# parameter-framework [](https://travis-ci.org/01org/parameter-framework) [](https://ci.appveyor.com/project/parameter-framework/parameter-framework) [](https://codecov.io/github/01org/parameter-framework?branch=master) ## Introduction The parameter-framework is a plugin-based and rule-based framework for handling parameters. This means that you can: 1. Describe your system's structure and its parameters (in XML) - aka. **What**; 2. Write (in C++) or reuse a backend (aka. plugin) for accessing the parameters that you just described - aka. **How**; 3. Define (in XML or in a domain-specific-language) conditions/rules upon which a given parameter must take a given value - aka. **When**.  ### Usage examples #### Alsa controls on embedded platforms The parameter-framework can be used to set the value of alsa controls (switches, volumes, etc.) on smartphones/tablets based on parameter-framework rules (in this example, they transcribe use-cases). For accessing parameters (i.e. alsa controls), you may use the [alsa plugin](https://github.com/01org/parameter-framework-plugins-alsa). #### Parameters in files The [filesystem plugin](https://github.com/01org/parameter-framework-plugins-filesystem) can be used to write parameters in files. This is particularly useful for files in `/sys` managing GPIOs. ### More details The parameter-framework's core comes in the form of a shared library. Its client has to provide: - configuration files describing the structure of the system to be managed by the parameter-framework and what plugins it must use to read/write into each subsystem; - a list of criteria (representing the state of the client) and their possible values; - configuration files describing the value that each part of the system (aka parameter) must take - this is done by writing rules based on the criteria described above. At runtime, the most usual communication between the client and the parameter-framework are: 1. The update of *criteria* (that are used in the rules introduced above) and 2. Update all relevant parameters according to the new criteria values. The parameter-framework uses the appropriate backend for writing the values in each underlying subsystem. The parameter-framework comes with several tools, including a command-line interface: `remote-process`. ## Going further See [the wiki on github](https://github.com/01org/parameter-framework/wiki). ## Compiling **You may take a look at `.travis.yml` and `appveyor.yml` for examples on how we build the Parameter Framework in the CI.** It will probably help if you have troubles building the Parameter Framework even after reading the following sections: ### Dependencies In order to compile you'll need, at the very least: - CMake (v3.2.2 or later) (v3.3.0 or later on Windows); - A C/C++ compiler supporting C++11; - libxml2 headers and libraries (Provided by the `libxml2-dev` on debian-based distributions); If you want to use the remote command interface (`NETWORKING=ON` by default), you'll also need: - Standalone ASIO (1.10.6 or later) (Provided by `libasio-dev` on debian-based distributions) ASIO is C++ header-only ASynchronous-IO library. If you want to compile the *Python bindings* (`PYTHON_BINDINGS=ON` by default), you'll also need: - SWIG 2.0 (A binding generator); - Python2.7 development environment (Provided by `python2.7-dev` on debian-based distributions) If you want to *compile and run the tests* (`BUILD_TESTING=ON` by default), you'll also need: - Catch (Provided by `catch` on debian-based distributions). Catch is a single-header test framework - as such you may also download it directly [here](https://raw.githubusercontent.com/philsquared/Catch/master/single_include/catch.hpp); - Python2.7 (Provided by `python2.7` on debian-based distribution - it is preinstalled on most distributions). If you want to *build the code documentation* (`DOXYGEN=OFF` by default), you'll need `doxygen` and `graphviz`. This doc is already available to you - see the wiki. **To list all available configuration options, try** `cmake -L` (you may also filter-out lines starting with `CMAKE_`). ### How-To If you are already familiar with CMake, you know what to do. Run `cmake .` then `make`. You may then install libraries, headers and binaries with `make install`. By default, they are installed under `/usr/local` on unix OSes; if you want to install them under a custom directory, you may do so by passing it to the `cmake .` command; e.g. # Always use absolute paths in CMake "-D" options: you don't know where # relative paths will be evaluated from. cmake -DCMAKE_INSTALL_PREFIX=/path/to/custom/install . If you want to provide your own dependencies (e.g. your own version of libxml2), you should pass the base paths as the `CMAKE_PREFIX_PATH` variable, e.g.: cmake -DCMAKE_PREFIX_PATH='/path/to/dependency1/;/path/to/dependency2/' For more information on how to use `CMAKE_PREFIX_PATH`, see CMake's documentation. Also, CMake can build a project out-of-tree, which is the recommended method: mkdir /path/to/build/directory cd /path/to/build/directory cmake /path/to/sources/of/parameter-framework make After a build you may want to run the parameter-framework tests with `make test` or `ctest`. ### Compiling on Windows The only supported compiler on Windows in Visual Studio 14 2015. The 2013 version does not support some C++11 features. When running CMake's configuration step (the first call to CMake) you must specify the build system you want to use, i.e. `-G Visual Studio 14 2015 Win64`. Again, you may refer to `appveyor.yml`. If you don't already have libxml2 headers/libraries and don't want to build them by yourself, we have a precompiled version for x86-64. *These are provided for reference and as a convenience for development purpose only; when making a final product, you should recompile the latest libxml2 release yourself.* Compiled with Visual Studio 12 2013: - [in debug configuration](https://01.org/sites/default/files/libxml2-x86_64-debug-3eaedba1b64180668fdab7ad2eba549586017bf3.zip) - [in release configuration](https://01.org/sites/default/files/libxml2-x86_64-3eaedba1b64180668fdab7ad2eba549586017bf3.zip) We have mirrored ASIO 1.10.6 [here](https://01.org/sites/default/files/asio-1.10.6.tar.gz). Once you have downloaded and uncompressed these two dependencies, add the following two entries to `CMAKE_PREFIX_PATH`: /path/to/libxml2-x86_64/ /path/to/asio-1.10.6/