Features

When inheriting the mender-full or mender-full-ubi class in local.conf, Mender provides a default set of features that covers a wide range of boards and needs. However, sometimes it may be necessary to enable or disable certain features depending on the needs of the particular build. Use MENDER_FEATURES_ENABLE and MENDER_FEATURES_DISABLE variables to enable and disable features provided by Mender.

To enable a feature, add this to your local.conf:

MENDER_FEATURES_ENABLE:append = " <FEATURE>"

To disable a feature, add this to your local.conf:

MENDER_FEATURES_DISABLE:append = " <FEATURE>"

List of features

Below is a list of the features that Mender provides, with descriptions. Please note the following markers:

internal: feature is meant for internal use by the Mender team only. The behaviour can be modified at any time.

experimental: feature is not undergoing regular QA.

• mender-bios - Enables booting of traditional BIOS based systems. Normally enabled together with mender-grub. Disabling this feature with mender-grub enabled will assume the booting process uses the UEFI standard.

• mender-client-install - Enables a build that has Mender installed, with configuration. Note that this does not include the default Mender partition layout, use mender-image for that. Note that on Yocto-5.0 "scarthgap" and later, you need to use mender-install instead.

• mender-growfs-data - Enable dynamic resizing of the data filesystem through systemd-growfs

• mender-grub - Enables integration with the GRUB bootloader.

• mender-image - Enables a build that uses the Mender defined partition layout.

• mender-image-bios - Enables a build that provides a Mender partitioned image for use with traditional BIOS based systems (.biosimg). Enabling this feature requires enabling mender-image too.

• mender-image-gpt - Enables a build that provides a Mender partitioned image for use with BIOS GPT based systems (.biosimg). Enabling this feature requires enabling mender-image too.

• mender-image-sd - Enables a build that provides a Mender partitioned SD card image (.sdimg). Enabling this feature requires enabling mender-image too.

• mender-image-ubi - Enables a build that provides a Mender partitioned UBI image (.ubimg). Enabling this feature requires enabling mender-image too.

• mender-image-uefi - Enables a build that provides a Mender partitioned UEFI image (.uefiimg). Enabling this feature requires enabling mender-image too.

• mender-install - Enables a build that has Mender installed, with configuration. Note that this does not include the default Mender partition layout, use mender-image for that. Note that on Yocto-4.0 "kirkstone" and older, you need to use mender-client-install instead.

• mender-partuuid - experimental - Enable usage of UUID as partition identifiers (GRUB only).

  You must set the UUID's for all parts in your environment, e.g

  # UUID's generated using the 'uuidgen -r' command
  MENDER_BOOT_PART = "/dev/disk/by-partuuid/9553c78a-bed1-40fe-9333-f7409e0585e5"
  MENDER_ROOTFS_PART_A = "/dev/disk/by-partuuid/cb8cc332-f5e3-4b53-a489-13d3a8dd5768"
  MENDER_ROOTFS_PART_B = "/dev/disk/by-partuuid/708798f3-4e9d-4338-bb69-bc92e0b51efb"
  MENDER_DATA_PART = "/dev/disk/by-partuuid/0965b52a-89bd-46c1-ac69-3b27fb6c2aae"

• mender-partlabel - experimental - Use PARTLABEL to avoid hardcoded drive device path.

• mender-systemd - Enables a Mender build that uses systemd. See also the section about disabling Mender as a system service.

• mender-systemd-boot - experimental - Use Mender together with systemd-boot.

• mender-efi-boot - internal - Enabled by GRUB/systemd-boot to extend UEFI overlay recipes.

• mender-ubi - Enables Mender configuration files specifically for UBI images.

• mender-uboot - Enables integration with the U-Boot bootloader.

• mender-persist-systemd-machine-id - Enables setting up the systemd machine ID to be persistent across OTA updates.

• mender-testing-enabled - internal - Enable the testing/* layers and functionality.

• mender-prepopulate-inactive-partition - Populate the inactive partition with the same contents of the active one, primarily for testing purposes.

Default features

By default, no features are enabled, but it is common to include a top level class in order to get some default features. Here is an example of how to enable such a class in local.conf:

INHERIT += "mender-full"

The currently available classes are:

• mender-full: Enables the most common features for Mender, which are:

  • mender-image
  • mender-install
  • mender-systemd
  • mender-image-uefi
  • mender-grub
  • mender-growfs-data

• mender-full-ubi: Enables the most common features for UBI based Mender installations, which are:

  • mender-image
  • mender-image-ubi
  • mender-install
  • mender-systemd
  • mender-ubi
  • mender-uboot
  • mender-growfs-data