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powertrain_build General Code Introduction
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Why is powertrain_build used?
The software is built using TargetLink, which generates c-code from Simulink models. Some models are used in multiple projects while others only serve for one project.
To make things easier to understand, let's say we want to produce a software for ABC_123 (fake car model) which handles the diesel.
Software generation before powertrain_build
- Gather all models used in ABC_123.
- Some models are used in several projects, therefore, we need to process those models and remove all non-ABC_123 parts. To save memory and avoid using the wrong software, matlab scripts is responsible for cutting out useless parts of the model.
- Generate c-code using TargetLink.
- Compile.
Such process had to be done every time we wanted software and we have X projects to maintain, which could take a while.
Software generation after powertrain_build
powertrain_build uses preprocessor blocks in the models, which means that the generated code has "#ifdef SOME_VAR" inside. It enables to switch between projects using variales, which means we can generate code for each model and store them in ./Models/.
- Gather all c-/h-files used in ABC_123.
- Set variales according to codeswitch documents.
- Compile.
Summary
Before powertrain_build, we had to generated code for each model (after modifying them through matlab scripts) for each projects and then compile. Now the latest version of the code is already in the repo, we just need to gather files, set variables and compile.
How to start with powertrain_build
To get familiar with powertrain_build, build.py is a good start since it contains all modules. Four important modules could also help you understand powertrain_build better: build_proj_cfg, unit_cfg, feature_cfg, signal_interface.
build_proj_cfg
This module is used to read ./Projects/<project_name>/Config/ProjectCfg.json and ./ConfigDocuments/BaseConfig.json, which provides configuration files location. The location of Base_Config is also stored in ProjectCfg. build_proj_cfg also provides methods of gathering information for other modules.
feature_cfg
feature_cfg module is also called the codeswitch module. It reads from ./ConfigDocuments/SPM_Codeswitch_Setup*.csv and provides methods for retrieving the currently used configurations of a unit. The first row of SPM_Codeswitch_Setup*.csv lists all projects and the first column lists codeswitch names. The values under each project states whether the corresponding codeswich is active in this project.
unit_cfg
The model list of a project is in ./Projects/<project_name>/local_cof/raster.json. Then unit_cfg reads unit definitions from models from the model list (/Models/<model_name>/pybuild_cfg/<model_name>.json). This module also provides methods to retrieve any unit definition, such as inports and outports, of a unit and all existing units.
signal_interface
This module gets supplier interface of the project from ./Projects/<project_name>/Config/ActiveInterfaces/. It provides methods of checking signal interfaces consistency between Supplier and VCC SW. It also reads inport/outport information from all units in raster and checks internally inports/outports consistency between VCC SW-units.
Additional Information
For more information about the project and unit configuration files see project configuration and unit configuration chapters.
Why powertrain_build, whats the advantages?
- Made in Python.
- Instead of Code Switches in the TargetLink models, there are C Pre Processor directives. In this way, we will have superset C code representing the superset Simulink models.
- Unit tests of build scripts as well as html documentation.
- Signal consistency checks by creating JSON files of the code.
How powertrain_build is used in different targets
vcu/hp
vcu/hi
ECM
TargetLink Limitations
- dSPACE delivers removal of limitation in TargetLink release 2019B, first said to be delivered 2018B.
These options gives code generation errors:
- Enabled subsystems, which reset the states when enabling them.
- Out ports which are reset when disabling a subsystem, which are used in subsystems under a pre-processor block.
- Solution of TargetLink limitation is refactoring of models.
powertrain_build dependencies
Python module dependency visualization from pydeps, https://github.com/thebjorn/pydeps looks like this:
How powertrain_build generates a SPA2 service
