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 afraid the nrfutil tool that Igor pointed wouldn't work with the nRF53 (only support nRF52 and nRF5 SDK). 

The nRF53 is not supported by our nRF5SDK (which the nrfutil supports) 

For nRF53 you would need to use NRF Connect SDK. To do DFU with UART on nRF Connect SDK you would need to use mcumgr and smpsvr. 
Please read about the smpsvr here. 

And mcumgr here.

We have an example of using smpsvr and mcumgr via UART for the Thingy91 here. It's for the nRF9160 but it should be similar syntax for the nRF53.

[Gabriele]

Hi Hung,
at first glance this seems a very complicated path. It makes me wonder if it will work in the end.
I'll try to understand the documents you've linked

[Gabriele]

Solved with
$ sudo pip3 install cbor

[Gabriele]

Hi Hung
I'm trying to follow your initial recipe

a) Build and flash mcuboot
  $ cd <ncs>/bootloader/mcuboot/boot/zephyr
  $ west build -b qi2m_nrf5340_cpuapp --build-dir buildout
  $ nrfjprog -f nrf53 --program buildout/zephyr/zephyr.hex

  I check out reading flash. One image found at
    0x00000000 - 0x0000891f (35104 B)

b) Build and flash smp_svr
  $ cd <ncs>/zephyr/samples/subsys/mgmt/mcumgr/smp_svr
  $ vim prj.conf
  Add these lines
    CONFIG_MCUMGR_SMP_UART=y
    CONFIG_NET_BUF_USER_DATA_SIZE=7
  $ west build -b qi2m_nrf5340_cpuapp --build-dir buildout
  $ nrfjprog -f nrf53 --program buildout/zephyr/zephyr.hex

  I check out reading flash. Two images found at
    0x00000000 - 0x0000891f (35104 B)
    0x00010200 - 0x0001a62b (42028 B)

On board restart I get out of UART

  *** Booting Zephyr OS build v2.3.0-rc1-ncs1 ***
  [00:00:00.003,051] <inf> mcuboot: Starting bootloader
  [00:00:00.009,063] <inf> mcuboot: Primary image: magic=unset, swap_type=0x1, copy_done=0x3, image_ok=0x3
  [00:00:00.019,165] <inf> mcuboot: Boot source: none
  [00:00:00.024,566] <wrn> mcuboot: Failed reading image headers; Image=0
  [00:00:00.032,012] <err> mcuboot: Unable to find bootable image

Issuing from host the test command

  $ mcumgr -t 20 --conntype serial --connstring='/dev/ttyUSB0,baud=115200' image list

I get "Error: NMP timeout"

What a hell to do ?

[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

[Gabriele]

Dear Huang

Thank you for guiding me with lot of patience.

1) At build time I get a couple of warnings
warning: implicit declaration of function 'os_mgmt_register_group'
warning: implicit declaration of function 'img_mgmt_register_group'

Is there something I can do about it, or just ignore and go on ?

2) Are you sure app_update.bin us the correct binary image ?
Indeed we have a variety of choices:

- app_update.bin
- app_signed.hex
- app_test_update.hex
- app_moved_test_update.hex

My goal is to control from MyApp whether to stay in MyApp or reboot in "SMP Server mode" to upload a new version of MyApp

[Hung Bui]

Hi Gabriele, 

1.I'm sorry I forgot to check the warnings. You need to add 

#include "os_mgmt/os_mgmt.h"

#include "img_mgmt/img_mgmt.h"

to you main.c

A good reference for using the bootloader is to have a look at the smpsvr sample located at \zephyr\samples\subsys\mgmt\mcumgr\smp_svr

2. Yes you use app_update.bin. If you have a look at the link on FOTA I pointed to earlier you can find that suggestion. 
You can sign the image yourself but I haven't been very successfully managed to do so. The documentation is here: https://docs.zephyrproject.org/latest/samples/subsys/mgmt/mcumgr/smp_svr/README.html

If you want to switch between smpsvr and your application, I think it's the mcumgr handle it. I haven't looked into how you do it automatically yet. Will get back when I find the way. 

[Gabriele]

Ok, thank you!