Add esp-idf cmake build system component registration

CMakeLists.txt

@@ -0,0 +1,15 @@
+# register esp-idf component
+if (ESP_PLATFORM)
+    idf_component_register(
+            SRCS
+            "src/Dhcp.cpp"
+            "src/Dns.cpp"
+            "src/Ethernet.cpp"
+            "src/EthernetClient.cpp"
+            "src/EthernetServer.cpp"
+            "src/EthernetUdp.cpp"
+            "src/socket.cpp"
+            "src/utility/w5100.cpp"
+            INCLUDE_DIRS "src" "src/utility"
+            REQUIRES arduino)
+endif ()

component.mk

@@ -0,0 +1 @@
+

src/Ethernet.h

@@ -258,6 +258,7 @@ class EthernetServer : public Server {
 	EthernetClient available();
 	EthernetClient accept();
 	virtual void begin();
+	void begin(uint16_t port);
 	virtual size_t write(uint8_t);
 	virtual size_t write(const uint8_t *buf, size_t size);
 	virtual operator bool();

src/EthernetServer.cpp

@@ -37,6 +37,12 @@ void EthernetServer::begin()
 	}
 }
 
+void EthernetServer::begin(uint16_t port)
+{
+    _port = port;
+    begin();
+}
+
 EthernetClient EthernetServer::available()
 {
 	bool listening = false;