CubedOS

A flight software framework for CubeSat spacecraft written in SPARK/Ada.

This folder contains the core CubedOS system. The sibling Merc repository contains the Merc tool used for generating CubedOS API encoder/decoder subprograms. The subfolders are as follows:

• bench: Benchmark programs for measuring the performance of CubedOS.

• doc: The documentation of CubedOS.

• samples: This folder contains various sample programs that illustrate CubedOS in action.

• src: The CubedOS source code repository.

• templates: Various templates to facilitate the construction of CubedOS applications. The developer can use these templates to simplify the programming of new applications, however their use is not strictly required.

Development Environment

We develop CubedOS on x86-64 platforms running Ubuntu Linux 22.04. Development on Windows and macOS is probably possible, but we do not use those systems. Most of the test, sample, and benchmark programs can be compiled and run on the development host. Some programs that target other platforms are also included. Final testing and performance evaluations should be done on your specific target platform, of course.

With generous support from AdaCore, we are able to use the GNAT Pro tool set (currently version 24.1) for our development. Some experimentation with using Alire and the community tool chain has been done, but that build environment is not officially supported by us at this time.

Some experimentation has also been done with using Visual Studio Code as a development environment. The file CubedOS.code-workspace defines a VSCode workspace for the project.

Build & Test Instructions

The basic build of CubedOS can be done by opening the cubedos.gpr project file using GNATstudio. Various executables are defined as follows.

• cubedos_check is a unit test program for various parts of the CubedOS core system.

• main_file demonstrates the file server interface with a program that reads and displays the contents of a file using verbose output. This program does not terminate since the CubedOS message handling loops are non-terminating. However, when the file has been completely read you should see output about Close_Request messages being sent for both input and output files.

• main_time demonstrates the timeserver module. It prints messages for periodic ticks and a one-shot tick for about 30 seconds. It then cancels the periodic ticks. The program does not terminate for the same reason as main_file but after the cancelation of Series #1 there should be no further output.

These programs are all written to the src/check/build folder.

The sample programs have their own project files. At this time there is no master project file defined for all CubedOS components.

Merc Helper Application

The program Merc, in a separate repository, is a Scala program for generating CubedOS API packages. It is possible to write these packages manually following, for example, the templates in the template folder (which are extensively commented). Merc makes the job much easier. Information about Merc, and how to build and use it, can be found in the Merc repository. Current there is an issue with Merc that limits its usefulness. Most API packages in CubedOS have been manually written!