boards: esp8684_devkitm: Add support

Add support for board esp8684_devkitm

Signed-off-by: Raffael Rostagno <raffael.rostagno@espressif.com>

boards/espressif/esp8684_devkitm/Kconfig.defconfig

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+# ESP8684 devkitm board configuration
+
+# Copyright (c) 2024 Espressif Systems (Shanghai) Co., Ltd.
+# SPDX-License-Identifier: Apache-2.0
+
+config HEAP_MEM_POOL_ADD_SIZE_BOARD
+	int
+	default 65535 if WIFI && BT
+	default 51200 if WIFI
+	default 40960 if BT
+	default 4096

boards/espressif/esp8684_devkitm/Kconfig.esp8684_devkitm

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+# ESP8684 devkitm board configuration
+
+# Copyright (c) 2024 Espressif Systems (Shanghai) Co., Ltd.
+# SPDX-License-Identifier: Apache-2.0
+
+config BOARD_ESP8684_DEVKITM
+	select SOC_ESP8684_MINI_H4

boards/espressif/esp8684_devkitm/Kconfig.sysbuild

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+# Copyright (c) 2024 Espressif Systems (Shanghai) Co., Ltd.
+# SPDX-License-Identifier: Apache-2.0
+
+choice BOOTLOADER
+	default BOOTLOADER_MCUBOOT
+endchoice
+
+choice BOOT_SIGNATURE_TYPE
+	default BOOT_SIGNATURE_TYPE_NONE
+endchoice

boards/espressif/esp8684_devkitm/board.cmake

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+# SPDX-License-Identifier: Apache-2.0
+
+if(NOT "${OPENOCD}" MATCHES "^${ESPRESSIF_TOOLCHAIN_PATH}/.*")
+  set(OPENOCD OPENOCD-NOTFOUND)
+endif()
+find_program(OPENOCD openocd PATHS ${ESPRESSIF_TOOLCHAIN_PATH}/openocd-esp32/bin NO_DEFAULT_PATH)
+
+include(${ZEPHYR_BASE}/boards/common/esp32.board.cmake)
+include(${ZEPHYR_BASE}/boards/common/openocd.board.cmake)

boards/espressif/esp8684_devkitm/board.yml

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+board:
+  name: esp8684_devkitm
+  vendor: espressif
+  socs:
+  - name: esp32c2

boards/espressif/esp8684_devkitm/doc/index.rst

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+.. _esp8684_devkitm:
+
+ESP32-C2
+########
+
+Overview
+********
+
+ESP32-C2 (ESP8684 core) is a low-cost, Wi-Fi 4 & Bluetooth 5 (LE) chip. Its unique design
+makes the chip smaller and yet more powerful than ESP8266. ESP32-C2 is built around a RISC-V
+32-bit, single-core processor, with 272 KB of SRAM (16 KB dedicated to cache) and 576 KB of ROM.
+ESP32-C2 has been designed to target simple, high-volume, and low-data-rate IoT applications,
+such as smart plugs and smart light bulbs. ESP32-C2 offers easy and robust wireless connectivity,
+which makes it the go-to solution for developing simple, user-friendly and reliable
+smart-home devices [1]_.
+
+Features include the following (`ESP8684 Datasheet`_):
+
+- 32-bit core RISC-V microcontroller with a maximum clock speed of 120 MHz
+- 2 MB or 4 MB in chip (ESP8684) or in package (ESP32-C2) flash
+- 272 KB of internal RAM
+- 802.11b/g/n
+- A Bluetooth LE subsystem that supports features of Bluetooth 5 and Bluetooth Mesh
+- Various peripherals:
+
+  - 14 programmable GPIOs
+  - 3 SPI
+  - 2 UART
+  - 1 I2C Master
+  - LED PWM controller, with up to 6 channels
+  - General DMA controller (GDMA)
+  - 1 12-bit SAR ADC, up to 5 channels
+  - 1 temperature sensor
+  - 1 54-bit general-purpose timer
+  - 2 watchdog timers
+  - 1 52-bit system timer
+
+- Cryptographic hardware acceleration (RNG, ECC, RSA, SHA-2, AES)
+
+For detailed information check `ESP8684 Technical Reference Manual`_.
+
+Supported Features
+==================
+
+Current Zephyr's ESP8684-Devkitm board supports the following features:
+
++------------+------------+-------------------------------------+
+| Interface  | Controller | Driver/Component                    |
++============+============+=====================================+
+| UART       | on-chip    | serial port                         |
++------------+------------+-------------------------------------+
+| GPIO       | on-chip    | gpio                                |
++------------+------------+-------------------------------------+
+| PINMUX     | on-chip    | pinmux                              |
++------------+------------+-------------------------------------+
+| Watchdog   | on-chip    | watchdog                            |
++------------+------------+-------------------------------------+
+| TRNG       | on-chip    | entropy                             |
++------------+------------+-------------------------------------+
+| Timers     | on-chip    | counter                             |
++------------+------------+-------------------------------------+
+
+For a getting started user guide, please check `ESP8684 Devkitm User Guide`_.
+
+System requirements
+*******************
+
+Prerequisites
+=============
+
+Espressif HAL requires WiFi and Bluetooth binary blobs in order work. Run the command
+below to retrieve those files.
+
+.. code-block:: console
+
+   west blobs fetch hal_espressif
+
+.. note::
+
+   It is recommended running the command above after :file:`west update`.
+
+Building & Flashing
+*******************
+
+Simple boot
+===========
+
+The board could be loaded using the single binary image, without 2nd stage bootloader.
+It is the default option when building the application without additional configuration.
+
+.. note::
+
+   Simple boot does not provide any security features nor OTA updates.
+
+MCUboot bootloader
+==================
+
+User may choose to use MCUboot bootloader instead. In that case the bootloader
+must be build (and flash) at least once.
+
+There are two options to be used when building an application:
+
+1. Sysbuild
+2. Manual build
+
+.. note::
+
+   User can select the MCUboot bootloader by adding the following line
+   to the board default configuration file.
+
+   .. code:: cfg
+
+      CONFIG_BOOTLOADER_MCUBOOT=y
+
+Sysbuild
+========
+
+The sysbuild makes possible to build and flash all necessary images needed to
+bootstrap the board with the ESP32 SoC.
+
+To build the sample application using sysbuild use the command:
+
+.. zephyr-app-commands::
+   :tool: west
+   :app: samples/hello_world
+   :board: esp8684_devkitm
+   :goals: build
+   :west-args: --sysbuild
+   :compact:
+
+By default, the ESP32 sysbuild creates bootloader (MCUboot) and application
+images. But it can be configured to create other kind of 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.bin
+  ├── mcuboot
+  │    └── zephyr
+  │       ├── zephyr.elf
+  │       └── zephyr.bin
+  └── domains.yaml
+
+.. note::
+
+   With ``--sysbuild`` option the bootloader will be re-build and re-flash
+   every time the pristine build is used.
+
+For more information about the system build please read the :ref:`sysbuild` documentation.
+
+Manual build
+============
+
+During the development cycle, it is intended to build & flash as quickly possible.
+For that reason, images can be build one at a time using traditional build.
+
+The instructions following are relevant for both manual build and sysbuild.
+The only difference is the structure of the build directory.
+
+.. note::
+
+   Remember that bootloader (MCUboot) needs to be flash at least once.
+
+Build and flash applications as usual (see :ref:`build_an_application` and
+:ref:`application_run` for more details).
+
+.. zephyr-app-commands::
+   :zephyr-app: samples/hello_world
+   :board: esp8684_devkitm
+   :goals: build
+
+The usual ``flash`` target will work with the ``esp8684_devkitm`` board
+configuration. Here is an example for the :ref:`hello_world`
+application.
+
+.. zephyr-app-commands::
+   :zephyr-app: samples/hello_world
+   :board: esp8684_devkitm
+   :goals: flash
+
+Open the serial monitor using the following command:
+
+.. code-block:: shell
+
+   west espressif monitor
+
+After the board has automatically reset and booted, you should see the following
+message in the monitor:
+
+.. code-block:: console
+
+   ***** Booting Zephyr OS vx.x.x-xxx-gxxxxxxxxxxxx *****
+   Hello World! esp8684_devkitm
+
+Debugging
+*********
+
+As with much custom hardware, the ESP8684 modules require patches to
+OpenOCD that are not upstreamed yet. Espressif maintains their own fork of
+the project. The custom OpenOCD can be obtained at `OpenOCD ESP32`_
+
+The Zephyr SDK uses a bundled version of OpenOCD by default. You can overwrite that behavior by adding the
+``-DOPENOCD=<path/to/bin/openocd> -DOPENOCD_DEFAULT_PATH=<path/to/openocd/share/openocd/scripts>``
+parameter when building.
+
+Here is an example for building the :ref:`hello_world` application.
+
+.. zephyr-app-commands::
+   :zephyr-app: samples/hello_world
+   :board: esp8684_devkitm
+   :goals: build flash
+   :gen-args: -DOPENOCD=<path/to/bin/openocd> -DOPENOCD_DEFAULT_PATH=<path/to/openocd/share/openocd/scripts>
+
+You can debug an application in the usual way. Here is an example for the :ref:`hello_world` application.
+
+.. zephyr-app-commands::
+   :zephyr-app: samples/hello_world
+   :board: esp8684_devkitm
+   :goals: debug
+
+.. _`OpenOCD ESP32`: https://github.com/espressif/openocd-esp32/releases
+
+References
+**********
+
+.. [1] https://www.espressif.com/en/products/socs/esp8684
+.. _ESP8684 Devkitm User Guide: https://docs.espressif.com/projects/esp-dev-kits/en/latest/esp8684/esp8684-devkitm-1/user_guide.html
+.. _ESP8684 Technical Reference Manual: https://www.espressif.com/sites/default/files/documentation/esp8684_technical_reference_manual_en.pdf
+.. _ESP8684 Datasheet: https://www.espressif.com/sites/default/files/documentation/esp8684_datasheet_en.pdf

boards/espressif/esp8684_devkitm/esp8684_devkitm-pinctrl.dtsi

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+/*
+ * Copyright (c) 2024 Espressif Systems (Shanghai) Co., Ltd.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <zephyr/dt-bindings/pinctrl/esp-pinctrl-common.h>
+#include <dt-bindings/pinctrl/esp32c2-pinctrl.h>
+#include <zephyr/dt-bindings/pinctrl/esp32c2-gpio-sigmap.h>
+
+&pinctrl {
+
+	uart0_default: uart0_default {
+		group1 {
+			pinmux = <UART0_TX_GPIO20>;
+			output-high;
+		};
+		group2 {
+			pinmux = <UART0_RX_GPIO19>;
+			bias-pull-up;
+		};
+	};
+};

boards/espressif/esp8684_devkitm/esp8684_devkitm.dts

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+/*
+ * Copyright (c) 2024 Espressif Systems (Shanghai) Co., Ltd.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/dts-v1/;
+
+#include <espressif/esp32c2/esp8684_mini_h4.dtsi>
+#include "esp8684_devkitm-pinctrl.dtsi"
+#include <zephyr/dt-bindings/input/input-event-codes.h>
+
+/ {
+	model = "Espressif ESP8684-DevkitM";
+	compatible = "espressif,esp32c2";
+
+	chosen {
+		zephyr,sram = &sram0;
+		zephyr,console = &uart0;
+		zephyr,shell-uart = &uart0;
+		zephyr,flash = &flash0;
+		zephyr,code-partition = &slot0_partition;
+	};
+
+	aliases {
+		sw0 = &user_button1;
+		watchdog0 = &wdt0;
+	};
+
+	gpio_keys {
+		compatible = "gpio-keys";
+		user_button1: button_1 {
+			label = "User SW1";
+			gpios = <&gpio0 9 (GPIO_PULL_UP | GPIO_ACTIVE_LOW)>;
+			zephyr,code = <INPUT_KEY_0>;
+		};
+	};
+};
+
+&uart0 {
+	status = "okay";
+	current-speed = <74880>;
+	pinctrl-0 = <&uart0_default>;
+	pinctrl-names = "default";
+};
+
+&trng0 {
+	status = "okay";
+};
+
+&gpio0 {
+	status = "okay";
+};
+
+&wdt0 {
+	status = "okay";
+};
+
+&timer0 {
+	status = "disabled";
+};
+
+&flash0 {
+	status = "okay";
+	partitions {
+		compatible = "fixed-partitions";
+		#address-cells = <1>;
+		#size-cells = <1>;
+
+		/* Reserve 60kB for the bootloader */
+		boot_partition: partition@0 {
+			label = "mcuboot";
+			reg = <0x00000000 0x0000F000>;
+			read-only;
+		};
+
+		/* Reserve 1024kB for the application in slot 0 */
+		slot0_partition: partition@10000 {
+			label = "image-0";
+			reg = <0x00010000 0x00100000>;
+		};
+
+		/* Reserve 1024kB for the application in slot 1 */
+		slot1_partition: partition@110000 {
+			label = "image-1";
+			reg = <0x00110000 0x00100000>;
+		};
+
+		/* Reserve 256kB for the scratch partition */
+		scratch_partition: partition@210000 {
+			   label = "image-scratch";
+			   reg = <0x00210000 0x00040000>;
+		};
+
+		storage_partition: partition@250000 {
+			label = "storage";
+			reg = <0x00250000 0x00006000>;
+		};
+	};
+};

boards/espressif/esp8684_devkitm/esp8684_devkitm.yaml

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+identifier: esp8684_devkitm
+name: ESP8684
+type: mcu
+arch: riscv
+toolchain:
+  - zephyr
+supported:
+  - gpio
+  - watchdog
+  - uart
+  - counter
+  - entropy
+testing:
+  ignore_tags:
+    - net
+    - bluetooth
+vendor: espressif

boards/espressif/esp8684_devkitm/esp8684_devkitm_defconfig

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+# SPDX-License-Identifier: Apache-2.0
+
+CONFIG_MAIN_STACK_SIZE=2048
+
+CONFIG_CONSOLE=y
+CONFIG_SERIAL=y
+CONFIG_UART_CONSOLE=y
+CONFIG_GPIO=y

boards/espressif/esp8684_devkitm/support/openocd.cfg

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+set ESP_RTOS none
+
+# Use external JTAG interface, such as ESP-Prog
+source [find interface/ftdi/esp32_devkitj_v1.cfg]
+source [find target/esp32c2.cfg]