https://devzone.nordicsemi.com/f/nordic-q-a/9166/bootloader-axf-to-bootloader-binI want to update the bootloader inside nRF51422 using iPhone. Updating applications hasn&#39;t been any problem. Following the same procedure but I cannot convert bootloader.axf to bootloader.bin This is the command I am using c:\keil_v5\arm\armccen-USTelligent Community 13Fri, 11 Sep 2015 12:48:44 GMThttps://devzone.nordicsemi.com/thread/33780?ContentTypeID=1Fri, 11 Sep 2015 12:48:44 GMT137ad170-7792-4731-bb38-c0d22fbe4515:65740f38-2736-436a-b16c-19d5074bf15eHung Bui<p>Hi Paul,</p> <p>There are some steps needed to convert bootloader binary image. It&#39;s described at the documentation mentioned at section G in <a href="https://devzone.nordicsemi.com/blogs/685/common-faq-on-dfu/">this FAQ</a>.</p> <p>Note that the need for generating .bin file is obsolete. You can use the nrfutil.exe tool to do the task for you. You can generate the .zip package with init data by using the .hex file.</p><div style="clear:both;"></div>