llext: add object test case

Adds a case to the simple llext test testing global
non-static object relocation.

Signed-off-by: Lauren Murphy <lauren.murphy@intel.com>

tests/subsys/llext/simple/CMakeLists.txt

@@ -16,7 +16,7 @@ target_include_directories(app PRIVATE
 )
 
 # generate extension targets foreach extension given by name
-foreach(ext_name hello_world logging relative_jump)
+foreach(ext_name hello_world logging relative_jump object)
   set(ext_src ${PROJECT_SOURCE_DIR}/src/${ext_name}_ext.c)
   set(ext_bin ${ZEPHYR_BINARY_DIR}/${ext_name}.llext)
   set(ext_inc ${ZEPHYR_BINARY_DIR}/include/generated/${ext_name}.inc)

tests/subsys/llext/simple/src/object_ext.c

@@ -0,0 +1,26 @@
+/*
+ * Copyright (c) 2024 Intel Corporation.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/*
+ * This code demonstrates object relocation support.
+ */
+
+#include <stdint.h>
+#include <zephyr/llext/symbol.h>
+#include <zephyr/kernel.h>
+
+/* Test non-static global object relocation */
+int number = 42;
+const char *string = "hello";
+
+void test_entry(void)
+{
+	printk("number: %d\n", number);
+	number = 0;
+	printk("number, updated: %d\n", number);
+	printk("string: %s\n", string);
+}
+LL_EXTENSION_SYMBOL(test_entry);

tests/subsys/llext/simple/src/test_llext_simple.c

@@ -152,6 +152,11 @@ static LLEXT_CONST uint8_t relative_jump_ext[] __aligned(4) = {
 };
 LLEXT_LOAD_UNLOAD(relative_jump, true)
 
+static LLEXT_CONST uint8_t object_ext[] __aligned(4) = {
+	#include "object.inc"
+};
+LLEXT_LOAD_UNLOAD(object, true)
+
 /*
  * Ensure that EXPORT_SYMBOL does indeed provide a symbol and a valid address
  * to it.