MCUboot rollback happening after successful upgrade on nRF9160 (NCS 2.7.0)

RE: MCUboot rollback happening after successful upgrade on nRF9160 (NCS 2.7.0)

Hung Bui — Tue, 02 Dec 2025 12:26:58 GMT

Hi Purushotham,
Could you let me know what exactly FOTA way you are doing ?
Did you base your application on one of the sample ? Did you try to test with FOTA samples we have ?

Could you explain what exactly you meant by "Another thing that i noticed is if i cut a formal release with proper versions like v2.2.2 then it worked, if i just do an incremental build and upload that to my server and download/install then i see this behaviour of rolling back "

Please tell how exactly you define the application version, did you use the VERSION file ? Or CONFIG_FW_INFO_FIRMWARE_VERSION , as far as I know CONFIG_FW_INFO_FIRMWARE_VERSION may not related to MCUBoot but NSIB

When you call boot_write_img_confirmed () do you receive an error. Please try to capture a log when the image is rolled back.

RE: MCUboot rollback happening after successful upgrade on nRF9160 (NCS 2.7.0)

purush123 — Mon, 01 Dec 2025 14:34:43 GMT

We use FOTA , We keep the firmware in our server and download the image and install it, With serial ( nrfjprog ) flashing it always work.

I am using NCS2.7.0, i am not sure which log option is available in mcuboot, but i get some logs

*** Using Zephyr OS v3.6.99-100befc70c74 ***
s0_info->version = 2, s1_info->version = 2
Attempting to boot slot 0.
Attempting to boot from address 0x8200.
Verifying signature against key 0.
Hash: 0x45...79
Firmware signature verified.
Firmware version 2
*** Booting Zephyr OS build v3.6.99-ncs2 ***

This is what i observed, In most cases i see device upgraded and it showed the new build details on the banner of console , Then immediately board rebooted and it went back to the old build. I am calling boot_write_img_confirmed as the first call .

Another thing that i noticed is if i cut a formal release with proper versions like v2.2.2 then it worked, if i just do an incremental build and upload that to my server and download/install then i see this behaviour of rolling back , I am not sure which MCUBOOT configuration is causing it.

RE: MCUboot rollback happening after successful upgrade on nRF9160 (NCS 2.7.0)

Hung Bui — Thu, 27 Nov 2025 11:52:43 GMT

Hi Purushotham,

What do you have in the log ? Have you enabled logging for MCUBoot ? I think by default it's enabled. You should see some log at boot.

How did you do DFU update ? I assume with serial ?

When you receive the new image, did the new image run ? Did you confirm the image or it only run on test ? If it run on test and then got a crash then reset the revert process will occur.

I don't think it's a firmware version issue because the firmware version is checked when the header is sent before the actual image is sent. So if you see the image being transmitted most likely the firmware version check was passed.

Have you tested with DFU update before ? I assume you are familiar with different boot mode test, confirm etc ?