Get Started

Congratulations on taking the first step to developing applications and systems with the Legato Application Framework!

Completing this section will familiarize you with the Legato Application Framework workflow and prepare you to start developing for your target.

Our tools and design patterns have been developed to make it easy to set up your development environment; develop, customize and/or update a system and/or apps; build the Legato runtime for your target; and install the updates on the target.


Setup Development Environment

The first thing to do to get started is to install the Source Code, Tools and configure your environment to build the Legato Application Framework for your target.

Leaf is a workspace manager that will take care of setting up your environment for you. It lists, downloads, installs and configures the software needed to start developing Legato Systems.

The Legato team has also developed a Legato Plugin for VSCode that integrates Leaf and the other Legato tools into a graphical IDE to help you develop and use the Legato tools easily.

Alternatively, you can set up your development environment manually.

Installation Description
Leaf Workspace Manager Download, install, and setup, the Legato Application Framework using Leaf
Legato Plugin for VSCode Install and configure VSCode and the Legato Plugin
Manually Install Dev Environment Manually install software and tools for the Legato Application Framework
Configure SWI Target Configure a Sierra Wireless Target
Configure Raspberry Pi Configure the Legato Application Framework for a Raspberry Pi

Leaf Quick Start

Detailed Install and Usage Instructions

To install leaf download and setup our debian package from the Sierra Wireless tools repository:

$ wget -O /tmp/leaf_latest.deb && sudo apt install /tmp/leaf_latest.deb
$ mkdir ~/myWorkspace; cd ~/myWorkspace

Search and install a package for your target (downloads and automatically installs Legato, the toolchain and tools):

$ leaf search -t <target>                          # search for all available SDKs for your target
$ leaf setup -p <packageIdentifier> <profileName>  # download, install and sets up your environment

List of supported targets (with default remote configuration):

  • wp750x - All wp75 family of modules
  • wp76xx - All wp76 family of modules
  • wp77xx - All wp77 family of modules
  • wp85 - All wp85 family of modules

Start developing using the Leaf Shell to configure your environment:

$ leaf shell
Use your myWorkspace directory to create your System, Apps and Components. The Legato Application Framework comes pre-built for your target so there is no need to run make unless you make changes to the framework itself. The $LEGATO_ROOT environment variable comes pre-configured into the environment and is profile aware, so you are able to reference or include Legato Systems, Platform Services and Apps in the Legato Application Framework by adding them to your own .sdef file using $LEGATO_ROOT in your path.

Visual Studio Code Install

The Legato Application Framework only builds on a Linux system. Windows and Mac systems are only supported by using a Linux VM and installing the Legato Application Framework and Visual Studio Code on Linux.

Step by step setup instructions are included here.

Download and install Visual Studio Code for Linux.

Install Leaf (if not already installed)

wget -O /tmp/leaf_latest.deb && sudo apt install /tmp/leaf_latest.deb

In the Microsoft marketplace search for Legato and install the plugin.

Open a folder to use as your development workspace (Ctrl + K + 0)

Use the Leaf Command Palate to configure your development environment for your target and install the IDE support tools.

Start developing, building and installing your code on your target.

Developer Mode App

When your target gets shipped to you it may be set up for production use. A number of libraries and settings will be removed from the Framework and the underlying OS because of licensing or security concerns. The Dev Mode app bundles up those libraries and sets configuration and sets the target up for development.

The developer mode app, provides the following tools and settings specific for development:

  • bundles gdbserver executable for use on the target device, allowing step-by-step debugging of Legato apps.
    • sets the probation period of apps to 10 seconds, to prevent aggressive roll-back.
  • holds a wake lock, so the target won't go to sleep when disconnected from USB.
  • removes the boot count file on startup to disable the boot loop detection feature of Legato.
  • runs the tcf-agent, so the target is auto discoverable by Developer Studio.
  • sets firewall rules to allow more permissive network access.

To install devMode on your target follow these install instructions.

With the Visual Studio Code IDE, devMode gets automatically installed on your target when you use the debugging features.


Now you are ready to start developing apps and installing them on your target. We first recommend starting with our Tutorials; they walk you through some of the basic concepts and how to create, install and test your first component and application.

Tutorial Description
helloWorld Create a "helloWorld" app and deploying it on a target
Extend helloWorld Create two apps and use IPC to communicate between the apps

Build and Update Target

When you are ready to update your target with the new software that you have created you need to combine it all into a system and then update your target with that system. While you can update each app on a target, it is recommended to build all of your apps together into a cohesive system. When your apps are combined and built into a system it validates inter-app dependencies and conflicts and will help you resolve binding issues at build time instead of at runtime.

Build tools:

  • mksys - Build tool to build systems (groups of applications)
  • mkapp - Build tool to build singular apps

Update/Install tools:

  • update - updates the read/write overlay partition of targets over USB.
  • fwupdate - updates the read only base partitions of targets over USB.
  • SWIflash - recovery tool that flashes images to the target via USB.


The following tutorials walk you through:

  • creating a system containing your sample apps
  • adding in optional kernel modules to your existing system (driver to enable hardware)
  • updating your target to a new system that includes your apps and an example kernel module
Tutorial Description
Legato Systems Create a system using a the default set of Platform Services and the helloWorld and helloIPC apps
Kernel Modules Add an example driver to your system
Update Target Update your target with your new system files

Concepts and Conventions

Now that you are familiar with the basic flow of the Legato Application Framework explore our documentation on our concepts and the programing conventions to create apps and systems with the Legato Application Framework.

Section Description
Definition Files Use Definition Files to build systems, Apps, components and drivers
API Files Work with the API files to develop Apps
C Language Standards C Language Coding Standards

Sample Apps and How To's

Our How To section contains useful articles to walk through some of our advance concepts and tools. There is also a repo of Sample Apps that provide demo apps and apps showing how to connect to and consume specific APIs.

Section Description
How To How To and Troubleshooting articles for common features
Sample Apps Sample Applications