Prefill FDS area while programming via SWD

[2PrintBeta]

Hello Nordic Team,

I have an application in development where some bigger files (~20kb) can be downloaded into the device, so they get stored in with the FDS system.

Now we are thinking about how we will manage this in production. As the device should be delivered with some files already stored in it.

Is it somehow possible to prefill the FDS area with correct data via SWD programming ? Downloading them in production via BLE would take a long time.

kind regards

[bjorn-spockeli]

Dominik: Yes, it possible to flash data to the FDS area as long as you follow the format used by FDS to store records. Do you need any details or are you able to manage this yourself?

Best regards

Bjørn

[2PrintBeta]

Thank you for this information.

I looked at: https://infocenter.nordicsemi.com/index.jsp?topic=%2Fcom.nordic.infocenter.sdk5.v15.0.0%2Flib_fds.html which describes the memory format. It seem pretty straight forward, but i have a few questions.

Record ID and File ID are presumably the IDs used in the FDS API, but then what is the RECORD_KEY ? Also which checksum algorithm is used for the CRC ? 

Maybe it is easier to just flash a module normally, upload the data via ble and the read back the full flash and use that for production ?

[Andy]

2PrintBeta said:

Maybe it is easier to just flash a module normally, upload the data via ble and the read back the full flash and use that for production ?

Yes, that's what I would do. I would read the flash contents of a device that already has the desired data, create a hex file out of that data, and I would use mergehex to create a single hex file for production.

[bjorn-spockeli]

• Record key: provided by the user and used for lookup
• Data length: expressed in number of 4-byte words
• File ID: provided by the user and used for lookup
• CRC16: optional CRC16 check value  (checks can be enabled by setting the FDS_CRC_ENABLED compile flag)
• Record ID: unique identifier generated by the system

Yes, I think the easiest approach is what you suggested. Load the data over BLE to one device and then readback the flash. Is the data stored by FDS identical for all the devices?