From aa53dfab02e238d37771faf8a2661ed1dfa18f3d Mon Sep 17 00:00:00 2001
From: Dominik Ermel <dominik.ermel@nordicsemi.no>
Date: Thu, 7 Apr 2022 13:22:09 +0000
Subject: [PATCH] doc/guides/device_mgmt: Add MCUMGR parameters command to OS
 grp

The commit add description of a new OS group command for MCUMGR
parameters retrieval.

Signed-off-by: Dominik Ermel <dominik.ermel@nordicsemi.no>
---
 .../device_mgmt/smp_groups/smp_group_0.rst    | 62 +++++++++++++++++++
 1 file changed, 62 insertions(+)

diff --git a/doc/services/device_mgmt/smp_groups/smp_group_0.rst b/doc/services/device_mgmt/smp_groups/smp_group_0.rst
index ab72479c71a..8caac53ad8f 100644
--- a/doc/services/device_mgmt/smp_groups/smp_group_0.rst
+++ b/doc/services/device_mgmt/smp_groups/smp_group_0.rst
@@ -24,6 +24,8 @@ OS management group defines following commands:
     +-------------------+-----------------------------------------------+
     | ``5``             | System reset                                  |
     +-------------------+-----------------------------------------------+
+    | ``6``             | MCUMGR parameters                             |
+    +-------------------+-----------------------------------------------+
 
 Echo command
 ************
@@ -456,3 +458,63 @@ where:
     | "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                               |
+    +-----------------------+---------------------------------------------------+