Integrate PicoRuby VM to run Ruby scripts on RP2350

- Add PicoRuby submodule and cross-build config for Cortex-M33
- Rewrite main.c to initialize VM and run Ruby LED-blink task
- Add HAL implementation (timer tick, I/O, stdin ringbuffer)
- Add Rakefile for build automation

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: harukasan

.editorconfig

@@ -0,0 +1,34 @@
+root = true
+
+[*]
+end_of_line = lf
+insert_final_newline = true
+charset = utf-8
+trim_trailing_whitespace = true
+
+[*.{c,h}]
+indent_style = space
+indent_size = 2
+
+[*.{rb,rake}]
+indent_style = space
+indent_size = 2
+
+[CMakeLists.txt]
+indent_style = space
+indent_size = 2
+
+[*.cmake]
+indent_style = space
+indent_size = 2
+
+[*.{json,yml,yaml}]
+indent_style = space
+indent_size = 2
+
+[Makefile]
+indent_style = tab
+
+[Rakefile]
+indent_style = space
+indent_size = 2

.github/workflows/build.yml

@@ -20,6 +20,11 @@ jobs:
         submodules: recursive
         fetch-depth: 0
 
+    - name: Set up Ruby
+      uses: ruby/setup-ruby@v1
+      with:
+        ruby-version: '4.0.1'
+
     - name: Install ARM toolchain
       run: |
         sudo apt-get update

.gitignore

@@ -1,4 +1,5 @@
 .cache
 build/
+lib/picoruby/build/
 
 !.vscode/*

.gitmodules

@@ -1,3 +1,6 @@
 [submodule "lib/pico-sdk"]
 	path = lib/pico-sdk
 	url = https://github.com/raspberrypi/pico-sdk.git
+[submodule "lib/picoruby"]
+	path = lib/picoruby
+	url = git@github.com:picoruby/picoruby.git

.vscode/launch.json

@@ -8,8 +8,9 @@
             "request": "launch",
             "type": "cortex-debug",
             "servertype": "openocd",
-            "serverpath": "${userHome}/.pico-sdk/openocd/0.12.0+dev/openocd.exe",
-            "gdbPath": "${command:raspberry-pi-pico.getGDBPath}",
+            "serverpath": "${userHome}/.pico-sdk/openocd/0.12.0+dev/openocd",
+            "gdbPath": "${userHome}/.pico-sdk/toolchain/14_2_Rel1/bin/arm-none-eabi-gdb",
+            "toolchainPrefix": "${userHome}/.pico-sdk/toolchain/14_2_Rel1/bin/arm-none-eabi",
             "device": "${command:raspberry-pi-pico.getChipUppercase}",
             "configFiles": [
                 "interface/cmsis-dap.cfg",
@@ -35,7 +36,8 @@
             "type": "cortex-debug",
             "servertype": "external",
             "gdbTarget": "localhost:3333",
-            "gdbPath": "${command:raspberry-pi-pico.getGDBPath}",
+            "gdbPath": "${userHome}/.pico-sdk/toolchain/14_2_Rel1/bin/arm-none-eabi-gdb",
+            "toolchainPrefix": "${userHome}/.pico-sdk/toolchain/14_2_Rel1/bin/arm-none-eabi",
             "device": "${command:raspberry-pi-pico.getChipUppercase}",
             "svdFile": "${userHome}/.pico-sdk/sdk/2.2.0/src/${command:raspberry-pi-pico.getChip}/hardware_regs/${command:raspberry-pi-pico.getChipUppercase}.svd",
             "runToEntryPoint": "main",

CLAUDE.md

@@ -0,0 +1,30 @@
+# CLAUDE.md
+
+## Project overview
+
+Harucom OS is firmware for the Harucom Board (RP2350-based single-board computer).
+It runs Ruby scripts on mruby VM with DVI output, USB keyboard input, and a file system.
+
+- Language: C (C11), with Ruby scripts executed on the embedded VM
+- Target: RP2350 (ARM Cortex-M33), built with pico-sdk
+- Build system: CMake, with a Rakefile wrapper for convenience
+
+## Build commands
+
+```sh
+rake          # configure + build (default)
+rake clean    # remove build/
+rake distclean # remove build/ and PicoRuby build
+```
+
+## Code style
+
+- Follow `.editorconfig` for indentation and whitespace rules
+- Use C11, K&R brace style
+- Keep HAL functions prefixed with `hal_` or `mrb_hal_`
+
+## Commit messages
+
+- First line: summary of the change
+- Following lines: concise bullet points of what was done
+- Do not include trivial accompanying changes (e.g. license additions, formatting fixes)

CMakeLists.txt

@@ -64,27 +64,97 @@ message(STATUS "harucom_os version: ${HARUCOM_VERSION} (${HARUCOM_BUILD_DATE})")
 # Initialise the Raspberry Pi Pico SDK
 pico_sdk_init()
 
-add_executable(harucom_os src/main.c)
+# --- PicoRuby ---
+set(PICORUBY_ROOT ${CMAKE_CURRENT_LIST_DIR}/lib/picoruby)
+set(PICORUBY_BUILD_CONFIG harucom-os-pico2)
+
+# Build libmruby.a
+add_custom_command(
+    OUTPUT ${PICORUBY_ROOT}/build/${PICORUBY_BUILD_CONFIG}/lib/libmruby.a
+    COMMAND rake MRUBY_CONFIG=${CMAKE_CURRENT_LIST_DIR}/build_config/${PICORUBY_BUILD_CONFIG}.rb
+    WORKING_DIRECTORY ${PICORUBY_ROOT}
+    COMMENT "Building PicoRuby (libmruby.a)..."
+)
+
+add_custom_target(build_picoruby
+    DEPENDS ${PICORUBY_ROOT}/build/${PICORUBY_BUILD_CONFIG}/lib/libmruby.a
+)
+
+add_library(mruby STATIC IMPORTED)
+set_target_properties(mruby PROPERTIES
+    IMPORTED_LOCATION ${PICORUBY_ROOT}/build/${PICORUBY_BUILD_CONFIG}/lib/libmruby.a
+)
+
+# --- Executable ---
+add_executable(harucom_os
+    src/main.c
+    src/hal.c
+    ${PICORUBY_ROOT}/mrbgems/picoruby-gpio/ports/rp2040/gpio.c
+)
+
+add_dependencies(harucom_os build_picoruby)
 
 pico_set_program_name(harucom_os "harucom_os")
 pico_set_program_version(harucom_os "${HARUCOM_VERSION}")
 
-set_target_properties(harucom_os PROPERTIES
-    OUTPUT_NAME "harucom_os-${HARUCOM_VERSION}-${HARUCOM_BUILD_DATE}"
+set(HARUCOM_RELEASE_NAME "harucom_os-${HARUCOM_VERSION}-${HARUCOM_BUILD_DATE}")
+
+target_compile_definitions(harucom_os PRIVATE
+    HARUCOM_VERSION="${HARUCOM_VERSION}"
+    HARUCOM_BUILD_DATE="${HARUCOM_BUILD_DATE}"
+    PICO_RP2350=1
+    PICORB_VM_MRUBY=1
+    MRB_INT64=1
+    MRB_32BIT=1
+    PICORB_ALLOC_ESTALLOC=1
+    PICORB_ALLOC_ALIGN=8
+    MRB_USE_CUSTOM_RO_DATA_P=1
+    MRB_LINK_TIME_RO_DATA_P=1
+    MRB_TICK_UNIT=1
+    MRB_TIMESLICE_TICK_COUNT=10
+    MRB_USE_TASK_SCHEDULER=1
+    NO_CLOCK_GETTIME=1
+    NDEBUG=1
+)
+
+target_compile_options(harucom_os PRIVATE -fshort-enums)
+
+target_include_directories(harucom_os PRIVATE
+    ${CMAKE_CURRENT_LIST_DIR}/src
+    ${PICORUBY_ROOT}/include
+    ${PICORUBY_ROOT}/build/${PICORUBY_BUILD_CONFIG}/include
+    ${PICORUBY_ROOT}/mrbgems/picoruby-mruby/lib/mruby/include
+    ${PICORUBY_ROOT}/mrbgems/picoruby-mruby/include
+    ${PICORUBY_ROOT}/mrbgems/mruby-compiler2/include
+    ${PICORUBY_ROOT}/mrbgems/mruby-compiler2/lib/prism/include
+    ${PICORUBY_ROOT}/mrbgems/picoruby-gpio/include
+    ${PICORUBY_ROOT}/mrbgems/picoruby-mruby/lib/mruby/mrbgems/mruby-task/include
+    ${PICORUBY_ROOT}/mrbgems/picoruby-machine/include
+    ${PICORUBY_ROOT}/build/${PICORUBY_BUILD_CONFIG}/mrbgems
 )
 
 # Enable UART output for debug
 pico_enable_stdio_uart(harucom_os 1)
 pico_enable_stdio_usb(harucom_os 1)
 
 target_link_libraries(harucom_os
-        pico_stdlib)
-
-target_include_directories(harucom_os PRIVATE
-        ${CMAKE_CURRENT_LIST_DIR}/src
+    pico_stdlib
+    hardware_timer
+    hardware_gpio
+    mruby
 )
 
 string(APPEND CMAKE_EXE_LINKER_FLAGS "-Wl,--print-memory-usage")
 
 pico_add_extra_outputs(harucom_os)
 
+# Copy release artifacts with version-stamped names
+add_custom_command(TARGET harucom_os POST_BUILD
+    COMMAND ${CMAKE_COMMAND} -E copy
+        ${CMAKE_BINARY_DIR}/harucom_os.elf
+        ${CMAKE_BINARY_DIR}/${HARUCOM_RELEASE_NAME}.elf
+    COMMAND ${CMAKE_COMMAND} -E copy
+        ${CMAKE_BINARY_DIR}/harucom_os.uf2
+        ${CMAKE_BINARY_DIR}/${HARUCOM_RELEASE_NAME}.uf2
+    COMMENT "Creating release files: ${HARUCOM_RELEASE_NAME}.{elf,uf2}"
+)

CREDITS.md

@@ -32,3 +32,30 @@ SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSE
 WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 ```
+
+## PicoRuby
+
+- Repository: https://github.com/picoruby/picoruby
+- License: MIT
+
+```
+Copyright © 2020 HASUMI Hitoshi
+
+Permission is hereby granted, free of charge, to any person obtaining a
+copy of this software and associated documentation files (the "Software"),
+to deal in the Software without restriction, including without limitation
+the rights to use, copy, modify, merge, publish, distribute, sublicense,
+and/or sell copies of the Software, and to permit persons to whom the
+Software is furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+DEALINGS IN THE SOFTWARE.
+```

Rakefile

@@ -0,0 +1,44 @@
+PROJECT_DIR = __dir__
+BUILD_DIR   = File.join(PROJECT_DIR, "build")
+
+def nproc
+  require "etc"
+  Etc.nprocessors
+end
+
+desc "Configure and build (default)"
+task default: :uf2
+
+desc "Run cmake configure"
+task :configure do
+  sh "cmake -B #{BUILD_DIR}"
+end
+
+desc "Build firmware"
+task build: :configure do
+  sh "cmake --build #{BUILD_DIR} -j#{nproc}"
+end
+
+desc "Build UF2"
+task uf2: :build
+
+desc "Flash firmware via picotool"
+task flash: :uf2 do
+  uf2 = Dir.glob(File.join(BUILD_DIR, "*.uf2")).first
+  abort "UF2 not found in #{BUILD_DIR}" unless uf2
+  sh "picotool load -f #{uf2}"
+end
+
+desc "Clean build directory"
+task :clean do
+  rm_rf BUILD_DIR
+end
+
+desc "Clean PicoRuby build"
+task :clean_picoruby do
+  picoruby_build = File.join(PROJECT_DIR, "lib", "picoruby", "build")
+  rm_rf picoruby_build
+end
+
+desc "Clean everything"
+task distclean: [:clean, :clean_picoruby]

build_config/harucom-os-pico2.rb

@@ -0,0 +1,43 @@
+MRuby::CrossBuild.new("harucom-os-pico2") do |conf|
+
+  conf.toolchain("gcc")
+
+  conf.cc.defines << "MRB_TICK_UNIT=1"
+  conf.cc.defines << "MRB_TIMESLICE_TICK_COUNT=10"
+
+  conf.cc.defines << "MRB_INT64"
+  conf.cc.defines << "MRB_32BIT"
+  conf.cc.defines << "PICORB_ALLOC_ESTALLOC"
+  conf.cc.defines << "PICORB_ALLOC_ALIGN=8"
+  conf.cc.defines << "MRB_USE_CUSTOM_RO_DATA_P"
+  conf.cc.defines << "MRB_LINK_TIME_RO_DATA_P"
+  conf.cc.defines << "NO_CLOCK_GETTIME=1"
+
+  conf.cc.command = "arm-none-eabi-gcc"
+  conf.linker.command = "arm-none-eabi-ld"
+  conf.linker.flags << "-static"
+  conf.archiver.command = "arm-none-eabi-ar"
+
+  conf.cc.host_command = "gcc"
+
+  conf.cc.flags.flatten!
+  conf.cc.flags << "-mcpu=cortex-m33"
+  conf.cc.flags << "-mthumb"
+
+  conf.cc.flags << "-fno-strict-aliasing"
+  conf.cc.flags << "-fno-unroll-loops"
+  conf.cc.flags << "-mslow-flash-data"
+
+  conf.cc.flags << "-fshort-enums"
+
+  conf.cc.flags << "-Wall"
+  conf.cc.flags << "-Wno-format"
+  conf.cc.flags << "-Wno-unused-function"
+  conf.cc.flags << "-ffunction-sections"
+  conf.cc.flags << "-fdata-sections"
+
+  conf.microruby
+
+  conf.gembox "minimum"
+  conf.gem core: 'picoruby-gpio'
+end