API Guides

Index of all available APIs within the Legato Application Framework


The Legato Application Framework contains a core set of daemons and a Legato library that make up the runtime environment and provide the controls and security for the systems, applications and components. There are also a set of modular Platform Services that by default are added to the Application Framework but can be added or removed as needed.

The Platform Services are applications that control the hardware on your target and provide APIs for you to bind to your applications and interface directly with the hardware. i.e., If you want to send data over the cell network then you need to bind your application to the dataConnection Service and open up a data connection over the cell network by calling the provided APIs. You do not need to know the AT command or QMI commands to do this yourself, as the dataConnection Service takes care of this for you.

All Legato AF Daemons and many of the Platform Services are multi-app safe, this means that the API's can be used by several Apps concurrently, and arbitration is fully managed among the Apps so multiple Apps can share the same resources.

Overview of Legato AF Architecture:


Lib Legato APIs

The Legato Application Framework provide a set of APIs to simplify common C programming tasks. lib legato adds object oriented functions to simplify and enhance the safety and reliability of your systems.

lib Legato provides a host of APIs that are automatically available to your code by including legato.h into your component.

Legato Application Framework Daemons

Legato Daemons are services that make up the Legato Runtime environment. They provide controls to start, stop, and configure the Platform Services and user applications. You do not need to bind daemons into your application and are available for all apps to use.

Daemons provide access to:

  • start and stop apps
  • preform fault recovery and rollback
  • API binding and configuration
  • find all service offerings and secure devices
  • provide in app configuration
  • monitoring services via a watchdog process
  • log control
  • update your target and the framework

Platform Services

Platform Services are Apps that come included in the default.sdef to enable hardware on your target. They are modular and can be removed if not needed though take care, as many of the services depend on other services to run. See the individual service for details.

Each of the Platform Services exposes a number of APIs that can bound with user applications to add the hardware functionality into your own applications. The APIs contain common functions to create, start, and stop connections to the specific hardware.

Platform Services APIs are pre-built IPC interfaces designed to create and run multiple services in different ways:

  • OEM's can create Legato apps to run as services on their specific hardware.
  • 3rd party software providers can create apps to enable supported hardware.
  • 3rd party software providers can use the built-in APIs for it's core daemons to control and configure other services and Apps.

To access the APIs the associated services must be running on the Legato System before you can use the API; targets may already have various service Apps installed on the default Legato System. Please check with your hardware vendor for the specifics of what services are enabled and supported as some of the services may have limited support for the target devices.

Some Services shouldn't be used together in the same app (e.g, if you use a multi-app safe service like Data Connection, you can't also use the Modem Data Control Service).