Protect NVM from being overwritten during reflash

[Brian]

I'm using the pstorage driver on the nRF51 to maintain several NVM variables. The NVM functions correctly and maintains state between power cycles. However, when I reflash the device using OTA reflash (application only, not SoftDevice), all of my NVM variables are reset to 0xFF. How do I prevent reflashing from modifying my NVM variables?

This is the command line I'm using to generate the zip file used for OTA reflash -

nrfutil dfu genpkg myProgram.zip --application myProgram.hex --application-version 0xffff --dev-revision 0xffff --dev-type 0xffff --sd-req 0xfffe

Thanks

Brian

[FormerMember]

The "Preserving application data" section in the bootloader documentation explains what to do to avoid loosing data during the DFU operation.

[Brian]

Thanks Kristin! I'm using SDK 9.0, and found the dfu_types.h file used by my bootloader. I changed the #define of DFU_APP_DATA_RESERVED from 0 to CODE_PAGE_SIZE (which is 0x400). I then rebuilt my bootloader and app, and combined them into a .zip file with nrfutil, like this: "nrfutil dfu genpkg strobe.zip --application myApplication.hex --bootloader myBootloader.hex --application-version 0xffff --dev-revision 0xffff --dev-type 0xffff --sd-req 0xfffe

When I try to reflash this zip file to my device using nRF Toolbox, I get a message that says it is updating part 1 of 2, then a message that it is disconnecting from the device, and then a message saying the upload failed. My device no longer boots up now. Any idea what went wrong? Thanks.