applications: nrf_desktop: doc: dfu: align with MCUboot RAM load

Updated the documentation of the DFU application module that is part
of the nRF Desktop application to describe the support for the MCUboot
RAM load mode.

Ref: NCSDK-36374

Signed-off-by: Kamil Piszczek <[email protected]>

Author: kapi-no

applications/nrf_desktop/doc/dfu.rst

@@ -47,19 +47,43 @@ If the buffer is small, the host must perform the DFU progress synchronization m
 MCUboot bootloader mode
 =======================
 
-The MCUboot bootloader can either move the image to the primary slot before booting it (``swap mode``) or boot the image directly from the secondary slot (``direct-xip mode``).
+This module supports the following modes of the MCUboot bootloader and reports the corresponding bootloader name:
 
-If the MCUboot bootloader in the swap mode is selected, the DFU module does the following:
+* ``swap`` (:kconfig:option:`CONFIG_MCUBOOT_BOOTLOADER_MODE_SWAP_USING_MOVE`) - ``MCUBOOT``
+* ``direct-xip`` (:kconfig:option:`CONFIG_MCUBOOT_BOOTLOADER_MODE_DIRECT_XIP`) - ``MCUBOOT+XIP``
+* ``RAM load`` (:kconfig:option:`CONFIG_MCUBOOT_BOOTLOADER_MODE_RAM_LOAD`) - ``MCUBOOT``
+
+The DFU module relies on the listed Kconfig options that indicate the MCUboot bootloader mode to determine the correct behavior.
+
+.. caution::
+   Other bootloader modes might be compatible with this module, but they are not actively tested as part of the nRF Desktop configurations.
+
+See the :ref:`nrf_desktop_bootloader` section for more information on the MCUboot bootloader modes.
+
+Swap mode
+---------
+
+If this bootloader mode is selected, the DFU module does the following:
 
  * Requests the image upgrade after the whole image is transferred over the :ref:`nrf_desktop_config_channel`.
  * Confirms the running image after the device is rebooted.
 
-If the MCUboot bootloader's direct-xip mode is used, the module does not mark the newly uploaded image as pending and does not confirm it after a successful boot.
-In that case, the DFU module assumes that the MCUboot direct-xip bootloader simply boots an image with the higher version, so there is no need to mark the image as pending and confirm it.
+Direct-xip mode
+---------------
+
+If this bootloader mode is selected, the DFU module does not mark the newly uploaded image as pending and does not confirm it after a successful boot.
 
-The :kconfig:option:`CONFIG_MCUBOOT_BOOTLOADER_MODE_DIRECT_XIP` Kconfig option is used to inform the DFU module that the device uses the MCUboot bootloader in the direct-xip mode.
-If the option is enabled, the DFU module reports the ``MCUBOOT+XIP`` bootloader name instead of ``MCUBOOT`` to indicate that the bootloader working in the direct-xip mode is used.
-See the :ref:`nrf_desktop_bootloader` section for more information on the MCUboot bootloader configuration.
+RAM load mode
+-------------
+
+If this bootloader mode is selected, the DFU module does not mark the newly uploaded image as pending and does not confirm it after a successful boot.
+
+.. note::
+   Support for the RAM load mode in this module is experimental.
+   For more details about the support of the MCUboot RAM load mode in the nRF Desktop application, see the MCUboot :ref:`nrf_desktop_configuring_mcuboot_bootloader_ram_load` section in the nRF Desktop documentation.
+
+.. note::
+   DTS is the only supported partitioning method when you use the MCUboot bootloader in the RAM load mode.
 
 Partitioning methods
 ====================