update changelog, add basic instructions for etl

CHANGELOG.md

@@ -37,6 +37,8 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 - Dedicated Version class and constant `fsfw::FSFW_VERSION` containing version information
   inside `fsfw/version.h`
   PR: https://egit.irs.uni-stuttgart.de/fsfw/fsfw/pulls/559
+- Added ETL dependency
+  PR: https://egit.irs.uni-stuttgart.de/fsfw/fsfw/pulls/592
 
 # [v4.0.0]
 

CMakeLists.txt

@@ -6,6 +6,7 @@ set(FSFW_REVISION 0)
 
 # Add the cmake folder so the FindSphinx module is found
 set(CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/cmake" ${CMAKE_MODULE_PATH})
+set(FSFW_ETL_LIB_VERSION 20.26.0)
 set(FSFW_ETL_LIB_NAME etl)
 
 option(FSFW_GENERATE_SECTIONS
@@ -103,7 +104,7 @@ if(NOT ${FSFW_ETL_LIB_NAME}_FOUND)
     FetchContent_Declare(
         ${FSFW_ETL_LIB_NAME}
         GIT_REPOSITORY https://github.com/ETLCPP/etl
-        GIT_TAG        20.26.0
+        GIT_TAG        ${FSFW_ETL_LIB_VERSION}
     )
 
     FetchContent_MakeAvailable(etl)

README.md

@@ -11,9 +11,15 @@ with Airbus Defence and Space GmbH.
 
 ## Quick facts
 
-The framework is designed for systems, which communicate with external devices, perform control loops, receive telecommands and send telemetry, and need to maintain a high level of availability. Therefore, a mode and health system provides control over the states of the software and the controlled devices. In addition, a simple mechanism of event based fault detection, isolation and recovery is implemented as well. 
+The framework is designed for systems, which communicate with external devices, perform control loops, 
+receive telecommands and send telemetry, and need to maintain a high level of availability. Therefore,
+a mode and health system provides control over the states of the software and the controlled devices.
+In addition, a simple mechanism of event based fault detection, isolation and recovery is implemented as well. 
 
-The FSFW provides abstraction layers for operating systems to provide a uniform operating system abstraction layer (OSAL). Some components of this OSAL are required internally by the FSFW but is also very useful for developers to implement the same application logic on different operating systems with a uniform interface.
+The FSFW provides abstraction layers for operating systems to provide a uniform operating system
+abstraction layer (OSAL). Some components of this OSAL are required internally by the FSFW but is
+also very useful for developers to implement the same application logic on different operating
+systems with a uniform interface.
 
 Currently, the FSFW provides the following OSALs:
 
@@ -45,6 +51,22 @@ A template configuration folder was provided and can be copied into the project
 a starting point. The [configuration section](docs/README-config.md#top) provides more specific 
 information about the possible options.
 
+## Prerequisites
+
+The Embedded Template Library (etl) is a dependency of the FSFW which is automatically
+installed and provided by the build system unless the correction version was installed.
+
+You can install the ETL library like this:
+
+```cpp
+git clone https://github.com/ETLCPP/etl
+cd etl
+git checkout <currentRecommendedVersion>
+mkdir build && cd build
+cmake ..
+cmake --install .
+```
+
 ## Adding the library
 
 The following steps show how to add and use FSFW components. It is still recommended to