Release Notes

Version: Legato 20.04.0
Date: March 28th, 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 latest version of Legato by installing the SDK through Leaf.

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

$ leaf search -t wp76xx -t latest

Update your profile to the latest version:

$ leaf update

New Features

List of new features in the 20.04 Release:

Legato Plugin for Visual Studio Code

The Legato team has launched version 1.0 of the Legato Plugin for VSCode.

Deprecated APIs

The following APIs have been removed and are no longer used within the Legato Application Framework

  • SMS - le_sms_SetTimeout() removed as it was not needed.
  • swiQmi_CheckResponseCode(), replaced by swiQmi_CheckResponse()
  • swiQmi_OEMCheckResponseCode(), replaced by swiQmi_CheckResponse()
  • AT Commands Server - le_atServer_SendFinalResponse(), replaced by le_atServer_SendFinalResultCode()
  • le_fd_MkDataPipe() has been removed as it is not supported in Linux.
  • le_sup_ctrl.api has been removed as it is no longer needed or referenced in Legato.

tty API Behavior Change

le_tty_Open() will now return a file descriptor or a -1 for a failure, this is a behavior change from previous version where le_tty_Open() would exit the process with an LE_FATAL.

Network Scan Timeout Change

The timeout value for le_mrc_PerformPciNetworkScan() has been changed from 300 seconds to 240 seconds for targets that have watchdog enabled.

eCall API changes

A new API function has been added to eCall to set/get the dial duration for the maximum time the target has to connect to the emergency call center including redial attempts.

APN name deprecation

Mobile Originated (MO-PDP context activation) is a blocking function and has a maximum timeout of 155 seconds, previously it was set to 150 seconds.

Beta Features

Alpha Features

The following are the list of features that have been added into the 20.04 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 "20.04.0". 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 20.04.0 in individual repositories on GitHub.

Known Issues

Constraints and Limitations

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.