fprime_cfs_reference: A cFS System Using F Prime cFS Applications

This repository contains a minimal cFS system that demonstrates the use of cFS applications built with F Prime. This demonstration includes the following two applications:

1. fprime_app: A simple demonstration app showing how to construct cFS applications using F Prime
2. fprime_gds: An application that bridges the F Prime GDS to the cFS messaging bus

The system also includes the standard cFS lab apps:

• sch_lab: publishes the 1 Hz tick that drives the F Prime application's rate groups
• ci_lab: command ingest, receiving cFS command packets over UDP (port 1234)
• to_lab: telemetry output, forwarding subscribed software bus telemetry over UDP (port 2234)

ci_lab and to_lab give the cFS GroundSystem a direct path to the software bus; to_lab is subscribed to the F Prime packetized telemetry message (0x0820) in fprime_cfs_reference_defs/tables/cpu1_to_lab_sub.c.

flowchart LR
    fprime_app(("fprime_app")) --- Bus[cFS Messaging Bus]
    fprime_gds(("fprime_gds")) --- Bus
    sch_lab(("sch_lab")) --- Bus
    ci_lab(("ci_lab")) --- Bus
    to_lab(("to_lab")) --- Bus
    gds["F Prime GDS"] --- fprime_gds
    cfsgds["cFS GroundSystem"] -- "UDP :1234" --> ci_lab
    to_lab -- "UDP :2234" --> cfsgds

Loading

Setup

Clone the repository and initialize the submodules:

git clone --recurse-submodules https://github.com/fprime-community/fprime_cfs_reference.git

Set up the python virtual environment and install the required dependencies:

python3 -m venv fprime-venv
source fprime-venv/bin/activate
pip install -r requirements.txt

You should be ready to prepare and build the reference system.

Tip

Always activate the virtual environment using source fprime-venv/bin/activate before running any of the following commands.

Building the Reference

This reference is built using the standard cFS build system. The first step is to prepare the build:

make SIMULATION=native prep

Once this build is prepared, build and install the reference system:

make
make install

Running the Reference

Note

The F Prime application's rate groups are driven by a 1 Hz tick message (command MID 0x1890, APID 0x090) published by the sch_lab scheduler app included in this system. The schedule is configured in fprime_cfs_reference_defs/tables/cpu1_sch_lab_table.c.

The build is installed in build-artifacts/exe/cpu1/. You can run the reference system using the following command:

cd build-artifacts/exe/cpu1/
./core-cpu1

Running the F Prime GDS

The reference hosts a TCP server for the GDS to connect on port 15010. The GDS can be run with:

fprime-gds --ip-port 15010 --dictionary ./build-artifacts/exe/Linux/fprime_app/dict/*Dictionary.json  -n --ip-client

Running the cFS GroundSystem

The cFS GroundSystem can command and monitor the system directly through ci_lab and to_lab using the fprime-cfs tooling from the fprime_cfs library:

fprime-cfs --dictionary ./build-artifacts/exe/Linux/fprime_app/dict/*Dictionary.json \
    --ground-system-dir tools/cFS-GroundSystem \
    --deployment build-artifacts/exe/cpu1 --app build-artifacts/exe/cpu1/core-cpu1

Enjoy!