This is the homepage/documentation for chromeos-config which provides access to the master configuration for Chrome OS.
See the design doc for information about the design. This is accessible only within Google. A public page will be published to chromium.org once the feature is complete and launched.
See CrosConfig for the class to use to access configuration strings on a target. See cros_config_host.py for access to the config on a host or during a build.
There are two CLIs built for Chrome OS configuration access, cros_config for use on the target, and cros_config_host_py for use on the host/during building. See the --help for each tool respectively for help on usage.
This section describes the binding for the master configuration. This defines the structure of the configuration and the nodes and properties that are permitted.
In Chromium OS, the word ‘model’ is used to distinguish different hardware or products for which we want to build software. A model shares the same hardware and the same brand. Typically two different models are distinguished by hardware variations (e.g. different screen size) or branch variations (a different OEM).
Note: In the description below, entries with children are nodes and leaves are properties.
family: Provides family-level configuration settings, which apply to all models in the family.
audio (optional): Contains information about audio devices used by this family. Each subnode is defined as a phandle that can be referenced from the model-specific configuration using the audio-type property.
<audio-type>: Node containing the audio config for one device type. All filenames referenced are in relation to the ${FILERDIR} directory of the ebuild containing them.cras-config-dir: Directory to pass to cras for the location of its config filesucm-suffix: Internal UCM suffix to pass to crastopology-name (optional): Name of the topology firmware to usecard: Name of the audio ‘card’volume: Template filename of volume curve filedsp-ini: Template filename of dsp.ini filehifi-conf: Template filename of the HiFi.conf filealsa-conf: Template filename of the card configuration filetopology-bin (optional): Template filename of the topology firmware file Template filenames may include the following fields, enclosed in ${...} defined by the audio node: card, cras-config-dir, topology-name, ucm-suffix as well as model for the model name. The expansion / interpretation happens in cros_config_host. Other users should not attempt to implement this. The purpose is to avoid having to repeat the filename in each model that uses a particular manufacturer's card, since the naming convention is typically consistent for that manufacturer.firmware (optional) : Contains information about firmware versions and files
script: Updater script to use. See the pack_dist directory for the scripts. The options are:updater1s.sh: Only used by mario. Do not use for new boards.updater2.sh: Only used by x86-alex and x86-zgb. Do not use for new boards.updater3.sh: Used for various devices shipped around 2012.updater4.sh: In current use. Supports software sync for the EC.updater5.sh: In current use. Supports firmware v4 (chromeos-ec, vboot2)shared: Contains information intended to be shared across all models (see firmware discussion under models below)bcs-overlay: Overlay name containing the firmware binaries. This is used to generate the full path. For example a value of overlay-reef-private in the reef model means that all files will be of the form gs://chromeos-binaries/HOME/bcs-reef-private/overlay-reef-private/chromeos-base/chromeos-firmware-reef/<filename>.build-targets: Sub-nodes of this define the name of the build artifact produced by a particular software project in the Portage tree.coreboot: Defines the Kconfig/target used for coreboot and chromeos-bootimage ebuilds.ec: Defines the “board” used to generate the ec firmware blob within the chromeos-ec ebuild.depthcharge: Defines the model target passed to the compile phase within the depthcharge ebuild.libpayload: Not currently used as the libpayload ebuild is not yet unibuild-aware.cr50 (optional): Defines the model target to build cr50, if this is used on the platform. This is actually a build target for the EC but is specified separately to make it clear that it is a build for a separate device.main-image: Main image location. This must start with bcs:// . It refers to a file available in BCS. The file will be unpacked to produce a firmware binary image.main-rw-image (optional): Main RW (Read/Write) image location. This must start with bcs://. It refers to a file available in BCS. The file will be unpacked to produce a firmware binary image.ec-image (optional): EC (Embedded Controller) image location. This must start with bcs:// . It refers to a file available in BCS. The file will be unpacked to produce a firmware binary image.pd-image (optional): PD (Power Delivery controller) image location. This must start with bcs:// . It refers to a file available in BCS. The file will be unpacked to produce a firmware binary image.stable-main-version (optional): Version of the stable firmware. On dogfood devices where RO firmware can be updated, we perform a full firmware update if the existing firmware on the device is older than this version. Deprecation in progress. See crbug.com/70541.stable-ec-version (optional): Version of the stable EC firmware. On dogfood devices where RO EC firmware can be updated, we perform a full firmware update if the existing EC firmware on the device is older than this version. Deprecation in progress. See crbug.com/70541.stable-pd-version (optional): Version of the stable PD firmware. On dogfood devices where RO PD firmware can be updated, we perform a full firmware update if the existing PD firmware on the device is older than this version. Deprecation in progress. See crbug.com/70541.extra (optional): A list of extra files or directories needed to update firmware, each being a string filename. Any filename is supported. If it starts with bcs:// then it is read from BCS as with main-image above. But normally it is a path. A typical example is ${FILESDIR}/extra which means that the extra diectory is copied from the firmware ebuild's files/extra directory. Full paths can be provided, e.g. ${SYSROOT}/usr/bin/ectool. If a directory is provided, its contents are copied (subdirectories are not supported). This mirrors the functionality of CROS_FIRMWARE_EXTRA_LIST. But note that multiple files or directories should use a normal device-tree list format, not be separated by semicolon.tools (optional): A list of additional tools which should be packed into the firmware update shellball. This is only needed if this model needs to run a special tool to do the firmware update.create-bios-rw-image (optional): If present this indicates that we should re-sign and generate a read-write firmware image. This replaces the CROS_FIRMWARE_BUILD_MAIN_RW_IMAGE ebuild variable.mapping: (optional): Used to determine the model/sub-model for a particular device. There can be any number of mappings. At present only a sku-map is allowed.
sku-map: Provides a mapping from SKU ID to model/sub-model. One of simple-sku-map or single-sku must be provided. smbios-name-match is needed only if the family supports models which have SKU ID conflicts and needs the SMBIOS name to disambiguate them. This is common when migrating legacy boards to unified builds, but may also occur if the SKU ID mapping is not used for some reason.platform-name: Indicates the platform name for this platform. This is reported by ‘mosys platform name’. It is typically the family name with the first letter capitalized.smbios-name-match (optional) Indicates the smbios name that this table mapping relates to. This map will be ignored on models which don't have a matching smbios name.simple-sku-map (optional): Provides a simple mapping from SKU (an integer value) to model / sub-model. Each entry consists of a sku value (typically 0-255) and a phandle pointing to the model or sub-model.single-sku (optional): Used in cases where only a single model is supported by this mapping. In other words, if the SMBIOS name matches, this is the model to use. The value is a phandle pointing to the model (it cannot point to a sub-model).touch (optional): Contains information about touch devices used by this family. Each node is defined as a Phandle that can be referenced from the model-specific configuration using the touch-type property.
vendor: Name of vendor.firmware-bin: Template filename to use for vendor firmware binary. The file is installed into /opt/google/touch.firmware-symlink: Template filename to use for the /lib/firmware symlink to the firmware file in /opt/google/touch. The /lib/firmware part is assumed.Template filenames may include the following fields, enclosed in ${...} defined by the touch node: vendor, pid, version as well as model for the model name. The expansion / interpretation happens in cros_config. Other users should not attempt to implement this. The purpose is to avoid having to repeat the filename in each model that uses a particular manufacturer's touchscreen, since the naming convention is typically consistent for that manufacturer.
models: Sub-nodes of this define models supported by this board.
<model name>: actual name of the model being defined, e.g. reef or pyroaudio (optional): Contains information about audio devices used by this model.
<audio_system>: Contains information about a particular audio device used by this model. Valid values for the package name are:
main: The main audio systemFor each of these:
audio-type: Phandle pointing to a subnode of the family audio configuration.All properties defined by the family subnode can be used here. Typically it is enough to define only cras-config-dir, ucm-suffix and topology-name. The rest are generally defined in terms of these, within the family configuration nodes.
brand-code: (optional): Brand code of the model (also called RLZ code). See list and one-pager.
default (optional): Indicates that all of the nodes and properties of this model should default to the same as another model. The value is a phandle pointing to the model. It is not possible to ‘remove’ nodes / properties defined by the other model. It is only possible to change properties or add new ones. Note: This is an experimental feature which will be evaluated in December 2017 to determine its usefulness versus the potential confusion it can cause.
thermal(optional): Contains information about thermel properties and settings.
dptf-dv: Filename of the .dv file containing DPTF (Dynamic Platform and Thermal Framework) settings, relative to the ebuild's FILESDIR.touch (optional): Contains information about touch devices such as touchscreens, touchpads, stylus.
present (optional): Indicates whether this model has a touchscreen. This is used by the ARC++ system to pass information to Android, for example. Valid values are:
no: This model does not have a touchscreen (default)yes: This model has a touchscreenprobe: This model might have a touchscreen but we need to probe at run-time to find out. This should ideally only be needed on legacy devices which were not shipped with unibuild.probe-regex (optional): Indicates the regular expression that should be used to match again device names in sys/class/input/input*/name. If the expression matches any device then the touchscreen is assumed to exist.
<device_type> (optional): Contains information about touch firmware packages. Valid values for package_name are:
stylus - a pen-like device with a sensor on or behind the display which together provide absolute positions with respect to the displaytouchpad - a touch surface separate from the displaytouchscreen - a transparent touch surface on a display which provides absolute positions with respect to the displayYou can use unit values (touchscreen@0, touchscreen@1) to allow multiple devices of the same type on a model.
For each of these:
touch-type: Phandle pointing to the touch node in the Family configuration. This allows the vendor name and default firmware file template to be defined.pid: Product ID string, as defined by the vendor.version: Version string, as defined by the vendor.firmware-bin (optional): Filename of firmware file. See the Family touch node above for the format. If not specified then the firmware-bin property from touch-type is used.firmware-symlink: Filename of firmware file within /lib/firmware on the device. See the Family touch node above for the format.wallpaper (optional): base filename of the default wallpaper to show on this device. The base filename points session_manager to two files in the /usr/share/chromeos-assets/wallpaper/<wallpaper> directory: /[filename]_[small|large].jpg. If these files are missing or the property does not exist, “default” is used.
whitelabel (optional): Sometimes models are so similar that we do not want to have separate settings. This happens in particular with ‘white-label’ devices, where the same device is shipped by several OEMs under difference brands. This is a phandle pointing to another model whose configuration is shared. All settings (except for a very few exceptions) will then come from the shares node. Currently if this properly is used, then only the firmware { key-id }, brand-code and wallpaper propertles can be provided. All other properties will come from the shared model.
firmware (optional) : Contains information about firmware versions and files. The properties and nodes inside this node are exactly the same as family/firmware/shared. By convention, tools looking for firmware properties for a model will fallback to the family-level firmware/shared configuration if the node or property is not found at the model level.
shares(optional): Phandle pointing to the firmware to use for this model. This is a list with a single phandle, pointing to the firmware node of another model. The presence of this property indicates that this model does not have separate firmware although it may have its own keyset. This property is used to share firmware across multiple models where hardware differences are small and we can detect the model from board ID pins. At this time, only a phandle reference to a node at family/firmware/shared is supported. The phandle target node must be named with a valid model (e.g. ‘reef’). Note that this property cannot be provided if the model configuration is shared at the model level (the whitelabel property under <model_name>).key-id (optional): Unique ID that matches which key will be used in for firmware signing as part of vboot. For context, see go/cros-unibuild-signingsig-id-in-customization-id (optional): Indicates that this model cannot be decoded by the mapping table. Instead the model is stored in the VPD (Vital Product Data) region in the customization_id property. This allows us to determine the model to use in the factory during the finalization stage. Note that if the VPD is wiped then the model will be lost. This may mean that the device will revert back to a generic model, or may not work. It is not possible in general to test whether the model in the VPD is correct at run-time. We simply assume that it is. The advantage of using this property is that no hardware changes are needed to change one model into another. For example we can create 20 different whitelabel boards, all with the same hardware, just by changing the customization_id that is written into SPI flash.powerd-prefs (optional): Name of a subdirectory under the powerd model_specific prefs directory where model-specific prefs files are stored.
chromeos {
family {
audio {
audio_type: audio-type {
card = "bxtda7219max";
volume = "cras-config/${cras-config-dir}/${card}";
dsp-ini = "cras-config/${cras-config-dir}/dsp.ini";
hifi-conf = "ucm-config/${card}.${ucm-suffix}/HiFi.conf";
alsa-conf = "ucm-config/${card}.${ucm-suffix}/${card}.${ucm-suffix}.conf";
topology-bin = "topology/5a98-reef-${topology-name}-8-tplg.bin";
};
};
firmware {
script = "updater4.sh";
shared: reef {
bcs-overlay = "overlay-reef-private";
main-image = "bcs://Reef.9042.50.0.tbz2";
ec-image = "bcs://Reef-EC.9042.43.0.tbz2";
extra = "${FILESDIR}/extra",
"${SYSROOT}/usr/sbin/ectool",
"bcs://Reef.something.tbz2";
build-targets {
coreboot = "reef";
ec = "reef";
depthcharge = "reef";
libpayload = "reef";
cr50 = "cr50";
};
};
pinned_version: sand {
bcs-overlay = "overlay-reef-private";
main-image = "bcs://Reef.9041.50.0.tbz2";
ec-image = "bcs://Reef-EC.9041.43.0.tbz2";
extra = "${FILESDIR}/extra",
"${SYSROOT}/usr/sbin/ectool",
"bcs://Reef.something.tbz2";
build-targets {
coreboot = "reef";
ec = "reef";
depthcharge = "reef";
libpayload = "reef";
};
};
};
mapping {
#address-cells = <1>;
#size-cells = <0>;
sku-map@0 {
reg = <0>;
platform-name = "Reef";
smbios-name-match = "reef";
/* This is an example! It does not match any real family */
simple-sku-map = <
0 &basking
4 &reef_4
5 &reef_5
8 &electro>;
};
sku-map@1 {
reg = <1>;
platform-name = "Pyro";
smbios-name-match = "pyro";
single-sku = <&pyro>;
};
sku-map@2 {
reg = <2>;
platform-name = "Snappy";
smbios-name-match = "snappy";
single-sku = <&snappy>;
};
sku-map@3 {
reg = <3>;
platform-name = "Sand";
smbios-name-match = "sand";
single-sku = <&sand>;
};
};
touch {
elan_touchscreen: elan-touchscreen {
vendor = "elan";
firmware-bin = "${vendor}/${pid}_${version}.bin";
firmware-symlink = "${vendor}ts_i2c_${pid}.bin";
};
elan_touchpad: elan-touchpad {
vendor = "elan";
firmware-bin = "${vendor}/${pid}_${version}.bin";
firmware-symlink = "${vendor}_i2c_${pid}.bin";
};
wacom_stylus: wacom-stylus {
vendor = "wacom";
firmware-bin = "wacom/wacom_${version}.hex";
firmware-symlink = "wacom_firmware_${model}.bin";
};
weida_touchscreen: weida-touchscreen {
vendor = "weida";
firmware-bin = "weida/${pid}_${version}_${date-code}.bin";
firmware-symlink = "wdt87xx.bin";
};
};
};
models {
reef: reef {
powerd-prefs = "reef";
wallpaper = "seaside_life";
brand-code = "ABCD";
firmware {
shares = <&shared>;
key-id = "REEF";
};
thermal {
dptf-dv = "reef/dptf.dv";
};
submodels {
reef_4: reef-touchscreen {
touch {
present = "yes";
};
audio {
main {
audio-type = <&audio_type>;
cras-config-dir = "front";
ucm-suffix = "front";
topology-name = "front";
};
};
};
reef_5: reef-notouch {
touch {
present = "no";
};
audio {
main {
audio-type = <&audio_type>;
cras-config-dir = "rear";
ucm-suffix = "rear";
topology-name = "rear";
};
};
};
};
touch {
present = "probe";
probe-regex = "[Tt]ouchscreen\|WCOMNTN2";
touchscreen {
touch-type = <&elan_touchscreen>;
pid = "0a97";
version = "1012";
};
};
};
pyro: pyro {
powerd-prefs = "pyro_snappy";
wallpaper = "alien_invasion";
brand-code = "ABCE";
audio {
main {
audio-type = <&audio_type>;
cras-config-dir = "pyro";
ucm-suffix = "pyro";
topology-name = "pyro";
};
};
firmware {
bcs-overlay = "overlay-pyro-private";
main-image = "bcs://Pyro.9042.41.0.tbz2";
ec-image = "bcs://Pyro_EC.9042.41.0.tbz2";
key-id = "PYRO";
build-targets {
coreboot = "pyro";
ec = "pyro";
depthcharge = "pyro";
libpayload = "reef";
};
};
thermal {
dptf-dv = "pyro/dptf.dv";
};
};
snappy: snappy {
powerd-prefs = "pyro_snappy";
wallpaper = "chocolate";
brand-code = "ABCF";
audio {
main {
audio-type = <&audio_type>;
cras-config-dir = "snappy";
ucm-suffix = "snappy";
topology-name = "snappy";
};
};
firmware {
bcs-overlay = "overlay-snappy-private";
main-image = "bcs://Snappy.9042.43.0.tbz2";
ec-image = "bcs://Snappy_EC.9042.43.0.tbz2";
key-id = "SNAPPY";
build-targets {
coreboot = "snappy";
ec = "snappy";
depthcharge = "snappy";
libpayload = "reef";
};
};
};
basking: basking {
powerd-prefs = "reef";
wallpaper = "coffee";
brand-code = "ABCG";
firmware {
shares = <&shared>;
key-id = "BASKING";
};
touch {
#address-cells = <1>;
#size-cells = <0>;
present = "yes";
stylus {
touch-type = <&wacom_stylus>;
version = "4209";
};
touchpad {
touch-type = <&elan_touchpad>;
pid = "97.0";
version = "6.0";
};
touchscreen@0 {
reg = <0>;
touch-type = <&elan_touchscreen>;
pid = "3062";
version = "5602";
};
touchscreen@1 {
reg = <1>;
touch-type = <&weida_touchscreen>;
pid = "01017401";
version = "2082";
date-code = "0133c65b";
};
};
};
sand: sand {
powerd-prefs = "reef";
wallpaper = "coffee";
brand-code = "ABCH";
audio {
main {
audio-type = <&audio_type>;
cras-config-dir = "sand";
ucm-suffix = "sand";
topology-name = "sand";
};
};
firmware {
shares = <&pinned_version>;
key-id = "SAND";
};
};
electro: electro {
powerd-prefs = "reef";
wallpaper = "coffee";
brand-code = "ABCI";
firmware {
shares = <&pinned_version>;
key-id = "ELECTRO";
};
};
/* Whitelabel model */
whitetip: whitetip {
firmware {
shares = <&shared>;
};
};
whitetip1 {
whitelabel = <&whitetip>;
wallpaper = "shark";
brand-code = "SHAR";
firmware {
key-id = "WHITELABEL1";
};
};
whitetip2 {
whitelabel = <&whitetip>;
wallpaper = "more_shark";
brand-code = "SHAQ";
firmware {
key-id = "WHITELABEL2";
};
};
zt_whitelabel: zero-touch-whitelabel {
firmware {
sig-id-in-customization-id;
shares = <&shared>;
};
};
zt1 {
whitelabel = <&zt_whitelabel>;
firmware {
key-id = "ZT1";
};
};
zt2 {
whitelabel = <&zt_whitelabel>;
firmware {
key-id = "ZT2";
};
};
};
};
In order to pin firmware for a single model, change the main-image and ec-image properties in that image. See snappy above as an example.
In order to pin firmware versions for several models and avoid entering the same information twice, create a new firmware instance pointing to the pinned rev and then update the repective model's shares phandle to point to the pinned revision.
In the example above, this is shown using sand (a model) referencing the pinned firmware.
This pinned firmware can then be shared as normal (e.g. electro in the example).
This will cause the different version to get installed under a different models sub-directory in the shellball. Which achieves the same effect of having 2 separate revisions (in a slightly round about way) installed in the shellball.
The shellball generated will contain the following (based on the example above) for the firmware pinning case:
To enable touch on a Chromebook you need to set up the touch firmware correctly.
First, create a touch node in your family. Add to that subnodes for each type of touch device you have, e.g. elan-touchpad, wacom-stylus. Each node should specify the firmware-bin and firmware-symlink filename patterns for that device.
Once you have done that you can add a touch node in your model. This should reference the touch firmware node using the touch-type property. It should also define things needed to identify the firmware, typically pid and version.
Make sure that the ebuild which installs your BSP files (e.g. chromeos-bsp-coral-private) calls the install_touch_files function from the cros-unibuild. Check that your ebuild inherits cros-unibuild too.
If you are adding touch support for a new model in the family, take a look at what other models have done.
To test your changes (e.g. for coral):
emerge-coral chromeos-config-bsp chromeos-config chromeos-bsp-coral-private
You should see it install each of the touch files. If not, or you get an error, check your configuration.
To test at run-time, build a new image and write it to your device. Check that the firmware files are installed in /lib/firmware and loaded correctly by your kernel driver.