Add EEPROM EUI-48 device identity across firmware and API.

Read the factory 24AA025E48 serial after ADAU I2C boot, derive SoftAP SSID, BT name, STA hostname, and expose serialNumber on GET /api/health with graceful fallbacks.

Co-authored-by: Cursor <cursoragent@cursor.com>

Software/main/CMakeLists.txt

@@ -3,5 +3,5 @@ idf_component_register(
         "main.cpp"
         "hardware_bootstrap.cpp"
     INCLUDE_DIRS "."
-    REQUIRES core net secure_store adau1701 si4684 tuner audio bt1035 bluetooth station integration
+    REQUIRES core net secure_store adau1701 si4684 tuner audio bt1035 bluetooth station integration eeprom24aa
 )

Software/main/hardware_bootstrap.cpp

@@ -18,6 +18,9 @@
 #include "audio/AudioService.hpp"
 #include "board_pins.hpp"
 #include "bt1035/Bt1035Driver.hpp"
+#include "core/DeviceIdentity.hpp"
+#include "driver/i2c_master.h"
+#include "eeprom24aa/Eeprom24aa.hpp"
 #include "secure_store/NvsAudioProfileStore.hpp"
 #include "si4684/Si4684Band.hpp"
 #include "si4684/Si4684Driver.hpp"
@@ -69,6 +72,7 @@ bt1035::Bt1035Driver gBt1035(
         .sysCtlGpio = board::pins::Bt1035SysCtl,
     });
 
+core::DeviceIdentity gDeviceIdentity = core::DeviceIdentity::unknown();
 bool gReady = false;
 } // namespace
 
@@ -91,6 +95,21 @@ std::expected<void, HardwareBootError> HardwareBootstrap::boot()
         }
     }
 
+    const auto* busHandle =
+        static_cast<i2c_master_bus_handle_t>(gAdau1701.i2cBusHandle());
+    eeprom24aa::Eeprom24aa eeprom(busHandle,
+                                  static_cast<std::uint8_t>(
+                                      board::pins::Eeprom24aaAddr));
+    if (auto identity = eeprom.readDeviceIdentity(); identity) {
+        gDeviceIdentity = std::move(*identity);
+        ESP_LOGI(kTag, "unit serial %.*s",
+                 static_cast<int>(gDeviceIdentity.serialNumber().size()),
+                 gDeviceIdentity.serialNumber().data());
+    } else {
+        gDeviceIdentity = core::DeviceIdentity::unknown();
+        ESP_LOGW(kTag, "EUI-48 read failed — using fallback identity");
+    }
+
     if (auto audioResult = gAudioService.loadAndApply(); !audioResult) {
         ESP_LOGW(kTag, "ADAU1701 profile apply failed");
     }
@@ -100,6 +119,11 @@ std::expected<void, HardwareBootError> HardwareBootstrap::boot()
         return std::unexpected(HardwareBootError::Bt1035BootFailed);
     }
 
+    if (auto nameResult =
+            gBt1035.setDeviceName(gDeviceIdentity.bluetoothName()); !nameResult) {
+        ESP_LOGW(kTag, "BT1035 device name set failed");
+    }
+
     gReady = true;
     ESP_LOGI(kTag, "companion chips ready");
     return {};
@@ -129,4 +153,9 @@ bt1035::Bt1035Driver& HardwareBootstrap::bt1035Driver()
     return gBt1035;
 }
 
+const core::DeviceIdentity& HardwareBootstrap::deviceIdentity() noexcept
+{
+    return gDeviceIdentity;
+}
+
 } // namespace hardware

Software/main/hardware_bootstrap.hpp

@@ -13,6 +13,7 @@
 #pragma once
 
 #include "core/CompanionChipStatus.hpp"
+#include "core/DeviceIdentity.hpp"
 
 #include "bt1035/Bt1035Driver.hpp"
 
@@ -124,6 +125,18 @@ public:
      * @date     2026-07-06
      */
     [[nodiscard]] static bt1035::Bt1035Driver& bt1035Driver();
+
+    /**
+     * @brief    deviceIdentity — per-board identity from the 24AA025E48 EUI-48.
+     *
+     * @dname    deviceIdentity
+     * @return   Reference to identity loaded during boot().
+     * @pubstate reads gDeviceIdentity after boot(); unknown() on EEPROM failure.
+     *
+     * @author   Michele Bigi
+     * @date     2026-07-07
+     */
+    [[nodiscard]] static const core::DeviceIdentity& deviceIdentity() noexcept;
 };
 
 } // namespace hardware

Software/main/main.cpp

@@ -85,7 +85,8 @@ extern "C" void app_main()
         bluetoothService,
         stationService,
         integration,
-        hardware::HardwareBootstrap::companionChipStatus());
+        hardware::HardwareBootstrap::companionChipStatus(),
+        hardware::HardwareBootstrap::deviceIdentity());
     if (!netResult) {
         ESP_LOGE(kTag, "network bootstrap failed");
         return;