.. _smp_svr_sample: SMP Server Sample ################# Overview ******** This sample application implements a Simple Management Protocol (SMP) server. SMP is a basic transfer encoding for use with the MCUmgr management protocol. For more information about MCUmgr and SMP, please see :ref:`device_mgmt`. This sample application supports the following mcumgr transports by default: * Shell * Bluetooth ``smp_svr`` enables support for the following command groups: * ``fs_mgmt`` * ``img_mgmt`` * ``os_mgmt`` * ``stat_mgmt`` Caveats ******* * The Zephyr port of ``smp_svr`` is configured to run on a Nordic nRF52x MCU. The application should build and run for other platforms without modification. * The MCUboot bootloader is required for ``img_mgmt`` to function properly. More information about the Device Firmware Upgrade subsystem and MCUboot can be found in :ref:`mcuboot`. * The :file:`mcumgr` command-line tool only works with Bluetooth Low Energy (BLE) on Linux and macOS. On Windows there is no support for Device Firmware Upgrade over BLE yet. Building a BLE Controller (optional) ************************************ .. note:: This section is only relevant for Linux users If you want to try out Device Firmware Upgrade (DFU) over the air using Bluetooth Low Energy (BLE) and do not have a built-in or pluggable BLE radio, you can build one and use it following the instructions in :ref:`bluetooth-hci-uart-bluez`. Building and Running ******************** The below steps describe how to build and run the ``smp_svr`` sample in Zephyr. Where examples are given, they assume the sample is being built for the Nordic nRF52 Development Kit (``BOARD=nrf52_pca10040``). If you would like to use a more constrained platform, such as the nRF51 DK, you should use the :file:`prj_tiny.conf` configuration file rather than the default :file:`prj.conf`. Step 1: Build MCUboot ===================== Build MCUboot by following the instructions in the :ref:`mcuboot` documentation page. Step 2: Flash MCUboot ====================== Flash the resulting image file to address 0x0 of flash memory. This can be done in multiple ways. Using make or ninja: .. code-block:: console make flash # or ninja flash Using GDB: .. code-block:: console restore binary 0 Step 3: Build smp_svr ===================== ``smp_svr`` can be built for the nRF52 as follows: .. zephyr-app-commands:: :zephyr-app: samples/subsys/mgmt/mcumgr/smp_svr :board: nrf52_pca10040 :build-dir: nrf52_pca10040 :goals: build .. _smp_svr_sample_sign: Step 4: Sign the image ====================== .. note:: From this section onwards you can use either a binary (``.bin``) or an Intel Hex (``.hex``) image format. This is written as ``(bin|hex)`` in this document. Using MCUboot's :file:`imgtool.py` script, sign the :file:`zephyr.(bin|hex)` file you built in Step 3. In the below example, the MCUboot repo is located at :file:`~/src/mcuboot`. .. code-block:: console ~/src/mcuboot/scripts/imgtool.py sign \ --key ~/src/mcuboot/root-rsa-2048.pem \ --header-size 0x200 \ --align 8 \ --version 1.0 \ --slot-size \ signed.(bin|hex) The above command creates an image file called :file:`signed.(bin|hex)` in the current directory. Step 5: Flash the smp_svr image =============================== Upload the :file:`signed.(bin|hex)` file from Step 4 to image slot-0 of your board. The location of image slot-0 varies by board, as described in :ref:`mcuboot_partitions`. For the nRF52 DK, slot-0 is located at address ``0xc000``. Using :file:`nrfjprog` you don't need to specify the slot-0 starting address, since :file:`.hex` files already contain that information: .. code-block:: console nrfjprog --program Using GDB: .. code-block:: console restore binary 0xc000 Step 6: Run it! =============== .. note:: If you haven't installed :file:`mcumgr` yet, then do so by following the instructions in the :ref:`mcumgr_cli` section of the Management subsystem documentation. .. note:: The :file:`mcumgr` command-line tool requires a connection string in order to identify the remote target device. In this sample we use a BLE-based connection string, and you might need to modify it depending on the BLE controller you are using. The ``smp_svr`` app is ready to run. Just reset your board and test the app with the :file:`mcumgr` command-line tool's ``echo`` functionality, which will send a string to the remote target device and have it echo it back: .. code-block:: console sudo mcumgr --conntype ble --connstring ctlr_name=hci0,peer_name='Zephyr' echo hello hello Step 7: Device Firmware Upgrade =============================== Now that the SMP server is running on your board and you are able to communicate with it using :file:`mcumgr`, you might want to test what is commonly called "OTA DFU", or Over-The-Air Device Firmware Upgrade. To do this, build a second sample (following the steps below) to verify it is sent over the air and properly flashed into slot-1, and then swapped into slot-0 by MCUboot. Build a second sample --------------------- Perhaps the easiest sample to test with is the :zephyr_file:`samples/hello_world` sample provided by Zephyr, documented in the :ref:`hello_world` section. Edit :zephyr_file:`samples/hello_world/prj.conf` and enable the required MCUboot Kconfig option as described in :ref:`mcuboot` by adding the following line to it: .. code-block:: console CONFIG_BOOTLOADER_MCUBOOT=y Then build the sample as usual (see :ref:`hello_world`). Sign the second sample ---------------------- Next you will need to sign the sample just like you did for :file:`smp_svr`, since it needs to be loaded by MCUboot. Follow the same instructions described in :ref:`smp_svr_sample_sign`, but this time you must use a :file:`.bin` image, since :file:`mcumgr` does not yet support :file:`.hex` files. Upload the image over BLE ------------------------- Now we are ready to send or upload the image over BLE to the target remote device. .. code-block:: console sudo mcumgr --conntype ble --connstring ctlr_name=hci0,peer_name='Zephyr' image upload signed.bin If all goes well the image will now be stored in slot-1, ready to be swapped into slot-0 and executed. .. note:: At the beginning of the upload process, the target might start erasing the image slot, taking several dozen seconds for some targets. This might cause an NMP timeout in the management protocol tool. Use the ``-t Now MCUBoot will swap the image on the next reset. Reset remotely -------------- We can reset the device remotely to observe (use the console output) how MCUboot swaps the images: .. code-block:: console sudo mcumgr --conntype ble --connstring ctlr_name=hci0,peer_name='Zephyr' reset Upon reset MCUboot will swap slot-0 and slot-1. The new image is the basic ``hello_world`` sample that does not contain SMP or BLE functionality, so we cannot communicate with it using :file:`mcumgr`. Instead simply reset the board manually to force MCUboot to revert (i.e. swap back the images) due to the fact that the new image has not been confirmed. If you had instead built and uploaded a new image based on ``smp_svr`` (or another BLE and SMP enabled sample), you could confirm the new image and make the swap permanent by using this command: .. code-block:: console sudo mcumgr --conntype ble --connstring ctlr_name=hci0,peer_name='Zephyr' image confirm Note that if you try to send the very same image that is already flashed in slot-0 then the procedure will not complete successfully since the hash values for both slots will be identical.