extmod/modbluetooth: Allow using mp_hal_get_mac as a static address.

Generally a controller should either have its own public address hardcoded,
or loaded by the driver (e.g. cywbt43).

However, for a controller that has no public address where you still want a
long-term stable address, this allows you to use a static address generated
by the port.  Typically on STM32 this will be an LAA, but a board might
override this.

extmod/btstack/modbluetooth_btstack.c

@@ -508,10 +508,12 @@ STATIC void btstack_init_deinit_timeout_handler(btstack_timer_source_t *ds) {
     mp_bluetooth_btstack_state = MP_BLUETOOTH_BTSTACK_STATE_TIMEOUT;
 }
 
+#if !MICROPY_BLUETOOTH_USE_MP_HAL_GET_MAC_STATIC_ADDRESS
 STATIC void btstack_static_address_ready(void *arg) {
     DEBUG_printf("btstack_static_address_ready.\n");
     *(volatile bool *)arg = true;
 }
+#endif
 
 STATIC bool set_public_address(void) {
     bd_addr_t local_addr;
@@ -534,14 +536,27 @@ STATIC void set_random_address(void) {
     } else
     #endif // MICROPY_BLUETOOTH_BTSTACK_ZEPHYR_STATIC_ADDRESS
     {
+        bd_addr_t static_addr;
+
+        #if MICROPY_BLUETOOTH_USE_MP_HAL_GET_MAC_STATIC_ADDRESS
+
+        DEBUG_printf("set_random_address: Generating static address using mp_hal_get_mac\n");
+        mp_hal_get_mac(MP_HAL_MAC_BDADDR, static_addr);
+        // Mark it as STATIC (not RPA or NRPA).
+        static_addr[0] |= 0xc0;
+
+        #else
+
         DEBUG_printf("set_random_address: Generating random static address.\n");
         btstack_crypto_random_t sm_crypto_random_request;
-        bd_addr_t static_addr;
         volatile bool ready = false;
         btstack_crypto_random_generate(&sm_crypto_random_request, static_addr, 6, &btstack_static_address_ready, (void *)&ready);
         while (!ready) {
             MICROPY_EVENT_POLL_HOOK
         }
+
+        #endif // MICROPY_BLUETOOTH_USE_MP_HAL_GET_MAC_STATIC_ADDRESS
+
         DEBUG_printf("set_random_address: Address generated.\n");
         gap_random_address_set(static_addr);
     }

extmod/nimble/modbluetooth_nimble.c

@@ -157,10 +157,22 @@ STATIC bool has_public_address(void) {
 STATIC void set_random_address(bool nrpa) {
     int rc;
     (void)rc;
-    DEBUG_printf("sync_cb: Generating random static address\n");
     ble_addr_t addr;
-    rc = ble_hs_id_gen_rnd(nrpa ? 1 : 0, &addr);
-    assert(rc == 0);
+    #if MICROPY_BLUETOOTH_USE_MP_HAL_GET_MAC_STATIC_ADDRESS
+    if (!nrpa) {
+        DEBUG_printf("set_random_address: Generating static address using mp_hal_get_mac\n");
+        uint8_t hal_mac_addr[6];
+        mp_hal_get_mac(MP_HAL_MAC_BDADDR, hal_mac_addr);
+        addr = create_nimble_addr(BLE_ADDR_RANDOM, hal_mac_addr);
+        // Mark it as STATIC (not RPA or NRPA).
+        addr.val[5] |= 0xc0;
+    } else
+    #endif
+    {
+        DEBUG_printf("set_random_address: Generating random static address\n");
+        rc = ble_hs_id_gen_rnd(nrpa ? 1 : 0, &addr);
+        assert(rc == 0);
+    }
     rc = ble_hs_id_set_rnd(addr.val);
     assert(rc == 0);
     rc = ble_hs_util_ensure_addr(1);