc
    depends_on: adc
      - arch:x86:CONFIG_ADC_ASYNC=y
      - platform:qemu_x86:CONFIG_DEBUG=y
build_only: <True|False> (default False)

If true, twister will not try to run the test even if the test is runnable on the platform.

This keyword is reserved for tests that are used to test if some code actually builds. A build_only test is not designed to be run in any environment and should not be testing any functionality, it only verifies that the code builds.

This option is often used to test drivers and the fact that they are correctly enabled in Zephyr and that the code builds, for example sensor drivers. Such test shall not be used to verify the functionality of the driver.

build_on_all: <True|False> (default False)

If true, attempt to build test on all available platforms. This is mostly used in CI for increased coverage. Do not use this flag in new tests.

depends_on: <list of features>

A board or platform can announce what features it supports, this option will enable the test only those platforms that provide this feature.

levels: <list of levels>

Test levels this test should be part of. If a level is present, this test will be selectable using the command line option --level <level name>

min_ram: <integer>

minimum amount of RAM in KB needed for this test to build and run. This is compared with information provided by the board metadata.

min_flash: <integer>

minimum amount of ROM in KB needed for this test to build and run. This is compared with information provided by the board metadata.

timeout: <number of seconds>

Length of time to run test before automatically killing it. Default to 60 seconds.

arch_allow: <list of arches, such as x86, arm, arc>

Set of architectures that this test case should only be run for.

arch_exclude: <list of arches, such as x86, arm, arc>

Set of architectures that this test case should not run on.

platform_allow: <list of platforms>

Set of platforms that this test case should only be run for. Do not use this option to limit testing or building in CI due to time or resource constraints, this option should only be used if the test or sample can only be run on the allowed platform and nothing else.

integration_platforms: <YML list of platforms/boards>

This option limits the scope to the listed platforms when twister is invoked with the --integration option. Use this instead of platform_allow if the goal is to limit scope due to timing or resource constraints.

platform_exclude: <list of platforms>

Set of platforms that this test case should not run on.

extra_sections: <list of extra binary sections>

When computing sizes, twister will report errors if it finds extra, unexpected sections in the Zephyr binary unless they are named here. They will not be included in the size calculation.

sysbuild: <True|False> (default False)

Build the project using sysbuild infrastructure. Only the main project’s generated devicetree and Kconfig will be used for filtering tests. on device testing must use the hardware map, or west flash to load the images onto the target. The --erase option of west flash is not supported with this option. Usage of unsupported options will result in tests requiring sysbuild support being skipped.

harness: <string>

A harness keyword in the testcase.yaml file identifies a Twister harness needed to run a test successfully. A harness is a feature of Twister and implemented by Twister, some harnesses are defined as placeholders and have no implementation yet.

A harness can be seen as the handler that needs to be implemented in Twister to be able to evaluate if a test passes criteria. For example, a keyboard harness is set on tests that require keyboard interaction to reach verdict on whether a test has passed or failed, however, Twister lack this harness implementation at the moment.

Supported harnesses:

  • ztest

  • test

  • console

  • pytest

  • gtest

  • robot

Harnesses ztest, gtest and console are based on parsing of the output and matching certain phrases. ztest and gtest harnesses look for pass/fail/etc. frames defined in those frameworks. Use gtest harness if you’ve already got tests written in the gTest framework and do not wish to update them to zTest. The console harness tells Twister to parse a test’s text output for a regex defined in the test’s YAML file. The robot harness is used to execute Robot Framework test suites in the Renode simulation framework.

Some widely used harnesses that are not supported yet:

  • keyboard

  • net

  • bluetooth

Harness bsim is implemented in limited way - it helps only to copy the final executable (zephyr.exe) from build directory to BabbleSim’s bin directory (${BSIM_OUT_PATH}/bin). This action is useful to allow BabbleSim’s tests to directly run after. By default, the executable file name is (with dots and slashes replaced by underscores): bs_<platform_name>_<test_path>_<test_scenario_name>. This name can be overridden with the bsim_exe_name option in harness_config section.

platform_key: <list of platform attributes>

Often a test needs to only be built and run once to qualify as passing. Imagine a library of code that depends on the platform architecture where passing the test on a single platform for each arch is enough to qualify the tests and code as passing. The platform_key attribute enables doing just that.

For example to key on (arch, simulation) to ensure a test is run once per arch and simulation (as would be most common):

  - arch
  - simulation

Adding platform (board) attributes to include things such as soc name, soc family, and perhaps sets of IP blocks implementing each peripheral interface would enable other interesting uses. For example, this could enable building and running SPI tests once for each unique IP block.

harness_config: <harness configuration options>

Extra harness configuration options to be used to select a board and/or for handling generic Console with regex matching. Config can announce what features it supports. This option will enable the test to run on only those platforms that fulfill this external dependency.

The following options are currently supported:

type: <one_line|multi_line> (required)

Depends on the regex string to be matched

regex: <list of regular expressions> (required)

Strings with regular expressions to match with the test’s output to confirm the test runs as expected.

ordered: <True|False> (default False)

Check the regular expression strings in orderly or randomly fashion

record: <recording options> (optional)
regex: <regular expression> (required)

The regular expression with named subgroups to match data fields at the test’s output lines where the test provides some custom data for further analysis. These records will be written into the build directory recording.csv file as well as recording property of the test suite object in twister.json.

For example, to extract three data fields metric, cycles, nanoseconds:

  regex: "(?P<metric>.*):(?P<cycles>.*) cycles, (?P<nanoseconds>.*) ns"
as_json: <list of regex subgroup names> (optional)

Data fields, extracted by the regular expression into named subgroups, which will be additionally parsed as JSON encoded strings and written into twister.json as nested recording object properties. The corresponding recording.csv columns will contain strings as-is.

Using this option, a test log can convey layered data structures passed from the test image for further analysis with summary results, traces, statistics, etc.

For example, this configuration:

  regex: "RECORD:(?P<type>.*):DATA:(?P<metrics>.*)"
  as_json: [metrics]

when matched to a test log string:

RECORD:jitter_drift:DATA:{"rollovers":0, "mean_us":1000.0}

will be reported in twister.json as:

fixture: <expression>

Specify a test case dependency on an external device(e.g., sensor), and identify setups that fulfill this dependency. It depends on specific test setup and board selection logic to pick the particular board(s) out of multiple boards that fulfill the dependency in an automation setup based on fixture keyword. Some sample fixture names are i2c_hts221, i2c_bme280, i2c_FRAM, ble_fw and gpio_loop.

Only one fixture can be defined per testcase and the fixture name has to be unique across all tests in the test suite.

pytest_root: <list of pytest testpaths> (default pytest)

Specify a list of pytest directories, files or subtests that need to be executed when a test case begins to run. The default pytest directory is pytest. After the pytest run is finished, Twister will check if the test case passed or failed according to the pytest report. As an example, a list of valid pytest roots is presented below:

    - "pytest/"
    - "../shell/pytest/"
    - "/tmp/"
    - "~/tmp/"
    - "$ZEPHYR_BASE/samples/subsys/testsuite/pytest/shell/pytest/"
    - "pytest/"  # select pytest subtest
    - "pytest/[param_a]"  # select pytest parametrized subtest
pytest_args: <list of arguments> (default empty)

Specify a list of additional arguments to pass to pytest e.g.: pytest_args: [‘-k=test_method’, ‘--log-level=DEBUG’]. Note that --pytest-args can be passed multiple times to pass several arguments to the pytest.

pytest_dut_scope: <function|class|module|package|session> (default function)

The scope for which dut and shell pytest fixtures are shared. If the scope is set to function, DUT is launched for every test case in python script. For session scope, DUT is launched only once.

robot_test_path: <robot file path> (default empty)

Specify a path to a file containing a Robot Framework test suite to be run.

bsim_exe_name: <string>

If provided, the executable filename when copying to BabbleSim’s bin directory, will be bs_<platform_name>_<bsim_exe_name> instead of the default based on the test path and scenario name.

The following is an example yaml file with a few harness_config options.

  name: HTS221 Temperature and Humidity Monitor
  tags: sensor
  harness: console
    type: multi_line
    ordered: false
      - "Temperature:(.*)C"
      - "Relative Humidity:(.*)%"
    fixture: i2c_hts221
    tags: sensors
    depends_on: i2c

The following is an example yaml file with pytest harness_config options, default pytest_root name “pytest” will be used if pytest_root not specified. please refer the examples in samples/subsys/testsuite/pytest/.

  harness: pytest
        - pytest_dir1
        - $ENV_VAR/samples/test/pytest_dir2
        - pytest/

The following is an example yaml file with robot harness_config options.

    harness: robot
      robot_test_path: [robot file path]
filter: <expression>

Filter whether the testcase should be run by evaluating an expression against an environment containing the following values:

{ ARCH : <architecture>,
  PLATFORM : <platform>,
  <all CONFIG_* key/value pairs in the test's generated defconfig>,
  *<env>: any environment variable available

Twister will first evaluate the expression to find if a “limited” cmake call, i.e. using package_helper cmake script, can be done. Existence of “dt_*” entries indicates devicetree is needed. Existence of “CONFIG*” entries indicates kconfig is needed. If there are no other types of entries in the expression a filtration can be done without creating a complete build system. If there are entries of other types a full cmake is required.

The grammar for the expression language is as follows:

expression : expression 'and' expression
           | expression 'or' expression
           | 'not' expression
           | '(' expression ')'
           | symbol '==' constant
           | symbol '!=' constant
           | symbol '<' NUMBER
           | symbol '>' NUMBER
           | symbol '>=' NUMBER
           | symbol '<=' NUMBER
           | symbol 'in' list
           | symbol ':' STRING
           | symbol

list : '[' list_contents ']';

list_contents : constant (',' constant)*;

constant : NUMBER | STRING;

For the case where expression ::= symbol, it evaluates to true if the symbol is defined to a non-empty string.

Operator precedence, starting from lowest to highest:

  • or (left associative)

  • and (left associative)

  • not (right associative)

  • all comparison operators (non-associative)

arch_allow, arch_exclude, platform_allow, platform_exclude are all syntactic sugar for these expressions. For instance:

arch_exclude = x86 arc

Is the same as:

filter = not ARCH in ["x86", "arc"]

The : operator compiles the string argument as a regular expression, and then returns a true value only if the symbol’s value in the environment matches. For example, if CONFIG_SOC="stm32f107xc" then

filter = CONFIG_SOC : "stm.*"

Would match it.

required_snippets: <list of needed snippets>

Snippets are supported in twister for test cases that require them. As with normal applications, twister supports using the base zephyr snippet directory and test application directory for finding snippets. Listed snippets will filter supported tests for boards (snippets must be compatible with a board for the test to run on them, they are not optional).

The following is an example yaml file with 2 required snippets.

      - cdc-acm-console
      - user-snippet-example

The set of test cases that actually run depends on directives in the testcase filed and options passed in on the command line. If there is any confusion, running with -v or examining the discard report (twister_discard.csv) can help show why particular test cases were skipped.

Metrics (such as pass/fail state and binary size) for the last code release are stored in scripts/release/twister_last_release.csv. To update this, pass the --all --release options.

To load arguments from a file, add + before the file name, e.g., +file_name. File content must be one or more valid arguments separated by line break instead of white spaces.

Most everyday users will run with no arguments.

Managing tests timeouts

There are several parameters which control tests timeouts on various levels:

  • timeout option in each test case. See here for more details.

  • timeout_multiplier option in board configuration. See here for more details.

  • --timeout-multiplier twister option which can be used to adjust timeouts in exact twister run. It can be useful in case of simulation platform as simulation time may depend on the host speed & load or we may select different simulation method (i.e. cycle accurate but slower one), etc…

Overall test case timeout is a multiplication of these three parameters.

Running in Integration Mode

This mode is used in continuous integration (CI) and other automated environments used to give developers fast feedback on changes. The mode can be activated using the --integration option of twister and narrows down the scope of builds and tests if applicable to platforms defined under the integration keyword in the testcase definition file (testcase.yaml and sample.yaml).

Running tests on custom emulator

Apart from the already supported QEMU and other simulated environments, Twister supports running any out-of-tree custom emulator defined in the board’s board.cmake. To use this type of simulation, add the following properties to custom_board/custom_board.yaml:

simulation: custom
simulation_exec: <name_of_emu_binary>

This tells Twister that the board is using a custom emulator called <name_of_emu_binary>, make sure this binary exists in the PATH.

Then, in custom_board/board.cmake, set the supported emulation platforms to custom:


Finally, implement the run_custom target in custom_board/board.cmake. It should look something like this:

  <name_of_emu_binary to invoke during 'run'>
  <any args to be passed to the command, i.e. ${BOARD}, ${APPLICATION_BINARY_DIR}/zephyr/zephyr.elf>
  DEPENDS ${logical_target_for_zephyr_elf}

Running Tests on Hardware

Beside being able to run tests in QEMU and other simulated environments, twister supports running most of the tests on real devices and produces reports for each run with detailed FAIL/PASS results.

Executing tests on a single device

To use this feature on a single connected device, run twister with the following new options:

scripts/twister --device-testing --device-serial /dev/ttyACM0 \
--device-serial-baud 115200 -p frdm_k64f  -T tests/kernel

The --device-serial option denotes the serial device the board is connected to. This needs to be accessible by the user running twister. You can run this on only one board at a time, specified using the --platform option.

The --device-serial-baud option is only needed if your device does not run at 115200 baud.

To support devices without a physical serial port, use the --device-serial-pty option. In this cases, log messages are captured for example using a script. In this case you can run twister with the following options:

scripts/twister --device-testing --device-serial-pty "" \
-p intel_adsp/cavs25 -T tests/kernel

The script is user-defined and handles delivering the messages which can be used by twister to determine the test execution status.

The --device-flash-timeout option allows to set explicit timeout on the device flash operation, for example when device flashing takes significantly large time.

The --device-flash-with-test option indicates that on the platform the flash operation also executes a test case, so the flash timeout is increased by a test case timeout.

Executing tests on multiple devices

To build and execute tests on multiple devices connected to the host PC, a hardware map needs to be created with all connected devices and their details such as the serial device, baud and their IDs if available. Run the following command to produce the hardware map:

./scripts/twister --generate-hardware-map map.yml

The generated hardware map file (map.yml) will have the list of connected devices, for example:

- connected: true
  id: OSHW000032254e4500128002ab98002784d1000097969900
  platform: unknown
  product: DAPLink CMSIS-DAP
  runner: pyocd
  serial: /dev/cu.usbmodem146114202
- connected: true
  id: 000683759358
  platform: unknown
  product: J-Link
  runner: unknown
  serial: /dev/cu.usbmodem0006837593581

Any options marked as unknown need to be changed and set with the correct values, in the above example the platform names, the products and the runners need to be replaced with the correct values corresponding to the connected hardware. In this example we are using a reel_board and an nrf52840dk/nrf52840:

- connected: true
  id: OSHW000032254e4500128002ab98002784d1000097969900
  platform: reel_board
  product: DAPLink CMSIS-DAP
  runner: pyocd
  serial: /dev/cu.usbmodem146114202
  baud: 9600
- connected: true
  id: 000683759358
  platform: nrf52840dk/nrf52840
  product: J-Link
  runner: nrfjprog
  serial: /dev/cu.usbmodem0006837593581
  baud: 9600

The baud entry is only needed if not running at 115200.

If the map file already exists, then new entries are added and existing entries will be updated. This way you can use one single master hardware map and update it for every run to get the correct serial devices and status of the devices.

With the hardware map ready, you can run any tests by pointing to the map

./scripts/twister --device-testing --hardware-map map.yml -T samples/hello_world/

The above command will result in twister building tests for the platforms defined in the hardware map and subsequently flashing and running the tests on those platforms.


Currently only boards with support for pyocd, nrfjprog, jlink, openocd, or dediprog are supported with the hardware map features. Boards that require other runners to flash the Zephyr binary are still work in progress.

Hardware map allows to set --device-flash-timeout and --device-flash-with-test command line options as flash-timeout and flash-with-test fields respectively. These hardware map values override command line options for the particular platform.

Serial PTY support using --device-serial-pty can also be used in the hardware map:

- connected: true
  id: None
  platform: intel_adsp/cavs25
  product: None
  runner: intel_adsp
  serial_pty: path/to/
    - --remote-host=remote_host_ip_addr
    - --key=/path/to/key.pem

The runner_params field indicates the parameters you want to pass to the west runner. For some boards the west runner needs some extra parameters to work. It is equivalent to following west and twister commands.

west flash --remote-host remote_host_ip_addr --key /path/to/key.pem

twister -p intel_adsp/cavs25 --device-testing --device-serial-pty


For serial PTY, the “–generate-hardware-map” option cannot scan it out and generate a correct hardware map automatically. You have to edit it manually according to above example. This is because the serial port of the PTY is not fixed and being allocated in the system at runtime.


Some tests require additional setup or special wiring specific to the test. Running the tests without this setup or test fixture may fail. A testcase can specify the fixture it needs which can then be matched with hardware capability of a board and the fixtures it supports via the command line or using the hardware map file.

Fixtures are defined in the hardware map file as a list:

- connected: true
    - gpio_loopback
  id: 0240000026334e450015400f5e0e000b4eb1000097969900
  platform: frdm_k64f
  product: DAPLink CMSIS-DAP
  runner: pyocd
  serial: /dev/ttyACM9

When running twister with --device-testing, the configured fixture in the hardware map file will be matched to testcases requesting the same fixtures and these tests will be executed on the boards that provide this fixture.


Fixtures can also be provided via twister command option --fixture, this option can be used multiple times and all given fixtures will be appended as a list. And the given fixtures will be assigned to all boards, this means that all boards set by current twister command can run those testcases which request the same fixtures.

Some fixtures allow for configuration strings to be appended, separated from the fixture name by a :. Only the fixture name is matched against the fixtures requested by testcases.


It may be useful to annotate board descriptions in the hardware map file with additional information. Use the notes keyword to do this. For example:

- connected: false
    - gpio_loopback
  id: 000683290670
  notes: An nrf5340dk/nrf5340 is detected as an nrf52840dk/nrf52840 with no serial
    port, and three serial ports with an unknown platform.  The board id of the serial
    ports is not the same as the board id of the development kit.  If you regenerate
    this file you will need to update serial to reference the third port, and platform
    to nrf5340dk/nrf5340/cpuapp or another supported board target.
  platform: nrf52840dk/nrf52840
  product: J-Link
  runner: jlink
  serial: null

Overriding Board Identifier

When (re-)generated the hardware map file will contain an id keyword that serves as the argument to --board-id when flashing. In some cases the detected ID is not the correct one to use, for example when using an external J-Link probe. The probe_id keyword overrides the id keyword for this purpose. For example:

- connected: false
  id: 0229000005d9ebc600000000000000000000000097969905
  platform: mimxrt1060_evk
  probe_id: 000609301751
  product: DAPLink CMSIS-DAP
  runner: jlink
  serial: null


Twister allows user to provide configuration files defining a list of tests or platforms to be put under quarantine. Such tests will be skipped and marked accordingly in the output reports. This feature is especially useful when running larger test suits, where a failure of one test can affect the execution of other tests (e.g. putting the physical board in a corrupted state).

To use the quarantine feature one has to add the argument --quarantine-list <PATH_TO_QUARANTINE_YAML> to a twister call. Multiple quarantine files can be used. The current status of tests on the quarantine list can also be verified by adding --quarantine-verify to the above argument. This will make twister skip all tests which are not on the given list.

A quarantine yaml has to be a sequence of dictionaries. Each dictionary has to have scenarios and platforms entries listing combinations of scenarios and platforms to put under quarantine. In addition, an optional entry comment can be used, where some more details can be given (e.g. link to a reported issue). These comments will also be added to the output reports.

When quarantining a class of tests or many scenarios in a single testsuite or when dealing with multiple issues within a subsystem, it is possible to use regular expressions, for example, kernel.* would quarantine all kernel tests.

An example of entries in a quarantine yaml:

- scenarios:
    - sample.basic.helloworld
  comment: "Link to the issue:"

- scenarios:
    - kernel.common
    - kernel.common.(misra|tls)
    - kernel.common.nano64
    - .*_cortex_.*
    - native_sim

To exclude a platform, use the following syntax:

- platforms:
  - qemu_x86
  comment: "broken qemu"

Additionally you can quarantine entire architectures or a specific simulator for executing tests.

Test Configuration

A test configuration can be used to customize various aspects of twister and the default enabled options and features. This allows tweaking the filtering capabilities depending on the environment and makes it possible to adapt and improve coverage when targeting different sets of platforms.

The test configuration also adds support for test levels and the ability to assign a specific test to one or more levels. Using command line options of twister it is then possible to select a level and just execute the tests included in this level.

Additionally, the test configuration allows defining level dependencies and additional inclusion of tests into a specific level if the test itself does not have this information already.

In the configuration file you can include complete components using regular expressions and you can specify which test level to import from the same file, making management of levels easier.

To help with testing outside of upstream CI infrastructure, additional options are available in the configuration file, which can be hosted locally. As of now, those options are available:

  • Ability to ignore default platforms as defined in board definitions (Those are mostly emulation platforms used to run tests in upstream CI)

  • Option to specify your own list of default platforms overriding what upstream defines.

  • Ability to override build_on_all options used in some testcases. This will treat tests or sample as any other just build for default platforms you specify in the configuration file or on the command line.

  • Ignore some logic in twister to expand platform coverage in cases where default platforms are not in scope.

Platform Configuration

The following options control platform filtering in twister:

  • override_default_platforms: override default key a platform sets in board configuration and instead use the list of platforms provided in the configuration file as the list of default platforms. This option is set to False by default.

  • increased_platform_scope: This option is set to True by default, when disabled, twister will not increase platform coverage automatically and will only build and run tests on the specified platforms.

  • default_platforms: A list of additional default platforms to add. This list can either be used to replace the existing default platforms or can extend it depending on the value of override_default_platforms.

And example platforms configuration:

  override_default_platforms: true
  increased_platform_scope: false
    - qemu_x86

Test Level Configuration

The test configuration allows defining test levels, level dependencies and additional inclusion of tests into a specific test level if the test itself does not have this information already.

In the configuration file you can include complete components using regular expressions and you can specify which test level to import from the same file, making management of levels simple.

And example test level configuration:

  - name: my-test-level
    description: >
      my custom test level
      - kernel.threads.*
      - kernel.timer.behavior
      - arch.interrupt
      - boards.*

Combined configuration

To mix the Platform and level configuration, you can take an example as below:

An example platforms plus level configuration:

  override_default_platforms: true
    - frdm_k64f
  - name: smoke
    description: >
        A plan to be used verifying basic zephyr features.
  - name: unit
    description: >
        A plan to be used verifying unit test.
  - name: integration
    description: >
        A plan to be used verifying integration.
  - name: acceptance
    description: >
        A plan to be used verifying acceptance.
  - name: system
    description: >
        A plan to be used verifying system.
  - name: regression
    description: >
        A plan to be used verifying regression.

To run with above test_config.yaml file, only default_platforms with given test level test cases will run.

scripts/twister --test-config=<path to>/test_config.yaml
 -T tests --level="smoke"

Running in Tests in Random Order

Enable ZTEST framework’s CONFIG_ZTEST_SHUFFLE config option to run your tests in random order. This can be beneficial for identifying dependencies between test cases. For native_sim platforms, you can provide the seed to the random number generator by providing -seed=value as an argument to twister. See Shuffling Test Sequence for more details.

Robot Framework Tests

Zephyr supports Robot Framework as one of solutions for automated testing.

Robot files allow you to express interactive test scenarios in human-readable text format and execute them in simulation or against hardware. At this moment Zephyr integration supports running Robot tests in the Renode simulation framework.

To execute a Robot test suite with twister, run the following command:

$ ./scripts/twister --platform hifive1 --test samples/subsys/shell/shell_module/

Writing Robot tests

For the list of keywords provided by the Robot Framework itself, refer to the official Robot documentation.

Information on writing and running Robot Framework tests in Renode can be found in the testing section of Renode documentation. It provides a list of the most commonly used keywords together with links to the source code where those are defined.

It’s possible to extend the framework by adding new keywords expressed directly in Robot test suite files, as an external Python library or, like Renode does it, dynamically via XML-RPC. For details see the extending Robot Framework section in the official Robot documentation.

Running a single testsuite

To run a single testsuite instead of a whole group of test you can run:

$ twister -p qemu_riscv32 -s tests/kernel/interrupt/arch.shared_interrupt