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

[Brian]

Thank you for the links above. I'm calling device_manager_init() before calling pstorage_register, so I've set DFU_APP_DATA_RESERVED to CODE_PAGE_SIZE * 3. I've also looked at the map files for both my bootloader and app. I should have plenty of free space to update both of these together. My bootloader starts at 0x3b800, and my app goes from 0x18000 to 0x24A28, which has a length of 0xca28. With DFU_APP_DATA_RESERVED set to CODE_PAGE_SIZE * 3, I believe that the App Data section then goes from 0x3ac00 to 0x3b800. This leaves a Free Space section from 0x24a28 to 0x3ac00, which is 0x161d5 in length. I've now tried to update my bootloader only over-the-air using the following command to generate the .zip file: nrfutil dfu genpkg my_bootloader.zip --bootloader my_bootloader.hex --dev-revision 0xffff --dev-type 0xffff --sd-req 0xfffe I copy the resulting file to my Android phone, and using nRF Toolbox, I reflash the bootloader. The reflash process indicates it is successful, however, my device will no longer boot up! The only change I've made is adding: #define DFU_APP_DATA_RESERVED CODE_PAGE_SIZE * 3 to dfu_types.h. I see in the last link above a reference to a similar problem. The suggested solution is to modify dfu_bl_image_validate() because the DFU_BANK_1_REGION_START has changed from the old bootloader to the new bootloader. Could you explain further what that modification should be? Thanks.

[FormerMember]

dfu_bl_image_validate() does only check the old DFU_BANK_1_REGION_START, in addition, you need to add a check for the new DFU_BANK_1_REGION_START.

[Brian]

Thanks Kristin - that worked!