MCUboot SMP Server

The MCUboot SMP Server sample demonstrates firmware update using the Simple Management Protocol (SMP) with MCUboot. It provides a starting point for working with multiple MCUboot configurations. You can update the device over UART or Bluetooth® Low Energy.

Requirements

The sample supports the following development kits:

Hardware platforms	PCA	Board name	Board target
nRF7120 DK		nrf7120dk	nrf7120dk/nrf7120/cpuapp
nRF54LV10 DK	PCA10188	nrf54lv10dk	nrf54lv10dk/nrf54lv10a/cpuapp
nRF54LS05 DK	PCA10214	nrf54ls05dk	nrf54ls05dk/nrf54ls05b/cpuapp
nRF54LM20 DK	PCA10184	nrf54lm20dk	nrf54lm20dk/nrf54lm20b/cpuapp nrf54lm20dk/nrf54lm20a/cpuapp
nRF54L15 DK	PCA10156	nrf54l15dk	nrf54l15dk/nrf54l15/cpuapp
nRF54L15 DK (emulating nRF54L10)	PCA10156	nrf54l15dk	nrf54l15dk/nrf54l10/cpuapp
nRF54L15 DK (emulating nRF54L05)	PCA10156	nrf54l15dk	nrf54l15dk/nrf54l05/cpuapp
nRF54H20 DK	PCA10175	nrf54h20dk	nrf54h20dk/nrf54h20/cpuapp
nRF5340 DK	PCA10095	nrf5340dk	nrf5340dk/nrf5340/cpuapp
nRF52840 DK	PCA10056	nrf52840dk	nrf52840dk/nrf52840

For update over UART, the nRF Util development tool mcu-manager command is recommended (nrfutil mcu-manager).

For update over Bluetooth Low Energy, you need the nRF Device Manager app:

• nRF Device Manager mobile app for Android

• nRF Device Manager mobile app for iOS

Overview

This sample implements an SMP server. SMP is a basic transfer encoding used with the MCUmgr management protocol. For more information about MCUmgr and SMP, see Device Management.

The sample supports the serial (UART) MCUmgr transport by default.

Bluetooth LE transport is supported when building with the overlay that enables it (for example, overlay-bt.conf).

The sample is built with sysbuild and includes MCUboot as the bootloader. Various build configurations are provided for different boards, MCUboot modes (including swap, direct-XIP and overwrite), signature types, and optional features such as encryption and compression, as well as external flash support.

The various sample build configurations are defined in the sample.yaml file. The following table describes the available configurations.

Note

Not all configuration and board combinations are supported. Refer to the sample.yaml file for the list of supported boards for each configuration.

Configuration	Transport	MCUboot mode	Other features
sample.dfu.smp_svr.serial	UART	Swap
sample.dfu.smp_svr.bt	Bluetooth LE	Swap
sample.dfu.smp_svr.mcuboot_flags.direct_xip_withrevert	UART	Direct-XIP
sample.dfu.smp_svr.encryption.rsa	UART	Swap	Encryption enabled, signature: RSA
sample.dfu.smp_svr.encryption.ecdsa_p256	UART	Swap	Encryption enabled, signature: ECDSA P-256
sample.dfu.smp_svr.encryption.ed25519	UART	Swap	Encryption enabled, signature: Ed25519
sample.dfu.smp_svr.signature.none	UART	Swap
sample.dfu.smp_svr.signature.ed25519	UART	Swap	Signature using Ed25519
sample.dfu.smp_svr.signature.ecdsa_p256	UART	Swap	Signature using ECDSA P-256
sample.dfu.smp_svr.signature.pure	UART	Swap	Signature using Ed25519 (pure)
sample.dfu.smp_svr.kmu.basic	UART	Swap	KMU-based signature (Ed25519)
sample.dfu.smp_svr.nsib.kmu.basic	UART	Swap	NSIB with KMU-based signature
sample.dfu.smp_svr.kmu.revocation	UART	Swap	KMU with key revocation
sample.dfu.smp_svr.nrf_compress.basic	UART	Overwrite-only	Compressed image support
sample.dfu.smp_svr.nrf_compress.encryption_rsa	UART	Overwrite-only	Compression and encryption (RSA)
sample.dfu.smp_svr.nrf_compress.encryption_ecdsa_p256	UART	Overwrite-only	Compression and encryption (ECDSA P-256)
sample.dfu.smp_svr.nrf_compress.encryption_ed25519	UART	Overwrite-only	Compression and encryption (Ed25519)
sample.dfu.smp_svr.bt.nrf5340dk.ext_flash	Bluetooth LE	Swap	External flash
sample.dfu.smp_svr.bt.nrf54l15	Bluetooth LE	Swap
sample.dfu.smp_svr.bt.nrf54l15dk.ext_flash	Bluetooth LE	Swap	External flash
sample.dfu.smp_svr.bt.nrf54l15dk.ext_flash.pure_dts	Bluetooth LE	Swap	External flash (pure DTS, no partition manager)
sample.dfu.smp_svr.bt.nrf54l15dk.ext_flash.sqspi	Bluetooth LE	Swap	External flash, communication through software QSPI on FLPR core
sample.dfu.smp_svr.bt.nrf54h20dk	Bluetooth LE	Swap
sample.dfu.smp_svr.bt.nrf54h20dk.direct_xip_withrevert	Bluetooth LE	Direct-XIP
sample.dfu.smp_svr.serial.nrf54h20dk.ecdsa	UART	Swap	Signature using ECDSA P-256
sample.dfu.smp_svr.bt.nrf54h20dk.direct_xip_withrequests	Bluetooth LE	Direct-XIP
sample.dfu.smp_svr.bt.nrf54h20dk.ext_flash	Bluetooth LE	Swap	External flash
sample.dfu.smp_svr.ram_load	UART	RAM load
sample.dfu.smp_svr.ram_load.kmu	UART	RAM load	KMU-based signature (Ed25519)

Building and running

This sample can be found under samples/dfu/smp_svr in the nRF Connect SDK folder structure.

To build the sample, follow the instructions in Building an application for your preferred building environment. See also Programming an application for programming steps and Testing and optimization for general information about testing and debugging in the nRF Connect SDK.

Note

When building repository applications in the SDK repositories, building with sysbuild is enabled by default. If you work with out-of-tree freestanding applications, you need to manually pass the --sysbuild parameter to every build command or configure west to always use it.

The steps described above build the basic configuration with the UART transport and MCUboot using swap mode. Other build configurations are available for different boards, MCUboot modes, signature types, and optional features.

When building a <configuration_name> configuration from the sample.yaml file, you can use the following command:

west build -b <board_name> -T ./<configuration_name>

Alternatively, you can manually specify the extra_args parameters listed in the configuration description. Pass each parameter with the -D prefix after --:

west build -b <board_name> -- -D<extra_arg1> -D<extra_arg2> ...

For example, build the sample.dfu.smp_svr.bt.nrf54h20dk configuration by running the following command:

west build -b nrf54h20dk/nrf54h20/cpuapp -T ./sample.dfu.smp_svr.bt.nrf54h20dk

Alternatively, review the extra_args parameters defined for this configuration:

EXTRA_CONF_FILE="overlay-bt.conf"
SB_CONFIG_NETCORE_IPC_RADIO=y
SB_CONFIG_NETCORE_IPC_RADIO_BT_HCI_IPC=y
mcuboot_CONFIG_PSA_CRYPTO=y
mcuboot_CONFIG_MULTITHREADING=y
CONFIG_MCUMGR_GRP_IMG_ALLOW_CONFIRM_NON_ACTIVE_IMAGE_ANY=y

You can then build the configuration by explicitly passing these parameters:

west build -b nrf54h20dk/nrf54h20/cpuapp -- -DEXTRA_CONF_FILE="overlay-bt.conf" -DSB_CONFIG_NETCORE_IPC_RADIO=y -DSB_CONFIG_NETCORE_IPC_RADIO_BT_HCI_IPC=y -Dmcuboot_CONFIG_MULTITHREADING=y -DCONFIG_MCUMGR_GRP_IMG_ALLOW_CONFIRM_NON_ACTIVE_IMAGE_ANY=y

Testing

The following steps are common for all configurations:

1. Build the sample.

2. Program the firmware to your development kit.

3. Observe the following output on the terminal:

   [00:00:00.007,978] <inf> smp_sample: build time: <BUILD TIME>
   

   <BUILD TIME> indicates the build time.

Performing DFU is specific to the configuration.

Testing over UART

The following steps show how to perform DFU using the nRF Util development tool mcu-manager command over UART. Not all steps apply to all configurations. For example, if the overwrite only mode is used, no confirmation is needed.

1. Disconnect the terminal to avoid conflicts. The SMP communication uses the same serial port as the log output. Some terminal emulators might not require this step.

2. List the images on the device. The serial port might differ depending on your development kit and operating system.

   nrfutil mcu-manager serial image-list --serial-port <serial_port>
   

   The output resembles the following example:

   Image
     slot: 0
     version: 0.0.0
     hash: ef8cc97cf2c873bde983a3a133cbc7468ef14cd42092ee131b00275aea0429522f256020129a51f9309078b1ca310ed1f76a091c484a496f8d3f7fd565d13468
     bootable: true
     pending: false
     confirmed: true
     active: true
     permanent: false
   

   The number of images can differ depending on the configuration and board (for example, separate radio core, or merged/split images).

3. Build the second version of the sample. For simplicity, it is assumed to be built in the build_v2 directory.

4. Upload the second version of the image to the device using the SMP protocol:

   nrfutil mcu-manager serial image-upload --serial-port /dev/ttyACM0 --image-number 0 --firmware ./build_v2/smp_svr/zephyr/zephyr.signed.bin
   

5. List the images on the device again to get the hash of the second version of the image:

   nrfutil mcu-manager serial image-list --serial-port /dev/ttyACM0
   

   The output resembles the following example:

   Image
     slot: 0
     version: 0.0.0
     hash: ef8cc97cf2c873bde983a3a133cbc7468ef14cd42092ee131b00275aea0429522f256020129a51f9309078b1ca310ed1f76a091c484a496f8d3f7fd565d13468
     bootable: true
     pending: false
     confirmed: true
     active: true
     permanent: false
   Image
     slot: 1
     version: 0.0.0
     hash: 35bd50242ad991aa5fd9374b33bc8ebcd2332fe26cae44f5f32172a62b7c4adcde1467f33b783e7c7090eb6dffc358bcb9a4efb8f50b99d587131418cd5da375
     bootable: true
     pending: false
     confirmed: false
     active: false
     permanent: false
   

6. Set the test flag for the second version of the image, using the acquired hash:

   nrfutil mcu-manager serial image-test --serial-port /dev/ttyACM0 --hash 35bd50242ad991aa5fd9374b33bc8ebcd2332fe26cae44f5f32172a62b7c4adcde1467f33b783e7c7090eb6dffc358bcb9a4efb8f50b99d587131418cd5da375
   

7. Reconnect to the terminal.

8. Reboot the device.

9. Verify that the build time in the terminal output reflects the new version.

10. To make the new version permanent, confirm the image:

    nrfutil mcu-manager serial image-confirm --serial-port /dev/ttyACM0 --hash 35bd50242ad991aa5fd9374b33bc8ebcd2332fe26cae44f5f32172a62b7c4adcde1467f33b783e7c7090eb6dffc358bcb9a4efb8f50b99d587131418cd5da375
    

Testing over Bluetooth LE

To perform DFU using the nRF Connect Device Manager mobile app over Bluetooth LE, follow these steps:

1. Start the nRF Connect Device Manager mobile app.

2. Follow the testing steps for the FOTA over Bluetooth LE. For more information, see the following documentation pages:

   • Testing steps for FOTA over Bluetooth LE with nRF52840

   • Testing steps for FOTA over Bluetooth LE with nRF5340

   • Testing steps for FOTA over Bluetooth LE with nRF54L15

   • Testing steps for FOTA over Bluetooth LE with nRF54H20

3. After the firmware update completes, check the UART output. Observe that the build time in the terminal output reflects the new version.

Dependencies

This sample uses the following nRF Connect SDK library:

• MCUboot