.. _mcumgr_smp_group_0:

Default/OS Management Group
###########################

OS management group defines following commands:

.. table::
    :align: center

    +-------------------+-----------------------------------------------+
    | ``Command ID``    | Command description                           |
    +===================+===============================================+
    | ``0``             | Echo                                          |
    +-------------------+-----------------------------------------------+
    | ``1``             | Console/Terminal echo control;                |
    |                   | unimplemented by Zephyr                       |
    +-------------------+-----------------------------------------------+
    | ``2``             | Statistics                                    |
    +-------------------+-----------------------------------------------+
    | ``3``             | Memory pool statistics                        |
    +-------------------+-----------------------------------------------+
    | ``4``             | Date-time string; unimplemented by Zephyr     |
    +-------------------+-----------------------------------------------+
    | ``5``             | System reset                                  |
    +-------------------+-----------------------------------------------+
    | ``6``             | MCUMGR parameters                             |
    +-------------------+-----------------------------------------------+

Echo command
************

Echo command responses by sending back string that it has received.

Echo request
============

Echo request header fields:

.. table::
    :align: center

    +--------------------+--------------+----------------+
    | ``OP``             | ``Group ID`` | ``Command ID`` |
    +====================+==============+================+
    | ``0`` or ``2``     | ``0``        |  ``0``         |
    +--------------------+--------------+----------------+

CBOR data of request:

.. code-block:: none

    {
        (str)"d" : (str)
    }

where:

.. table::
    :align: center

    +-----------------------+---------------------------------------------------+
    | "d"                   | string to be replied by echo service              |
    +-----------------------+---------------------------------------------------+

Echo response
=============

Echo response header fields:

.. table::
    :align: center

    +--------+--------------+----------------+----------------------------------+
    | ``OP`` | ``Group ID`` | ``Command ID`` | Note                             |
    +========+==============+================+==================================+
    | ``1``  | ``0``        |  ``0``         | When request ``OP`` was ``0``    |
    +--------+--------------+----------------+----------------------------------+
    | ``3``  | ``0``        |  ``0``         | When request ``OP`` was ``2``    |
    +--------+--------------+----------------+----------------------------------+

CBOR data of successful response:

.. code-block:: none

    {
        (str)"r"        : (str)
    }

In case of error the CBOR data takes form:

.. code-block:: none

    {
        (str)"rc"       : (int)
    }

where:

.. table::
    :align: center

    +-----------------------+---------------------------------------------------+
    | "r"                   | Replying echo string                              |
    +-----------------------+---------------------------------------------------+
    | "rc"                  | :ref:`mcumgr_smp_protocol_status_codes`           |
    +-----------------------+---------------------------------------------------+

Task statistics command
***********************

The command responds with some system statistics.

Task statistics request
=======================

Task statistics request header fields:

.. table::
    :align: center

    +--------+--------------+----------------+
    | ``OP`` | ``Group ID`` | ``Command ID`` |
    +========+==============+================+
    | ``0``  | ``0``        |  ``2``         |
    +--------+--------------+----------------+

The command sends empty CBOR map as data.


Task statistics response
========================

Task statistics response header fields:

.. table::
    :align: center

    +--------+--------------+----------------+
    | ``OP`` | ``Group ID`` | ``Command ID`` |
    +========+==============+================+
    | ``1``  | ``0``        |  ``2``         |
    +--------+--------------+----------------+

CBOR data of response:

.. code-block:: none

    {
        (str)"tasks" : {
            (str)<task_name> : {
                (str)"prio"         : (uint)
                (str)"tid"          : (uint)
                (str)"state"        : (uint)
                (str)"stkuse"       : (uint)
                (str)"stksiz"       : (uint)
                (str)"cswcnt"       : (uint)
                (str)"runtime"      : (uint)
                (str)"last_checkin" : (uint)
                (str)"next_checkin" : (uint)
            }
            ...
        }
        (str)"rc" : (int)
    }


where:

.. table::
    :align: center

    +-----------------------+---------------------------------------------------+
    | <task_name>           | string identifying task                           |
    +-----------------------+---------------------------------------------------+
    | "prio"                | task priority                                     |
    +-----------------------+---------------------------------------------------+
    | "tid"                 | numeric task ID                                   |
    +-----------------------+---------------------------------------------------+
    | "state"               | numeric task state                                |
    +-----------------------+---------------------------------------------------+
    | "stkuse"              | task's/thread's stack usage                       |
    +-----------------------+---------------------------------------------------+
    | "stksiz"              | task's/thread's stack size                        |
    +-----------------------+---------------------------------------------------+
    | "cswcnt"              | task's/thread's context switches                  |
    +-----------------------+---------------------------------------------------+
    | "runtime"             | task's/thread's runtime in "ticks"                |
    +-----------------------+---------------------------------------------------+
    | "last_checkin"        | set to 0 by Zephyr                                |
    +-----------------------+---------------------------------------------------+
    | "next_checkin"        | set to 0 by Zephyr                                |
    +-----------------------+---------------------------------------------------+
    | "rc"                  | :ref:`mcumgr_smp_protocol_status_codes`           |
    +-----------------------+---------------------------------------------------+

.. note::
    The unit for "stkuse" and "stksiz" is system dependent and in case of Zephyr
    this is number of 4 byte words.

Memory pool statistics
**********************

The command is used to obtain information on memory pools active in running
system.

Memory pool statistic request
=============================

Memory pool statistics request header fields:

.. table::
    :align: center

    +--------+--------------+----------------+
    | ``OP`` | ``Group ID`` | ``Command ID`` |
    +========+==============+================+
    | ``0``  | ``0``        |  ``3``         |
    +--------+--------------+----------------+

The command sends empty CBOR map as data.

Memory pool statistics response
===============================

Memory pool statistics response header fields:

.. table::
    :align: center

    +--------+--------------+----------------+
    | ``OP`` | ``Group ID`` | ``Command ID`` |
    +========+==============+================+
    | ``1``  | ``0``        |  ``3``         |
    +--------+--------------+----------------+

CBOR data of response:

.. code-block:: none

    {
        (str)<pool_name> {
            (str)"blksiz"   : (int)
            (str)"nblks"    : (int)
            (str)"nfree"    : (int)
            (str)"min'      : (int)
        }
        ...
        (str)"rc" : (int)
    }

where:

.. table::
    :align: center

    +-----------------------+---------------------------------------------------+
    | <pool_name>           | string representing the pool name, used as a key  |
    |                       | for dictionary with pool statistics data          |
    +-----------------------+---------------------------------------------------+
    | "blksiz"              | size of the memory block in the pool              |
    +-----------------------+---------------------------------------------------+
    | "nblks"               | number of blocks in the pool                      |
    +-----------------------+---------------------------------------------------+
    | "nrfree"              | number of free blocks                             |
    +-----------------------+---------------------------------------------------+
    | "min"                 | lowest number of free blocks the pool reached     |
    |                       | during run-time                                   |
    +-----------------------+---------------------------------------------------+
    | "rc"                  | :ref:`mcumgr_smp_protocol_status_codes`           |
    +-----------------------+---------------------------------------------------+

Date-time command
*****************

The command allows to obtain string representing current time-date on a device
or set a new time to a device.
The time format used, by both set and get operations, is:

    "yyyy-MM-dd'T'HH:mm:ss.SSSSSSZZZZZ"

Date-time get
=============

The command allows to obtain date-time from a device.

Date-time get request
---------------------

Date-time request header fields:

.. table::
    :align: center

    +--------+--------------+----------------+
    | ``OP`` | ``Group ID`` | ``Command ID`` |
    +========+==============+================+
    | ``0``  | ``0``        |  ``4``         |
    +--------+--------------+----------------+

The command sends empty CBOR map as data.

Data-time get response
----------------------

Date-time get response header fields:

.. table::
    :align: center

    +--------+--------------+----------------+
    | ``OP`` | ``Group ID`` | ``Command ID`` |
    +========+==============+================+
    | ``1``  | ``0``        |  ``4``         |
    +--------+--------------+----------------+

CBOR data of response:

.. code-block:: none

    {
        (str)"datetime" : (str)
        (opt,str)"rc"   : (int)
    }

where:

.. table::
    :align: center

    +-----------------------+---------------------------------------------------+
    | "datetime"            | String in format                                  |
    |                       | yyyy-MM-dd'T'HH:mm:ss.SSSSSSZZZZZ                 |
    +-----------------------+---------------------------------------------------+
    | "rc"                  | :ref:`mcumgr_smp_protocol_status_codes`;          |
    |                       | may not appear if 0                               |
    +-----------------------+---------------------------------------------------+


Date-time set
=============

The command allows to set date-time to a device.

Date-time set request
---------------------

Date-time set request header fields:

.. table::
    :align: center

    +--------+--------------+----------------+
    | ``OP`` | ``Group ID`` | ``Command ID`` |
    +========+==============+================+
    | ``2``  | ``0``        |  ``4``         |
    +--------+--------------+----------------+

CBOR data of response:

.. code-block:: none

    {
        (str)"datetime" : (str)
    }

where:

.. table::
    :align: center

    +-----------------------+---------------------------------------------------+
    | "datetime"            | String in format                                  |
    |                       | yyyy-MM-dd'T'HH:mm:ss.SSSSSSZZZZZ                 |
    +-----------------------+---------------------------------------------------+

Data-time set response
----------------------

Date-time set response header fields:

.. table::
    :align: center

    +--------+--------------+----------------+
    | ``OP`` | ``Group ID`` | ``Command ID`` |
    +========+==============+================+
    | ``1``  | ``0``        |  ``4``         |
    +--------+--------------+----------------+

CBOR data of response:

.. code-block:: none

    {
        (str)"rc"       : (int)
    }

where:

.. table::
    :align: center

    +-----------------------+---------------------------------------------------+
    | "rc"                  | :ref:`mcumgr_smp_protocol_status_codes`           |
    +-----------------------+---------------------------------------------------+

System reset
************

Performs reset of system. The device should issue response before resetting so
that the SMP client could receive information that the command has been
accepted. By default, this command is accepted in all conditions, however if
the :kconfig:option:`CONFIG_MCUMGR_GRP_OS_OS_RESET_HOOK` is enabled and an
application registers a callback, the callback will be called when this command
is issued and can be used to perform any necessary tidy operations prior to the
module rebooting, or to reject the reset request outright altogether with an
error response. For details on this functionality, see `ref:`mcumgr_callbacks`.

System reset request
====================

System reset request header fields:

.. table::
    :align: center

    +--------+--------------+----------------+
    | ``OP`` | ``Group ID`` | ``Command ID`` |
    +========+==============+================+
    | ``2``  | ``0``        |  ``5``         |
    +--------+--------------+----------------+

Normally the command sends empty CBOR map as data, but if previous
reset attempt has been responded with "rc" code equal ``10`` (busy),
then following map may be send to force the reset:

.. code-block:: none

    {
        (opt)"force"       : (int)
    }

where:

.. table::
    :align: center

    +-----------------------+---------------------------------------------------+
    | "force"               | Force reset if value > 0, optional if 0.          |
    +-----------------------+---------------------------------------------------+


System reset response
=====================

System reset response header fields

.. table::
    :align: center

    +--------+--------------+----------------+
    | ``OP`` | ``Group ID`` | ``Command ID`` |
    +========+==============+================+
    | ``3``  | ``0``        |  ``5``         |
    +--------+--------------+----------------+

CBOR data of response:

.. code-block:: none

    {
        (opt,str)"rc"       : (int)
    }

where:

.. table::
    :align: center

    +-----------------------+---------------------------------------------------+
    | "rc"                  | :ref:`mcumgr_smp_protocol_status_codes`;          |
    |                       | may not appear if 0                               |
    +-----------------------+---------------------------------------------------+

MCUMGR Parameters
*****************

Used to obtain parameters of mcumgr library.

MCUMGR Parameters Request
=========================

MCUMGR parameters request header fields:

.. table::
    :align: center

    +--------+--------------+----------------+
    | ``OP`` | ``Group ID`` | ``Command ID`` |
    +========+==============+================+
    | ``0``  | ``0``        |  ``6``         |
    +--------+--------------+----------------+

The command sends empty CBOR map as data.

MCUMGR Parameters Response
==========================

MCUMGR parameters response header fields

.. table::
    :align: center

    +--------+--------------+----------------+
    | ``OP`` | ``Group ID`` | ``Command ID`` |
    +========+==============+================+
    | ``2``  | ``0``        |  ``6``         |
    +--------+--------------+----------------+

CBOR data of response:

.. code-block:: none

    {
        (str)"buf_size"     : (uint)
        (str)"buf_count"    : (uint)
        (opt,str)"rc"       : (int)
    }

where:

.. table::
    :align: center

    +-----------------------+---------------------------------------------------+
    | "buf_size"            | Single SMP buffer size, this includes SMP header  |
    |                       | and CBOR payload                                  |
    +-----------------------+---------------------------------------------------+
    | "buf_count"           | Number of SMP buffers supported                   |
    +-----------------------+---------------------------------------------------+
    | "rc"                  | :ref:`mcumgr_smp_protocol_status_codes`;          |
    |                       | may not appear if 0                               |
    +-----------------------+---------------------------------------------------+