Release Notes

Version: Legato 20.08.0
Date: October 13th, 2020
Legato Application Framework Licensing Information

Visit the release page to download the tarball, clone the repositories from GitHub, or view previous released versions.

Get started with the 20.08 version of Legato by installing the SDK through Leaf.

Search for the 20.08 version for your target (using wp76xx as an example):

$ leaf search 20.08 -t wp76xx
leaf setup <profile name> -p <package identifier>

New Features

List of new features in the 20.08 Release:

New wifiClient.api functions

3 new functions have been added to the c_le_wifi_client:

  • GetCurrentSignalStrength() - returns the signal strength in dBm
  • GetRxData() - returns the data recieved from the access point in bytes
  • GetTxData() - returns the data transmitted to the access point in bytes

New ulpm.api function

SetShutDownStratagy() function has been added to the c_le_ulpm to configure the device behaviour on shutdown.

New Log Levels

Framework Daemon Log level settings have been added to the KConfig menus

Framework --> Daemon Setup --> Framework Daemon Log Level Setting


The log levels can also be set from the build config:

LE_<daemon>_LOG_LEVEL= <log level> make <target>

Daemons Log Level:


GNSS Extended Ephemeris File change

The le_gnss_EnableExtendedEphemerisFile() is now set to 2 by default instead of 1.

le_audio API change

A new duration limit is set for the le_audio_PlayDtmf() function. If any of the given DTMF duration or pause is greater than 5 seconds, the function will return LE_FAULT.

cm data connect cmd change

The connection test in the cm data connect tool has been removed as it was causing issues for customers.

Deprecated API/functions

  • The QMI_NAS_SET_EVENT_REPORT and QMI_NAS_GET_EVENT_REPORT have been deprecated and removed The replacement function is QMI_NAS_INDICATION_REGISTER.
  • le_gnss_GetDop() function has been removed and is replaced by le_gnss_GetDilutionOfPrecision().
  • LE_GNSS_NMEA_MASK_PQXFI has also been removed and replaced by LE_GNSS_NMEA_MASK_PTYPE.

eDRX AirVantage Support

Legato now includes object10 enablement for eRDX

Beta Features

Alpha Features

The following are the list of features that have been added into the 20.08 Release but are still being developed and should not be used on production targets. Please provide feedback for these features on our forums:

Legato RPC

RPC has been added as an experimental feature (Remote-procedure Call Remote procedure call). Please refer to getStartRPC Legato RPC on how to get started.

Fixed Issues

All changes are tagged in GitHub as "20.08.0". The full list of changes and commit messages can be found on GitHub.

This is only the list of fixes for the Application Framework and Platform Services, for the list of changes in the Platform Adapter view the commits under the tag 20.08.0 in individual repositories on GitHub.

Known Issues

Giving LE_MRC_BITMASK_RAT_ALL as the input in le_mrc_SetRatPreferences() to set the Radio Access Technology (RAT) to auto mode isn't supported on WP77.

Constraints and Limitations

Legato Image Update

Legato image has to be upgraded or downgraded via a bundle across an image incompatibility boundary described below.

In the Legato upgrade from pre-20.08.0 versions (e.g. 20.04.0) to 20.08.0+, an image incompatibility boundary has been introduced. This is due to the included Yocto update from version 2.5 to 3.0 in which are different libssl versions.

Whenever the Legato image is upgraded or downgraded across this boundary line, it has to be done together with its corresponding LXSWI image in a bundle. Otherwise, Legato would not run and not take any image update to recover.

Dev Machine Linux Version

To develop applications within the Legato Application Framework, a current supported Long Term Support version of Ubuntu Linux is required on your dev machine (or running in a virtual box on Windows). Ubuntu 18.04 is the current recommended version to use on your dev machine.

ECM-USB modem manager issue

Ubuntu 15.10 and newer has Modem Manager version 1.4.12-1ubuntu1 installed by default which conflicts with the ECM-USB driver when connecting a target. Modem manager may cause the Ubuntu Network Manager to crash on your host and/or your target device to become unavailable over USB.


  • NetworkManager crashing when plugging into your device over USB, or
  • The target device becomes inaccessible after 30 seconds.

Recommended Work Around:

FOTA upgrade warning

A device that has trustzones enabled, may re-bootstrap (obtain new keys from the AirVantage server) durring a FOTA (firmware over-the-air) upgrade.