https://devzone.nordicsemi.com/f/nordic-q-a/39477/dfu-enter-checkIn SDK 15 the bootloader DFU enter check in nrf_bootloader.c has the following code: if (NRF_BL_DFU_ENTER_METHOD_GPREGRET &amp;&amp; (nrf_power_gpregret_get() &amp; BOOTLOADER_DFU_START)) { NRF_LOG_DEBUG(&quot;DFU mode requested via GPREGRET.&quot;); return true; } Whyen-USTelligent Community 13Tue, 16 Oct 2018 12:48:19 GMThttps://devzone.nordicsemi.com/thread/153063?ContentTypeID=1Tue, 16 Oct 2018 12:48:19 GMT137ad170-7792-4731-bb38-c0d22fbe4515:5d81ccc2-8313-4853-974b-9217cf0aa244tesc<p>Hi,</p> <p>Thank you for reporting this issue. Bug reports are always appreciated!</p> <p>Yes, your suggestion is correct. This is a known issue and the fix is just as you describe.</p> <p>There is also a related issue in nrf_bootloader.c, see <a href="https://devzone.nordicsemi.com/f/nordic-q-a/38048/bug-in-how-bootloader-treats-gpregret">Bug in how bootloader treats GPREGRET</a> and <a href="https://devzone.nordicsemi.com/f/nordic-q-a/36601/gpregret-and-nrf_bootloader-c-evolution-proposal">GPREGRET and nrf_bootloader.c evolution proposal</a>.</p> <p>Regards,<br />Terje</p><div style="clear:both;"></div>