chore: import upstream snapshot with attribution

tools/test_apps/system/init_array/CMakeLists.txt

@@ -0,0 +1,6 @@
+cmake_minimum_required(VERSION 3.16)
+
+set(COMPONENTS main)
+
+include($ENV{IDF_PATH}/tools/cmake/project.cmake)
+project(test_init_array)

tools/test_apps/system/init_array/README.md

@@ -0,0 +1,20 @@
+| Supported Targets | ESP32 | ESP32-C2 | ESP32-C3 | ESP32-C5 | ESP32-C6 | ESP32-C61 | ESP32-H2 | ESP32-H21 | ESP32-H4 | ESP32-P4 | ESP32-S2 | ESP32-S3 | ESP32-S31 | Linux |
+| ----------------- | ----- | -------- | -------- | -------- | -------- | --------- | -------- | --------- | -------- | -------- | -------- | -------- | --------- | ----- |
+
+# Historical note
+
+Initially, ESP-IDF used the `do_global_ctors()` function to run global constructors.
+This was done to accommodate Xtensa targets that emit `.ctors.*` sections, which are ordered in descending order.
+
+For RISC-V, compilation used `.init_array.*` sections, which are designed to have ascending order.
+Priority constructors in `.init_array.*` sections were correctly processed in ascending order.
+However, non-priority `.init_array` section was processed in descending order (as it was done for Xtensa `.ctors`).
+
+Starting with ESP-IDF v6.0, the implementation switched to the standard LibC behavior (`__libc_init_array()`),
+which processes both priority and non-priority constructors in ascending order.
+
+To achieve this, a breaking changes were introduced:
+  - Xtensa `.ctors.*` entries converted to `.init_array.*` format (ascending), to be passed to `__libc_init_array()`.
+  - Processing order of non-priority `.init_array` and `.ctors` sections was changed from descending to ascending.
+
+This test ensures that the initialization order is correct and consistent between ESP-IDF and Linux targets.

tools/test_apps/system/init_array/main/CMakeLists.txt

@@ -0,0 +1,2 @@
+idf_component_register(SRCS "test_app_main.c"
+                       REQUIRES esp_system)

tools/test_apps/system/init_array/main/test_app_main.c

@@ -0,0 +1,50 @@
+/*
+ * SPDX-FileCopyrightText: 2025 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Unlicense OR CC0-1.0
+ */
+#include <stdio.h>
+#include <stdint.h>
+
+__attribute__((constructor))
+void foo(void)
+{
+    printf("%s\n", __FUNCTION__);
+}
+
+__attribute__((constructor(103)))
+void init_prio_103(void)
+{
+    printf("%s\n", __FUNCTION__);
+}
+
+__attribute__((constructor(101)))
+void init_prio_101(void)
+{
+    printf("%s\n", __FUNCTION__);
+}
+
+__attribute__((constructor(102)))
+void init_prio_102(void)
+{
+    printf("%s\n", __FUNCTION__);
+}
+
+__attribute__((constructor))
+void bar(void)
+{
+    printf("%s\n", __FUNCTION__);
+}
+
+void preinit_func(void)
+{
+    printf("%s\n", __FUNCTION__);
+}
+
+__attribute__((section(".preinit_array"), used))
+uintptr_t test_preinit = (uintptr_t) preinit_func;
+
+void app_main(void)
+{
+    printf("app_main running\n");
+}

tools/test_apps/system/init_array/pytest_init_array.py

@@ -0,0 +1,17 @@
+# SPDX-FileCopyrightText: 2025 Espressif Systems (Shanghai) CO LTD
+# SPDX-License-Identifier: CC0-1.0
+import pytest
+from pytest_embedded import Dut
+from pytest_embedded_idf.utils import idf_parametrize
+
+
+@pytest.mark.generic
+@idf_parametrize('target', ['supported_targets', 'preview_targets', 'linux'], indirect=['target'])
+def test_init_array(dut: Dut) -> None:
+    dut.expect_exact('preinit_func')
+    dut.expect_exact('init_prio_101')
+    dut.expect_exact('init_prio_102')
+    dut.expect_exact('init_prio_103')
+    dut.expect_exact('foo')
+    dut.expect_exact('bar')
+    dut.expect_exact('app_main running')