Configuration

This chapter describes the individual drivers and resources used in a device configuration. Drivers can depend on resources or other drivers, whereas resources have no dependencies.

_images/config_graph.svg

Here the resource RawSerialPort provides the information for the SerialDriver, which in turn is needed by the ShellDriver. Driver dependency resolution is done by searching for the driver which implements the dependent protocol, all drivers implement one or more protocols.

Resources

Serial Ports

RawSerialPort

A RawSerialPort is a serial port which is identified via the device path on the local computer. Take note that re-plugging USB serial converters can result in a different enumeration order.

RawSerialPort:
  port: /dev/ttyUSB0
  speed: 115200

The example would access the serial port /dev/ttyUSB0 on the local computer with a baud rate of 115200.

  • port (str): path to the serial device
  • speed (int): desired baud rate
Used by:

NetworkSerialPort

A NetworkSerialPort describes a serial port which is exported over the network, usually using RFC2217 or raw tcp.

NetworkSerialPort:
  host: remote.example.computer
  port: 53867
  speed: 115200

The example would access the serial port on computer remote.example.computer via port 53867 and use a baud rate of 115200 with the RFC2217 protocol.

  • host (str): hostname of the remote host
  • port (str): TCP port on the remote host to connect to
  • speed (int): baud rate of the serial port
  • protocol (str): optional, protocol used for connection: raw or rfc2217
Used by:

USBSerialPort

A USBSerialPort describes a serial port which is connected via USB and is identified by matching udev properties. This allows identification through hot-plugging or rebooting.

USBSerialPort:
  match:
    'ID_SERIAL_SHORT': 'P-00-00682'
  speed: 115200

The example would search for a USB serial converter with the key ID_SERIAL_SHORT and the value P-00-00682 and use it with a baud rate of 115200.

  • match (str): key and value for a udev match, see udev Matching
  • speed (int): baud rate of the serial port
Used by:

NetworkPowerPort

A NetworkPowerPort describes a remotely switchable power port.

NetworkPowerPort:
  model: gude
  host: powerswitch.example.computer
  index: 0

The example describes port 0 on the remote power switch powerswitch.example.computer, which is a gude model.

  • model (str): model of the power switch
  • host (str): hostname of the power switch
  • index (int): number of the port to switch
Used by:

NetworkService

A NetworkService describes a remote SSH connection.

NetworkService:
  address: example.computer
  username: root

The example describes a remote SSH connection to the computer example.computer with the username root.

  • address (str): hostname of the remote system
  • username (str): username used by SSH
Used by:

OneWirePIO

A OneWirePIO describes a onewire programmable I/O pin.

OneWirePIO:
  host: example.computer
  path: /29.7D6913000000/PIO.0

The example describes a PIO.0 at device address 29.7D6913000000 via the onewire server on example.computer.

  • host (str): hostname of the remote system running the onewire server
  • path (str): path on the server to the programmable I/O pin
Used by:

USBMassStorage

A USBMassStorage resource describes a USB memory stick or similar device.

USBMassStorage:
  match:
    'ID_PATH': 'pci-0000:06:00.0-usb-0:1.3.2:1.0-scsi-0:0:0:3'
Used by:

IMXUSBLoader

An IMXUSBLoader resource describes a USB device in the imx loader state.

IMXUSBLoader:
  match:
    'ID_PATH': 'pci-0000:06:00.0-usb-0:1.3.2:1.0'
Used by:

MXSUSBLoader

An MXSUSBLoader resource describes a USB device in the mxs loader state.

MXSUSBLoader:
  match:
    'ID_PATH': 'pci-0000:06:00.0-usb-0:1.3.2:1.0'
Used by:

NetworkMXSUSBLoader

A NetworkMXSUSBLoader descibes an MXSUSBLoader available on a remote computer.

NetworkIMXUSBLoader

A NetworkIMXUSBLoader descibes an IMXUSBLoader available on a remote computer.

AndroidFastboot

An AndroidFastboot resource describes a USB device in the fastboot state.

AndroidFastboot:
  match:
    'ID_PATH': 'pci-0000:06:00.0-usb-0:1.3.2:1.0'
Used by:

USBEthernetInterface

A USBEthernetInterface resource describes a USB device Ethernet adapter.

USBEthernetInterface:
  match:
    'ID_PATH': 'pci-0000:06:00.0-usb-0:1.3.2:1.0'

AlteraUSBBlaster

An AlteraUSBBlaster resource describes an Altera USB blaster.

AlteraUSBBlaster:
  match:
    'ID_PATH': 'pci-0000:06:00.0-usb-0:1.3.2:1.0'
Used by:

RemotePlace

A RemotePlace describes a set of resources attached to a labgrid remote place.

RemotePlace:
  name: example-place

The example describes the remote place example-place. It will connect to the labgrid remote coordinator, wait until the resources become available and expose them to the internal environment.

  • name (str): name or pattern of the remote place
Used by:
  • potentially all drivers

udev Matching

udev matching allows labgrid to identify resources via their udev properties. Any udev property key and value can be used, path matching USB devices is allowed as well. This allows exporting a specific USB hub port or the correct identification of a USB serial converter across computers.

The initial matching and monitoring for udev events is handled by the UdevManager class. This manager is automatically created when a resource derived from USBResource (such as USBSerialPort, IMXUSBLoader or AndroidFastboot) is instantiated.

To identify the kernel device which corresponds to a configured USBResource, each existing (and subsequently added) kernel device is matched against the configured resources. This is based on a list of match entries which must all be tested successfully against the potential kernel device. Match entries starting with an @ are checked against the device’s parents instead of itself; here one matching parent causes the check to be successful.

A given USBResource class has builtin match entries that are checked first, for example that the SUBSYSTEM is tty as in the case of the USBSerialPort. Only if these succeed, match entries provided by the user for the resource instance are considered.

In addition to the properties reported by udevadm monitor --udev --property, elements of the ATTR(S){} dictionary (as shown by udevadmin info <device> -a) are useable as match keys. Finally sys_name allows matching against the name of the directory in sysfs. All match entries must succeed for the device to be accepted.

The following examples show how to use the udev matches for some common use-cases.

Matching a USB Serial Converter on a Hub Port

This will match any USB serial converter connected below the hub port 1.2.5.5 on bus 1. The sys_name value corresponds to the hierarchy of buses and ports as shown with lsusb -t and is also usually displayed in the kernel log messages when new devices are detected.

USBSerialPort:
  match:
    '@sys_name': '1-1.2.5.5'

Note the @ in the @sys_name match, which applies this match to the device’s parents instead of directly to itself. This is necessary for the USBSerialPort because we actually want to find the ttyUSB? device below the USB serial converter device.

Matching an Android Fastboot Device

In this case, we want to match the USB device on that port directly, so we don’t use a parent match.

AndroidFastboot:
  match:
    'sys_name': '1-1.2.3'

Matching a Specific UART in a Dual-Port Adapter

On this board, the serial console is connected to the second port of an on-board dual-port USB-UART. The board itself is connected to the bus 3 and port path 10.2.2.2. The correct value can be shown by running udevadm info /dev/ttyUSB9 in our case:

$ udevadm info /dev/ttyUSB9
P: /devices/pci0000:00/0000:00:14.0/usb3/3-10/3-10.2/3-10.2.2/3-10.2.2.2/3-10.2.2.2:1.1/ttyUSB9/tty/ttyUSB9
N: ttyUSB9
S: serial/by-id/usb-FTDI_Dual_RS232-HS-if01-port0
S: serial/by-path/pci-0000:00:14.0-usb-0:10.2.2.2:1.1-port0
E: DEVLINKS=/dev/serial/by-id/usb-FTDI_Dual_RS232-HS-if01-port0 /dev/serial/by-path/pci-0000:00:14.0-usb-0:10.2.2.2:1.1-port0
E: DEVNAME=/dev/ttyUSB9
E: DEVPATH=/devices/pci0000:00/0000:00:14.0/usb3/3-10/3-10.2/3-10.2.2/3-10.2.2.2/3-10.2.2.2:1.1/ttyUSB9/tty/ttyUSB9
E: ID_BUS=usb
E: ID_MODEL=Dual_RS232-HS
E: ID_MODEL_ENC=Dual\x20RS232-HS
E: ID_MODEL_FROM_DATABASE=FT2232C Dual USB-UART/FIFO IC
E: ID_MODEL_ID=6010
E: ID_PATH=pci-0000:00:14.0-usb-0:10.2.2.2:1.1
E: ID_PATH_TAG=pci-0000_00_14_0-usb-0_10_2_2_2_1_1
E: ID_REVISION=0700
E: ID_SERIAL=FTDI_Dual_RS232-HS
E: ID_TYPE=generic
E: ID_USB_DRIVER=ftdi_sio
E: ID_USB_INTERFACES=:ffffff:
E: ID_USB_INTERFACE_NUM=01
E: ID_VENDOR=FTDI
E: ID_VENDOR_ENC=FTDI
E: ID_VENDOR_FROM_DATABASE=Future Technology Devices International, Ltd
E: ID_VENDOR_ID=0403
E: MAJOR=188
E: MINOR=9
E: SUBSYSTEM=tty
E: TAGS=:systemd:
E: USEC_INITIALIZED=9129609697

We use the ID_USB_INTERFACE_NUM to distinguish between the two ports:

USBSerialPort:
  match:
    '@sys_name': '3-10.2.2.2'
    'ID_USB_INTERFACE_NUM': '01'

Matching a USB UART by Serial Number

Most of the USB serial converters in our lab have been programmed with unique serial numbers. This makes it easy to always match the same one even if the USB topology changes or a board has been moved between host systems.

USBSerialPort:
  match:
    'ID_SERIAL_SHORT': 'P-00-00679'

To check if your device has a serial number, you can use udevadm info:

$ udevadm info /dev/ttyUSB5 | grep SERIAL_SHORT
E: ID_SERIAL_SHORT=P-00-00679

Drivers

SerialDriver

A SerialDriver connects to a serial port. It requires one of the serial port resources.

Binds to:
SerialDriver:
  txdelay: 0.05
Implements:
Arguments:
  • txdelay (float): time in seconds to wait before sending each byte

ShellDriver

A ShellDriver binds on top of a ConsoleProtocol and is designed to interact with a login prompt and a Linux shell.

Binds to:
Implements:
ShellDriver:
  prompt: 'root@\w+:[^ ]+ '
  login_prompt: ' login: '
  username: 'root'
Arguments:
  • prompt (regex): shell prompt to match after logging in
  • login_prompt (regex): match for the login prompt
  • username (str): username to use during login
  • password (str): password to use during login
  • keyfile (str): optional keyfile to upload after login, making the SSHDriver usable
  • login_timeout (int): optional, timeout for login prompt detection in seconds (default 60)

SSHDriver

A SSHDriver requires a NetworkService resource and allows the execution of commands and file upload via network.

Binds to:
Implements:
SSHDriver:
  keyfile: example.key
Arguments:
  • keyfile (str): filename of private key to login into the remote system

InfoDriver

An InfoDriver provides an interface to retrieve system settings and state. It requires a CommandProtocol.

Binds to:
Implements:
InfoDriver: {}
Arguments:
  • None

UBootDriver

A UBootDriver interfaces with a u-boot boot loader via a ConsoleProtocol.

Binds to:
Implements:
UBootDriver:
  prompt: 'Uboot> '
Arguments:
  • prompt (regex): u-boot prompt to match
  • password (str): optional u-boot unlock password
  • init_commands (tuple): tuple of commands to execute after matching the prompt

BareboxDriver

A BareboxDriver interfaces with a barebox bootloader via a ConsoleProtocol.

Binds to:
Implements:
BareboxDriver:
  prompt: 'barebox@[^:]+:[^ ]+ '
Arguments:
  • prompt (regex): barebox prompt to match
  • autoboot (regex, default=”stop autoboot”): autoboot message to match
  • interrupt (str, default=”\n”): string to interrupt autoboot (use “\x03” for CTRL-C)
  • bootstring (regex, default=”Linux version d”): succesfully jumped into the kernel

ExternalConsoleDriver

An ExternalConsoleDriver implements the ConsoleProtocol on top of a command executed on the local computer.

Implements:
ExternalConsoleDriver:
  cmd: 'microcom /dev/ttyUSB2'
  txdelay: 0.05
Arguments:
  • cmd (str): command to execute and then bind to.
  • txdelay (float): time in seconds to wait before sending each byte

AndroidFastbootDriver

An AndroidFastbootDriver allows the upload of images to a device in the USB fastboot state.

Binds to:
Implements:
  • None (yet)
AndroidFastbootDriver:
  image: mylocal.image
Arguments:
  • image (str): filename of the image to upload to the device

OpenOCDDriver

An OpenOCDDriver controls OpenOCD to bootstrap a target with a bootloader.

Binds to:
Implements:
Arguments:
  • config (str): OpenOCD configuration file
  • search (str): include search path for scripts
  • image (str): filename of image to bootstrap onto the device

ManualPowerDriver

A ManualPowerDriver requires the user to control the target power states. This is required if a strategy is used with the target, but no automatic power control is available.

Implements:
ManualPowerDriver:
  name: 'example-board'
Arguments:
  • name (str): name of the driver (will be displayed during interaction)

ExternalPowerDriver

An ExternalPowerDriver is used to control a target power state via an external command.

Implements:
ExternalPowerDriver:
  cmd_on: example_command on
  cmd_off: example_command off
  cmd_cycle: example_command cycle
Arguments:
  • cmd_on (str): command to turn power to the board on
  • cmd_off (str): command to turn power to the board off
  • cycle (str): optional command to switch the board off and on
  • delay (float): configurable delay in seconds between off and on if cycle is not set

NetworkPowerDriver

A NetworkPowerDriver controls a NetworkPowerPort, allowing control of the target power state without user interaction.

Binds to:
Implements:
NetworkPowerDriver:
  delay: 5.0
Arguments:
  • delay (float): optional delay in seconds between off and on

DigitalOutputPowerDriver

A DigitalOutputPowerDriver can be used to control a device with external commands and a digital output port. The digital output port is used to reset the device.

Binds to:
DigitalOutputPowerDriver:
  cmd_on: example_command on
  cmd_off: example_command off
Arguments:
  • cmd_on (str): command to turn power to the board on
  • cmd_off (str): command to turn power to the board off
  • delay (float): configurable delay in seconds between off and on

MXSUSBDriver

A MXUSBDriver is used to upload an image into a device in the mxs USB loader state. This is useful to bootstrap a bootloader onto a device.

Binds to:
Implements:
MXSUSBDriver:
  image: mybootloader.img
Arguments:
  • image (str): The image to bootstrap onto the target

IMXUSBDriver

A IMXUSBDriver is used to upload an image into a device in the imx USB loader state. This is useful to bootstrap a bootloader onto a device.

Binds to:
Implements:
IMXUSBDriver:
  image: mybootloader.img
Arguments:
  • image (str): The image to bootstrap onto the target

USBStorageDriver

A USBStorageDriver allows access to a USB stick or similar device via the USBMassStorage resource.

Binds to:
Implements:
  • None (yet)
USBStorageDriver: {}
Arguments:
  • None

OneWirePIODriver

A OneWirePIODriver controls a OneWirePIO resource. It can set and get the current state of the resource.

Binds to:
Implements:
OneWirePIODriver: {}
Arguments:
  • None

QEMUDriver

The QEMUDriver allows the usage of a qemu instance as a target. It requires several arguments, listed below. The kernel, flash, rootfs and dtb arguments refer to images and paths declared in the environment configuration.

Binds to:
  • None
QEMUDriver:
  qemu_bin: qemu_arm
  machine: vexpress-a9
  cpu: cortex-a9
  memory: 512M
  boot_args: "root=/dev/root console=ttyAMA0,115200"
  extra_args: ""
  kernel: kernel
  rootfs: rootfs
  dtb: dtb
tools:
  qemu_arm: /bin/qemu-system-arm
paths:
  rootfs: ../images/root
images:
  dtb: ../images/mydtb.dtb
  kernel: ../images/vmlinuz
Implements:
Arguments:
  • qemu_bin (str): reference to the tools key for the QEMU binary
  • machine (str): QEMU machine type
  • cpu (str): QEMU cpu type
  • memory (str): QEMU memory size (ends with M or G)
  • extra_args (str): extra QEMU arguments, they are passed directly to the QEMU binary
  • boot_args (str): optional, additional kernel boot argument
  • kernel (str): optional, reference to the images key for the kernel
  • disk (str): optional, reference to the images key for the disk image
  • flash (str): optional, reference to the images key for the flash image
  • rootfs (str): optional, reference to the paths key for use as the virtio-9p filesystem
  • dtb (str): optional, reference to the image key for the device tree

The qemudriver also requires the specification of:

  • a tool key, this contains the path to the qemu binary
  • an image key, the path to the kernel image and optionally the dtb key to specify the build device tree
  • a path key, this is the path to the rootfs

Strategies

Strategies are used to ensure that the device is in a certain state during a test. Such a state could be the boot loader or a booted Linux kernel with shell.

BareboxStrategy

A BareboxStrategy has three states:

  • unknown
  • barebox
  • shell

to transition to the shell state:

t = get_target("main")
s = BareboxStrategy(t)
s.transition("shell")

this command would transition from the boot loader into a Linux shell and activate the shelldriver.

ShellStrategy

A ShellStrategy has three states:

  • unknown
  • off
  • shell

to transition to the shell state:

t = get_target("main")
s = ShellStrategy(t)
s.transition("shell")

this command would transition directly into a Linux shell and activate the shelldriver.

UBootStrategy

A UBootStrategy has three states:

  • unknown
  • uboot
  • shell

to transition to the shell state:

t = get_target("main")
s = UBootStrategy(t)
s.transition("shell")

this command would transition from the boot loader into a Linux shell and activate the shelldriver.

Environment Configuration

The environment configuration for a test environment consists of a YAML file which contains targets, drivers and resources. The invocation order of objects is important here since drivers may depend on other drivers or resources.

The skeleton for an environment consists of:

targets:
  <target-1>:
    resources:
      <resource-1>:
        <resource-1 parameters>
      <resource-2>:
        <resource-2 parameters>
    drivers:
      <driver-1>:
        <driver-1 parameters>
      <driver-2>: {} # no parameters for driver-2
  <target-2>:
    resources:
      <resources>
    drivers:
      <drivers>
  <more targets>
options:
  <option-1 name>: <value for option-1>
  <more options>
images:
  <image-1 name>: <absolute or relative path for image-1>
  <more images>
tools:
  <tool-1 name>: <absolute or relative path for tool-1>
  <more tools>

If you have a single target in your environment, name it “main”, as the get_target function defaults to “main”.

All the resources and drivers in this chapter have a YAML example snippet which can simply be added (at the correct indentation level, one level deeper) to the environment configuration.

Exporter Configuration

The exporter is configured by using a YAML file (with a syntax similar to the environment configs used for pytest) or by instantiating the Environment object. To configure the exporter, you need to define one or more resource groups, each containing one or more resources. This allows the exporter to group resources for various usage scenarios, e.g. all resources of a specific place or for a specific test setup. For information on how the exporter fits into the rest of labgrid, see Remote Resources and Places.

The basic structure of an exporter configuration file is:

<group-1>:
  <resources>
<group-2>:
  <resources>

The simplest case is with one group called “group1” containing a single USBSerialPort:

group1:
  USBSerialPort:
    match:
      '@sys_name': '3-1.3'

To reduce the amount of repeated declarations when many similar resources need to be exported, the Jinja2 template engine is used as a preprocessor for the configuration file:

## Iterate from group 1001 to 1016
# for idx in range(1, 17)
{{ 1000 + idx }}:
  NetworkSerialPort:
    {host: rl1, port: {{ 4000 + idx }}}
  NetworkPowerPort:
    # if 1 <= idx <= 8
    {model: apc, host: apc1, index: {{ idx }}}
    # elif 9 <= idx <= 12
    {model: netio, host: netio4, index: {{ idx - 8 }}}
    # elif 13 <= idx <= 16
    {model: netio, host: netio5, index: {{ idx - 12 }}}
    # endif
# endfor

Use # for line statements (like the for loops in the example) and ## for line comments. Statements like {{ 4000 + idx }} are expanded based on variables in the Jinja2 template.