Merge branch 'mdns_mac_storage_reduce_ram' into integration

esphome/components/mdns/__init__.py

@@ -184,10 +184,8 @@ async def to_code(config):
 
     # Calculate compile-time dynamic TXT value count
     # Dynamic values are those that cannot be stored in flash at compile time
+    # Note: MAC address is now stored in a fixed char[13] buffer, not dynamic storage
     dynamic_txt_count = 0
-    if "api" in CORE.config:
-        # Always: get_mac_address()
-        dynamic_txt_count += 1
     # User-provided templatable TXT values (only lambdas, not static strings)
     dynamic_txt_count += sum(
         1
@@ -196,8 +194,10 @@ async def to_code(config):
         if cg.is_template(txt_value)
     )
 
-    # Ensure at least 1 to avoid zero-size array
-    cg.add_define("MDNS_DYNAMIC_TXT_COUNT", max(1, dynamic_txt_count))
+    # Only add define if we actually need dynamic storage
+    if dynamic_txt_count > 0:
+        cg.add_define("USE_MDNS_DYNAMIC_TXT")
+        cg.add_define("MDNS_DYNAMIC_TXT_COUNT", dynamic_txt_count)
 
     # Enable storage if verbose logging is enabled (for dump_config)
     if get_logger_level() in ("VERBOSE", "VERY_VERBOSE"):

esphome/components/mdns/mdns_component.cpp

@@ -86,7 +86,7 @@ void MDNSComponent::compile_records_(StaticVector<MDNSService, MDNS_SERVICE_COUN
       txt_records.push_back({MDNS_STR(TXT_FRIENDLY_NAME), MDNS_STR(friendly_name.c_str())});
     }
     txt_records.push_back({MDNS_STR(TXT_VERSION), MDNS_STR(VALUE_VERSION)});
-    txt_records.push_back({MDNS_STR(TXT_MAC), MDNS_STR(this->add_dynamic_txt_value(get_mac_address()))});
+    txt_records.push_back({MDNS_STR(TXT_MAC), MDNS_STR(this->mac_address_)});
 
 #ifdef USE_ESP8266
     MDNS_STATIC_CONST_CHAR(PLATFORM_ESP8266, "ESP8266");

esphome/components/mdns/mdns_component.h

@@ -60,18 +60,38 @@ class MDNSComponent : public Component {
 
   void on_shutdown() override;
 
+#ifdef USE_MDNS_DYNAMIC_TXT
   /// Add a dynamic TXT value and return pointer to it for use in MDNSTXTRecord
   const char *add_dynamic_txt_value(const std::string &value) {
     this->dynamic_txt_values_.push_back(value);
     return this->dynamic_txt_values_[this->dynamic_txt_values_.size() - 1].c_str();
   }
+#endif
 
-  /// Storage for runtime-generated TXT values (MAC address, user lambdas)
+ protected:
+  /// Common setup logic called by all platform-specific setup() implementations
+  void on_setup() {
+#ifdef USE_API
+    // Populate MAC address buffer once during setup
+    get_mac_address_into_buffer(std::span<char, 13>(this->mac_address_));
+#endif
+
+#ifdef USE_MDNS_STORE_SERVICES
+    this->compile_records_(this->services_);
+#endif
+  }
+
+#ifdef USE_MDNS_DYNAMIC_TXT
+  /// Storage for runtime-generated TXT values from user lambdas
   /// Pre-sized at compile time via MDNS_DYNAMIC_TXT_COUNT to avoid heap allocations.
   /// Static/compile-time values (version, board, etc.) are stored directly in flash and don't use this.
   StaticVector<std::string, MDNS_DYNAMIC_TXT_COUNT> dynamic_txt_values_;
+#endif
 
- protected:
+#ifdef USE_API
+  /// Fixed buffer for MAC address (populated once in setup())
+  char mac_address_[13];  // 12 hex chars + null terminator
+#endif
 #ifdef USE_MDNS_STORE_SERVICES
   StaticVector<MDNSService, MDNS_SERVICE_COUNT> services_{};
 #endif

esphome/components/mdns/mdns_esp32.cpp

@@ -12,8 +12,9 @@ namespace esphome::mdns {
 static const char *const TAG = "mdns";
 
 void MDNSComponent::setup() {
+  this->on_setup();
+
 #ifdef USE_MDNS_STORE_SERVICES
-  this->compile_records_(this->services_);
   const auto &services = this->services_;
 #else
   StaticVector<MDNSService, MDNS_SERVICE_COUNT> services;

esphome/components/mdns/mdns_esp8266.cpp

@@ -12,8 +12,9 @@
 namespace esphome::mdns {
 
 void MDNSComponent::setup() {
+  this->on_setup();
+
 #ifdef USE_MDNS_STORE_SERVICES
-  this->compile_records_(this->services_);
   const auto &services = this->services_;
 #else
   StaticVector<MDNSService, MDNS_SERVICE_COUNT> services;

esphome/components/mdns/mdns_host.cpp

@@ -9,6 +9,7 @@
 namespace esphome::mdns {
 
 void MDNSComponent::setup() {
+  this->on_setup();
   // Host platform doesn't have actual mDNS implementation
 }
 

esphome/components/mdns/mdns_libretiny.cpp

@@ -12,8 +12,9 @@
 namespace esphome::mdns {
 
 void MDNSComponent::setup() {
+  this->on_setup();
+
 #ifdef USE_MDNS_STORE_SERVICES
-  this->compile_records_(this->services_);
   const auto &services = this->services_;
 #else
   StaticVector<MDNSService, MDNS_SERVICE_COUNT> services;

esphome/components/mdns/mdns_rp2040.cpp

@@ -12,8 +12,9 @@
 namespace esphome::mdns {
 
 void MDNSComponent::setup() {
+  this->on_setup();
+
 #ifdef USE_MDNS_STORE_SERVICES
-  this->compile_records_(this->services_);
   const auto &services = this->services_;
 #else
   StaticVector<MDNSService, MDNS_SERVICE_COUNT> services;

esphome/core/defines.h

@@ -88,7 +88,8 @@
 #define USE_MDNS
 #define USE_MDNS_STORE_SERVICES
 #define MDNS_SERVICE_COUNT 3
-#define MDNS_DYNAMIC_TXT_COUNT 3
+#define USE_MDNS_DYNAMIC_TXT
+#define MDNS_DYNAMIC_TXT_COUNT 2
 #define SNTP_SERVER_COUNT 3
 #define USE_MEDIA_PLAYER
 #define USE_NEXTION_TFT_UPLOAD

tests/components/stts22h/common.yaml

@@ -1,4 +1,5 @@
 sensor:
   - platform: stts22h
+    i2c_id: i2c_bus
     name: Temperature
     update_interval: 15s