The RTE is responsible for establishing communication between the AUTOSAR software components. It is also through the RTE that the software components access the basic software modules including the OS and communication service. AUTOSAR software components cannot access the basic software modules directly. All the communication happens only through the AUTOSAR interfaces and is directly under the control of the RTE.

RTE generation process

The RTE generator Is a set of tools to realise the descriptions defined in the AUTOSAR Virtual Function Bus for an ECU. The RTE generator creates the AUTOSAR software component API functions. The generated API functions have three responsibilities.

link the AUTOSAR software components to the OS
Manage communication between AUTOSAR software components
Realises communication between AUTOSAR software components and basic software modules

The RTE generation process consists of two phases

RTE Contract Phase – In this phase only limited information about the component is available. In this phase, the AUTOSAR interface definitions are used to create an application header for the component type. The application header file defines the contract between the component and the RTE.

RTE generation Phase – In this phase all the relevant information about components, deployment to ECU, communication connections of the ECU is defined and the information is used to generate the RTE. One RTE is generated for each ECU in the system.

The RTE is configured and generated for each ECU individually

RTE Contract Phase:

In the Contract Phase, the application software component type is defined, ports are included, interfaces are defined, connections between the ports through the interfaces are defined. All these are defined in the VFB level and the SW-Component Internal Behaviour Description’ is also defined. From this information, the ‘Component API’ (application header file) is generated. AUTOSAR Application Software development Process

With the generated ’Component API’ (application header file) the Software Component developer can provide the Software Component’s source code without being concerned as to whether the communication will later be local or using some network(s).
It has to be considered that the SW-Component development process is iterative and that the SW-Component description might be changed during the development of the SW-Component. This requires the application header file to be regenerated to reflect the changes done in the SW-Component description.
So when a SW-Component is delivered in the RTE Contract Phase it will consist of the following parts:

Component Type Description
Component Internal Behaviour Description
The actual source and/or object code
Component Implementation Description

RTE generation Phase:

The RTE Generation Phase can be split into two sections

RTE Configuration editing
RTE Generation Phase

RTE Configuration Editing

’RTE Configuration Editor’ is a tool that is used to collect all the information about the ECU to create an operational RTE. This gathering includes information on the SW-Component instances and their communication relationships, the Runnable Entities and the involved RTE-Events and so on. The main source for all this information is the ’ECU Configuration Description’.
When the ’RTE Configuration Editor’ has gathered all necessary information and built its internal structure it can start to place requirements on the configuration of other modules like COM and OS.
The ’ECU Configuration Editors’ work iteratively on the ’ECU Configuration Description’ until all configuration issues are resolved. There will be the need for several configuration editors, each specialized on a specific part of ECU Configuration. So one editor might be configuring the COM stack (not the communication matrix but the interaction of the individual modules) while another editor is used to configure the RTE.
The ’ECU Configuration Editors’ work iteratively on the ’ECU Configuration Description’ until all configuration issues are resolved. There will be the need for several configuration editors, each specialized on a specific part of ECU Configuration. So one editor might be configuring the COM stack (not the communication matrix but the interaction of the individual modules) while another editor is used to configure the RTE.

RTE Generation Phase

After the ECU has been entirely configured the generation of the actual RTE can be performed. Since all the relationships to and from the other Basic-SW modules have been already resolved during the ECU Configuration phase, the generation can be performed in parallel for all modules.