doc: Updated nRF54H20 keys docs

Updated nRF54H20 keys docs.

Signed-off-by: Francesco Domenico Servidio <[email protected]>

Author: FrancescoSer

doc/nrf/app_dev/device_guides/nrf54h/ug_nrf54h20_custom_pcb.rst

@@ -26,6 +26,8 @@ It is highly recommended to use the PCB layouts and component values provided by
 * The **P9** port cannot be used with internal or external pull-down resistors.
 * For optimal performance, the output impedance of the **P6** and **P7** ports should match the PCB and external device pin impedance.
 
+.. _ug_nrf54h20_custom_pcb_board:
+
 Prepare the configuration files for your custom board in the |NCS|
 ******************************************************************
 
@@ -47,6 +49,8 @@ See the following documentation pages for more information:
 
    See :ref:`zephyr:board_porting_guide` for more information.
 
+.. _ug_nrf54h20_custom_pcb_bicr:
+
 Configure, generate, and program the BICR
 *****************************************
 

doc/nrf/app_dev/device_guides/nrf54h/ug_nrf54h20_ironside.rst

@@ -698,6 +698,8 @@ The UICR.WDTSTART configuration consists of three sub-registers:
   This value determines the watchdog timeout period.
   The CRV must be at least 15 (0xF) to ensure proper watchdog operation.
 
+.. _ug_nrf54h20_ironside_uicr_securestorage:
+
 UICR.SECURESTORAGE
 ==================
 

doc/nrf/app_dev/device_guides/nrf54h/ug_nrf54h20_keys.rst

@@ -7,6 +7,22 @@ Provisioning keys on the nRF54H20 SoC
    :local:
    :depth: 2
 
+This guide describes how to generate and provision cryptographic public keys on an nRF54H20 SoC in the Root of Trust (RoT) lifecycle state.
+It is intended for developers defining manifest signing keys for the application core, radio core, and OEM root.
+A successful provisioning makes the keys available to Secure Domain Firmware through PSA Crypto key identifiers.
+
+Prerequisites
+=============
+
+To follow this guide, your nRF54H20 device must meet the following requirement:
+
+* On the nRF54H20 DK, you must :ref:`provision <ug_nrf54h20_gs_bringup_soc_bin>` the DK as described in the :ref:`ug_nrf54h20_gs` page.
+* On a custom nRF54H20-based device, you must :ref:`configure, generate, and program the BICR <ug_nrf54h20_custom_pcb_bicr>` as described in the :ref:`ug_nrf54h20_custom_pcb` page.
+* You must configure :ref:`ug_nrf54h20_ironside_uicr_securestorage` in your |ISE| UICR configuration.
+
+Overview
+========
+
 The keys provisioning workflow for the nRF54H20 SoC consists of two main steps:
 
 1. Generating the required metadata using a script provided with the |NCS|.