doc: tfm: Add tfm_ram_report and tfm_rom_report

Add usage examples from tfm_ram_report and tfm_rom_report.

Signed-off-by: Markus Lassila <[email protected]>

doc/nrf/security/tfm.rst

@@ -271,10 +271,10 @@ We will decrease the size of the (optional) ``mcuboot_pad`` partition and thus t
       address: 0x8000
       size: 0x4000
 
-Analyzing TF-M partition size
-=============================
+Analyzing ``tfm_secure`` partition size
+=======================================
 
-The size of the TF-M partition can be analyzed from the build output.
+The size of the ``tfm_secure`` partition can be analyzed from the build output.
 
   .. code-block:: console
 
@@ -283,12 +283,26 @@ The size of the TF-M partition can be analyzed from the build output.
         FLASH:       31972 B       256 KB     12.20%
         RAM:         4804 B        88 KB      5.33%
 
-The example above shows that the TF-M partition :kconfig:option:`CONFIG_PM_PARTITION_SIZE_TFM` is set to 256 kB and the TF-M binary uses 32 kB of the available space.
-Similarly the TF-M partition :kconfig:option:`CONFIG_PM_PARTITION_SIZE_TFM_SRAM` is set to 88 kB and the TF-M binary uses 5 kB of the available space.
-This information can be used to optimize the size of the TF-M partition, as long as it is within the alignment requirements explained in the previous section.
+The example above shows that the ``tfm_secure`` partition :kconfig:option:`CONFIG_PM_PARTITION_SIZE_TFM` is set to 256 kB and the TF-M binary uses 32 kB of the available space.
+Similarly the ``tfm_secure`` partition :kconfig:option:`CONFIG_PM_PARTITION_SIZE_TFM_SRAM` is set to 88 kB and the TF-M binary uses 5 kB of the available space.
+This information can be used to optimize the size of the TF-M, as long as it is within the alignment requirements explained in the previous section.
 
-To see more detailed information about the memory usage, refer to :ref:`tfm_build_system` documentation.
-Build system offers tools like ``tfm_ram_report`` and ``tfm_rom_report`` to analyze the RAM and ROM usage in generated images.
+Tools for analyzing the ``tfm_secure`` partition size
+-----------------------------------------------------
+
+TF-M build system provides ``tfm_ram_report`` and ``tfm_rom_report`` targets for analyzing the memory usage of the TF-M partitions inside ``tfm_secure`` partition.
+
+With |NCS|, the following commands can be used to generate the reports:
+
+  .. code-block:: console
+
+     west build -p -b nrf9151dk/nrf9151/ns samples/tfm/tfm_hello_world
+     cd build/tfm_hello_world
+     ninja tfm_ram_report
+     ninja tfm_rom_report
+
+Reports can be used to analyze the memory usage of the different TF-M partitions and how changing the Kconfig options affects the memory usage.
+For more information about the ``tfm_ram_report`` and ``tfm_rom_report`` targets, refer to the :ref:`tfm_build_system` documentation.
 
 .. _tfm_encrypted_its: