Add NuttX RV32 QEMU Example (#64)

Adds an example project using the Apache NuttX RTOS which runs under QEMU.

Author: kassane

.github/workflows/build-nuttx.yml

@@ -0,0 +1,67 @@
+name: Build NuttX Examples
+
+on:
+  push:
+    branches: ["main"]
+  pull_request:
+    branches: ["main"]
+  schedule:
+    # Build on Mondays at 9am PST every week
+    - cron:  '0 17 * * 1'
+
+jobs:
+  build-nuttx:
+    runs-on: ubuntu-24.04
+
+    strategy:
+      fail-fast: false
+      matrix:
+        example: [nuttx-riscv-blink]
+        swift: [swift-DEVELOPMENT-SNAPSHOT-2024-12-22-a]
+
+    steps:
+      - name: Checkout repo
+        uses: actions/checkout@v4
+
+      - name: Install apt dependencies
+        run: |
+          sudo apt-get -qq update && sudo apt-get -qq -y install \
+            bison flex gettext texinfo libncurses5-dev libncursesw5-dev \
+            gperf automake libtool pkg-config build-essential gperf genromfs \
+            libgmp-dev libmpc-dev libmpfr-dev libisl-dev binutils-dev libelf-dev \
+            libexpat-dev gcc-multilib g++-multilib u-boot-tools util-linux \
+            kconfig-frontends ninja-build
+
+      - name: Install CMake 3.30.2
+        run: |
+          ARCH=`uname -m`
+          curl -sL https://github.com/Kitware/CMake/releases/download/v3.30.2/cmake-3.30.2-linux-$ARCH.tar.gz -O
+          tar xzf cmake-3.30.2-linux-$ARCH.tar.gz
+          export PATH="`pwd`/cmake-3.30.2-linux-$ARCH/bin:$PATH"
+          echo "PATH=$PATH" >> $GITHUB_ENV
+          cmake --version
+
+      - name: Install RISC-V toolchain
+        run: |
+          mkdir -p riscv-none-elf-gcc && \
+          curl -s -L "https://github.com/xpack-dev-tools/riscv-none-elf-gcc-xpack/releases/download/v13.2.0-2/xpack-riscv-none-elf-gcc-13.2.0-2-linux-x64.tar.gz" \
+            | tar -C riscv-none-elf-gcc --strip-components 1 -xz
+          export PATH="$PATH:`pwd`/riscv-none-elf-gcc/bin/"
+          echo "PATH=$PATH" >> $GITHUB_ENV
+          riscv-none-elf-gcc --version
+
+      - name: Install ${{ matrix.swift }}
+        run: |
+          wget -q https://download.swift.org/development/ubuntu2404/${{ matrix.swift }}/${{ matrix.swift }}-ubuntu24.04.tar.gz
+          tar xzf ${{ matrix.swift }}-ubuntu24.04.tar.gz
+          export PATH="`pwd`/${{ matrix.swift }}-ubuntu24.04/usr/bin/:$PATH"
+          echo "PATH=$PATH" >> $GITHUB_ENV
+          swiftc --version
+
+      - name: Config ${{ matrix.example }}
+        working-directory: ${{ matrix.example }}
+        run: cmake -B build -GNinja -DBOARD_CONFIG=rv-virt:leds_swift -DENABLE_NUTTX_TRACE=ON
+
+      - name: Build ${{ matrix.example }}
+        working-directory: ${{ matrix.example }}
+        run: cmake --build build

README.md

@@ -32,19 +32,20 @@ Each example in this repository contains build and deployment instructions, howe
 
 | Name | Platform | SDK | Description | Photo |
 | ---- | -------- | --- | ----------- | ----- |
+| [esp32-led-blink-sdk](./esp32-led-blink-sdk) | ESP32-C6-Bug | ESP-IDF SDK | Blink an LED repeatedly with Swift & the ESP-IDF. | <img width="300" src="esp32-led-blink-sdk/assets/images/ledon.jpg"> |
+| [esp32-led-strip-sdk](./esp32-led-strip-sdk) | ESP32-C6-DevKitC-1 | ESP-IDF SDK | Control NeoPixel LEDs with Swift & the ESP-IDF. | <img width="300" src="https://github.com/apple/swift-embedded-examples/assets/1186214/15f8a3e0-953e-426d-ad2d-3902baf859be"> |
+| [nrfx-blink-sdk](./nrfx-blink-sdk) | nRF52840-DK | Zephyr SDK | Blink an LED repeatedly with Swift & Zephyr. | <img width="300" src="https://github.com/apple/swift-embedded-examples/assets/1186214/ae3ff153-dd33-4460-8a08-4eac442bf7b0"> |
+| [nuttx-riscv-blink] | QEMU | NuttX | Blink a virualized led in QEMU using the Apache NuttX RTOS | |
+| [pico-blink-sdk](./pico-blink-sdk) | Raspberry Pi Pico, Pico 2 | Pico SDK | Blink an LED repeatedly with Swift & the Pico SDK. | <img width="300" src="https://github.com/apple/swift-embedded-examples/assets/1186214/f2c45c18-f9a4-48b4-a941-1298ecc942cb"> |
+| [pico-blink](./pico-blink) | Raspberry Pi Pico | None  | Blink an LED repeatedly. | <img width="300" src="https://github.com/apple/swift-embedded-examples/assets/1186214/f2c45c18-f9a4-48b4-a941-1298ecc942cb"> |
+| [pico-w-blink-sdk](./pico-w-blink-sdk) | Raspberry Pi Pico W | Pico SDK | Blink an LED to signal 'SOS' in Morse code repeatedly with Swift & the Pico SDK. | <img width="300" src="https://github.com/apple/swift-embedded-examples/assets/26223064/a4949a2e-1887-4325-8f5f-a681963c93d7"> |
+| [pico2-neopixel](./pico2-neopixel) | Raspberry Pi Pico 2 | None | Control Neopixel LEDs using the RP2350 PIO. | <img width="300" src="pico2-neopixel/assets/images/example.jpg"> |
 | [stm32-blink](./stm32-blink) | STM32F746G-DISCO | None | Blink an LED repeatedly. | <img width="300" src="https://github.com/apple/swift-embedded-examples/assets/1186214/739e98fd-a438-4a64-a7aa-9dddee25034b"> |
 | [stm32-lcd-logo](./stm32-lcd-logo) | STM32F746G-DISCO | None | Animate the Swift Logo on the built-in LCD. | <img width="300" src="https://github.com/apple/swift-embedded-examples/assets/1186214/9e117d81-e808-493e-a20c-7284ea630f37"> |
 | [stm32-neopixel](./stm32-neopixel) | STM32F746G-DISCO | None | Control NeoPixel LEDs using SPI. | <img width="300" src="https://github.com/apple/swift-embedded-examples/assets/1186214/9c5d8f74-f8aa-4632-831e-212a3e35e75a"> |
 | [stm32-uart-echo](./stm32-uart-echo) | STM32F746G-DISCO | None | Echo user input using UART. | <img width="300" src="https://github.com/apple/swift-embedded-examples/assets/1186214/97d3c465-9a07-4b86-9654-0c2aaaa43b3d">|
-| [pico-blink](./pico-blink) | Raspberry Pi Pico | None  | Blink an LED repeatedly. | <img width="300" src="https://github.com/apple/swift-embedded-examples/assets/1186214/f2c45c18-f9a4-48b4-a941-1298ecc942cb"> |
-| [pico-blink-sdk](./pico-blink-sdk) | Raspberry Pi Pico, Pico 2 | Pico SDK | Blink an LED repeatedly with Swift & the Pico SDK. | <img width="300" src="https://github.com/apple/swift-embedded-examples/assets/1186214/f2c45c18-f9a4-48b4-a941-1298ecc942cb"> |
-| [pico-w-blink-sdk](./pico-w-blink-sdk) | Raspberry Pi Pico W | Pico SDK | Blink an LED to signal 'SOS' in Morse code repeatedly with Swift & the Pico SDK. | <img width="300" src="https://github.com/apple/swift-embedded-examples/assets/26223064/a4949a2e-1887-4325-8f5f-a681963c93d7"> |
-| [pico2-neopixel](./pico2-neopixel) | Raspberry Pi Pico 2 | None | Control Neopixel LEDs using the RP2350 PIO. | <img width="300" src="pico2-neopixel/assets/images/example.jpg"> |
-| [nrfx-blink-sdk](./nrfx-blink-sdk) | nRF52840-DK | Zephyr SDK | Blink an LED repeatedly with Swift & Zephyr. | <img width="300" src="https://github.com/apple/swift-embedded-examples/assets/1186214/ae3ff153-dd33-4460-8a08-4eac442bf7b0"> |
-| [esp32-led-strip-sdk](./esp32-led-strip-sdk) | ESP32-C6-DevKitC-1 | ESP-IDF SDK | Control NeoPixel LEDs with Swift & the ESP-IDF. | <img width="300" src="https://github.com/apple/swift-embedded-examples/assets/1186214/15f8a3e0-953e-426d-ad2d-3902baf859be"> |
-| [esp32-led-blink-sdk](./esp32-led-blink-sdk) | ESP32-C6-Bug | ESP-IDF SDK | Blink an LED repeatedly with Swift & the ESP-IDF. | <img width="300" src="esp32-led-blink-sdk/assets/images/ledon.jpg"> |
 
-Note that the SDK integration examples (Pico SDK, Zephyr SDK, etc.) are not recommendations or endorsement, the same is true for build system choice (Make, CMake, SwiftPM, shell scripts). Embedded Swift aims to be versatile and to allow for integration into more existing SDKs and build systems, and the example projects are merely showing the possibilities.
+Note that the SDK integration examples (Pico SDK, Zephyr SDK, etc.) are not recommendations or endorsement, the same is true for build system choice (Make, CMake, SwiftPM, shell scripts). Embedded Swift aims to be versatile and allowing integration into existing SDKs and build systems, and the example projects show some of the possibilities.
 
 ## Community Examples
 

nuttx-riscv-blink/CMakeLists.txt

@@ -0,0 +1,134 @@
+cmake_minimum_required(VERSION 3.14...3.30)
+
+project(blink
+    VERSION 1.0
+    DESCRIPTION "Blink on NuttX"
+    LANGUAGES Swift
+)
+
+if("${CMAKE_Swift_COMPILER_VERSION}" VERSION_LESS 6.1)
+    message(FATAL_ERROR "Swift 6.1 or later is required")
+endif()
+
+if(POLICY CMP0169)
+    # allow to call FetchContent_Populate directly
+    cmake_policy(SET CMP0169 OLD)
+endif()
+
+option(LIST_ALL_BOARDS "List all available boards" OFF)
+option(ENABLE_NUTTX_TRACE "Enable NuttX trace" OFF)
+
+if(ENABLE_NUTTX_TRACE)
+    set(TRACEFLAG "--trace")
+else()
+    set(TRACEFLAG "")
+endif()
+
+set(FETCHCONTENT_QUIET FALSE)
+include(FetchContent)
+FetchContent_Declare(
+    apps
+    GIT_REPOSITORY https://github.com/apache/nuttx-apps.git
+    GIT_TAG nuttx-12.7.0
+    SOURCE_DIR ${CMAKE_BINARY_DIR}/apps
+    FIND_PACKAGE_ARGS
+)
+FetchContent_GetProperties(apps)
+if(NOT apps_POPULATED)
+    FetchContent_Populate(apps)
+endif()
+
+FetchContent_Declare(
+    nuttx
+    GIT_REPOSITORY https://github.com/apache/nuttx.git
+    GIT_TAG nuttx-12.7.0
+    SOURCE_DIR ${CMAKE_BINARY_DIR}/nuttx
+    FIND_PACKAGE_ARGS
+)
+FetchContent_GetProperties(nuttx)
+if(NOT nuttx_POPULATED)
+    FetchContent_Populate(nuttx)
+endif()
+
+if(CMAKE_HOST_SYSTEM_NAME STREQUAL "Windows")
+    set(SCRIPT_SUFFIX .bat)
+else()
+    set(SCRIPT_SUFFIX .sh)
+endif()
+
+if(LIST_ALL_BOARDS)
+    execute_process(
+        COMMAND ${CMAKE_COMMAND} -E chdir ${nuttx_SOURCE_DIR}
+        ${CMAKE_COMMAND} -E env PATH=${nuttx_SOURCE_DIR}/tools:$ENV{PATH}
+        ${nuttx_SOURCE_DIR}/tools/configure${SCRIPT_SUFFIX} -L
+        RESULT_VARIABLE result
+    )
+    if(result)
+        message(FATAL_ERROR "Failed to run tools/configure")
+    endif()
+else()
+    if(NOT DEFINED BOARD_CONFIG)
+        message(FATAL_ERROR "Please define configuration with BOARD_CONFIG")
+    else()
+        message(STATUS "BOARD_CONFIG: ${BOARD_CONFIG}")
+    endif()
+
+    # Send swift-blinky example to nuttx-apps path
+    file(COPY ${CMAKE_SOURCE_DIR}/leds_swift DESTINATION ${apps_SOURCE_DIR}/examples)
+    file(COPY ${CMAKE_SOURCE_DIR}/defconfig DESTINATION ${nuttx_SOURCE_DIR}/boards/risc-v/qemu-rv/rv-virt/configs/leds_swift)
+
+    add_custom_target(distclean
+        COMMAND ${CMAKE_COMMAND} -E chdir ${nuttx_SOURCE_DIR}
+        ${CMAKE_COMMAND} -E env PATH=${nuttx_SOURCE_DIR}/tools:$ENV{PATH}
+        make distclean
+        COMMENT "Clean NuttX"
+    )
+
+    execute_process(
+        COMMAND ${CMAKE_COMMAND} -E chdir ${nuttx_SOURCE_DIR}
+        ${CMAKE_COMMAND} -E env PATH=${nuttx_SOURCE_DIR}/tools:$ENV{PATH}
+        ${nuttx_SOURCE_DIR}/tools/configure${SCRIPT_SUFFIX} -l ${BOARD_CONFIG}
+        RESULT_VARIABLE result
+    )
+    if(result)
+        message(FATAL_ERROR "Failed to run tools/configure")
+    endif()
+
+    add_custom_target(copy_swift_example
+        COMMAND ${CMAKE_COMMAND} -E copy_directory ${CMAKE_SOURCE_DIR}/leds_swift ${apps_SOURCE_DIR}/examples/leds_swift
+        COMMENT "Copying leds_swift example to nuttx-apps"
+    )
+
+    add_custom_target(build_nuttx ALL
+        COMMAND ${CMAKE_COMMAND} -E chdir ${nuttx_SOURCE_DIR}
+        ${CMAKE_COMMAND} -E env PATH=${nuttx_SOURCE_DIR}/tools:$ENV{PATH}
+        make ${TRACEFLAG} -j ${JOB_POOLS}
+        DEPENDS copy_swift_example
+        COMMENT "Building NuttX"
+    )
+
+    add_custom_command(
+        TARGET build_nuttx
+        POST_BUILD
+        COMMAND ${CMAKE_COMMAND} -E copy ${nuttx_SOURCE_DIR}/nuttx ${CMAKE_BINARY_DIR}/nuttx.elf
+    )
+
+    add_custom_target(export_nuttx
+        COMMAND ${CMAKE_COMMAND} -E chdir ${nuttx_SOURCE_DIR}
+        ${CMAKE_COMMAND} -E env PATH=${nuttx_SOURCE_DIR}/tools:$ENV{PATH}
+        make export
+        COMMENT "Exporting NuttX"
+    )
+
+    add_custom_target(extract_nuttx_export
+        COMMAND ${CMAKE_COMMAND} -E tar xzf ${nuttx_SOURCE_DIR}/nuttx-export-12.7.0.tar.gz
+        WORKING_DIRECTORY ${CMAKE_BINARY_DIR}
+        COMMAND ${CMAKE_COMMAND} -E remove ${nuttx_SOURCE_DIR}/nuttx-export-12.7.0.tar.gz
+        DEPENDS export_nuttx
+        COMMENT "Extracting NuttX export"
+    )
+
+    add_custom_target(nuttx-libs
+        DEPENDS build_nuttx export_nuttx extract_nuttx_export
+    )
+endif()

nuttx-riscv-blink/README.md

@@ -0,0 +1,71 @@
+# Swift 6 on NuttX RTOS using CMake
+
+## Description
+
+Run blink rv32-blink_leds (QEMU) example on NuttX RTOS.
+
+> [!NOTE]
+> CMake is adapted to build NuttX and NuttX-apps (Makefiles) with Swift 6.
+
+## Requirements
+
+- [NuttX](https://github.com/apache/nuttx) & [NuttX-apps](https://github.com/apache/nuttx-apps)
+- [kconfig-frontends](https://bitbucket.org/nuttx/tools)
+- [CMake](https://cmake.org/download/)
+- [QEMU](https://www.qemu.org/)
+- [Swift 6](https://swift.org/download/) - Swift 6.1 or greater
+- [RISC-V GNU Toolchain](https://github.com/riscv-collab/riscv-gnu-toolchain/releases)
+
+## How to build
+
+```bash
+# list all supported boards
+cmake -B build -DLIST_ALL_BOARDS=ON | less
+# build configuration
+cmake -B build -GNinja -DBOARD_CONFIG=rv-virt:leds_swift -DENABLE_NUTTX_TRACE=[ON|OFF]
+# build
+cmake --build build
+# clean
+cmake --build build -t distclean
+# export NuttX as library
+cmake --build build -t nuttx-libs
+```
+
+- **Output**
+```bash
+qemu-system-riscv32 \
+    -semihosting \
+    -M virt,aclint=on \
+    -cpu rv32 -smp 8 \
+    -bios none \
+    -kernel build/nuttx.elf -nographic
+NuttShell (NSH) NuttX-12.7.0
+nsh> leds_swift
+leds_main: led_daemon started
+
+led_daemon (pid# 4): Running
+led_daemon: Opening /dev/userleds
+led_daemon: Supported LEDs 0x7
+led_daemon: LED set 0x1
+board_userled: LED 1 set to 1
+board_userled: LED 2 set to 0
+board_userled: LED 3 set to 0
+nsh> led_daemon: LED set 0x0
+board_userled: LED 1 set to 0
+board_userled: LED 2 set to 0
+board_userled: LED 3 set to 0
+led_daemon: LED set 0x1
+board_userled: LED 1 set to 1
+board_userled: LED 2 set to 0
+board_userled: LED 3 set to 0
+led_daemon: LED set 0x0
+# [...] see output in QEMU
+```
+
+Quit from QEMU: `Ctrl-a x`
+
+## References
+
+- [Nuttx - Compiling with CMake](https://nuttx.apache.org/docs/latest/quickstart/compiling_cmake.html)
+- [NuttX - C++ Example using CMake](https://nuttx.apache.org/docs/latest/guides/cpp_cmake.html)
+- [NuttX - leds_rust](https://lupyuen.github.io/articles/rust6)

nuttx-riscv-blink/defconfig

@@ -0,0 +1,76 @@
+#
+# This file is autogenerated: PLEASE DO NOT EDIT IT.
+#
+# You can use "make menuconfig" to make any modifications to the installed .config file.
+# You can then do "make savedefconfig" to generate a new defconfig file that includes your
+# modifications.
+#
+# CONFIG_DISABLE_OS_API is not set
+# CONFIG_NSH_DISABLE_LOSMART is not set
+CONFIG_16550_ADDRWIDTH=0
+CONFIG_16550_UART0=y
+CONFIG_16550_UART0_BASE=0x10000000
+CONFIG_16550_UART0_CLOCK=3686400
+CONFIG_16550_UART0_IRQ=37
+CONFIG_16550_UART0_SERIAL_CONSOLE=y
+CONFIG_16550_UART=y
+CONFIG_ARCH="risc-v"
+CONFIG_ARCH_BOARD="rv-virt"
+CONFIG_ARCH_BOARD_QEMU_RV_VIRT=y
+CONFIG_ARCH_CHIP="qemu-rv"
+# CONFIG_ARCH_CHIP_QEMU_RV64=y
+CONFIG_ARCH_CHIP_QEMU_RV=y
+CONFIG_ARCH_CHIP_QEMU_RV_ISA_A=y
+CONFIG_ARCH_CHIP_QEMU_RV_ISA_C=y
+CONFIG_ARCH_CHIP_QEMU_RV_ISA_M=y
+CONFIG_ARCH_INTERRUPTSTACK=2048
+CONFIG_ARCH_RISCV=y
+CONFIG_ARCH_STACKDUMP=y
+CONFIG_BCH=y
+CONFIG_BOARDCTL_POWEROFF=y
+CONFIG_BOARD_LATE_INITIALIZE=y
+CONFIG_BOARD_LOOPSPERMSEC=6366
+CONFIG_BUILTIN=y
+CONFIG_DEBUG_FEATURES=y
+CONFIG_DEBUG_FULLOPT=y
+CONFIG_DEBUG_SYMBOLS=y
+CONFIG_DEVICE_TREE=y
+CONFIG_DEV_ZERO=y
+CONFIG_ELF=y
+# CONFIG_EXAMPLES_HELLO=y
+CONFIG_EXAMPLES_LEDS=y
+CONFIG_EXAMPLES_LEDS_SWIFT=y
+CONFIG_FS_HOSTFS=y
+CONFIG_FS_PROCFS=y
+CONFIG_IDLETHREAD_STACKSIZE=2048
+CONFIG_INIT_ENTRYPOINT="nsh_main"
+CONFIG_INIT_STACKSIZE=3072
+CONFIG_LIBC_ENVPATH=y
+CONFIG_LIBC_EXECFUNCS=y
+CONFIG_LIBC_PERROR_STDOUT=y
+CONFIG_LIBC_STRERROR=y
+CONFIG_LIBM=y
+CONFIG_NFILE_DESCRIPTORS_PER_BLOCK=6
+CONFIG_NSH_ARCHINIT=y
+CONFIG_NSH_BUILTIN_APPS=y
+CONFIG_NSH_FILEIOSIZE=512
+CONFIG_NSH_READLINE=y
+CONFIG_PATH_INITIAL="/system/bin"
+CONFIG_RAM_SIZE=33554432
+CONFIG_RAM_START=0x80000000
+CONFIG_READLINE_CMD_HISTORY=y
+CONFIG_RISCV_SEMIHOSTING_HOSTFS=y
+CONFIG_RR_INTERVAL=200
+CONFIG_SCHED_WAITPID=y
+CONFIG_SERIAL_UART_ARCH_MMIO=y
+CONFIG_STACK_COLORATION=y
+CONFIG_START_MONTH=12
+CONFIG_START_YEAR=2021
+CONFIG_SYMTAB_ORDEREDBYNAME=y
+CONFIG_SYSTEM_NSH=y
+CONFIG_SYSTEM_NSH_STACKSIZE=3072
+CONFIG_TESTING_GETPRIME=y
+CONFIG_TESTING_OSTEST=y
+CONFIG_USEC_PER_TICK=1000
+CONFIG_USERLED=y
+CONFIG_USERLED_LOWER=y