stm32mp257f_dk: add m33 support

boards/st/stm32mp257f_dk/Kconfig.stm32mp257f_dk

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+# Copyright (C) 2025 Savoir-faire Linux, Inc.
+# SPDX-License-Identifier: Apache-2.0
+
+config BOARD_STM32MP257F_DK
+	select SOC_STM32MP2X_M33 if BOARD_STM32MP257F_DK_STM32MP257FXX_M33

boards/st/stm32mp257f_dk/board.cmake

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+# Copyright (C) 2025 Savoir-faire Linux, Inc.
+# SPDX-License-Identifier: Apache-2.0
+
+if(CONFIG_BOARD_STM32MP257F_DK_STM32MP257FXX_M33)
+  board_runner_args(
+    openocd "--config=${BOARD_DIR}/support/openocd_stm32mp257f_dk_m33.cfg")
+  board_runner_args(openocd "--gdb-init=target extended-remote :3334")
+endif()
+
+include(${ZEPHYR_BASE}/boards/common/openocd.board.cmake)

boards/st/stm32mp257f_dk/board.yml

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+board:
+  name: stm32mp257f_dk
+  full_name: STM32MP257F-DK Discovery Kit
+  vendor: st
+  socs:
+    - name: stm32mp257fxx

boards/st/stm32mp257f_dk/doc/index.rst

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+.. zephyr:board:: stm32mp257f_dk
+
+Overview
+********
+
+The STM32MP257F-DK Discovery kit is designed as a complete demonstration
+and development platform for the STMicroelectronics STM32MP257F microprocessor
+based on Arm |reg| dual-core Cortex |reg|-A35 (1.5 GHz) and Cortex |reg|-M33
+(400 MHz), and the STPMIC25 companion chip.
+Zephyr OS is ported to run on the Cortex |reg|-M33 core, as a coprocessor of
+the Cortex |reg|-A35 core.
+
+Features:
+=========
+
+- STM32MP257FAI3 microprocessor featuring dual-core Arm |reg| Cortex |reg|-A35,
+  a Cortex |reg|-M33 in a VFBGA424 package
+- ST power management STPMIC25
+- 32‑Gbit LPDDR4 DRAM
+- 64-Gbit eMMC v5.1
+- 1‑Gbit/s Ethernet (RGMII)
+- Two USB 2.0 high speed
+- USB 3.0 SuperSpeed PD (DRP/DRD)
+- Wi‑Fi® 802.11b/g/n
+- Bluetooth® LE
+- Four user LEDs
+- Two user, one tamper, and one reset push-buttons
+- Wake-up button
+- Four boot pin switches
+- Board connectors:
+
+  - Ethernet RJ45
+  - Two stacked USB 2.0 HS Type-A
+  - USB 3.0 USB Type-C |reg| PD
+  - microSD |trade| card holder
+  - Dual-lane MIPI CSI-2 |reg| camera module expansion connector
+  - HDMI |reg|
+  - LVDS
+  - GPIO expansion connector
+  - VBAT for power backup
+
+- On-board STLINK-V3EC:
+
+  - Debugger with USB re-enumeration capability: Virtual COM port and debug port
+  - Board power source through USB Type-C |reg|
+
+- Mainlined open-source Linux |reg| STM32 MPU OpenSTLinux Distribution and
+  STM32CubeMP2 software with examples
+- Linux |reg| Yocto project |reg|, Buildroot, and STM32CubeIDE as
+  development environments
+
+More information about the board can be found at the
+`STM32MP257F-DK website`_.
+
+Hardware
+********
+
+Cores:
+======
+
+- 64-bit dual-core Arm |reg| Cortex |reg|-A35 with 1.5 GHz max frequency
+  - 32-Kbyte I + 32-Kbyte D level 1 cache for each Cortex |reg|-A35 core
+  - 512-Kbyte unified level 2 cache
+  - Arm |reg| NEON |trade| and Arm |reg| TrustZone |reg|
+- 32-bit Arm |reg| Cortex |reg|-M33 with FPU/MPU, Arm |reg| TrustZone |reg|,
+  and 400 MHz max frequency
+  - L1 16-Kbyte ICache / 16-Kbyte DCache for Cortex |reg|-M33
+
+Memories:
+=========
+
+- External DDR memory up to 4 Gbytes
+  - Up to DDR3L-2133 16/32-bit
+  - Up to DDR4-2400 16/32-bit
+  - Up to LPDDR4-2400 16/32-bit
+- 808-Kbyte internal SRAM: 256-Kbyte AXI SYSRAM, 128-Kbyte AXI video RAM or
+  SYSRAM extension, 256-Kbyte AHB SRAM, 128-Kbyte AHB SRAM with ECC in backup
+  domain, 8-Kbyte SRAM with ECC in backup domain, 32 Kbytes in SmartRun domain
+- Two Octo-SPI memory interfaces
+- Flexible external memory controller with up to 16-bit data bus: parallel
+  interface to connect external ICs, and SLC NAND memories with up to 8-bit ECC
+
+Power
+=====
+
+- STPMIC25 for voltage regulation (multiple buck/LDO regulators)
+- USB-C power input
+
+Clock management
+================
+
+- External oscillators:
+  - 32.768 kHz LSE crystal
+  - 40 MHz HSE crystal
+- Internal oscillators:
+  - 64 MHz HSI oscillator
+  - 4 MHz CSI oscillator
+  - 32 kHz LSI oscillator
+  - Five separate PLLs with integer and fractional mode
+
+Security/Safety
+===============
+
+- Secure boot, TrustZone |reg| peripherals, active tamper, environmental
+  monitors, display secure layers, hardware accelerators
+- Complete resource isolation framework
+
+Connectivity
+============
+
+- 1x Gigabit Ethernet (RGMII)
+- USB 2.0 High-Speed Host (dual-port)
+- USB Type-C |reg| DRP
+- GPIO expansion connector
+
+Display & Camera
+================
+
+- LVDS interface (4-lane)
+- Camera CSI-2 interface (2-lane)
+
+Debug
+=====
+
+- STLINK-V3EC (onboard debugger with VCP, JTAG and SWD)
+
+More information about STM32MP257F can be found here:
+
+- `STM32MP257F on www.st.com`_
+
+Supported Features
+==================
+
+.. zephyr:board-supported-hw::
+
+Connections and IOs
+===================
+
+STM32MP257F-DK Discovery kit schematic is available here:
+`STM32MP257F-DK Discovery kit schematics`_
+
+System Clock
+============
+
+Cortex |reg|-A35
+----------------
+
+Not yet supported in Zephyr.
+
+Cortex |reg|-M33
+----------------
+
+The Cortex |reg|-M33 Core is configured to run at a 400 MHz clock speed.
+
+Programming and Debugging
+*************************
+
+.. zephyr:board-supported-runners::
+
+Prerequisite
+============
+
+Before you can run Zephyr on the STM32MP257F-DK Discovery kit, you need to
+set up the Cortex |reg|-A35 core with a Linux |reg| environment. The Cortex
+|reg|-M33 core runs Zephyr as a coprocessor, and it requires the Cortex
+|reg|-A35 to load and start the firmware using remoteproc.
+
+One way to set up the Linux environment is to use the official ST
+OpenSTLinux distribution, following the `Starter Package`_. (more information
+about the procedure can be found in the `STM32MPU Wiki`_)
+
+Loading the firmware
+====================
+
+Once the OpenSTLinux distribution is installed on the board, the Cortex |reg|
+-A35 is responsible (in the current distribution) for loading the Zephyr
+firmware image in DDR and/or SRAM and starting the Cortex |reg| -M33 core. The
+application can be built using west, taking the :zephyr:code-sample:`blinky` as
+an example.
+
+.. zephyr-app-commands::
+   :zephyr-app: samples/basic/blinky
+   :board: stm32mp257f_dk/stm32mp257fxx/m33
+   :goals: build
+
+The firmware can be copied to the board file system and started with the Linux
+remoteproc framework. (more information about the procedure can be found in the
+`STM32MP257F boot Cortex-M33 firmware`_)
+
+Debugging
+=========
+Applications can be debugged using OpenOCD and GDB. The OpenOCD files can be
+found at `device-stm-openocd`_.
+The firmware must first be started by the Cortex |reg|-A35. The debugger can
+then be attached to the running Zephyr firmware using OpenOCD.
+
+- Build the sample:
+
+.. zephyr-app-commands::
+   :zephyr-app: samples/basic/blinky
+   :board: stm32mp257f_dk/stm32mp257fxx/m33
+   :goals: build
+
+- Copy the firmware to the board, load it and start it with remoteproc
+  (`STM32MP257F boot Cortex-M33 firmware`_). The orange LED should be blinking.
+- Attach to the target:
+
+.. code-block:: console
+
+   $ west attach
+
+References
+==========
+
+.. target-notes::
+
+.. _STM32MP257F-DK website:
+  https://www.st.com/en/evaluation-tools/stm32mp257f-dk.html#overview
+
+.. _STM32MP257F-DK Discovery kit User Manual:
+  https://www.st.com/resource/en/user_manual/um3385-discovery-kit-with-stm32mp257f-mpu-stmicroelectronics.pdf
+
+.. _STM32MP257F-DK Discovery kit schematics:
+  https://www.st.com/resource/en/schematic_pack/mb1605-mp257f-c01-schematic.pdf
+
+.. _STM32MP25xC/F Discovery kit datasheet:
+  https://www.st.com/resource/en/datasheet/stm32mp257c.pdf
+
+.. _STM32MP257F on www.st.com:
+  https://www.st.com/en/microcontrollers-microprocessors/stm32mp257f.html
+
+.. _STM32MP257F reference manual:
+  https://www.st.com/resource/en/reference_manual/rm0457-stm32mp25xx-advanced-armbased-3264bit-mpus-stmicroelectronics.pdf
+
+.. _STM32MP257F boot Cortex-M33 firmware:
+  https://wiki.st.com/stm32mpu/wiki/Linux_remoteproc_framework_overview#Remote_processor_boot_through_sysfs
+
+.. _Starter Package:
+  https://wiki.stmicroelectronics.cn/stm32mpu/wiki/STM32MP25_Discovery_kits_-_Starter_Package
+
+.. _STM32MPU Wiki:
+  https://wiki.st.com/stm32mpu/wiki/Main_Page
+
+.. _device-stm-openocd:
+  https://github.com/STMicroelectronics/device-stm-openocd/tree/main

boards/st/stm32mp257f_dk/stm32mp257f_dk_stm32mp257fxx_m33.dts

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+/*
+ * Copyright (C) 2025 Savoir-faire Linux, Inc.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/dts-v1/;
+#include <st/mp2/stm32mp257_m33.dtsi>
+#include <st/mp2/stm32mp257faix-pinctrl.dtsi>
+#include <zephyr/dt-bindings/input/input-event-codes.h>
+
+/ {
+	model = "STMicroelectronics STM32MP257F-DK board";
+	compatible = "st,stm32mp257f-dk", "st,stm32mp25";
+
+	chosen {
+		zephyr,console = &uart5;
+		zephyr,flash = &ddr_code;
+		zephyr,shell-uart = &uart5;
+		zephyr,sram = &ddr_sys;
+	};
+
+	leds {
+		compatible = "gpio-leds";
+
+		orange_led_9: led_9 {
+			gpios = <&gpioh 6 GPIO_ACTIVE_HIGH>;
+			label = "LD9";
+		};
+	};
+
+	gpio_keys {
+		compatible = "gpio-keys";
+
+		button_user2: button4 {
+			gpios = <&gpioc 11 GPIO_ACTIVE_LOW>;
+			label = "User 2";
+			zephyr,code = <INPUT_KEY_0>;
+		};
+	};
+
+	aliases {
+		led0 = &orange_led_9;
+		sw0 = &button_user2;
+	};
+};
+
+&rcc {
+	clock-frequency = <DT_FREQ_M(400)>;
+};
+
+&gpioc {
+	status = "okay";
+};
+
+&gpiof {
+	status = "okay";
+};
+
+&gpiog {
+	status = "okay";
+};
+
+&gpioh {
+	status = "okay";
+};
+
+&uart5 {
+	pinctrl-0 = <&uart5_tx_pg9 &uart5_rx_pg10>;
+	pinctrl-names = "default";
+	current-speed = <115200>;
+	status = "okay";
+};
+
+&usart6 {
+	pinctrl-0 = <&usart6_tx_pf13 &usart6_rx_pf14>;
+	pinctrl-names = "default";
+	current-speed = <115200>;
+	status = "okay";
+};

boards/st/stm32mp257f_dk/stm32mp257f_dk_stm32mp257fxx_m33.yaml

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+identifier: stm32mp257f_dk/stm32mp257fxx/m33
+name: STM32MP257F_DK
+type: mcu
+arch: arm
+toolchain:
+  - zephyr
+  - gccarmemb
+supported:
+  - LED
+  - gpio
+  - shell
+testing:
+  ignore_tags:
+    - cmsis_rtos_v2
+    - net
+    - mpu
+    - tinycrypt
+    - crypto
+    - aes
+    - cmm
+    - nfc
+ram: 8192
+flash: 8192
+vendor: st

boards/st/stm32mp257f_dk/stm32mp257f_dk_stm32mp257fxx_m33_defconfig

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+# Copyright (C) 2025 Savoir-faire Linux, Inc.
+# SPDX-License-Identifier: Apache-2.0
+
+# Enable MPU
+CONFIG_ARM_MPU=y
+
+# Enable GPIO
+CONFIG_GPIO=y
+
+# Enable HW stack protection
+CONFIG_HW_STACK_PROTECTION=y
+
+# Enable UART driver
+CONFIG_SERIAL=y
+CONFIG_UART_INTERRUPT_DRIVEN=y
+
+# UART console
+CONFIG_CONSOLE=y
+CONFIG_UART_CONSOLE=y