DFU failing with nRF Secure Immutable Bootloader(NSIB) as the first stage bootloader

[Devanshu5]

Hi,

We are using the nRF Secure Immutable Bootloader(NSIB) as the first stage bootloader along with MCUboot as the second stage bootloader in our nrf5340 project. We have observed that the BLE (SMP based) DFU fails when we add the immutable bootloader to the project. The firmware get's downloaded to the device, but after reset it doesn't boot into the new application and gets stuck somewhere. There are no logs that get printed to indicate any issue. I am using the 'nRF Connect' mobile application in Android for our testing. The SDK is  NCSv2.1.0.

I have made the bare minimum changes needed to reproduce this in the example projects(machine learning and matter lock) provided by Nordic. I have added the CONFIG_SECURE_BOOT=y in the prj.conf of both examples and made sure to use the same memory partitions in both the the projects(pm_static.yml). Below are the zip files of the two projects:

1. Machine learning

  machine_learning.zip

2. Matter lock:

lock.zip

Please try performing the DFU from the first project to the second project or vice-a-versa on nrf5340DK board. It is failing for us.

This same upgrade works fine if we don't use the first stage immutable bootloader(NSIB) in the project.

Please help us in resolving this issue.

Also, I would like to know how we could upgrade the MCUboot image. Which is the binary that needs to be used? Is it the 'signed_by_b0_s0_image.bin'? Can we use the 'nRF Connect' mobile application itself for updating the MCUboot image?

Regards,

Devanshu Agarwal

[Menon]

Hello,

Really sorry. I was not able to reproduce the issue you are saying. 

I tried the files you shared and I was not able to build the Matter_lock sample that you shared and I cannot see a signed image from mcuboot in case of the machine learning sample. 

If you enable both B0 and Mcuboot, the available images will be as shown below:

And Minimum configuration you need to include for enabling both B0 and MCUboot are:

CONFIG_SECURE_BOOT=y
CONFIG_BOOTLOADER_MCUBOOT=y
CONFIG_MCUMGR=y
CONFIG_MCUMGR_CMD_OS_MGMT=y
CONFIG_MCUMGR_CMD_IMG_MGMT=y
CONFIG_MCUMGR_SMP_BT=y
CONFIG_MCUMGR_SMP_BT_AUTHEN=n
CONFIG_BUILD_S1_VARIANT=y

I am attaching a sample project where two stage bootloaders have been enabled. You can keep this as a  reference and I have disabled the configuration for Key in this file.

1614.peripheral_hr_smp_b0.zip

Kind Regards,

Abhijith

[Devanshu5]

Hi,

I have included the build folder in my attached zip files. You can use my binaries to test it. 

Steps to reproduce:

1. Flash the merged_domains.hex from either of the project in nRF5340 DK.

2. Use the dfu_application.zip file from the other project in the nRF Connect mobile application for performing DFU.

Please let me know if you need additional details.

Regards,

Devanshu Agarwal