nRF54LM20 FOTA BLE doesn't swap images

[iotdeveloper]

Hello 

I need some advice on FOTA via BLE on the nRF54LM20B. I use SDK v 3.3.0, building /ns variant.

I managed to get FOTA working to upload an updated image via BLE, but after a reboot, the new image doesn't load and remains in a "pending" state.

Could you please advise me on what needs to be configured on the nRF54LM20B to enable the image update?

I previously tried FOTA via BLE on the nRF5340 according Norxic Academy course, where it worked without any issues.

In RTT, I see the following:

1. 00> *** Booting MCUboot v2.3.0-dev-fce4dac2e629 ***
   00> *** Using nRF Connect SDK v3.3.0-ba167d9f3db4 ***
   00> *** Using Zephyr OS v4.3.99-fd9204a02d52 ***
   00> [00:00:00.001,667] <inf> mcuboot: Starting bootloader
   00> [00:00:00.002,113] <wrn> mcuboot: Cannot upgrade: not a compatible amount of sectors
   00> [00:00:00.002,372] <dbg> mcuboot: boot_slots_compatible: slot0 sectors: 238, slot1 sectors: 223, usable slot0 sectors: 237
   00> [00:00:00.002,568] <dbg> mcuboot: boot_validate_slot: boot_validate_slot: slot 0, expected_swap_type 0
   00> [00:00:00.002,735] <dbg> mcuboot: bootutil_img_validate: bootutil_img_validate: flash area 0xd344
   00> [00:00:00.002,888] <dbg> mcuboot: bootutil_img_hash: bootutil_img_hash
   00> [00:00:00.098,972] <dbg> mcuboot: bootutil_tlv_iter_begin: bootutil_tlv_iter_begin: type 65535, prot == 0
   00> [00:00:00.099,162] <dbg> mcuboot: bootutil_img_validate: bootutil_img_validate: TLV off 489
   00> [00:00:00.128,957] <inf> mcuboot: Bootloader chainload address offset: 0x18000
   00> [00:00:00.129,108] <inf> mcuboot: Image version: v3.3.4
   00> [00:00:00.129,219] <inf> mcuboot: Jumping to the first image slot
   00> [00:00:00.002,114] <dbg> os: z_impl_k_mutex_lock: 0x20000970 took mutex 0x2000088c, count: 1, orig prio: 0
   00> [00:00:00.002,300] <dbg> os: z_impl_k_mutex_unlock: mutex 0x2000088c lock_count: 1
   00> [00:00:00.002,445] <dbg> os: z_impl_k_mutex_unlock: new owner of mutex 0x2000088c: (nil) (prio: -1000)
   00> [00:00:00.002,616] <dbg> os: z_impl_k_mutex_lock: 0x20000970 took mutex 0x20000878, count: 1, orig prio: 0
   00> [00:00:00.002,788] <dbg> os: z_impl_k_mutex_unloc

Thank you

[iotdeveloper]

Hello,

Yes, when performing a DFU using the "Test & Confirm" option, the DFU process still completes successfully. However, the "GATT TIMEOUT" message appears in the Device Manager mobile app. After flashing the new image, I can connect to the device (via both the mobile app and AuTerm).

When performing DFU with the "Confirm only" option, everything works correctly - both the mobile app and the upload via AuTerm.

After flashing and opening RTT without a reset, it will likely display some uncleared area because the firmware update actually takes place - for example, I tried changing the LED blink speed on the DevKit which actually changed after the OTA update. After resetting with the button, RTT now displays the output from the new version.

Thanks

[Hung Bui]

Hi Iot, 

Could you let me know a little bit more about the application ? The issue you have is most likely because it take too much time to reboot and swap image so the app on the phone tried to reconnect but unsuccessful and show the GATT TIMEOUT. But as you mentioned, it was advertising and possible to connect to after the new image booting up. 
I would suggest to try testing with very simple application so that the swapping time is shorter. 

If you develop  your own app, you can delay the reconnection time to give more time for the DUT to swap image and advertise. 

[Hung Bui]

Hi again, 
Please try to increase this timing to see if it help with the "Test&Confirm" DFU: