The Probe Framework

Overview

The Probe Framework focuses on supplying different ways to scan the device so that the user can easily figure out whether a specific hardware component is installed. The overall introduction is in this README.

This document describes all functions available throughout the Probe Framework.

Functions

AbstractCombinationFunction

While evaluation, the function first evaluates the functions specified in the functions arguments and then combines the outputs in a certain way.

Function Name	Short Description
concat	Returns the concatenation of output.
inner_join	Inner join the result of functions.
or	Returns the first successful output.
sequence	Sequential execute the functions.

AbstractProbeFunction

While evaluation, the function probes the result, and update to the input data by the probed results. If there are multiple probed results, the output list contains all the combination of the input and the probed data.

Function Name	Short Description
audio_codec
chromeos_firmware	Get firmware information from a flash chip.
detachable_base	Probe the detachable base information.
ec_component	Probe EC Component.
edid
embedded_controller	Get information of EC.
factory_device_data	Reads some fields from the device data.
feature_management_flags	Probes the feature management flags.
file	Read the content of a file.
flash_chip	Get information of flash chips.
generic_battery
generic_bluetooth	Probe the generic Bluetooth information.
generic_camera
generic_cpu
generic_dram	Probe the generic DRAM information.
generic_fingerprint	Probe the fingerprint information.
generic_hps	Probe the HPS (human presence sensor) information.
generic_storage
generic_usb_hosts	Probe the generic USB host information.
glob_path	Finds all the pathnames matching the pattern.
gpu
i2c	Probes the I2C device.
input_device
mmc	Probes all eMMC devices listed in the sysfs /sys/bus/mmc/devices/.
mmc_host
network
nfc_reader	Probes internal USB NFC reader devices.
pci	Probes all PCI devices listed in the sysfs /sys/bus/pci/devices/.
sdio	Probes all SDIO devices listed in the sysfs /sys/bus/sdio/devices/.
shell	Execute the shell command and return the output.
smart_card_usb	Probes all USB smart card reader devices.
sysfs	Read the required files in a directory.
tcpc
tpm
usb	Probes all usb devices listed in the sysfs /sys/bus/usb/devices/.
vpd	Reads the information from VPD.

MatchFunction

Description

The rule might be a dict or a string. A result is matched if every value of the rule is matched. If the rule is a string, then the matched result should only contain one item and the value is matched to the string.

If the string starts with !re, then the remaining string is treated as a regular expression.

If the string starts with !num, the probed value will be treated as floating point number, and the remaining of rule string should be < '==' | '>' | '<' | '>=' | '<=' | '!=' > ' ' NUMBER, e.g. !num >= 10.

Otherwise, the value of the result should be the same.

Examples

This function is used by the probe framework itself to filter the outputs of the evaluated functions by expect field in the probe statement. Below is a probe statement which simply asks the probe framework to output all usb devices:

{
  "eval": "usb"
}

Let’s assume the probed output is:

[
  {
    "idVendor": "01ab",
    "idProduct": "1122",
    ...
  },
  {
    "idVendor": "01ac",
    "idProduct": "3344",
    ...
  },
  {
    "idVendor": "23cd",
    "idProduct": "3344",
    ...
  }
]

If we modify the probe statement to:

{
  "eval": "usb",
  "expect": {
    "idVendor": "01ab"
  }
}

, then the probed results will become:

[
  {
    "idVendor": "01ab",
    "idProduct": "1122",
    ...
  }
]

We can also use the regular expression described in above. For example, if we modify expect field in the probe statement to:

"expect": {
  "idVendor": "!re ^01.*$"
}

, then the probed results will contain both the item with idVendor=01ab and the item with idVendor=01ac.

Function Name	Short Description
approx_match	Return the items which match the most rules.

Misc

Function Name	Short Description
match	Filter the results which does not match the rule.