Merge branch 'central-netif' into multi-interface-poc

# Conflicts:
#	esphome/components/wifi/wifi_component.cpp

esphome/components/espnow/__init__.py

@@ -17,7 +17,7 @@ from esphome.core import HexInt
 from esphome.types import ConfigType
 
 CODEOWNERS = ["@jesserockz"]
-
+AUTO_LOAD = ["network"]
 
 byte_vector = cg.std_vector.template(cg.uint8)
 peer_address_t = cg.std_ns.class_("array").template(cg.uint8, 6)

esphome/components/espnow/espnow_component.cpp

@@ -149,12 +149,6 @@ bool ESPNowComponent::is_wifi_enabled() {
 }
 
 void ESPNowComponent::setup() {
-#ifndef USE_WIFI
-  // Initialize LwIP stack for wake_loop_threadsafe() socket support
-  // When WiFi component is present, it handles esp_netif_init()
-  ESP_ERROR_CHECK(esp_netif_init());
-#endif
-
   if (this->enable_on_boot_) {
     this->enable_();
   } else {
@@ -174,8 +168,6 @@ void ESPNowComponent::enable() {
 
 void ESPNowComponent::enable_() {
   if (!this->is_wifi_enabled()) {
-    esp_event_loop_create_default();
-
     wifi_init_config_t cfg = WIFI_INIT_CONFIG_DEFAULT();
 
     ESP_ERROR_CHECK(esp_wifi_init(&cfg));

esphome/components/ethernet/__init__.py

@@ -3,7 +3,11 @@ import logging
 
 from esphome import automation, pins
 import esphome.codegen as cg
-from esphome.components.network import ip_address_literal
+from esphome.components.network import (
+    KEY_NETWORK_PRIORITY,
+    get_network_priority,
+    ip_address_literal,
+)
 from esphome.config_helpers import filter_source_files_from_platform
 import esphome.config_validation as cv
 from esphome.const import (
@@ -13,6 +17,7 @@ from esphome.const import (
     CONF_DNS1,
     CONF_DNS2,
     CONF_DOMAIN,
+    CONF_ENABLE_ON_BOOT,
     CONF_GATEWAY,
     CONF_ID,
     CONF_INTERRUPT_PIN,
@@ -27,6 +32,7 @@ from esphome.const import (
     CONF_PAGE_ID,
     CONF_PIN,
     CONF_POLLING_INTERVAL,
+    CONF_PRIORITY,
     CONF_RESET_PIN,
     CONF_SPI,
     CONF_STATIC_IP,
@@ -48,7 +54,6 @@ from esphome.core import (
 import esphome.final_validate as fv
 from esphome.types import ConfigType
 
-CONFLICTS_WITH = ["wifi"]
 AUTO_LOAD = ["network"]
 LOGGER = logging.getLogger(__name__)
 
@@ -348,6 +353,7 @@ BASE_SCHEMA = cv.Schema(
         cv.Optional(CONF_DOMAIN, default=".local"): cv.domain_name,
         cv.Optional(CONF_USE_ADDRESS): cv.string_strict,
         cv.Optional(CONF_MAC_ADDRESS): cv.mac_address,
+        cv.Optional(CONF_ENABLE_ON_BOOT, default=True): cv.boolean,
         cv.Optional(CONF_ON_CONNECT): automation.validate_automation(single=True),
         cv.Optional(CONF_ON_DISCONNECT): automation.validate_automation(single=True),
     }
@@ -487,6 +493,11 @@ async def to_code(config):
     var = cg.new_Pvariable(config[CONF_ID])
     await cg.register_component(var, config)
 
+    # Apply network priority if configured, otherwise use the existing default
+    prio = get_network_priority("ethernet")
+    if prio is not None:
+        cg.add(var.set_setup_priority(prio))
+
     if CORE.is_esp32:
         await _to_code_esp32(var, config)
     elif CORE.is_rp2040:
@@ -494,6 +505,9 @@ async def to_code(config):
 
     cg.add(var.set_type(ETHERNET_TYPES[config[CONF_TYPE]]))
     cg.add(var.set_use_address(config[CONF_USE_ADDRESS]))
+    # enable_on_boot defaults to true in C++ - only set if false
+    if not config[CONF_ENABLE_ON_BOOT]:
+        cg.add(var.set_enable_on_boot(False))
     CORE.data.setdefault(KEY_ETHERNET, {})[ETHERNET_TYPE_KEY] = config[CONF_TYPE]
 
     if CONF_MANUAL_IP in config:
@@ -576,10 +590,16 @@ async def _to_code_esp32(var: cg.Pvariable, config: ConfigType) -> None:
             )
             cg.add(var.add_phy_register(reg))
 
-    # Disable WiFi when using Ethernet to save memory
+    # Disable WiFi when using Ethernet alone to save memory.
-    add_idf_sdkconfig_option("CONFIG_ESP_WIFI_ENABLED", False)
+    # When network: priority: lists both interfaces, WiFi must remain enabled.
-    # Also disable WiFi/BT coexistence since WiFi is disabled
+    net_priority = CORE.data.get(KEY_NETWORK_PRIORITY, [])
-    add_idf_sdkconfig_option("CONFIG_SW_COEXIST_ENABLE", False)
+    priority_ifaces = {e["interface"] for e in net_priority}
+    running_with_wifi = "wifi" in priority_ifaces and "ethernet" in priority_ifaces
+    if not running_with_wifi:
+        # Disable WiFi when using Ethernet to save memory
+        add_idf_sdkconfig_option("CONFIG_ESP_WIFI_ENABLED", False)
+        # Also disable WiFi/BT coexistence since WiFi is disabled
+        add_idf_sdkconfig_option("CONFIG_SW_COEXIST_ENABLE", False)
 
     # Re-enable ESP-IDF's Ethernet driver (excluded by default to save compile time)
     include_builtin_idf_component("esp_eth")
@@ -665,6 +685,17 @@ def _final_validate_rmii_pins(config: ConfigType) -> None:
 
 def _final_validate(config: ConfigType) -> ConfigType:
     """Final validation for Ethernet component."""
+    # Allow ethernet + wifi coexistence only when both are declared in network: priority:
+    full = fv.full_config.get()
+    net_priority = full.get("network", {}).get(CONF_PRIORITY, [])
+    priority_ifaces = {e["interface"] for e in net_priority}
+    has_priority_config = "ethernet" in priority_ifaces and "wifi" in priority_ifaces
+    if "wifi" in full and not has_priority_config:
+        raise cv.Invalid(
+            "Component ethernet cannot be used together with component wifi "
+            "unless both are listed under 'network: priority:'"
+        )
+
     _final_validate_spi(config)
     _final_validate_rmii_pins(config)
     return config

esphome/components/ethernet/ethernet_component.h

@@ -124,6 +124,17 @@ class EthernetComponent final : public Component {
   void on_powerdown() override { powerdown(); }
   bool is_connected() { return this->state_ == EthernetComponentState::CONNECTED; }
 
+  // Per-interface lifecycle (parallels WiFiComponent::enable/disable/is_disabled).
+  // enable_on_boot defaults to true; when false, setup() runs all the driver/netif
+  // installation but skips esp_eth_start(), keeping the link cold until enable() is
+  // called. This is the primary lever for memory reclamation in multi-interface
+  // configurations where only one interface should carry traffic at a time.
+  void set_enable_on_boot(bool enable_on_boot) { this->enable_on_boot_ = enable_on_boot; }
+  void enable();
+  void disable();
+  bool is_disabled() { return this->disabled_; }
+  bool is_enabled() { return !this->disabled_; }
+
   void set_type(EthernetType type);
 #ifdef USE_ETHERNET_MANUAL_IP
   void set_manual_ip(const ManualIP &manual_ip);
@@ -194,6 +205,16 @@ class EthernetComponent final : public Component {
   void finish_connect_();
   void dump_connect_params_();
 
+#ifdef USE_ESP32
+  // ESP-IDF only: defers the SPI bus init, netif creation, MAC/PHY install, driver
+  // install, netif attach, and event handler registration (which together allocate
+  // ~3-8KB of DMA-capable internal SRAM via SPI driver state + eth driver RX queue)
+  // until ethernet actually needs to come up. Idempotent — guarded by the
+  // ethernet_initialized_ flag. Called from setup() when enable_on_boot_=true, or
+  // from enable() on first runtime enable. Mirrors wifi_lazy_init_() in WiFi.
+  void ethernet_lazy_init_();
+#endif
+
 #ifdef USE_ETHERNET_IP_STATE_LISTENERS
   void notify_ip_state_listeners_();
 #endif
@@ -287,6 +308,17 @@ class EthernetComponent final : public Component {
   bool started_{false};
   bool connected_{false};
   bool got_ipv4_address_{false};
+  // Codegen-time YAML option. When false, setup() defers esp_eth_start().
+  bool enable_on_boot_{true};
+  // Mirror of "is the link intentionally stopped" — set when setup() honors
+  // enable_on_boot=false, cleared by enable(), set again by disable().
+  bool disabled_{false};
+#ifdef USE_ESP32
+  // Tracks whether ethernet_lazy_init_() has completed successfully. Allows enable()
+  // to be called at runtime after enable_on_boot:false without re-allocating, and
+  // ensures setup() skips the heavy init when enable_on_boot_ is false.
+  bool ethernet_initialized_{false};
+#endif
 #if LWIP_IPV6
   uint8_t ipv6_count_{0};
   bool ipv6_setup_done_{false};

esphome/components/ethernet/ethernet_component_esp32.cpp

@@ -138,6 +138,24 @@ void EthernetComponent::setup() {
     delay(300);  // NOLINT
   }
 
+  if (this->enable_on_boot_) {
+    this->ethernet_lazy_init_();
+    if (!this->ethernet_initialized_) {
+      // lazy_init bailed early via ESPHL_ERROR_CHECK or mark_failed; nothing more to do.
+      return;
+    }
+    esp_err_t err = esp_eth_start(this->eth_handle_);
+    ESPHL_ERROR_CHECK(err, "ETH start error");
+  } else {
+    ESP_LOGCONFIG(TAG, "Skipping init (enable_on_boot: false)");
+    this->disabled_ = true;
+  }
+}
+
+void EthernetComponent::ethernet_lazy_init_() {
+  if (this->ethernet_initialized_)
+    return;
+
   esp_err_t err;
 
 #ifdef USE_ETHERNET_SPI
@@ -164,11 +182,7 @@ void EthernetComponent::setup() {
   err = spi_bus_initialize(host, &buscfg, SPI_DMA_CH_AUTO);
   ESPHL_ERROR_CHECK(err, "SPI bus initialize error");
 #endif
-
+  // Network interface setup handled by network component
-  err = esp_netif_init();
-  ESPHL_ERROR_CHECK(err, "ETH netif init error");
-  err = esp_event_loop_create_default();
-  ESPHL_ERROR_CHECK(err, "ETH event loop error");
 
   esp_netif_config_t cfg = ESP_NETIF_DEFAULT_ETH();
   this->eth_netif_ = esp_netif_new(&cfg);
@@ -375,9 +389,41 @@ void EthernetComponent::setup() {
   ESPHL_ERROR_CHECK(err, "GOT IPv6 event handler register error");
 #endif /* USE_NETWORK_IPV6 */
 
-  /* start Ethernet driver state machine */
+  this->ethernet_initialized_ = true;
-  err = esp_eth_start(this->eth_handle_);
+}
-  ESPHL_ERROR_CHECK(err, "ETH start error");
+
+void EthernetComponent::enable() {
+  if (!this->disabled_)
+    return;
+
+  ESP_LOGD(TAG, "Enabling");
+  this->ethernet_lazy_init_();
+  if (!this->ethernet_initialized_) {
+    ESP_LOGE(TAG, "Cannot enable - init failed");
+    return;
+  }
+  esp_err_t err = esp_eth_start(this->eth_handle_);
+  if (err != ESP_OK) {
+    ESP_LOGE(TAG, "esp_eth_start failed: %s", esp_err_to_name(err));
+    return;
+  }
+  this->disabled_ = false;
+  // The ETH_EVENT_START handler will set started_=true; the loop state machine
+  // will then drive the STOPPED -> CONNECTING -> CONNECTED transitions.
+  this->enable_loop();
+}
+
+void EthernetComponent::disable() {
+  if (this->disabled_)
+    return;
+
+  ESP_LOGD(TAG, "Disabling");
+  esp_err_t err = esp_eth_stop(this->eth_handle_);
+  if (err != ESP_OK) {
+    ESP_LOGW(TAG, "esp_eth_stop failed: %s — disabling anyway", esp_err_to_name(err));
+  }
+  this->disabled_ = true;
+  // ETH_EVENT_STOP will clear started_; loop() will transition to STOPPED.
 }
 
 void EthernetComponent::dump_config() {
@@ -491,6 +537,8 @@ void EthernetComponent::dump_config() {
 
 network::IPAddresses EthernetComponent::get_ip_addresses() {
   network::IPAddresses addresses;
+  if (!this->ethernet_initialized_)
+    return addresses;  // all-zero IPs
   esp_netif_ip_info_t ip;
   esp_err_t err = esp_netif_get_ip_info(this->eth_netif_, &ip);
   if (err != ESP_OK) {
@@ -713,6 +761,10 @@ void EthernetComponent::start_connect_() {
 }
 
 void EthernetComponent::dump_connect_params_() {
+  if (!this->ethernet_initialized_) {
+    ESP_LOGCONFIG(TAG, "  uninitialized/disabled");
+    return;
+  }
   esp_netif_ip_info_t ip;
   esp_netif_get_ip_info(this->eth_netif_, &ip);
   const ip_addr_t *dns_ip1;
@@ -780,6 +832,13 @@ void EthernetComponent::add_phy_register(PHYRegister register_value) { this->phy
 #endif
 
 void EthernetComponent::get_eth_mac_address_raw(uint8_t *mac) {
+  if (!this->ethernet_initialized_) {
+    // External callers (sendspin, ethernet_info, mdns, etc.) may ask for the MAC
+    // before/regardless of whether ethernet is enabled. Fall back to the system MAC
+    // assigned to the ETH interface — same value the driver would have returned.
+    esp_read_mac(mac, ESP_MAC_ETH);
+    return;
+  }
   esp_err_t err;
   err = esp_eth_ioctl(this->eth_handle_, ETH_CMD_G_MAC_ADDR, mac);
   ESPHL_ERROR_CHECK(err, "ETH_CMD_G_MAC error");
@@ -799,6 +858,8 @@ const char *EthernetComponent::get_eth_mac_address_pretty_into_buffer(
 }
 
 eth_duplex_t EthernetComponent::get_duplex_mode() {
+  if (!this->ethernet_initialized_)
+    return ETH_DUPLEX_HALF;
   esp_err_t err;
   eth_duplex_t duplex_mode;
   err = esp_eth_ioctl(this->eth_handle_, ETH_CMD_G_DUPLEX_MODE, &duplex_mode);
@@ -807,6 +868,8 @@ eth_duplex_t EthernetComponent::get_duplex_mode() {
 }
 
 eth_speed_t EthernetComponent::get_link_speed() {
+  if (!this->ethernet_initialized_)
+    return ETH_SPEED_10M;
   esp_err_t err;
   eth_speed_t speed;
   err = esp_eth_ioctl(this->eth_handle_, ETH_CMD_G_SPEED, &speed);

esphome/components/ethernet/ethernet_component_rp2040.cpp

@@ -361,6 +361,23 @@ void EthernetComponent::set_cs_pin(uint8_t cs_pin) { this->cs_pin_ = cs_pin; }
 void EthernetComponent::set_interrupt_pin(int8_t interrupt_pin) { this->interrupt_pin_ = interrupt_pin; }
 void EthernetComponent::set_reset_pin(int8_t reset_pin) { this->reset_pin_ = reset_pin; }
 
+void EthernetComponent::enable() {
+  // RP2040 uses arduino-pico's LwipIntfDev which manages link state internally;
+  // there is no clean enable/disable hook today. The YAML option is accepted on
+  // RP2040 for schema parity but has no effect.
+  if (!this->disabled_)
+    return;
+  ESP_LOGW(TAG, "enable_on_boot/disable not supported");
+  this->disabled_ = false;
+}
+
+void EthernetComponent::disable() {
+  if (this->disabled_)
+    return;
+  ESP_LOGW(TAG, "enable_on_boot/disable not supported");
+  this->disabled_ = true;
+}
+
 }  // namespace esphome::ethernet
 
 #endif  // USE_ETHERNET && USE_RP2040

esphome/components/network/__init__.py

@@ -5,8 +5,15 @@ import esphome.codegen as cg
 from esphome.components.esp32 import add_idf_sdkconfig_option
 from esphome.components.psram import is_guaranteed as psram_is_guaranteed
 import esphome.config_validation as cv
-from esphome.const import CONF_ENABLE_IPV6, CONF_MIN_IPV6_ADDR_COUNT
+from esphome.const import (
+    CONF_ENABLE_IPV6,
+    CONF_ID,
+    CONF_MIN_IPV6_ADDR_COUNT,
+    CONF_PRIORITY,
+    CONF_TIMEOUT,
+)
 from esphome.core import CORE, CoroPriority, coroutine_with_priority
+import esphome.final_validate as fv
 
 CODEOWNERS = ["@esphome/core"]
 AUTO_LOAD = ["mdns"]
@@ -18,7 +25,30 @@ _LOGGER = logging.getLogger(__name__)
 KEY_HIGH_PERFORMANCE_NETWORKING = "high_performance_networking"
 CONF_ENABLE_HIGH_PERFORMANCE = "enable_high_performance"
 
+# Network priority tracking infrastructure
+# Components can query this to determine their relative setup priority and fallback timeout.
+# CORE.data[KEY_NETWORK_PRIORITY] is a list of dicts:
+#   [{"interface": "ethernet", "timeout": 30000}, {"interface": "wifi", "timeout": None}, ...]
+# where timeout is in milliseconds, or None meaning "start the next interface immediately".
+KEY_NETWORK_PRIORITY = "network_priority"
+
+VALID_NETWORK_TYPES = ["ethernet", "openthread", "wifi", "modem"]
+
+# Setup priority base values — first in list gets the highest priority.
+#
+# The base equals the historical setup_priority::WIFI / ::ETHERNET default
+# (250.0), so a single-entry priority list yields exactly the same setup order
+# as a config with no priority block. Subsequent entries step down by a small
+# amount to break ties without crossing other priority bands.
+#
+# Important: must stay strictly less than setup_priority::AFTER_BLUETOOTH
+# (300.0), which NetworkComponent itself uses — otherwise the highest-priority
+# interface could tie with NetworkComponent and run before esp_netif_init().
+NETWORK_PRIORITY_BASE = 250.0
+NETWORK_PRIORITY_STEP = 5.0
+
 network_ns = cg.esphome_ns.namespace("network")
+NetworkComponent = network_ns.class_("NetworkComponent", cg.Component)
 IPAddress = network_ns.class_("IPAddress")
 
 
@@ -105,8 +135,160 @@ def has_high_performance_networking() -> bool:
     return CORE.data.get(KEY_HIGH_PERFORMANCE_NETWORKING, False)
 
 
+def _get_priority_entry(iface: str) -> dict | None:
+    """Return the priority entry dict for the given interface, or None if not configured."""
+    priority_list = CORE.data.get(KEY_NETWORK_PRIORITY)
+    if priority_list is None:
+        return None
+    iface_lower = iface.lower()
+    for entry in priority_list:
+        if entry["interface"] == iface_lower:
+            return entry
+    return None
+
+
+def get_network_priority(iface: str) -> float | None:
+    """Get the setup priority for the given network interface type.
+
+    Returns the float setup priority for ``iface`` based on the order declared
+    under ``network: priority:``.  Interfaces listed first receive a higher
+    setup priority so they are initialised before lower-priority ones.
+
+    If no ``network: priority:`` has been configured this returns ``None`` and
+    the calling component should fall back to its own default setup priority.
+
+    Args:
+        iface: Interface type string — one of ``"ethernet"``, ``"wifi"``,
+               ``"openthread"`` or ``"modem"`` (case-insensitive).
+
+    Returns:
+        float setup priority, or None if no priority list was configured.
+
+    Example usage inside a component's ``to_code``::
+
+        from esphome.components import network
+
+        async def to_code(config):
+            var = cg.new_Pvariable(config[CONF_ID])
+            await cg.register_component(var, config)
+
+            prio = network.get_network_priority("ethernet")
+            if prio is not None:
+                cg.add(var.set_setup_priority(prio))
+            ...
+    """
+    priority_list = CORE.data.get(KEY_NETWORK_PRIORITY)
+    if priority_list is None:
+        return None
+    iface_lower = iface.lower()
+    for idx, entry in enumerate(priority_list):
+        if entry["interface"] == iface_lower:
+            return NETWORK_PRIORITY_BASE - (idx * NETWORK_PRIORITY_STEP)
+    return None
+
+
+def get_network_timeout(iface: str) -> int | None:
+    """Get the fallback timeout in milliseconds for the given network interface.
+
+    Returns the timeout (in ms) that the runtime should wait for ``iface`` to
+    connect before attempting to bring up the next interface in the priority
+    list.  Returns ``None`` if no timeout was configured for this interface,
+    meaning the next interface should start immediately.
+
+    Args:
+        iface: Interface type string — one of ``"ethernet"``, ``"wifi"``,
+               ``"openthread"`` or ``"modem"`` (case-insensitive).
+
+    Returns:
+        int timeout in milliseconds, or None if no timeout is configured.
+
+    Example usage inside a component's ``to_code``::
+
+        from esphome.components import network
+
+        async def to_code(config):
+            ...
+            timeout_ms = network.get_network_timeout("ethernet")
+            if timeout_ms is not None:
+                cg.add(var.set_fallback_timeout(timeout_ms))
+            ...
+    """
+    entry = _get_priority_entry(iface)
+    if entry is None:
+        return None
+    return entry.get("timeout")
+
+
+def _validate_timeout(value):
+    """Accept any common ESPHome/HA time period format, or a plain integer as seconds.
+
+    Accepted formats: 30s, 10sec, 1min, 500ms, 1h, 1.5h, 30 (plain int → 30s).
+    """
+    if isinstance(value, int):
+        # Plain integer — treat as seconds, e.g. timeout: 30 means 30s
+        return cv.positive_time_period_milliseconds(f"{value}s")
+    return cv.positive_time_period_milliseconds(value)
+
+
+def _priority_entry_schema(value):
+    """Validate a single priority list entry in either plain string or mapping form.
+
+    Plain string form (no timeout):
+        - ethernet
+
+    Mapping form with optional timeout:
+        - ethernet:
+            timeout: 30s
+    """
+    if isinstance(value, str):
+        return cv.one_of(*VALID_NETWORK_TYPES, lower=True)(value)
+    if isinstance(value, dict):
+        if len(value) != 1:
+            raise cv.Invalid(
+                "Each priority entry must have exactly one interface name as its key"
+            )
+        iface = next(iter(value))
+        cv.one_of(*VALID_NETWORK_TYPES, lower=True)(iface)
+        opts = cv.Schema(
+            {
+                cv.Optional(CONF_TIMEOUT): _validate_timeout,
+            }
+        )(value[iface] or {})
+        return {iface: opts}
+    raise cv.Invalid(
+        f"Expected an interface name string or a mapping, got {type(value).__name__}"
+    )
+
+
+def _normalize_priority_entry(value) -> dict:
+    """Normalize a validated priority entry to a canonical dict.
+
+    Returns a dict with keys:
+      - ``interface``: str, lowercase interface name
+      - ``timeout``: int milliseconds, or None
+    """
+    if isinstance(value, str):
+        return {"interface": value, "timeout": None}
+    # Mapping form — exactly one key (the interface name)
+    iface, opts = next(iter(value.items()))
+    timeout = opts.get(CONF_TIMEOUT)
+    timeout_ms = int(timeout.total_milliseconds) if timeout is not None else None
+    return {"interface": iface, "timeout": timeout_ms}
+
+
+def _validate_priority_list(value):
+    """Validate and normalize the full priority list, rejecting duplicates."""
+    raw = cv.ensure_list(_priority_entry_schema)(value)
+    entries = [_normalize_priority_entry(e) for e in raw]
+    interfaces = [e["interface"] for e in entries]
+    if len(interfaces) != len(set(interfaces)):
+        raise cv.Invalid("Duplicate entries are not allowed in 'priority'")
+    return entries
+
+
 CONFIG_SCHEMA = cv.Schema(
     {
+        cv.GenerateID(): cv.declare_id(NetworkComponent),
         cv.SplitDefault(
             CONF_ENABLE_IPV6,
             bk72xx=False,
@@ -130,15 +312,53 @@ CONFIG_SCHEMA = cv.Schema(
         ),
         cv.Optional(CONF_MIN_IPV6_ADDR_COUNT, default=0): cv.positive_int,
         cv.Optional(CONF_ENABLE_HIGH_PERFORMANCE): cv.All(cv.boolean, cv.only_on_esp32),
+        cv.Optional(CONF_PRIORITY): _validate_priority_list,
     }
 )
 
 
+def _final_validate(config):
+    """Check that every interface named in 'priority' has a corresponding component block."""
+    full = fv.full_config.get()
+    for entry in config.get(CONF_PRIORITY, []):
+        iface = entry["interface"]
+        if iface not in full:
+            raise cv.Invalid(
+                f"'{iface}' is listed in 'network: priority:' but no '{iface}:' "
+                f"component is configured",
+                [CONF_PRIORITY],
+            )
+
+
+FINAL_VALIDATE_SCHEMA = _final_validate
+
+
 @coroutine_with_priority(CoroPriority.NETWORK)
 async def to_code(config):
     cg.add_define("USE_NETWORK")
     # ESP32 with Arduino uses ESP-IDF network APIs directly, no Arduino Network library needed
 
+    # Store the user-declared network priority list in CORE.data so that ethernet,
+    # wifi and other network components can query it via get_network_priority() and
+    # get_network_timeout() during their own to_code phase.
+    if CONF_PRIORITY in config:
+        priority_list = config[CONF_PRIORITY]
+        CORE.data[KEY_NETWORK_PRIORITY] = priority_list
+        # Enable Component::set_setup_priority() so the per-interface to_code
+        # calls below have a defined symbol to link against. Without this define
+        # the implementation in core/component.cpp is compiled out.
+        cg.add_define("USE_SETUP_PRIORITY_OVERRIDE")
+
+        def _fmt(entry):
+            if entry["timeout"] is not None:
+                return f"{entry['interface']} (timeout: {entry['timeout']}ms)"
+            return entry["interface"]
+
+        _LOGGER.info(
+            "Network interface priority: %s",
+            " > ".join(_fmt(e) for e in priority_list),
+        )
+
     # Apply high performance networking settings
     # Config can explicitly enable/disable, or default to component-driven behavior
     enable_high_perf = config.get(CONF_ENABLE_HIGH_PERFORMANCE)
@@ -224,3 +444,22 @@ async def to_code(config):
                 cg.add_build_flag("-DPIO_FRAMEWORK_ARDUINO_LWIP2_IPV6_LOW_MEMORY")
             if CORE.is_rp2040:
                 cg.add_build_flag("-DPIO_FRAMEWORK_ARDUINO_ENABLE_IPV6")
+    # Pvariable creation lives in a separate coroutine at NETWORK_SERVICES so it
+    # emits after wifi/ethernet at COMMUNICATION. This keeps compile-time config
+    # (above) separate from C++ object lifecycle and allows wiring in interface
+    # pointers via get_variable().
+    if CORE.is_esp32:
+        CORE.add_job(network_component_to_code, config)
+
+
+@coroutine_with_priority(CoroPriority.NETWORK_SERVICES)
+async def network_component_to_code(config: ConfigType) -> None:
+    var = cg.new_Pvariable(config[CONF_ID])
+    await cg.register_component(var, config)
+
+    # Pass the priority list to the C++ component. NetworkComponent::add_priority_entry
+    # captures the interface-name string literal pointer; CORE.data[KEY_NETWORK_PRIORITY]
+    # holds the normalized list of dicts (`{"interface": str, "timeout": int|None}`).
+    for entry in CORE.data.get(KEY_NETWORK_PRIORITY, []):
+        timeout_ms = entry["timeout"] if entry["timeout"] is not None else 0
+        cg.add(var.add_priority_entry(entry["interface"], timeout_ms))

esphome/components/network/network_component.cpp

@@ -0,0 +1,119 @@
+#include "network_component.h"
+
+#include "esphome/core/defines.h"
+#if defined(USE_NETWORK) && defined(USE_ESP32)
+#include "esphome/core/log.h"
+
+#include <cstring>
+
+#include "esp_err.h"
+#include "esp_event.h"
+#include "esp_netif.h"
+
+namespace esphome::network {
+
+static const char *const TAG = "network";
+
+void NetworkComponent::setup() {
+  // Initialize ESP-IDF network interfaces and ensure the default event loop exists
+  esp_err_t err;
+  err = esp_netif_init();
+  if (err != ESP_OK) {
+    ESP_LOGE(TAG, "esp_netif_init failed: (%d) %s", err, esp_err_to_name(err));
+    this->mark_failed();
+    return;
+  }
+  err = esp_event_loop_create_default();
+  // ESP_ERR_INVALID_STATE is returned if the default loop already exists,
+  // which is fine since we just want to make sure it exists
+  if (err != ESP_OK && err != ESP_ERR_INVALID_STATE) {
+    ESP_LOGE(TAG, "esp_event_loop_create_default failed: (%d) %s", err, esp_err_to_name(err));
+    this->mark_failed();
+    return;
+  }
+
+  // Register an IP_EVENT handler so we can re-arbitrate the default netif on every
+  // interface up/down. ESP-IDF's built-in auto-selection picks by route_prio (WiFi STA = 100
+  // > Ethernet = 50), which inverts the user's stated priority for same-subnet configurations.
+  // We register AFTER esp-idf's internal handler, so our esp_netif_set_default_netif() call
+  // wins and stays sticky thanks to esp-idf's "manual override" flag.
+  err = esp_event_handler_register(IP_EVENT, ESP_EVENT_ANY_ID, &NetworkComponent::event_handler_, this);
+  if (err != ESP_OK) {
+    ESP_LOGW(TAG, "IP_EVENT handler register failed: %s — default route arbitration disabled",
+             esp_err_to_name(err));
+  }
+
+  // Defensive: arbitrate now in case an interface came up before our handler registered
+  // (unlikely given our AFTER_BLUETOOTH priority but cheap).
+  this->update_default_netif_();
+}
+
+void NetworkComponent::add_priority_entry(const char *interface, uint32_t timeout_ms) {
+  if (this->priority_list_.size() >= MAX_NETWORK_PRIORITY_ENTRIES) {
+    ESP_LOGW(TAG, "Priority list full; ignoring '%s'", interface);
+    return;
+  }
+  this->priority_list_.push_back({interface, timeout_ms});
+}
+
+const char *NetworkComponent::interface_to_ifkey_(const char *interface) {
+  // Standard ESP-IDF netif keys. esphome's wifi/ethernet/openthread components create
+  // netifs using these defaults.
+  if (std::strcmp(interface, "ethernet") == 0)
+    return "ETH_DEF";
+  if (std::strcmp(interface, "wifi") == 0)
+    return "WIFI_STA_DEF";  // STA carries uplink; AP never wins default route
+  if (std::strcmp(interface, "openthread") == 0)
+    return "OT_DEF";
+  if (std::strcmp(interface, "modem") == 0)
+    return "PPP_DEF";
+  return nullptr;
+}
+
+void NetworkComponent::event_handler_(void *arg, esp_event_base_t /*base*/, int32_t /*id*/, void * /*data*/) {
+  auto *self = static_cast<NetworkComponent *>(arg);
+  self->update_default_netif_();
+}
+
+void NetworkComponent::update_default_netif_() {
+  // No priority list configured → leave ESP-IDF's route_prio-based auto-selection alone.
+  // Single-interface configs behave exactly as before.
+  if (this->priority_list_.empty()) {
+    return;
+  }
+
+  for (const auto &entry : this->priority_list_) {
+    const char *ifkey = interface_to_ifkey_(entry.interface);
+    if (ifkey == nullptr)
+      continue;
+
+    esp_netif_t *netif = esp_netif_get_handle_from_ifkey(ifkey);
+    if (netif == nullptr)
+      continue;  // component for this interface hasn't run setup() yet
+
+    // is_netif_up returns true only when the netif has link + IP, which is what
+    // we want for "this interface can carry traffic right now."
+    if (!esp_netif_is_netif_up(netif))
+      continue;
+
+    if (netif != this->active_netif_) {
+      ESP_LOGI(TAG, "Default interface: %s", entry.interface);
+      esp_netif_set_default_netif(netif);
+      this->active_interface_ = entry.interface;
+      this->active_netif_ = netif;
+    }
+    return;
+  }
+
+  // No priority-listed interface is currently up.
+  if (this->active_netif_ != nullptr) {
+    ESP_LOGD(TAG, "No active interface in priority list");
+    this->active_interface_ = nullptr;
+    this->active_netif_ = nullptr;
+    // We intentionally don't clear esp-idf's default — the next interface that comes
+    // up will trigger our handler again and we'll re-pick.
+  }
+}
+
+}  // namespace esphome::network
+#endif

esphome/components/network/network_component.h

@@ -0,0 +1,54 @@
+#pragma once
+#include "esphome/core/defines.h"
+#if defined(USE_NETWORK) && defined(USE_ESP32)
+#include "esphome/core/component.h"
+#include "esphome/core/helpers.h"
+
+#include "esp_event.h"
+#include "esp_netif.h"
+
+namespace esphome::network {
+
+// Cap matches the number of interface types the priority list accepts in YAML
+// (ethernet, wifi, openthread, modem). StaticVector keeps zero heap allocation.
+inline constexpr size_t MAX_NETWORK_PRIORITY_ENTRIES = 4;
+
+struct NetworkPriorityEntry {
+  const char *interface;  // YAML name: "ethernet", "wifi", "openthread", "modem"
+  uint32_t timeout_ms;    // 0 = no timeout; consumed by Unit D (runtime fallback)
+};
+
+class NetworkComponent : public Component {
+ public:
+  void setup() override;
+  // AFTER_BLUETOOTH: BLE controller must initialize before esp_netif_init per IDF guidance.
+  float get_setup_priority() const override { return setup_priority::AFTER_BLUETOOTH; }
+
+  // Codegen-time priority list construction. Called once per `network: priority:` entry
+  // in YAML order. The interface name pointer must have static storage duration.
+  void add_priority_entry(const char *interface, uint32_t timeout_ms);
+
+  // Currently-active interface in priority order (the one set as default netif).
+  // Returns nullptr if no priority list is configured or no interface is up.
+  const char *get_active_interface() const { return this->active_interface_; }
+  esp_netif_t *get_active_netif() const { return this->active_netif_; }
+
+ protected:
+  // Maps a YAML interface name to its ESP-IDF netif if-key.
+  // Returns nullptr if the interface name is not recognized.
+  static const char *interface_to_ifkey_(const char *interface);
+
+  // ESP-IDF event handler trampoline. Fires on IP_EVENT_* and re-arbitrates the default netif.
+  static void event_handler_(void *arg, esp_event_base_t base, int32_t id, void *data);
+
+  // Walk priority_list_ in order. Set the highest-priority netif that is up as the
+  // ESP-IDF default. No-op if priority_list_ is empty (single-interface configs).
+  void update_default_netif_();
+
+  StaticVector<NetworkPriorityEntry, MAX_NETWORK_PRIORITY_ENTRIES> priority_list_;
+  const char *active_interface_{nullptr};
+  esp_netif_t *active_netif_{nullptr};
+};
+
+}  // namespace esphome::network
+#endif

esphome/components/openthread/openthread_esp.cpp

@@ -35,9 +35,8 @@ void OpenThreadComponent::setup() {
   esp_vfs_eventfd_config_t eventfd_config = {
       .max_fds = 3,
   };
+  // Network interface setup handled by network component
   ESP_ERROR_CHECK(nvs_flash_init());
-  ESP_ERROR_CHECK(esp_event_loop_create_default());
-  ESP_ERROR_CHECK(esp_netif_init());
   ESP_ERROR_CHECK(esp_vfs_eventfd_register(&eventfd_config));
 
   xTaskCreate(

esphome/components/wifi/__init__.py

@@ -12,6 +12,7 @@ from esphome.components.esp32 import (
     only_on_variant,
 )
 from esphome.components.network import (
+    get_network_priority,
     has_high_performance_networking,
     ip_address_literal,
 )
@@ -42,7 +43,6 @@ from esphome.const import (
     CONF_ON_CONNECT,
     CONF_ON_DISCONNECT,
     CONF_ON_ERROR,
-    CONF_OUTPUT_POWER,
     CONF_PASSWORD,
     CONF_POWER_SAVE_MODE,
     CONF_PRIORITY,
@@ -440,6 +440,7 @@ def _validate(config):
     return config
 
 
+CONF_OUTPUT_POWER = "output_power"
 CONF_PASSIVE_SCAN = "passive_scan"
 CONFIG_SCHEMA = cv.All(
     cv.Schema(
@@ -573,6 +574,10 @@ def wifi_network(config, ap, static_ip):
 @coroutine_with_priority(CoroPriority.COMMUNICATION)
 async def to_code(config):
     var = cg.new_Pvariable(config[CONF_ID])
+
+    prio = get_network_priority("wifi")
+    if prio is not None:
+        cg.add(var.set_setup_priority(prio))
     cg.add(var.set_use_address(config[CONF_USE_ADDRESS]))
 
     # Track if any network uses Enterprise authentication

esphome/components/wifi/wifi_component.cpp

@@ -632,11 +632,11 @@ void WiFiComponent::setup() {
 #endif
 
   if (this->enable_on_boot_) {
+#ifdef USE_ESP32
+    this->wifi_lazy_init_();
+#endif
     this->start();
   } else {
-#ifdef USE_ESP32
-    esp_netif_init();
-#endif
     this->state_ = WIFI_COMPONENT_STATE_DISABLED;
   }
 }
@@ -1278,6 +1278,11 @@ void WiFiComponent::enable() {
 
   ESP_LOGD(TAG, "Enabling");
   this->state_ = WIFI_COMPONENT_STATE_OFF;
+#ifdef USE_ESP32
+  // Idempotent — only allocates DMA buffers + netifs on the first call. After this,
+  // start() can safely run.
+  this->wifi_lazy_init_();
+#endif
   this->start();
 }
 

esphome/components/wifi/wifi_component.h

@@ -694,6 +694,12 @@ class WiFiComponent final : public Component {
   bool wifi_apply_hostname_();
   bool wifi_sta_connect_(const WiFiAP &ap);
   void wifi_pre_setup_();
+#ifdef USE_ESP32
+  // ESP-IDF only: defers esp_wifi_init() + netif creation (which allocate ~15-30KB of
+  // DMA-capable internal SRAM) until wifi actually needs to come up. Idempotent.
+  // Called from setup() only when enable_on_boot_=true, and from enable() on first use.
+  void wifi_lazy_init_();
+#endif
   WiFiSTAConnectStatus wifi_sta_connect_status_() const;
   bool is_connected_() const {
     return this->state_ == WIFI_COMPONENT_STATE_STA_CONNECTED &&
@@ -889,6 +895,12 @@ class WiFiComponent final : public Component {
   bool rrm_{false};
 #endif
   bool enable_on_boot_{true};
+#ifdef USE_ESP32
+  // Tracks whether esp_wifi_init() + netif creation has happened. Allows enable()
+  // to be called at runtime without re-allocating, and ensures the heavy init is
+  // skipped entirely when enable_on_boot_ is false until first enable().
+  bool wifi_initialized_{false};
+#endif
   bool got_ipv4_address_{false};
   bool keep_scan_results_{false};
   bool has_completed_scan_after_captive_portal_start_{

esphome/components/wifi/wifi_component_esp_idf.cpp

@@ -145,23 +145,15 @@ void WiFiComponent::wifi_pre_setup_() {
     get_mac_address_raw(mac);
     set_mac_address(mac);
   }
-  esp_err_t err = esp_netif_init();
+  // Network interface setup handled by network component
-  if (err != ERR_OK) {
-    ESP_LOGE(TAG, "esp_netif_init failed: %s", esp_err_to_name(err));
-    return;
-  }
   s_wifi_event_group = xEventGroupCreate();
   if (s_wifi_event_group == nullptr) {
     ESP_LOGE(TAG, "xEventGroupCreate failed");
     return;
   }
-  err = esp_event_loop_create_default();
-  if (err != ERR_OK) {
-    ESP_LOGE(TAG, "esp_event_loop_create_default failed: %s", esp_err_to_name(err));
-    return;
-  }
   esp_event_handler_instance_t instance_wifi_id, instance_ip_id;
-  err = esp_event_handler_instance_register(WIFI_EVENT, ESP_EVENT_ANY_ID, &event_handler, nullptr, &instance_wifi_id);
+  esp_err_t err =
+      esp_event_handler_instance_register(WIFI_EVENT, ESP_EVENT_ANY_ID, &event_handler, nullptr, &instance_wifi_id);
   if (err != ERR_OK) {
     ESP_LOGE(TAG, "esp_event_handler_instance_register failed: %s", esp_err_to_name(err));
     return;
@@ -171,6 +163,16 @@ void WiFiComponent::wifi_pre_setup_() {
     ESP_LOGE(TAG, "esp_event_handler_instance_register failed: %s", esp_err_to_name(err));
     return;
   }
+  // NOTE: netif creation + esp_wifi_init() used to live here. They allocate ~15-30KB of
+  // DMA-capable internal SRAM, which competes with W5500 SPI DMA and I2S DMA on
+  // memory-tight devices. They are now deferred to wifi_lazy_init_(), called from
+  // setup() when enable_on_boot_ is true, or from enable() on first runtime enable.
+  // This makes enable_on_boot:false genuinely skip the wifi DMA allocation.
+}
+
+void WiFiComponent::wifi_lazy_init_() {
+  if (this->wifi_initialized_)
+    return;
 
   s_sta_netif = esp_netif_create_default_wifi_sta();
 
@@ -183,7 +185,7 @@ void WiFiComponent::wifi_pre_setup_() {
     ESP_LOGW(TAG, "starting wifi without nvs");
     cfg.nvs_enable = false;
   }
-  err = esp_wifi_init(&cfg);
+  esp_err_t err = esp_wifi_init(&cfg);
   if (err != ERR_OK) {
     ESP_LOGE(TAG, "esp_wifi_init failed: %s", esp_err_to_name(err));
     return;
@@ -193,6 +195,7 @@ void WiFiComponent::wifi_pre_setup_() {
     ESP_LOGE(TAG, "esp_wifi_set_storage failed: %s", esp_err_to_name(err));
     return;
   }
+  this->wifi_initialized_ = true;
 }
 
 bool WiFiComponent::wifi_mode_(optional<bool> sta, optional<bool> ap) {