https://devzone.nordicsemi.com/f/nordic-q-a/7433/add-a-uart-command-in-app-to-enter-bootloaderI want to add a command ordering by uart to make MCU entering Bootloader mode in app. To achieve this function, I plan to use the two following example in SDK 8.0 ex1.\peripheral\uart ex2.\dfu\bootloader\pca10028\dual_bank_serial_s110 The procedureen-USTelligent Community 13Mon, 08 Jun 2015 11:21:21 GMThttps://devzone.nordicsemi.com/thread/26470?ContentTypeID=1Mon, 08 Jun 2015 11:21:21 GMT137ad170-7792-4731-bb38-c0d22fbe4515:9d4a794d-cc8a-496a-b261-8e61aaf93878Hung Bui<p>@sdrest: Q1-1: The maximum size of application should be smaller than DFU_IMAGE_MAX_SIZE_BANKED as calculated in the bootloader (dfu_types.h). Q1-2: Yes, they can. When switching between bootloader and application, we go through the reset handler for each of them so they can be overlapped. Except for the IRAM2 where we set it at NoInit. But you only need IRAM2 if you planing to share bondinformation between application and bootloader.</p> <p>Q2-1: Please have a look at Question #C in this <a href="https://devzone.nordicsemi.com/blogs/685/common-faq-on-dfu/">blog</a>.</p> <p>If you want to follow our approach to re-use the bondinformation, you should follow what we do in the ble_app_hrs_dfu. In that approach, we don&#39;t do reset when jumping to bootloader, therefore we don&#39;t do softdevice re-initialization. This is why you have trouble starting bootloader with your code.</p> <p>If you set the NRF_POWER-&gt;GPREGRET equal something not 0xB1, you should be fine.</p><div style="clear:both;"></div>