feat(wifi): Add wifi APIs according to IDF

components/esp8266/source/esp_wifi.c

@@ -0,0 +1,44 @@
+// Copyright 2018 Espressif Systems (Shanghai) PTE LTD
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "esp_libc.h"
+#include "esp_system.h"
+#include "esp_wifi.h"
+#include "esp_socket.h"
+#include "net/sockio.h"
+
+/**
+  * @brief  Init WiFi
+  *         Alloc resource for WiFi driver, such as WiFi control structure, RX/TX buffer,
+  *         WiFi NVS structure etc, this WiFi also start WiFi task
+  *
+  * @attention 1. This API must be called before all other WiFi API can be called
+  * @attention 2. Always use WIFI_INIT_CONFIG_DEFAULT macro to init the config to default values, this can
+  *               guarantee all the fields got correct value when more fields are added into wifi_init_config_t
+  *               in future release. If you want to set your owner initial values, overwrite the default values
+  *               which are set by WIFI_INIT_CONFIG_DEFAULT, please be notified that the field 'magic' of 
+  *               wifi_init_config_t should always be WIFI_INIT_CONFIG_MAGIC!
+  *
+  * @param  config pointer to WiFi init configuration structure; can point to a temporary variable.
+  *
+  * @return
+  *    - ESP_OK: succeed
+  *    - ESP_ERR_NO_MEM: out of memory
+  *    - others: refer to error code esp_err.h
+  */
+esp_err_t esp_wifi_init(const wifi_init_config_t *config)
+{
+    esp_event_set_default_wifi_handlers();
+    return esp_wifi_init_internal(config);
+}