https://devzone.nordicsemi.com/f/nordic-q-a/2903/dfu-not-preserving-app-dataHi all, I have made some modifications to the bootloader example project (dfu_dual_bank_ble, s110) to get a bootloader that meets my requirements. It is working ok, I can upgrade the firmware over the air but application data does not get preserved.en-USTelligent Community 13Wed, 25 Jun 2014 08:01:42 GMThttps://devzone.nordicsemi.com/thread/11058?ContentTypeID=1Wed, 25 Jun 2014 08:01:42 GMT137ad170-7792-4731-bb38-c0d22fbe4515:08b12565-81e7-4500-a454-f4f9a8d744edjezule<p>Alright, solved. My mistake. The size I was reserving in the bootloader (DFU_APP_DATA_RESERVED=0x400) didn&#39;t match the size I was reserving in the application through pstorage_init.h: I was reserving 2048B (PSTORAGE_MAX_APPLICATIONS=2) and I was telling the bootloader to preserver just one page. I have changed DFU_APP_DATA_RESERVED and everything is working ok.</p> <p>Best regards</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/11057?ContentTypeID=1Tue, 24 Jun 2014 15:57:25 GMT137ad170-7792-4731-bb38-c0d22fbe4515:b1c020e4-8ed6-4a9b-952d-c2320f349f5djezule<p>Forgot to mention that I have incresed the size reserved for the bootloader as I had added some functionality but I have made the pertinent changes in BOOTLOADER_REGION_START and in the project properties, as stated in the documentation.</p><div style="clear:both;"></div>