samples: openthread: Enabled ZMS for OpenThread samples

The settings backend for the nRF54L SoC family should be
selected to the ZMS, so it was applied for all OpenThread samples.

Additionally, added a cmake check that prints warning in case
someone uses NVS with nRF54L SoC and informs about
the consequences.

Signed-off-by: Kamil Kasperczyk <kamil.kasperczyk@nordicsemi.no>

samples/openthread/cli/boards/nrf54l15dk_nrf54l15_cpuapp.conf

@@ -11,3 +11,9 @@ CONFIG_NRFX_UARTE0=n
 # while using CRACEN
 CONFIG_MAIN_STACK_SIZE=6144
 CONFIG_SHELL_STACK_SIZE=5120
+
+# Workaround required as Zephyr L2 implies usage of NVS backend for settings.
+# It should be removed once the proper fix will be applied in Zephyr.
+CONFIG_NVS=n
+CONFIG_ZMS=y
+CONFIG_SETTINGS_ZMS=y

samples/openthread/coprocessor/boards/nrf54l15dk_nrf54l15_cpuapp.conf

@@ -6,3 +6,9 @@
 
 CONFIG_FPU=n
 CONFIG_SPI_NOR=n
+
+# Workaround required as Zephyr L2 implies usage of NVS backend for settings.
+# It should be removed once the proper fix will be applied in Zephyr.
+CONFIG_NVS=n
+CONFIG_ZMS=y
+CONFIG_SETTINGS_ZMS=y

subsys/net/CMakeLists.txt

@@ -8,3 +8,4 @@ add_subdirectory(lib)
 add_subdirectory_ifdef(CONFIG_OPENTHREAD_RPC openthread/rpc)
 add_subdirectory_ifdef(CONFIG_L2_WIFI_CONNECTIVITY l2_wifi_if_conn)
 add_subdirectory_ifdef(CONFIG_OPENTHREAD_REPORT openthread/report)
+add_subdirectory_ifdef(CONFIG_NET_L2_OPENTHREAD openthread/settings_check)

subsys/net/openthread/settings_check/CMakeLists.txt

@@ -0,0 +1,23 @@
+#
+# Copyright (c) 2024 Nordic Semiconductor
+#
+# SPDX-License-Identifier: LicenseRef-Nordic-5-Clause
+#
+
+# This script checks if NVS settings backend is used with nRF54L SoC target and prints
+# the warning that the recommended backend is ZMS due to the RRAM design.
+
+if (CONFIG_SOC_SERIES_NRF54LX AND CONFIG_SETTINGS_NVS)
+    message(WARNING " ###################################################################################\n"
+                    " #                                                                                 #\n"
+                    " # Your application uses NVS backend for the settings storage that is not          #\n"
+                    " # optimal solution for the nRF54L SoC family and it may negatively impact         #\n"
+                    " # the non-volatile RRAM life-time.                                                #\n"
+                    " #                                                                                 #\n"
+                    " # The recommended settings backend for nRF54L SoC family is ZMS.                  #\n"
+                    " # You can enable it by selecting CONFIG_SETTINGS_ZMS=y and CONFIG_ZMS=y.          #\n"
+                    " # Please note that the other Kconfig options related to NVS like cache            #\n"
+                    " # or block size will require alignment on the ZMS side as well.                   #\n"
+                    " #                                                                                 #\n"
+                    " ###################################################################################\n")
+endif()