nRF52 Delete bonds while in Bootloader

RE: nRF52 Delete bonds while in Bootloader

Zami — Wed, 31 Aug 2022 16:37:19 GMT

When you refer to flash configuration, are you talking about the linker flash/ram size and location configurations?

RE: nRF52 Delete bonds while in Bootloader

Hung Bui — Wed, 31 Aug 2022 10:11:56 GMT

Hi Andrew,

It's possible to erase bond information in the bootloader without pulling the entire peer maanger but it will be more like wipeout the whole flash storage and when the application run again it will need to re-initialize the flash database. This could be an issue if you have other data to be preserved.

So what you are doing with the GPREGRET2 and do the bond erasing in the application could be a better solution. One thing to take into account is that when you update a new app it should be able to use the same flash configuration (or prepare a way to re-initialize the flash if it can't re-use the original flash configuration from previous version).

RE: nRF52 Delete bonds while in Bootloader

Zami — Tue, 30 Aug 2022 23:35:34 GMT

I suppose one way I could do this is setting a delete-bonds-flag in GPREGRET2. Then if the app is valid it would read the flag, delete bonds, and reset GPREGRET2. ..I'll try this first but I'm open to more suggestions.

EDIT: So I got it working but I had to change the bootloader behavior when the power button is pressed as follows:

button pressed < 5sec run bootloader normally

button pressed >= 5sec set the delete-bonds flag in GPREGRET2 and let the bootloader run normally when released, ie if valid app then it will jump to it.

button pressed >= 10sec then stay in the bootloader (delete-bonds flag still set)