From 00ac8ea69aef1f7ce00b0a890bbe880082793893 Mon Sep 17 00:00:00 2001
From: Gunar Schorcht <gunar@schorcht.net>
Date: Wed, 30 Jan 2019 18:54:51 +0100
Subject: [PATCH] cpu/esp8266: add init function in dummy lwIP

Calling the initialization function ensures that the dummy lwIP library is used instead of the real lwIP, even if the esp_wifi module for esp8266 is not used.
---
 cpu/esp8266/sdk/lwip.c | 7 +++++++
 cpu/esp8266/startup.c  | 4 ++++
 2 files changed, 11 insertions(+)

diff --git a/cpu/esp8266/sdk/lwip.c b/cpu/esp8266/sdk/lwip.c
index 8c851ba7fc..ecf9ea08df 100644
--- a/cpu/esp8266/sdk/lwip.c
+++ b/cpu/esp8266/sdk/lwip.c
@@ -210,4 +210,11 @@ uint32_t espconn_init(uint32 arg)
     return 1;
 }
 
+extern struct netif * eagle_lwip_getif(uint8_t index);
+
+void esp_lwip_init(void)
+{
+    netif_set_default((struct netif *)eagle_lwip_getif(0));
+}
+
 #endif /* MODULE_ESP_SDK */
diff --git a/cpu/esp8266/startup.c b/cpu/esp8266/startup.c
index 6a221d5562..0d50dd36c6 100644
--- a/cpu/esp8266/startup.c
+++ b/cpu/esp8266/startup.c
@@ -123,6 +123,10 @@ void ets_run(void)
     ets_isr_unmask(BIT(ETS_SOFT_INUM));
     #endif
 
+    /* initialize dummy lwIP library to link it even if esp_wifi is not used */
+    extern void esp_lwip_init(void);
+    esp_lwip_init();
+
     thread_create(ets_task_stack, sizeof(ets_task_stack),
             ETS_TASK_PRIORITY,
             THREAD_CREATE_WOUT_YIELD | THREAD_CREATE_STACKTEST,