llext

Author: soburi

CMakeLists.txt

@@ -1,8 +1,43 @@
 # SPDX-License-Identifier: Apache-2.0
 
 if (CONFIG_ARDUINO_API)
-add_subdirectory(cores)
-add_subdirectory(libraries)
-zephyr_include_directories(variants/${BOARD})
+  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)
+
+  add_llext_target(${ext_name}_ext
+    OUTPUT  ${ext_bin}
+    SOURCES
+	cores/arduino/module_export.c
+	cores/arduino/zephyrPrint.cpp
+	cores/arduino/zephyrSerial.cpp
+	cores/arduino/zephyrCommon.cpp
+	cores/arduino/main.cpp
+	cores/arduino/api/CanMsgRingbuffer.cpp
+	cores/arduino/api/String.cpp
+	cores/arduino/api/Stream.cpp
+	cores/arduino/api/Common.cpp
+	cores/arduino/api/CanMsg.cpp
+	cores/arduino/api/PluggableUSB.cpp
+	cores/arduino/api/Print.cpp
+	cores/arduino/api/IPAddress.cpp
+	libraries/SPI/SPI.cpp
+	libraries/Wire/Wire.cpp
+	${ARDUINO_SOURCES}
+  )
+
+  llext_include_directories(${ext_name}_ext
+	  cores/arduino/
+	  cores/arduino/api/
+	  libraries/SPI/
+	  libraries/Wire/
+	  variants/${BOARD}
+  )
+
+  generate_inc_file_for_target(app ${ext_bin} ${ext_inc})
+
+  if(DEFINED CONFIG_ARDUINO_ENTRY)
+    target_sources(app PRIVATE cores/arduino/main_loader.c)
+  endif()
 endif()
 

Kconfig

@@ -13,10 +13,16 @@ config ARDUINO_API
 	imply CBPRINTF_FP_SUPPORT
 	imply RING_BUFFER
 	select UART_INTERRUPT_DRIVEN
+	select LLEXT
+	select MODULES
 	default n
 
 if ARDUINO_API
 
+choice LLEXT_BINARY_TYPE
+	default LLEXT_TYPE_ELF_RELOCATABLE
+endchoice
+
 config QEMU_ICOUNT
 	bool "QEMU icount mode"
 	default n

cores/CMakeLists.txt

@@ -6,7 +6,9 @@
 
 #include "Arduino.h"
 
-int main(void) {
+extern "C" {
+
+int arduino_main(void) {
   setup();
 
   for (;;) {
@@ -16,3 +18,5 @@ int main(void) {
 
   return 0;
 }
+
+}

cores/arduino/CMakeLists.txt

@@ -0,0 +1,46 @@
+/*
+ * Copyright (c) 2024 Arduino SA
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#define LOG_LEVEL CONFIG_LOG_DEFAULT_LEVEL
+#include <zephyr/logging/log.h>
+LOG_MODULE_REGISTER(app);
+
+#include <zephyr/llext/llext.h>
+#include <zephyr/llext/buf_loader.h>
+
+static const uint8_t llext_buf[] = {
+#include "arduino_ext.inc"
+};
+
+int main(void)
+{
+	LOG_INF("Calling hello world as a module");
+
+	size_t llext_buf_len = ARRAY_SIZE(llext_buf);
+	struct llext_buf_loader buf_loader = LLEXT_BUF_LOADER(llext_buf, llext_buf_len);
+	struct llext_loader *ldr = &buf_loader.loader;
+
+	struct llext_load_param ldr_parm = LLEXT_LOAD_PARAM_DEFAULT;
+	struct llext *ext;
+	int res;
+
+	res = llext_load(ldr, "ext", &ext, &ldr_parm);
+	if (res != 0) {
+		LOG_ERR("Failed to load extension, return code %d\n", res);
+		return res;
+	}
+
+	int (*arduino_main)() = llext_find_sym(&ext->exp_tab, "arduino_main");
+
+	if (arduino_main == NULL) {
+		LOG_ERR("Failed to find symbol\n");
+		return -1;
+	}
+
+	arduino_main();
+
+	return llext_unload(&ext);
+}

cores/arduino/main.cpp

@@ -0,0 +1,5 @@
+#include <zephyr/llext/symbol.h>
+
+int arduino_main(void);
+
+LL_EXTENSION_SYMBOL(arduino_main);

cores/arduino/main_loader.c

@@ -87,16 +87,3 @@ size_t print_number_base_pow2(void *ctx, unsigned long long ull, unsigned bits)
 
 } // namespace zephyr
 } // namespace arduino
-
-/*
- * This is the default implementation.
- * It will be overridden by subclassese.
- */
-size_t arduino::Print::write(const uint8_t *buffer, size_t size)
-{
-  size_t i;
-  for (i=0; i<size && write(buffer[i]); i++) {
-  }
-
-  return i;
-}