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Running FAFT with MobLab

***DEPRECATED, PLEASE VISIT *** (20170714)


FAFT (Fully Automated Firmware Tests) is a collection of tests that exercise and verify low level capabilities of Chrome OS. The features tested by FAFT are implemented through low-level software (firmware/BIOS) and hardware.  For additional information, please see the main FAFT page.

FAFT can either be run using a desktop set up or using a MobLab.  MobLab is a self-contained automated test environment running on a Chromebox.  

Below are instructions to run FAFT on a single DUT using MobLab.  These instructions assume that you have a servo v2 board as well as a development device and are aware of how to install a servo cable onto the device.

Running FAFT tests with servo v2 requires a non-standard MobLab set-up.  The servo v2 board provides several capabilities.  It provides the ability to send additional hardware signals through the debug connector.  These include recovery mode, dev mode, lid close, power button, reset, etc.


  • Functional MobLab on version 7073 or later. You can confirm what version MobLab is running by reviewing the version and platform at chrome://chrome on your MobLab device.
  • Device Under Test (DUT):
  • Running test image
  • Servo cable attached. If you are unsure of how to attach a servo cable to your development device, please contact your Google Partner Representative.

Additional Items needed for running FAFT through MobLab

Servo V2 Setup


Running tests with servo v2 requires a non-standard MobLab set-up.  At this time, you can only run FAFT tests on a single DUT using the MobLab.  You should disconnect all DUTs from the MobLab except for the one you plan to test.

Connecting the Servo V2 Board to the MobLab

  1. Using an ethernet cable, connect the Servo V2 board to the MobLab.  You will need a usb-to-ethernet dongle on the Moblab side.
  2. Connect the HOST_IN port on the servo v2 board to the MobLab using a micro-usb to usb cable. 

Connecting the DUT to the Servo V2 Board

Your device needs to be a developer device, that is a debug port should be located on the motherboard in order to connect the servoflex cable.  If you have additional questions regarding hardware setup, please see your Chrome OS partner representative.
  1. Connect the DUT_CONN_V2 port on the servo board to the DUT with the flex cable as pictured in the diagram above.  Instructions is additional detail are available at  The servo cable allows you to simulate keystrokes and mouse actions.
  2. Connect the DUT_HUB_IN port on the servo board to the DUT using a micro-USB to USB cable.   The micro-USB connection should be plugged into the servo v2 board. NOTE: for newer devices with USB-C ports only, you would need a USB-C to USB-A converter that connects to a USB-A to micro-usb connector instead.
  3. Load a recovery test image onto a USB key and plug it into the USB port on the servo board.

Servo software set up and basic tests

Before running tests, you will need to register the DUT if it has not been registered.  In addition, you will need to make some changes to run FAFT.
  1. Register the DUT
  2. Configure host attributes for the DUT
    1. From the AFE
      1. Click on the “Admin Interface” link in the top right corner of the MobLab Front End.
      2. Select Labels
        1. Ensure label “pool:suites” exists
        2. If not click Add label and create it.
      3. Click on AFE at the top right to go back to the main menu.
      4. Select Hosts
      5. Select the host to which the servo will be attached and enter the host configuration page
        1. Add the following to the labels field for the DUT with servo attached:  pool:faft
        2. Add the following attribute to the DUT under test:  servo_host=localhost
  3. make sure servo board is connected to Moblab and DUT
    1. in VT2 login Moblab shell as user "moblab" run this at command line  $sudo servod --board=$BOARD  #where $BOARD should be the board name of your DUT. e.g. $ sudo servod --board=lumpy
    2. this will start servo itself
  4. in VT3 (ctrl+alt+F3) Test that servo is properly working with the DUT by typing the following commands in the terminal(moblab shell).  See the troubleshooting section at the bottom if things are not working.
    1. dut-control power_state:off
    2. dut-control power_state:on
  5. Recommend running  firmware_FAFTSetup test (test type: server) to ensure the setup is all correct before running either faft_ec or faft_bios. Please see next section "Running...a  Single FAFT Test" for detailed instructions.

Running FAFT Suites or a Single FAFT Test

  1. To run FAFT on a given image, you will first need to put the recovery test image for DUT on the USB stick attached to the servo.  To put a recovery image on the USB, you can use cros flash from the chroot at your workstation.  The Chrome OS developer guide has additional information.
  2. To run a FAFT suite (faft_ec, faft_bios)
    1. Click Create Job link from moblab web url
    2. Next to Job name: field, enter an unique job name.
    3. Next to the Image URL/Build: field enter an available build name (ex veyron_jerry/R40-6380.0.0).
  3. [Optional] Expand Firmware Build Options (optional) in order to specify different firmware builds.
  4. [Optional] Specify Test Source Build.
  5. In the Select Tests to Run: section, select Server next to Filter by test type:
  6. [For Suite]  Type in the suite name in Filter by test name.  FAFT suites include include:  “test_suites:faft_ec” AND “test_suites:faft_bios”
  7. [For a single test]
    1. Type in the test name in Filter by test name.
  8. Click on the check box for the test you want to run in the search result
  9. [For a single test]  Under the Select Hosts for Running Tests section, click on the hostname. This should result in the same host to be displayed in the ‘Selected hosts’ section.
  10. [For Suite] Click on Advanced Options.  Next to the Pool (Optional): field, enter faft
  11. Click Submit job to run. 


  • The servo cable has a tendency to come loose from the DUT.  Make sure that it has not fallen off.  While running FAFT tests, you may need to prop the DUT sideways if the servo cable keeps falling off the DUT.
  • You may need to restart the servo v2 board (by pressing the button on the board) or restart the MobLab.
  • Make sure that you are not accidentally running two instances of servod.  In addition, make sure that the one running is running on port 9999 which is the default port.
  • If you use a different port you need to assign the servo_port host attribute.
    • From the AFE
      • Click on the Admin Interface link in the top right corner of the MobLab Front End.
      • Select Hosts
      • Select the host to which the servo will be attached and enter the host configuration page
      • Add the following attribute to the DUT under test:  servo_port=<port>