[FEATURE] File Uplink/Downlink with Yamcs

[ineskhou]

Short summary

Yamcs uses CFDP File Uplink, which is not compatible with F prime

Motivation and user story

In order to preform essential spacecraft functions, such as sequencing and data processing on the ground, we need to make sure there is a bridge for the satellites to be able to send and receive files from file uplink and downlink. Currently, Yamcs uses CFDP protocol. And F Prime uses FileUplink and downlink components.

The goal is to preserve have working yamcs ground side while not modifying the satellites on the F´ side as

Proposed implementation

There are two options for implementation:

1. Parallel Connection via F´ GDS
   Use Yamcs CFDP for file transfer while maintaining a separate connection to F´ GDS for command and telemetry routing.

2. Middleware
   Insert a middleware service between Yamcs and F´ GDS that translates:
   CFDP transactions → F´ FileUplink commands
   F´ FileDownlink packets → CFDP PDUs

Resources

https://fprime.jpl.nasa.gov/latest/Svc/FileUplink/docs/sdd/

https://ccsds.org/Pubs/720x1g4.pdf

https://docs.yamcs.org/yamcs-server-manual/services/instance/cfdp/

https://fprime.jpl.nasa.gov/latest/Svc/FileDownlink/docs/sdd/

We can start testing with the standard YAMCS reference (no FPRIME) and make progress.

Note: @LeStarch is working on the dictionary. If YAMCS expects anything in the dicionsaty, define the container in XTCE and send it to him.

Priority

High

[ineskhou]

For part 1:

1. File definition within the xtce so it knows what to do when it recieves a file uplink
3. new service (but not cfdb) we want the files to go staight though)

For the xtce:

1 |fprime_yamcs/main.py

3 | fprime_yamcs/yamcs/src/main/yamcs/etc/yamcs.fprime-project.yaml

UDP 50000, send uplink on UDP 50001
RUn fprime-yamcs-events

6 | fprime_yamcs/yamcs/src/main/java/com/example/myproject/MyCommandPostprocessor.java

In yamcs.fprime-project.yaml, UDP_TC_OUT sets:
commandPostprocessorClassName: com.example.myproject.MyCommandPostprocessor

this specifically is the piece right before things get on the satelie

7 | fprime_yamcs/events/main.py
8 | fprime_yamcs/events/processor.py
9 | fprime_yamcs/events/logging.py
10 | fprime_yamcs/yamcs/src/main/yamcs/mdb/fprime.xtce.xml

[ineskhou]

Relevent PRs:

- fprime-community/fprime-xtce#3
Adds the file relacted thinhs to the xcte so that the translatino can happen within yamcs and f prime.

Today, generic dictionary → XTCE conversion doesn’t describe those file-transfer packets as first-class containers in XTCE. This PR adds that so YAMCS (and anything consuming the generated XTCE) can parse and interpret file packets in TM, not only “normal” telemetry/command types.

param for FilePacket: type, sequenceIndex, fileSize, byteOffset, dataSize, checksum, sourcePath, destinationPath

sub-containers from Fw::FilePacket::Type:

FPrimeFilePacketStart
FPrimeFilePacketData
FPrimeFilePacketEnd
FPrimeFilePacketCancel

able to decode file uplink/downlink packet structure

See https://github.com/Open-Source-Space-Foundation/fprime-yamcs-reference/tree/connection for current uplink/downlink stuff

(status uplink works)

Subscribe to tm_realtime, filter by file APID, reassemble Start/Data/End, validate checksum, write completed files to a YAMCS bucket.
For uplink, emit Start/Data/End on tc_realtime from files queued for upload.

the accompanying YAMCS Java service (plugin) that consumes these containers and the design doc at
docs/file-transfer-integration.md.

(note that is is in the refernece fork, long term we want it in the yamcs submodule potentially and add the vesion to the requirements)

TO TEST ADD fprime-xtce @ git+https://github.com/fprime-community/fprime-xtce.git@refs/pull/3/head to the requirements on the fork above