doc: app_dev: dfu: Update minimum sizes for bootloader

The minimum sizes for release builds are now smaller

Signed-off-by: Jamie McCrae <[email protected]>

Author: nordicjm

doc/nrf-bm/app_dev/dfu/bootloader_keys.rst

@@ -45,5 +45,5 @@ KMU (Key Management Unit)
 *************************
 
 The nRF54L series of SoCs contain a KMU - key management unit, this on-die peripheral can be used by CRACEN to securely store and use keys without allowing the contents to be read out.
-In order to boot images when the KMU feature is enabled, the MCUboot singing key must be programmed to the KMU prior to loading the firmware or the device will be unable to boot.
+In order to boot images when the KMU feature is enabled, the MCUboot signing key must be programmed to the KMU prior to loading the firmware or the device will be unable to boot.
 This feature can be enabled with :kconfig:option:`SB_CONFIG_BM_BOOTLOADER_MCUBOOT_SIGNATURE_USING_KMU`, another sysbuild Kconfig is used to determine if the public key file should be automatically programmed to boards when ``west flash`` is used with the ``--erase`` or ``--recover`` arguments, when :kconfig:option:`SB_CONFIG_BM_BOOTLOADER_MCUBOOT_GENERATE_DEFAULT_KMU_KEYFILE` is enabled (it is enabled by default) then this process is enabled and should be the first command used after building the project to set the board up for development.

doc/nrf-bm/app_dev/dfu/ug_dfu.rst

@@ -18,20 +18,21 @@ Partition Configuration
 The memory of your device must be partitioned appropriately to accommodate the bootloader, application, and firmware update mechanisms.
 |BMshort| uses Zephyr's `DTS`_ system for memory partitioning.
 
-+--------------------------+---------------------------------------------------------------+--------------------+-------------------+
-| Partition Name           | Description                                                   | Minimum size  |br| | Minimum size |br| |
-|                          |                                                               | (Development)      | (Release)         |
-+==========================+===============================================================+====================+===================+
-| ``boot_partition``       | Bootloader (MCUboot)                                          | 36 KB              | 28 KB             |
-+--------------------------+---------------------------------------------------------------+--------------------+-------------------+
-| ``slot0_partition``      | Main application slot                                         |                    |                   |
-+--------------------------+---------------------------------------------------------------+--------------------+-------------------+
-| ``slot1_partition``      | `Firmware loader`_                                            | 44 KB              | 28 KB             |
-+--------------------------+---------------------------------------------------------------+--------------------+-------------------+
-| ``softdevice_partition`` | For the SoftDevice, including an MCUboot header of size 0x800 |                                        |
-+--------------------------+---------------------------------------------------------------+--------------------+-------------------+
-| ``metadata_partition``   | Stores metadata, placed at the last 0x200 of NVM              |                    |                   |
-+--------------------------+---------------------------------------------------------------+--------------------+-------------------+
++--------------------------+---------------------------------------------------------------+--------------------+----------------------+
+| Partition Name           | Description                                                   | Minimum size  |br| | Minimum size |br|    |
+|                          |                                                               | (Development)      | (Release)            |
++==========================+===============================================================+====================+======================+
+| ``boot_partition``       | Bootloader (MCUboot)                                          | 31 KiB             | 21 KiB (using KMU)   |
+|                          |                                                               |                    | 26 KiB (without KMU) |
++--------------------------+---------------------------------------------------------------+--------------------+----------------------+
+| ``slot0_partition``      | Main application slot                                         |                    |                      |
++--------------------------+---------------------------------------------------------------+--------------------+----------------------+
+| ``slot1_partition``      | `Firmware loader`_                                            | 44 KiB             | 28 KiB               |
++--------------------------+---------------------------------------------------------------+--------------------+----------------------+
+| ``softdevice_partition`` | For the SoftDevice, including an MCUboot header of size 0x800 |                                           |
++--------------------------+---------------------------------------------------------------+--------------------+----------------------+
+| ``metadata_partition``   | Stores metadata, placed at the last 0x200 of NVM              |                    |                      |
++--------------------------+---------------------------------------------------------------+--------------------+----------------------+
 
 .. note::
    The sizes and configurations of slot0 and slot1 are asymmetrical.