AUTOSAR project process methodology
<1> .exe
Although above figure shows executable as .exe but it should not be confused with .exe file of Windows PC .
Here .exe file means a general executable file which can be .elf, .bin, etc.
<2> .arxml
AUTOSAR uses a specific file format for information exchange between different steps in the process. That file format is similar to XML but in AUTOSAR context its called .arxml ( AUTOSAR Extensible Markup Language ) file.
The configuration software will interpret this file and generate code according to the information contained in this file.
Some Steps in configuration are:
- System Configuration: In this step, overall ECUs required in car(System) and their hardware is configured along with SWCs and the Compostion SWCs are mapped to respective ECUs.
- Generate System Configuration Description: After configuration from first step, the output of the first step is called System Configuration Description file which is in .arxml file format.
- ECU Extract generation: By using the System Configuration description arxml file from step 2 as input, a new file is generated which is called ECU Extract arxml file. It has information for single ECUs only unlike the System Configuration description file which has information of all the ECUs in a Car.
- ECU Configuration: In this step, the ECU Extract is used as input and respective ECU is configured according to application requirements. Configurations like BSW configuration, OS configuration etc.
- Generate ECU Configuration Description: This step will be used to generate the output of step 4 ( i.e. generate ECU Configuration Description arxml file which will be used further to generate Executable ) .
You can note file nomenclature (命名法), the files with suffix “Description” is the output of the respective step or process. For example System Configuration Description arxml is the output of System Configuration step.
What Information System Configuration Description File Has?
The System Configuration Description file (generated after System Configuration) have all the system configuration information such as :
- ECUs present in the system
- Communication systems interconnecting those ECUs and their configuration
- Communication matrices which will indicate the data which will be sent and received for those communication systems. As AUTOSAR aims to standardize whole development, all the data, size,etc that will be transmitted or received needs to be configured at the configuration time.
- Definition of SWCs with their ports and interfaces and connections.
- Mapping of SWCs(Software Components) to ECUs.
This file serves as a input to ECU configuration. The ECU Extract file is the same as the System Configuration Description but having information related to relevant ECU only.
What Information ECU Configuration Description File Has?
（The ECU Extract only defines the configuration elements that needs to be agreed by all ECUs in the system, but this is not sufficient to generate a code that can run on hardware. As this file don’t have any low level configuration information which can be used for configuring lower layers of the AUTOSAR architecture.）
So, ECU Configuration description has that information which the configuration software utilizes and generates the .c and .h files which are further compiled and run on hardware.
