nRF5340 - UART programming option

[Gabriele]

Hello,

I'm in the process of developing the HW board for a nRF5340-based product.
I need the customer could update the firmware using a serial port (USB or Bluetooth is not acceptable).
Is it possible to do that ? Where to found documentation on this ?

Regards,
Gabriele

[Hung Bui]

Hi Gabriele, 

I'm sorry that it's been a long time and you still having issue with FOTA on nRF53. 

We now have better documentation for nRF53 including FOTA instruction. 

Please have a look here: 
https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/nrf/ug_nrf5340.html#fota-upgrades

The instruction is for FOTA using BLE. And I think you should test first using this transport. Just to make sure smpsvr is working fine. After that you can change CONFIG_MCUMGR_SMP_BT to CONFIG_MCUMGR_SMP_UART to support UART (and add CONFIG_SERIAL=y) 

[Gabriele]

Thank you for your reply.

I think the problem was due to flashing non signed binary for smp_srv.

Now I'm able to

a) Build and flash mcuboot in bootloadr_partition (using JLink)
b) Build and flash smp_svr in slot0_partition (using JLink)
c) Build and flash MyApp in slot1_partition (using DFU)

This is the resulting mcumgr image list

Images:
 image=0 slot=0
    version: 0.0.0
    bootable: true
    flags: active confirmed
    hash: 6645ebafd4a33787a52b5f76c18f9b66038a25b3413238e22d2432e6bba47677
 image=0 slot=1
    version: 1.3.0
    bootable: true
    flags:
    hash: 17563829483019977c328c7c89114dcb2f872c65b9b5c8d663011e617b9915ad
Split status: N/A (0)

Now I see a problem.

On system restart I get out of UART

 *** Booting Zephyr OS build v2.3.0-rc1-ncs1  ***
 [00:00:00.003,051] <inf> mcuboot: Starting bootloader
 [00:00:00.009,246] <inf> mcuboot: Primary image: magic=unset, swap_type=0x1, copy_done=0x3, image_ok=0x3
 [00:00:00.019,348] <inf> mcuboot: Boot source: none
 [00:00:00.024,810] <inf> mcuboot: Swap type: none
 [00:00:00.138,214] <inf> mcuboot: Bootloader chainload address offset: 0x10000
 [00:00:00.146,026] <inf> mcuboot: Jumping to the first image slot
 *** Booting Zephyr OS build v2.3.0-rc1-ncs1  ***
 [00:00:00.004,425] <inf> smp_sample: build time: Sep 11 2020 13:29:22

The smp_srv is running, not MyApp !

How to switch from smp_srv to MyApp, and viceversa ?

Thank you

[Hung Bui]

Hi,

After you have flashed the smp_svr you can use the mcumgr to DFU your image . 

After you have your image list with 2 images, you need to either test or confirm the image and trigger a reset for your app to run. 
Call `Image test <image sha>` or `image confirm <image sha>` and then do a reset. Your application should run after that. 

[Gabriele]

Hi,

The swap mechanism went well!
After a "image confirm" the new image (My App) is the active one, persistently.

But what ? I cannot upload a brand new image.
How to restore the DFU functionality ?

[Hung Bui]

Hi Gabriele, 
You would need to integrate smpsvr into your application. 
It's pretty simple. You can just follow the instruction here. 
The instruction is for BLE , to do UART DFU you use CONFIG_MCUMGR_SMP_UART = y instead of CONFIG_MCUMGR_SMP_BT. 
In your main.c you need to call 

os_mgmt_register_group();
img_mgmt_register_group();

In the example, I have prepared the .bin files that you can use to update. Note that after you do : 

mcumgr -t 20 --conntype serial --connstring=COM37 image upload app_update_new.bin

You still need to confirm the image "image confirm <img_sha>" and then do a reset. I haven't looked into how you can confirm the image and reset automatically yet.

peripheral_lbs_dfu_uart.zip