https://devzone.nordicsemi.com/f/nordic-q-a/27362/softdevice-update-procedureHello, For the softdevice update, is it the responsibility of the bootloader to make sure, that the softdevice was copied correctly? If for example the bootloader calls sd_mbr_command() and the device powers down during that copy operations. Isen-USTelligent Community 13Mon, 20 Nov 2017 13:14:45 GMThttps://devzone.nordicsemi.com/thread/108056?ContentTypeID=1Mon, 20 Nov 2017 13:14:45 GMT137ad170-7792-4731-bb38-c0d22fbe4515:3f92deac-e157-4889-a335-262a338fd8b0Torsten Robitzki<p>Thanks a lot; that makes perfect sense!</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/108055?ContentTypeID=1Mon, 20 Nov 2017 13:10:09 GMT137ad170-7792-4731-bb38-c0d22fbe4515:ec788587-08b9-4b66-8506-1d30466a6f3fHung Bui<p>Hi Torsten,</p> <p>We use the MBR to copy the softdevice because the softdevice +MBR area can be protected and requires the flash operation to be called from inside the protected area, not from the bootloader.</p> <p>The SD_MBR_COMMAND_COPY_SD will do an erase, then write the new softdevice and then do a memcmp() to check, before returning NRF_SUCCESS or NRF_ERROR_INTERNAL.</p> <p>So it&#39;s the responsibility of the bootloader to check if the call with SD_MBR_COMMAND_COPY_SD return with NRF_SUCCESS or not before moving to the next step.</p><div style="clear:both;"></div>