Modularization Experiments with LLEXT

CMakeLists.txt

@@ -1,16 +1,75 @@
 # SPDX-License-Identifier: Apache-2.0
 
-if (IS_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/variants/${BOARD})
-  set(variant_dir variants/${BOARD})
-elseif (IS_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/variants/${BOARD}${NORMALIZED_BOARD_QUALIFIERS})
-  set(variant_dir variants/${BOARD}${NORMALIZED_BOARD_QUALIFIERS})
-else()
-  message(FATAL_ERROR "Variant dir not found: variants/${BOARD}, variants/${BOARD}${NORMALIZED_BOARD_QUALIFIERS}")
-endif()
 
-if (CONFIG_ARDUINO_API)
-add_subdirectory(cores)
-add_subdirectory(libraries)
-zephyr_include_directories(${variant_dir})
+if (CONFIG_ARDUINO_CORE)
+
+function(arduino_sources)
+  if (IS_DIRECTORY ${CMAKE_CURRENT_FUNCTION_LIST_DIR}/variants/${BOARD})
+    set(variant_dir variants/${BOARD})
+  elseif (IS_DIRECTORY ${CMAKE_CURRENT_FUNCTION_LIST_DIR}/variants/${BOARD}${NORMALIZED_BOARD_QUALIFIERS})
+    set(variant_dir variants/${BOARD}${NORMALIZED_BOARD_QUALIFIERS})
+  else()
+    message(FATAL_ERROR "Variant dir not found: variants/${BOARD}, variants/${BOARD}${NORMALIZED_BOARD_QUALIFIERS}")
+  endif()
+
+  set(ext_name arduino)
+  set(ext_bin ${ZEPHYR_BINARY_DIR}/${ext_name}.llext)
+  set(ext_inc ${ZEPHYR_BINARY_DIR}/include/generated/${ext_name}_ext.inc)
+
+  set(core_srcs
+    ${CMAKE_CURRENT_FUNCTION_LIST_DIR}/cores/arduino/module_export.c
+    ${CMAKE_CURRENT_FUNCTION_LIST_DIR}/cores/arduino/zephyrPrint.cpp
+    ${CMAKE_CURRENT_FUNCTION_LIST_DIR}/cores/arduino/zephyrSerial.cpp
+    ${CMAKE_CURRENT_FUNCTION_LIST_DIR}/cores/arduino/zephyrCommon.cpp
+    ${CMAKE_CURRENT_FUNCTION_LIST_DIR}/cores/arduino/main.cpp
+    ${CMAKE_CURRENT_FUNCTION_LIST_DIR}/cores/arduino/api/String.cpp
+    ${CMAKE_CURRENT_FUNCTION_LIST_DIR}/cores/arduino/api/Stream.cpp
+    ${CMAKE_CURRENT_FUNCTION_LIST_DIR}/cores/arduino/api/Common.cpp
+    ${CMAKE_CURRENT_FUNCTION_LIST_DIR}/cores/arduino/api/Print.cpp
+  )
+
+  if (CONFIG_SPI)
+    list(APPEND core_srcs ${CMAKE_CURRENT_FUNCTION_LIST_DIR}/libraries/SPI/SPI.cpp)
+  endif()
+
+  if (CONFIG_I2C)
+    list(APPEND core_srcs ${CMAKE_CURRENT_FUNCTION_LIST_DIR}/libraries/Wire/Wire.cpp)
+  endif()
+
+  if (CONFIG_CAN)
+    list(APPEND core_srcs ${CMAKE_CURRENT_FUNCTION_LIST_DIR}/cores/arduino/api/CanMsgRingbuffer.cpp
+	                  ${CMAKE_CURRENT_FUNCTION_LIST_DIR}/cores/arduino/api/CanMsg.cpp)
+  endif()
+
+  if (CONFIG_USB)
+    list(APPEND core_srcs ${CMAKE_CURRENT_FUNCTION_LIST_DIR}/cores/arduino/api/PluggableUSB.cpp)
+  endif()
+
+  if (CONFIG_NET_IP)
+    list(APPEND core_srcs ${CMAKE_CURRENT_FUNCTION_LIST_DIR}/cores/arduino/api/IPAddress.cpp)
+  endif()
+
+  add_llext_target(${ext_name}_ext
+    OUTPUT  ${ext_bin}
+    SOURCES
+      ${core_srcs}
+      ${ARGV}
+  )
+
+  llext_include_directories(${ext_name}_ext
+    ${CMAKE_CURRENT_FUNCTION_LIST_DIR}/cores/arduino/
+    ${CMAKE_CURRENT_FUNCTION_LIST_DIR}/cores/arduino/api/
+    ${CMAKE_CURRENT_FUNCTION_LIST_DIR}/libraries/SPI/
+    ${CMAKE_CURRENT_FUNCTION_LIST_DIR}/libraries/Wire/
+    ${CMAKE_CURRENT_FUNCTION_LIST_DIR}/${variant_dir}
+  )
+
+  generate_inc_file_for_target(app ${ext_bin} ${ext_inc})
+endfunction()
+
+  if(DEFINED CONFIG_ARDUINO_ENTRY)
+    target_sources(app PRIVATE cores/arduino/main_loader.c)
+  endif()
+
 endif()
 

Kconfig

@@ -4,25 +4,30 @@
 # SPDX-License-Identifier: Apache-2.0
 #
 
-config ARDUINO_API
-	bool "ARDUINO_API"
+config ARDUINO_CORE
+	bool "ARDUINO_CORE"
 	imply CPP
 	imply GPIO
 	imply I2C
 	imply NEWLIB_LIBC_FLOAT_PRINTF
 	imply CBPRINTF_FP_SUPPORT
 	imply RING_BUFFER
 	select UART_INTERRUPT_DRIVEN
-	default n
+	select LLEXT
+	select MODULES
+
+if ARDUINO_CORE
 
-if ARDUINO_API
+choice LLEXT_BINARY_TYPE
+	default LLEXT_TYPE_ELF_RELOCATABLE
+endchoice
 
 config QEMU_ICOUNT
 	bool "QEMU icount mode"
 	default n
 	depends on QEMU_TARGET
 
-config ARDUINO_API_SERIAL_BUFFER_SIZE
+config ARDUINO_CORE_SERIAL_BUFFER_SIZE
 	int "Buffer size for Arduino Serial API"
 	default 64
 

cores/arduino/api/ArduinoAPI.h

@@ -0,0 +1,57 @@
+/*
+  Arduino API main include
+  Copyright (c) 2016 Arduino LLC. All right reserved.
+
+  This library is free software; you can redistribute it and/or
+  modify it under the terms of the GNU Lesser General Public
+  License as published by the Free Software Foundation; either
+  version 2.1 of the License, or (at your option) any later version.
+
+  This library is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public
+  License along with this library; if not, write to the Free Software
+  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+*/
+
+#ifndef ARDUINO_API_H
+#define ARDUINO_API_H
+
+// version 1.5.1
+#define ARDUINO_API_VERSION 10501
+
+#include "Binary.h"
+
+#ifdef __cplusplus
+#include "Interrupts.h"
+#include "IPAddress.h"
+#include "Print.h"
+#include "Printable.h"
+#include "PluggableUSB.h"
+#include "Server.h"
+#include "String.h"
+#include "Stream.h"
+#include "Udp.h"
+#include "USBAPI.h"
+#include "WCharacter.h"
+#endif
+
+/* Standard C library includes */
+#include <stdlib.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <string.h>
+#include <math.h>
+
+// Misc Arduino core functions
+#include "Common.h"
+
+#ifdef __cplusplus
+// Compatibility layer for older code
+#include "Compat.h"
+#endif
+
+#endif