board: nrf: Add nRF54LM20DK board

# Copyright (c) 2025 Nordic Semiconductor ASA

# SPDX-License-Identifier: Apache-2.0

if BOARD_NRF54LM20DK_NRF54LM20A_CPUAPP

config ROM_START_OFFSET

	default 0x800 if BOOTLOADER_MCUBOOT

endif # BOARD_NRF54LM20DK_NRF54LM20A_CPUAPP

# Copyright (c) 2025 Nordic Semiconductor ASA

# SPDX-License-Identifier: Apache-2.0

config BOARD_NRF54LM20DK

	select SOC_NRF54LM20A_ENGA_CPUAPP if BOARD_NRF54LM20DK_NRF54LM20A_CPUAPP

	select SOC_NRF54LM20A_ENGA_CPUFLPR if BOARD_NRF54LM20DK_NRF54LM20A_CPUFLPR

# Copyright (c) 2025 Nordic Semiconductor ASA

# SPDX-License-Identifier: Apache-2.0

if(CONFIG_SOC_NRF54LM20A_ENGA_CPUAPP)

  board_runner_args(jlink "--device=cortex-m33" "--speed=4000")

elseif(CONFIG_SOC_NRF54LM20A_ENGA_CPUFLPR)

  board_runner_args(jlink "--speed=4000")

endif()

include(${ZEPHYR_BASE}/boards/common/nrfutil.board.cmake)

include(${ZEPHYR_BASE}/boards/common/jlink.board.cmake)

board:

  name: nrf54lm20dk

  full_name: nRF54LM20 DK

  vendor: nordic

  socs:

  - name: nrf54lm20a

    variants:

    - name: xip

      cpucluster: cpuflpr

runners:

  run_once:

    '--recover':

    - runners:

      - nrfjprog

      - nrfutil

      run: first

      groups:

      - boards:

        - nrf54lm20dk/nrf54lm20a/cpuapp

        - nrf54lm20dk/nrf54lm20a/cpuflpr

        - nrf54lm20dk/nrf54lm20a/cpuflpr/xip

    '--erase':

    - runners:

      - nrfjprog

      - jlink

      - nrfutil

      run: first

      groups:

      - boards:

        - nrf54lm20dk/nrf54lm20a/cpuapp

        - nrf54lm20dk/nrf54lm20a/cpuflpr

        - nrf54lm20dk/nrf54lm20a/cpuflpr/xip

    '--reset':

    - runners:

      - nrfjprog

      - jlink

      - nrfutil

      run: last

      groups:

      - boards:

        - nrf54lm20dk/nrf54lm20a/cpuapp

        - nrf54lm20dk/nrf54lm20a/cpuflpr

        - nrf54lm20dk/nrf54lm20a/cpuflpr/xip

.. zephyr:board:: nrf54lm20dk

Overview

********

The nRF54LM20 Development Kit hardware provides support for the Nordic Semiconductor

nRF54LM20A Arm Cortex-M33 CPU and the following devices:

* :abbr:`SAADC (Successive Approximation Analog to Digital Converter)`

* CLOCK

* RRAM

* :abbr:`GPIO (General Purpose Input Output)`

* :abbr:`TWIM (I2C-compatible two-wire interface master with EasyDMA)`

* MEMCONF

* :abbr:`MPU (Memory Protection Unit)`

* :abbr:`NVIC (Nested Vectored Interrupt Controller)`

* :abbr:`PWM (Pulse Width Modulation)`

* :abbr:`GRTC (Global real-time counter)`

* Segger RTT (RTT Console)

* :abbr:`SPI (Serial Peripheral Interface)`

* :abbr:`UARTE (Universal asynchronous receiver-transmitter)`

* :abbr:`WDT (Watchdog Timer)`

Hardware

********

nRF54LM20 DK has two crystal oscillators:

* High-frequency 32 MHz crystal oscillator (HFXO)

* Low-frequency 32.768 kHz crystal oscillator (LFXO)

The crystal oscillators can be configured to use either

internal or external capacitors.

Supported Features

==================

.. zephyr:board-supported-hw::

Programming and Debugging

*************************

.. zephyr:board-supported-runners::

Applications for the ``nrf54lm20dk/nrf54lm20a/cpuapp`` board target can be

built, flashed, and debugged in the usual way. See

:ref:`build_an_application` and :ref:`application_run` for more details on

building and running.

Applications for the ``nrf54lm20dk/nrf54lm20a/cpuflpr`` board target need

to be built using sysbuild to include the ``vpr_launcher`` image for the application core.

Enter the following command to compile ``hello_world`` for the FLPR core:

.. code-block:: console

   west build -p -b nrf54lm20dk/nrf54lm20a/cpuflpr --sysbuild

Flashing

========

As an example, this section shows how to build and flash the :zephyr:code-sample:`hello_world`

application.

.. warning::

   When programming the device, you might get an error similar to the following message::

    ERROR: The operation attempted is unavailable due to readback protection in

    ERROR: your device. Please use --recover to unlock the device.

   This error occurs when readback protection is enabled.

   To disable the readback protection, you must *recover* your device.

   Enter the following command to recover the core::

    west flash --recover

   The ``--recover`` command erases the flash memory and then writes a small binary into

   the recovered flash memory.

   This binary prevents the readback protection from enabling itself again after a pin

   reset or power cycle.

Follow the instructions in the :ref:`nordic_segger` page to install

and configure all the necessary software. Further information can be

found in :ref:`nordic_segger_flashing`.

To build and program the sample to the nRF54LM20 DK, complete the following steps:

First, connect the nRF54LM20 DK to you computer using the IMCU USB port on the DK.

Next, build the sample by running the following command:

.. zephyr-app-commands::

   :zephyr-app: samples/hello_world

   :board: nrf54lm20dk/nrf54lm20a/cpuapp

   :goals: build flash

Testing the LEDs and buttons in the nRF54LM20 DK

************************************************

Test the nRF54LM20 DK with a :zephyr:code-sample:`blinky` sample.