Clone this repo:
  1. da8a3fa pytests: sync_factory_server: Allow setting new server URL by Hung-Te Lin · 10 hours ago master
  2. 5fbaf44 Umpire: revise Umpire services config to support JSON schema by Chih-wei Ning · 10 hours ago
  3. b27b935 setup: Publish cros_docker image version 20170823123754. by Hung-Te Lin · 10 hours ago
  4. f747157 Exclude py/umpire/client from generated change list. by You-Cheng Syu · 10 hours ago
  5. a121a9d Umpire: Add an "extract-payload" subcommand by Chih-Wei Ning · 10 hours ago

Google Chromium OS Factory Software Platform


This repository contains tools and utilities used for manufacturing solution. The Chromium OS reference factory software provides various imaging methods, test flow, and log collection pipeline for manufacturing Chrome devices. It is available as part of the public Chromium OS repository on This code is meant as a starting point, to modify and adapt to different projects.

The Chromium OS Factory Software Platform has three major components:

  • DUT Software: Everything runs on DUT (Device Under Test), including a test harness “Goofy”, qualification, calibration and functional test programs, and steps for finalization like battery cutoff or wiping.
  • Factory Server: The bridge between DUT and partner's shopfloor backends, including imaging service, shopfloor proxy, and a management console.
  • Google Backend: Solutions for integration with Google infrastructure, including extensible pipeline for sending manufacturing logs back to Google Cloud.


  • Test image: the Chromium OS test image (built by build_image test).
  • Release image: the (usually signed) release image that end user is using (built by build_image base).
  • Recovery image: the (usually signed) release image with recovery installer so it's in install-able form (built by build_image base; mod_image_for_recovery and can be downloaded directly from ChromeOS Buildbots or CPFE).
  • Factory server: A server program providing imaging source and proxy to shopfloor. This can be released as a set of setup programs (also known as mini-Omaha). The new version is now a Docker image built and installed by, with a web interface “Dome”.
  • Factory shim image: a special multi-purpose image that provides:
    • Installation from USB. Also known as RMA shim.
    • Installation from factory server. Also known as Factory Install shim.
    • Reset or cutoff a device after OOBE. Also known as Reset Shim in this case.
  • Factory toolkit: a self-extraction package that contains a set of python programs, YAML/JSON configuration, and shell scripts that will install itself into /usr/local/factory. This is also considered as the main “factory test program” (built by running emerge-$BOARD factory or make BOARD=$BOARD toolkit inside factory repository).
  • Factory bundle: An archive containing everything: a release (recovery) image, test image, factory shim image, factory toolkit, and few setup programs.

Typical Factory Flow

The basic steps are:

  1. An initial/bootable version of the firmware for AP (and EC) is pre-flashed onto the SPI-ROM (and Chromium EC chip) before system assembly.
  2. After mainboard is ready, use one of the imaging methods to get the factory toolkit, test image, signed release image, and AP/EC firmware are installed or updated. Included on disk are two full Chrome OS images: the test image and the shipping image.
  3. The system automatically reboots using the test image and begins manufacturing tests. This test suite is based on pytest. The software supports sequencing tests, configuration, firmware and configuration updates, reboots, and other events in a configurable sequence.
  4. Functional, Run-In, and manual tests run as configured. Upon completion, results are displayed on the screen. Results are also available as an electronic pass/fail record with detailed logs for uploading to the shopfloor server.
  5. The test image and test code are automatically erased, leaving the release image as bootable in the “finalization” step.
  6. On failure, the system continues running subsequent tests and reports failures on completion. Alternatively you can configure it to halt on failure at specific break points. For details, see the Options class in src/platform/factory/py/test/ and generic test lists under src/platform/factory/py/test/test_lists/* .
  7. The factory test image and release image can be combined into an SSD image and imaged onto the internal drive before assembly. The first time the device boots, the sequence starts at step 4 above, using the factory test image.

Building Factory Toolkit

Under chroot, after setting up board, you have few different ways to build toolkit.

Build toolkit with dependency

If you have only finished setup_board, for the first time there are few dependencies you need to build before able to work on toolkits.

  1. If you will need to build test images later, do a build_packages --board $BOARD to get all dependency packages merged.

  2. If you don't need to build full images (which may download huge files or build Chrome locally with very long time, another solution is to run following commands:

    cros_workon --baord $BOARD start factory
    emerge-$BOARD factory-board factory --getbinpkg -j 16

    The -j 16 means to merge in parallel, and should be changed to how many cores your machine has.

Rebuild and get toolkit

Once you have get dependency ready, there are two different ways to help you quickly get toolkit recompiled:

  1. Using emerge. Simply run emerge-$BOARD factory and find it in /build/$BOARD/usr/local/factory/bundle/toolkit/

  2. Build manually. In factory repo, run make BOARD=$BOARD toolkit and find it in build/

If you encounter build problems, try to update chroot and rebuild necessary dependencies by running build_packages --board $BOARD then try again.

The toolkit can be installed into a Chromium OS test image, by either running that locally on a DUT, or apply to a test image directly as blow:

./ path/to/chromiumos_test_image.bin

Building Test Image

Under chroot, after setting up board, you can get the test image by running following commands in trunk/src/scripts:

build_packages --board $BOARD
build_image --board $BOARD test

After image is built, you can flash it into an USB stick (assume your USB appears as sdX):

# inside chroot
cros flash usb:// path/to/chromiumos_test_image.bin

# outside chroot
sudo dd bs=4M if=path/to/image/chromiumos_test_image.bin of=/dev/sdX \
        iflag=fullblock oflag=dsync

Building Factory (Install) Shim

Under chroot, after setting up board, you can get the factory shim by running following commands in trunk/src/scripts:

build_packages --board $BOARD
build_image --board $BOARD factory_install

There are few options that you may want to change. The most important one is URL to factory server. You have to set that as CHROMEOS_AUSERVER in dev_image/etc/lsb-factory from first (stateful) partition. The utility setup/ can help that. For example, if your server will run in and using default port 8080:

setup/edit_lsb_factory -i path/to/factory_install_shim.bin

And inside editor, change CHROMEOS_AUSERVER to:


After image is ready, you can flash it into an USB stick (assume your USB appears as sdX):

# inside chroot
cros flash usb:// path/to/factory_install_shim.bin

# outside chroot
sudo dd bs=4M if=path/to/image/factory_install_shim.bin of=/dev/sdX \
        iflag=fullblock oflag=dsync

On boot, the factory shim displays a download status and downloads the image from the server. On completion, the shim reboots. If you are using legacy firmware (not Chrome OS firmware), you might need to remove the SD card to allow booting the newly-installed image.

After the image starts downloading and the status message turns green, you can remove the SD card—it is not needed after that point.

Building Chromium OS Factory SDK Document

The API specification and details of each test are documented in the online Chromium OS Factory SDK.

You can build with latest source locally:

  1. Enter chroot.
  2. Build the SDK documentation
    make doc
  1. Open the following file in a browser window:

Booting your (factory) test image via USB

For development and local testing, it is possible to boot the factory test image from a USB memory stick rather than using a network installation. The following steps sare optional:

  1. Copy the test image to USB storage.
  2. On your device, switch to developer mode. For most recent devices, this is done by pressing Esc-F3-Power (F3 is the refresh key on top row) then press Ctrl-D when the screen said that you need to insert a recovery USB stick, and press ENTER when the screen asked you to do.
  3. After system reboot, enter VT2 by pressing Ctrl-Alt-F2 (F2 refers to the right-arrow key on top row).
  4. Log in as root with password test0000 if required.
  5. Run the following command: enable_dev_usb_boot.
  6. Insert the USB memory stick, reboot and press Ctrl-U at the dev mode warning screen. You can also enter VT2 and install the image to SSD using the chromeos-install command.

Imaging methods

All of the methods will make sure the internal storage and firmware flash chip are having right contents. A typical factory installation places the factory test image in the first slot of Chrome OS image partitions (#2 and #3), and the release image in the second slot (#4 and #5).

Note: All imaging methods except pre-installation will try to update Main (AP) and EC firmware on target machine using a chromeos-firmwareupdate updater program. If not specified, this will be pulled from the release (recovery) image (i.e., --release) you've provided.

If you need to use a special version that is different from the one combined in release image, add a --firmware PATH option to command, or manually upload the updater file in Dome web UI.

Also, if you only want the DEV signed firmware (also known as unsigned), grab the from the ChromeOS-firmware-Rxx-yyyy.0.0-<BOARD>.tar.bz2 or firmware_from_source.tar.bz2 and assign its path to --firmware path/to/

Otherwise (a “signed firmware” like PreMP signed or MP signed), you have to ask firmware engineer to upload right image, update ebuild files, get a new image built and signed, extract the firmware from it:

./setup/ -i path/to/OS_IMAGE.bin

Then you can find a chromeos-firmwareupdate file and use it for as --firmware path/to/chromeos-firmwareupdate.

Also, if you are simply testing and no HWID bundle yet, change the --hwid PATH to --hwid none.

We support different imaging methods and here are the details:

Network Installation

The typical way is to install from Factory Server via network. To do that, you have to first setup the server.

Using mini-Omaha as factory server

The mini-Omaha is a python program in setup/ folder. You have to first prepare the payloads for it by command

./setup/ \
  --board=BOARD \
  --test_image=path/to/chromiumos_test_image.bin \
  --toolkit=path/to/ \
  --release_image=path/to/chromiumos_image.bin \

# Start the mini-Omaha server after package is ready.

If you have a prepared factory bundle, you can simply extract it and then run the script in it. This will call and automatically:


Using Dome and Umpire as factory server

If you want to try the edge-bleeding technology instead of mini-Omaha, fetch, install, and run the factory server by command:

# Download factory server docker images.
./setup/ pull
# Install factory server docker images.
./setup/ install
# Create and start Dome containers.
./setup/ run

After Dome containers started, open a browser to http://localhost:8000, follow the instruction to create a board, upload individual files to it or import a prepared bundle.

Boot from USB

Diagram of Network Install, booted from USB

After factory server is setup, flash the Factory Install Shim to an USB stick and boot with it, select Install when you see a menu and proceed.

Boot from Netboot Firmware

Diagram of Network Install, booted from Netboot Firmware

If the Netboot firmware is available, flash the that to main (AP) SPI firmware and just boot. You will need to setup the network environment (details to be provided in future) so it can download a special kernel and then run same installer as [Boot from USB](#Boot-from-USB]. For more details, please refer to Netboot Setup.

Pre-Installation (Copy Machine)

Diagram of Pre-Installation

To speed up the process, many factories will try to pre-flash the internal storage so no imaging process is needed. You can generate the disk image from a factory test image and a release (recovery) image using setup scripts.

To do that, use --diskimg option in

./setup/ --diskimg=disk_image.bin \
  --board=BOARD \
  --test_image=path/to/chromiumos_test_image.bin \
  --toolkit=path/to/ \
  --release_image=path/to/chromiumos_image.bin \

You can image directly to a device, or to a .bin file. Available options are:

  • --diskimg=XX specifies the destination device or file
  • --sectors=XX specifies the number of sectors in the bin file
  • --preserve prevents wiping of the unused space for faster imaging

USB Installation (RMA)

Diagram of USB (RMA) Installation

It is possible to install everything from same USB that boots system without network. This is helpful in proto builds if network is not ready, and if copy machine is not available. This is also known as the “RMA shim” since it is widely used in RMA (Return Materiel Authorization) flow:

To do that, use --usbimg option in

./ --usbimg=usb_image.bin \
  --board=BOARD \
  --factory_shim=path/to/factory_install_shim.bin \
  --test_image=path/to/chromiumos_test_image.bin \
  --toolkit=path/to/ \
  --release_image=path/to/chromiumos_image.bin \

Flash the usb_image.bin to a USB stick, boot it in with developer switch enabled in recovery mode, and then you will see the installation menu that can install directly from same USB stick without network.

Modifying factory test image or adding test cases

The factory test image runs the series of pytests located at src/platform/factory/py/test/pytests/ (installed in /usr/local/factory/py/test/pytests/ on the DUT). The sequence of pytest cases are determined by test_lists files under /usr/local/factory/py/test/test_lists/. Status is logged to /var/log/factory.log and more details can be found under /var/factory/*.

After modifying the source code, you can run the following commands to push files to the DUT. The host machine and DUT must be on the same subnet.

  1. Enter chroot.
  2. Update factory source code on DUT:
  ./bin/goofy_remote DUT_IP_ADDRESS

For more information on how to add test cases, read Chromium OS Factory SDK.

More Resources

Here are few resources you will want to dig into more details:

Factory Server Components

The new generation of factory server consists of few components: the backend Umpire and frontend Dome.

Umpire needs the software bits prepared in a defined structure as “Factory Bundle”.


The DUT Software (Goofy) and pytests can be localized. Read the Localization Guide for more information.

Shopfloor Backend Integration

To help manufacturing line to track DUT status, and to retrieve information from shopfloor backends (for example serial number, vital product data, serial number, ... etc), ODM factory has to implement a XMLRPC web service following Shopfloor Service API.

Test Lists

Most projects will want to adjust the ordering and parameter of tests. This is controlled by a “test list” that will be read by the test harness “Goofy”. See Test Lists Document for more details.


Chrome OS devices are required to have an unique “hardware identifier (HWID)” when leaving factory. This is involved with component qualification, probing and verification. In factory there is a file controlling how HWID is generated. Read HWID Database User Guide for more details.

DUT Software Boot Initialization

When running software on DUT for manufacturing, we may usually need to do something different from standard test images - for example disabling power-saving control, or starting some special services.

We have a set of scripting controlling this. See Init System for more details.

Developer Notes

The layout of /usr/local/factory, as installed on devices' stateful partitions, is as follows. Most of these files are installed from this repository, and follow this repository's directory structure.

  • bin/: Symbolic links to executable scripts and Python modules.

  • build/: Folder to contain build output artifacts.

  • devtools/: Tools and scripts for developers.

  • doc/: Document templates and resources.

  • go/: Programs written in Go language.

  • init/: Initialization of factory environment for Chrome OS.

  • misc/: Miscellaneous resources used outside of Goofy

  • proto/: Proto-buf schema definition.

  • setup/: Scripts and programs for partner to setup the environment.

  • sh/: Shell scripts.

  • py_pkg/: Symbolic link to enable importing Python packages

  • py/: Python source code in the cros.factory module and sub-modules.

  • board/: Board-specific files (optional and only provided by board overlays, not this repository.) in board overlay:

    • A script to add board-specific arguments when starting the Goofy (the factory test harness).
    • Other files needed by board-specific tests.
  • po/: i18n resources.

Within the build root (/build/$BOARD), /usr/local/factory/bundle is a “pseudo-directory” for the factory bundle: it is masked with INSTALL_MASK so it is not actually installed onto devices, but any files in this directory will be included in factory bundles built by Buildbot. For example, the shopfloor and mini-Omaha servers are placed into this directory.

Within board overlays, the chromeos-base/factory-board package may overlay files into this directory structure.

For instance, a board overlay may install:

  • A board-specific test into /usr/local/factory/py/test/pytests.

  • /usr/local/factory/bundle/README to include a README in the factory bundle.

  • Any arbitrary board-specific file (e.g., a proprietary tool licensed only for use on a particular board) into /usr/local/factory/board.

  • /usr/local/factory/board/board_setup_{factory,x}.sh to customize Goofy or X arguments.