Mechanism that Nordic is using with iTunes?

[SRA]

I've been a little out of the loop. Can someone explain how this "drag and drop" DFU is working? And in what method iTunes is being used!?

Best I can figure iTunes is being used to access an iPhone's BLE connection to update the devkit/nrf52 over BLE? So... This would mean Nordic has an app that runs temporarily to access an iphone? Like a dev app?

I'm just guessing here, I really don't get it.

Side question: Is there a way to prevent a user from overwriting my code on a module via BLE? Like if I wanted to make sure no one was repurposing my hardware.

[RK]

Nothing unusual - the ability to add files to an apps filestore by dragging them into the app on iTunes is a standard iOS feature, in fact it's pretty much the original way of communicating with an app from the desktop. It's very useful, you just set a key in the app description and a small part of the app's filesystem is exposed via iTunes.

Then the app itself accesses the dev board over BLE just like any other bluetooth app.

[SRA]

I see. Thanks!

So it's just some mock filesystem thing.

So I guess my next question is (and I'll make a post about this if I don't find the answer in docs) is does the DFU proceedure take the packaged zip, unpack it and send the entire thing over to the device at once for the bootloader to flash - or does it to it in small chunks via bootloader GATT frames where the app is streaming flash data?