LightWeight Platform Abstraction

Introduction

lwpa is a C-language library for platform abstraction. It supports the writing of platform-neutral C and C++ libraries by providing a set of modules to abstract common system calls. There are also a few platform-neutral utilities (i.e. data structures, logging) thrown in here and there for convenience.

lwpa modules are typically optimized for embedded platforms and thus designed to be as thin a wrapper over the underlying OS functionality as possible.

To jump right into the documentation, check out the Modules Overview.

Source Location

the sources for lwpa are located in the heirarchy:

src/
  [platform_name]/
    [platform-specific lwpa sources]
  [platform-neutral lwpa sources]

The includes are in the heirarchy:

include/
  [platform_name]/
    [platform-specific lwpa headers]
  [platform-neutral lwpa headers]

Some lwpa headers are platform-specific and duplicated for each platform. Platform-specific headers for the same module will always conform to an identical interface, as documented in that module's documentation.

Platforms

lwpa is currently ported for the following platforms:

• Microsoft Windows
• MQX RTOS

Building lwpa for Your Platform

lwpa is built with CMake, a popular cross-platform build system generator. CMake can also be used to include lwpa as a dependency to other projects, i.e. using the add_subdirectory() command.

To configure and build lwpa on its own using CMake, follow these steps:

1. Download and install CMake version 3.3 or higher.
2. Create a directory in your location of choice to hold your build projects or Makefiles:

   $ mkdir build
   $ cd build

   This directory can be inside or outside the lwpa repository.
3. Run CMake to configure the lwpa project:

   $ cmake path/to/lwpa/root

   You can optionally specify your build system with the -G option; otherwise, CMake will choose a system-appropriate default. Use cmake --help to see all available options.
4. Use CMake to invoke the generated build system to build the lwpa library and unit tests:

   $ cmake --build .

   If you are generating IDE project files, you can use CMake to open the projects in the IDE:

   $ cmake --open .

5. To run the unit tests after building:

   # On Windows
   > .\test\[Build_Configuration]\test_lwpa.exe
    
   # Elsewhere
   $ ./test/test_lwpa

   Or, if you are generating IDE project files, simply run the test_lwpa project from your IDE.

Alternatively, if you don't want to use CMake, your project can simply build in the lwpa sources directly using the appropriate directories for your target platform. This is currently the only option for MQX RTOS.

Platform Dependencies

The platform ports of lwpa have the following dependencies:

• Microsoft Windows
  • Windows XP or higher
• MQX RTOS
  • MQX 4.2.0