boards: st: nucleo_h7s3l8: Add ext_flash_app variant

Add ext_flash_app variant to nucleo_h7s3l8 to allow building
applications running on ext flash.

Based on Erwan Gouriou's work on stm32h7s78_dk in PR zephyrproject-rtos#97992
(which is based on A.Jarmouni's work on stm32h750_dk in PR 97037).

Signed-off-by: Thomas Decker <[email protected]>

Author: TD-JBL

boards/st/nucleo_h7s3l8/Kconfig.sysbuild

@@ -0,0 +1,19 @@
+# Copyright (c) 2024-2025 STMicroelectronics
+# Copyright (c) 2025 JB-Lighting Lichtanlagentechnik
+# SPDX-License-Identifier: Apache-2.0
+
+if BOARD_NUCLEO_H7S3L8_STM32H7S3XX_EXT_FLASH_APP
+
+choice BOOTLOADER
+	default BOOTLOADER_MCUBOOT
+endchoice
+
+choice BOOT_SIGNATURE_TYPE
+	default BOOT_SIGNATURE_TYPE_NONE
+endchoice
+
+choice MCUBOOT_MODE
+	default MCUBOOT_MODE_SWAP_USING_OFFSET
+endchoice
+
+endif # BOARD_NUCLEO_H7S3L8_STM32H7S3XX_EXT_FLASH_APP

boards/st/nucleo_h7s3l8/board.cmake

@@ -2,7 +2,7 @@
 
 # keep first
 board_runner_args(stm32cubeprogrammer "--port=swd" "--reset-mode=hw")
-if(CONFIG_XIP AND (CONFIG_STM32_MEMMAP OR CONFIG_BOOTLOADER_MCUBOOT))
+if(CONFIG_STM32_MEMMAP OR CONFIG_BOOTLOADER_MCUBOOT)
   board_runner_args(stm32cubeprogrammer "--extload=MX25UW25645G_NUCLEO-H7S3L8.stldr")
 endif()
 board_runner_args(openocd --target-handle=_CHIPNAME.cpu0)

boards/st/nucleo_h7s3l8/board.yml

@@ -4,3 +4,5 @@ board:
   vendor: st
   socs:
     - name: stm32h7s3xx
+      variants:
+        - name: ext_flash_app

boards/st/nucleo_h7s3l8/doc/index.rst

@@ -213,6 +213,7 @@ the ``--runner`` (or ``-r``) option:
 .. code-block:: console
 
    $ west flash --runner openocd
+   $ west flash --runner jlink
 
 Flashing an application to Nucleo H7S3L8
 ----------------------------------------
@@ -255,7 +256,7 @@ Blinky example can also be used:
    :goals: build flash
 
 Debugging
-=========
+---------
 
 You can debug an application in the usual way.  Here is an example for the
 :zephyr:code-sample:`hello_world` application.
@@ -266,6 +267,112 @@ You can debug an application in the usual way.  Here is an example for the
    :maybe-skip-config:
    :goals: debug
 
+Application in External Flash
+=============================
+
+Because of the limited amount of SoC Flash (64KB), you may want to store the application
+in external OSPI Flash instead, and run it from there. In that case, the MCUboot bootloader
+is needed to chainload the application. A dedicate board variant, ``ext_flash_app``, was created
+for this usecase.
+
+:ref:`sysbuild` makes it possible to build and flash all necessary images needed to run a user application
+from external Flash.
+
+The following example shows how to build :zephyr:code-sample:`hello_world` with Sysbuild enabled:
+
+.. zephyr-app-commands::
+   :tool: west
+   :zephyr-app: samples/hello_world
+   :board: nucleo_h7s3l8/stm32h7s3xx/ext_flash_app
+   :goals: build
+   :west-args: --sysbuild
+
+By default, Sysbuild creates MCUboot and user application images.
+
+Build directory structure created by Sysbuild is different from traditional
+Zephyr build. Output is structured by the domain subdirectories:
+
+.. code-block::
+
+  build/
+  ├── hello_world
+  |    └── zephyr
+  │       ├── zephyr.elf
+  │       ├── zephyr.hex
+  │       ├── zephyr.bin
+  │       ├── zephyr.signed.bin
+  │       └── zephyr.signed.hex
+  ├── mcuboot
+  │    └── zephyr
+  │       ├── zephyr.elf
+  │       ├── zephyr.hex
+  │       └── zephyr.bin
+  └── domains.yaml
+
+.. note::
+
+   With ``--sysbuild`` option, MCUboot will be re-built every time the pristine build is used,
+   but only needs to be flashed once if none of the MCUboot configs are changed.
+
+For more information about the system build please read the :ref:`sysbuild` documentation.
+
+Both MCUboot and user application images can be flashed by running:
+
+.. code-block:: console
+
+   $ west flash
+
+You should see the following message in the serial host program:
+
+.. code-block:: console
+
+   *** Booting MCUboot v2.2.0-224-g0a52195c8181 ***
+   *** Using Zephyr OS build v4.3.0-937-ge0490cf53e03 ***
+   I: Starting bootloader
+   I: Image index: 0, Swap type: none
+   I: Image index: 0, Swap type: none
+   I: Primary image: magic=unset, swap_type=0x1, copy_done=0x3, image_ok=0x3
+   I: Secondary image: magic=unset, swap_type=0x1, copy_done=0x3, image_ok=0x3
+   I: Boot source: none
+   I: Image index: 0, Swap type: none
+   I: Image index: 0, Swap type: none
+   I: Image index: 0, Swap type: none
+   I: Image index: 0, Swap type: none
+   I: Bootloader chainload address offset: 0x0
+   I: Image version: v0.0.0
+   I: Jumping to the first image slot
+   *** Booting Zephyr OS build v4.3.0-937-ge0490cf53e03 ***
+   Hello World! nucleo_h7s3l8/stm32h7s3xx/ext_flash_app
+
+To only flash the user application in the subsequent builds, Use:
+
+.. code-block:: console
+
+   $ west flash --domain hello_world
+
+With the default configuration, the board uses MCUboot's Swap-using-offset mode.
+To get more information about the different MCUboot operating modes and how to
+perform application upgrade, refer to `MCUboot design`_.
+To learn more about how to secure the application images stored in external Flash,
+refer to `MCUboot Encryption`_.
+
+Debugging
+---------
+
+You can debug the application in external flash using ``west`` and ``GDB``.
+
+After flashing MCUboot and the app, execute the following command:
+
+.. code-block:: console
+
+   $ west debugserver
+
+Then, open another terminal (don't forget to activate Zephyr's environment) and execute:
+
+.. code-block:: console
+
+   $ west attach
+
 .. _Nucleo H7S3L8 website:
    https://www.st.com/en/evaluation-tools/nucleo-h7s3l8.html
 

boards/st/nucleo_h7s3l8/nucleo_h7s3l8-common.dtsi

@@ -0,0 +1,233 @@
+/*
+ * Copyright (c) 2024 STMicroelectronics
+ * Copyright (c) 2025 JB-Lighting Lichtanlagentechnik
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/dts-v1/;
+#include <st/h7rs/stm32h7s3X8.dtsi>
+#include <st/h7/stm32h7s3l8hx-pinctrl.dtsi>
+#include "arduino_r3_connector.dtsi"
+#include <zephyr/dt-bindings/input/input-event-codes.h>
+
+/ {
+	chosen {
+		zephyr,console = &usart3;
+		zephyr,shell-uart = &usart3;
+		zephyr,dtcm = &dtcm;
+		zephyr,sram = &sram0;
+		zephyr,canbus = &fdcan1;
+	};
+
+	leds: leds {
+		compatible = "gpio-leds";
+
+		green_led: led_1 {
+			gpios = <&gpiod 10 GPIO_ACTIVE_HIGH>;
+			label = "User LD1";
+		};
+
+		yellow_led: led_2 {
+			gpios = <&gpiod 13 GPIO_ACTIVE_HIGH>;
+			label = "User LD2";
+		};
+
+		red_led: led_3 {
+			gpios = <&gpiob 7 GPIO_ACTIVE_HIGH>;
+			label = "User LD3";
+		};
+	};
+
+	gpio_keys {
+		compatible = "gpio-keys";
+
+		user_button: button_0 {
+			label = "User";
+			gpios = <&gpioc 13 GPIO_ACTIVE_HIGH>;
+			zephyr,code = <INPUT_KEY_0>;
+		};
+	};
+
+	aliases {
+		led0 = &green_led;
+		led1 = &yellow_led;
+		led2 = &red_led;
+		sw0 = &user_button;
+		watchdog0 = &iwdg;
+		spi-flash0 = &mx25uw25645;
+	};
+
+	ext_memory: memory@70000000 {
+		compatible = "zephyr,memory-region";
+		reg = <0x70000000 DT_SIZE_M(32)>;
+		zephyr,memory-region = "EXTMEM";
+		zephyr,memory-attr = <DT_MEM_ARM(ATTR_MPU_FLASH)>;
+	};
+};
+
+&clk_hse {
+	clock-frequency = <DT_FREQ_M(24)>;
+	status = "okay";
+};
+
+&clk_lse {
+	status = "okay";
+};
+
+&pll {
+	div-m = <12>;
+	mul-n = <200>;
+	div-p = <2>;
+	div-q = <2>;
+	div-r = <2>;
+	div-s = <2>;
+	div-t = <2>;
+	clocks = <&clk_hse>;
+	status = "okay";
+};
+
+/* PLL2 for clocking the xspi peripheral */
+&pll2 {
+	div-m = <12>;
+	mul-n = <200>;
+	div-p = <2>;
+	div-q = <2>;
+	div-r = <2>;
+	div-s = <2>;
+	div-t = <2>;
+	clocks = <&clk_hse>;
+	status = "okay";
+};
+
+&rcc {
+	clocks = <&pll>;
+	clock-frequency = <DT_FREQ_M(200)>;
+	dcpre = <1>;
+	hpre = <1>;
+	ppre1 = <2>;
+	ppre2 = <2>;
+	ppre4 = <2>;
+	ppre5 = <2>;
+};
+
+&pwr {
+	power-supply = "ldo";
+};
+
+&usart1 {
+	pinctrl-0 = <&usart1_tx_pb14 &usart1_rx_pa10>;
+	pinctrl-names = "default";
+	current-speed = <115200>;
+	status = "okay";
+};
+
+&usart3 {
+	pinctrl-0 = <&usart3_tx_pd8 &usart3_rx_pd9>;
+	pinctrl-names = "default";
+	current-speed = <115200>;
+	status = "okay";
+};
+
+&iwdg {
+	status = "okay";
+};
+
+&wwdg {
+	status = "okay";
+};
+
+&adc1 {
+	pinctrl-0 = <&adc1_inp15_pa3>; /* Arduino A0 */
+	pinctrl-names = "default";
+	st,adc-clock-source = "SYNC";
+	st,adc-prescaler = <4>;
+	status = "okay";
+};
+
+&spi1 {
+	status = "okay";
+	pinctrl-0 = <&spi1_sck_pa5 &spi1_miso_pa6 &spi1_mosi_pb5>;
+	pinctrl-names = "default";
+	cs-gpios = <&gpiod 14 (GPIO_ACTIVE_LOW | GPIO_PULL_UP)>;
+};
+
+&i2c1 {
+	pinctrl-0 = <&i2c1_scl_pb8 &i2c1_sda_pb9>;
+	pinctrl-names = "default";
+	status = "okay";
+	clock-frequency = <I2C_BITRATE_FAST>;
+};
+
+&fdcan1 {
+	pinctrl-0 = <&fdcan1_rx_pd0 &fdcan1_tx_pd1>;
+	pinctrl-names = "default";
+	clocks = <&rcc STM32_CLOCK(APB1_2, 8)>,
+		 <&rcc STM32_SRC_HSE FDCAN_SEL(0)>;
+	status = "okay";
+};
+
+&mac {
+	pinctrl-0 = <&eth_rmii_rxd0_pg4
+		     &eth_rmii_rxd1_pg5
+		     &eth_rmii_ref_clk_pb6
+		     &eth_rmii_crs_dv_pa7
+		     &eth_rmii_tx_en_pg11
+		     &eth_rmii_txd0_pg13
+		     &eth_rmii_txd1_pg12>;
+	pinctrl-names = "default";
+	phy-connection-type = "rmii";
+	phy-handle = <&eth_phy>;
+	status = "okay";
+};
+
+&mdio {
+	pinctrl-0 = <&eth_mdio_pa2 &eth_mdc_pg6>;
+	pinctrl-names = "default";
+	status = "okay";
+
+	eth_phy: ethernet-phy@0 {
+		compatible = "ethernet-phy";
+		reg = <0x00>;
+	};
+};
+
+&xspi2 {
+	pinctrl-0 = <&xspim_p2_clk_pn6 &xspim_p2_ncs1_pn1
+		     &xspim_p2_io0_pn2 &xspim_p2_io1_pn3
+		     &xspim_p2_io2_pn4 &xspim_p2_io3_pn5
+		     &xspim_p2_io4_pn8 &xspim_p2_io5_pn9
+		     &xspim_p2_io6_pn10 &xspim_p2_io7_pn11
+		     &xspim_p2_dqs0_pn0>;
+	pinctrl-names = "default";
+
+	status = "okay";
+
+	ext_flash_ctrl: xspi-nor-flash@0 {
+		compatible = "st,stm32-xspi-nor";
+		reg = <0>;
+		size = <DT_SIZE_M(256)>; /* 256Mbits */
+		ospi-max-frequency = <DT_FREQ_M(50)>;
+		spi-bus-width = <XSPI_OCTO_MODE>;
+		data-rate = <XSPI_DTR_TRANSFER>;
+		four-byte-opcodes;
+		status = "okay";
+
+		#address-cells = <1>;
+		#size-cells = <1>;
+		ranges = <0x0 0x70000000 DT_SIZE_M(32)>;
+
+		ext_flash: mx25uw25645: xspi-nor-flash@0 {
+			compatible = "soc-nv-flash";
+			reg = <0x0 DT_SIZE_M(32)>;
+			write-block-size = <1>;
+			erase-block-size = <DT_SIZE_K(4)>;
+
+			partitions {
+				compatible = "fixed-partitions";
+				#address-cells = <1>;
+				#size-cells = <1>;
+			};
+		};
+	};
+};