boards: others: neorv32: add minimalboot board variant

Add a MinimalBoot board variant for the NEORV32 board. The software
configuration of this board matches the NEORV32 "MinimalBoot" processor
template.

Signed-off-by: Henrik Brix Andersen <[email protected]>

Author: henrikbrixandersen

boards/others/neorv32/Kconfig

@@ -1,6 +1,14 @@
 # Copyright (c) 2021,2025 Henrik Brix Andersen <[email protected]>
 # SPDX-License-Identifier: Apache-2.0
 
+if BOARD_NEORV32_NEORV32_MINIMALBOOT
+
+config BOARD_NEORV32
+	select RISCV_ISA_RV32I
+	select ATOMIC_OPERATIONS_C
+
+endif # BOARD_NEORV32_NEORV32_MINIMALBOOT
+
 if BOARD_NEORV32_NEORV32_UP5KDEMO
 
 config BOARD_NEORV32

boards/others/neorv32/board.cmake

@@ -6,5 +6,5 @@ include(${ZEPHYR_BASE}/boards/common/openocd.board.cmake)
 
 if("${BOARD_QUALIFIERS}" STREQUAL "/neorv32")
   message(FATAL_ERROR "Please specify a variant for the neorv32 board "
-                      "(e.g. neorv32/neorv32/up5kdemo)")
+                      "(e.g. neorv32/neorv32/minimalboot or neorv32/neorv32/up5kdemo)")
 endif()

boards/others/neorv32/board.yml

@@ -5,4 +5,5 @@ board:
   socs:
     - name: neorv32
       variants:
+        - name: "minimalboot"
         - name: "up5kdemo"

boards/others/neorv32/neorv32_neorv32_minimalboot.dts

@@ -0,0 +1,90 @@
+/*
+ * Copyright (c) 2025 Henrik Brix Andersen <[email protected]>
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/dts-v1/;
+
+#include <neorv32.dtsi>
+#include <mem.h>
+
+/ {
+	model = "NEORV32 MinimalBoot";
+	compatible = "neorv32";
+
+	aliases {
+		led0 = &led0;
+		led1 = &led1;
+		led2 = &led2;
+		led3 = &led3;
+	};
+
+	chosen {
+		zephyr,flash = &imem;
+		zephyr,sram = &dmem;
+		zephyr,console = &uart0;
+		zephyr,shell-uart = &uart0;
+		zephyr,uart-pipe = &uart0;
+	};
+
+	leds {
+		compatible = "gpio-leds";
+
+		led0: led0 {
+			gpios = <&gpio 0 GPIO_ACTIVE_HIGH>;
+			label = "LED_0";
+		};
+
+		led1: led1 {
+			gpios = <&gpio 1 GPIO_ACTIVE_HIGH>;
+			label = "LED_1";
+		};
+
+		led2: led2 {
+			gpios = <&gpio 2 GPIO_ACTIVE_HIGH>;
+			label = "LED_2";
+		};
+
+		led3: led3 {
+			gpios = <&gpio 3 GPIO_ACTIVE_HIGH>;
+			label = "LED_3";
+		};
+	};
+};
+
+&cpu0 {
+	riscv,isa = "rv32i_zicsr_zifencei";
+};
+
+&bootrom {
+	status = "okay";
+};
+
+&imem {
+	status = "okay";
+	reg = <0x0 DT_SIZE_K(64)>;
+};
+
+&dmem {
+	status = "okay";
+	reg = <0x80000000 DT_SIZE_K(64)>;
+};
+
+&clint {
+	status = "okay";
+};
+
+&mtimer {
+	status = "okay";
+};
+
+&uart0 {
+	status = "okay";
+	current-speed = <19200>;
+};
+
+&gpio {
+	status = "okay";
+	ngpios = <4>;
+};

boards/others/neorv32/neorv32_neorv32_minimalboot.yaml

@@ -0,0 +1,11 @@
+identifier: neorv32/neorv32/minimalboot
+name: NEORV32 MinimalBoot
+type: mcu
+arch: riscv
+toolchain:
+  - cross-compile
+  - zephyr
+ram: 64
+flash: 64
+supported:
+  - gpio

boards/others/neorv32/neorv32_neorv32_minimalboot_defconfig

@@ -0,0 +1,7 @@
+# Copyright (c) 2025 Henrik Brix Andersen <[email protected]>
+# SPDX-License-Identifier: Apache-2.0
+
+CONFIG_SERIAL=y
+CONFIG_CONSOLE=y
+CONFIG_UART_CONSOLE=y
+CONFIG_UART_INTERRUPT_DRIVEN=y

tests/drivers/gpio/gpio_api_1pin/testcase.yaml

@@ -16,6 +16,7 @@ tests:
       - mps2/an383
       - mps2/an386
       - mps2/an500
+      - neorv32/neorv32/minimalboot
       - neorv32/neorv32/up5kdemo
   drivers.gpio.1pin.aw9523b:
     tags:

tests/drivers/gpio/gpio_get_direction/testcase.yaml

@@ -8,5 +8,6 @@ tests:
     # Fix exclude when we can exclude just sim run
     platform_exclude:
       - mps2/an385
+      - neorv32/neorv32/minimalboot
       - neorv32/neorv32/up5kdemo
     filter: dt_enabled_alias_with_parent_compat("led0", "gpio-leds")