Saving a fota progress is in case the device resets mid-process,

RE: Saving a fota progress is in case the device resets mid-process,

brandon_ask_questions — Mon, 30 Jan 2023 17:13:29 GMT

I just came accross this Kconfig option.

Go check out.

developer.nordicsemi.com/.../CONFIG_DFU_TARGET_STREAM_SAVE_PROGRESS.html

RE: Saving a fota progress is in case the device resets mid-process,

brandon_ask_questions — Wed, 25 Jan 2023 15:14:37 GMT

[quote userid="117272" url="~/f/nordic-q-a/96017/saving-a-fota-progress-is-in-case-the-device-resets-mid-process/406457"]

Please correct me if I am wrong. It seems fota_lib provides an interface to start a download at an offset. here please have a look at.

In fota_download.c. After initializing dfu_target_init, checking if there is an offset or not. So if there is an offset, the app aborts the download requests and schedules a new download from the offset.

[/quote]

Yes I think you are correct actually but that offset logic is only if the download stops and then is restarted during the same session (e.g. no reboot occurs). E.g.

The way the fota_lib uses the dfu_target stuff makes it really hard to do what you are trying. It relies on metadata from the current session to know where to flash the downloaded chunk.

RE: Saving a fota progress is in case the device resets mid-process,

zsn — Wed, 25 Jan 2023 12:45:15 GMT

[quote userid="122792" url="~/f/nordic-q-a/96017/saving-a-fota-progress-is-in-case-the-device-resets-mid-process/406365"]The fota_download library does not provide an interface to start a download at a offset.[/quote]

I am not sure about this. I think there is an inconsistency between your comment and the app's behaviour. Please correct me if I am wrong. It seems fota_lib provides an interface to start a download at an offset. here please have a look at.

[quote userid="122792" url="~/f/nordic-q-a/96017/saving-a-fota-progress-is-in-case-the-device-resets-mid-process/406365"]You could use the download_client library for this purpose, but you would need to handle writing the chunks to flash.[/quote]

Thanks for this point. I need to look at this how I can use and implement this into my app.

[quote userid="122792" url="~/f/nordic-q-a/96017/saving-a-fota-progress-is-in-case-the-device-resets-mid-process/406365"] this is in RAM and is lost on reset. [/quote]

yes, I agree, I think this may reason why the device cannot continue downloading process from an offset val after rebooting.

I was thinking if I can find a way to store all these data which are necessary to continue from an offset into flash memory. Then after booting up, I can bring all these data for dfu_target_offset_get.

RE: Saving a fota progress is in case the device resets mid-process,

brandon_ask_questions — Wed, 25 Jan 2023 01:34:52 GMT

The fota_download library does not provide an interface to start a download at a offset. You could use the download_client library for this purpose, but you would need to handle writing the chunks to flash.

The dfu_target_offset_get returns the value from the current flash stream context, this is in RAM and is lost on reset.