Add missing files for hello world

main/CMakeLists.txt

@@ -0,0 +1,33 @@
+set(headers
+)
+
+set(sources
+    main.cpp
+)
+
+set(dependencies
+    freertos nvs_flash esp_http_server esp_https_ota mdns app_update esp_system esp_websocket_client driver
+    arduino-esp32 ArduinoJson cpputils cxx-ring-buffer date espasynchttpreq espasyncota espchrono espcpputils
+    espconfiglib esphttpdutils espwifistack expected fmt
+)
+
+idf_component_register(
+    SRCS
+        ${headers}
+        ${sources}
+    INCLUDE_DIRS
+        .
+    REQUIRES
+        ${dependencies}
+)
+
+target_compile_options(${COMPONENT_TARGET}
+    PRIVATE
+        -fstack-reuse=all
+        -fstack-protector-all
+        -fdiagnostics-color=always
+        -Wno-unused-function
+        -Wno-deprecated-declarations
+        -Wno-missing-field-initializers
+        -Wno-parentheses
+)

main/main.cpp

@@ -0,0 +1,10 @@
+#include <esp_log.h>
+
+namespace {
+constexpr const char * const TAG = "MAIN";
+} // namespace
+
+extern "C" void app_main()
+{
+    ESP_LOGI(TAG, "hello world");
+}