diff --git a/README.md b/README.md
index a0b9f4c0e..70ead24dc 100644
--- a/README.md
+++ b/README.md
@@ -153,9 +153,7 @@ APIs related to deep sleep and watchdog timer are available in the ```ESP``` obj
 
 ```ESP.deepSleep(microseconds, mode)``` will put the chip into deep sleep. ```mode``` is one of ```WAKE_RF_DEFAULT```, ```WAKE_RFCAL```, ```WAKE_NO_RFCAL```, ```WAKE_RF_DISABLED```. (GPIO16 needs to be tied to RST to wake from deepSleep.)
 
-```ESP.wdtEnable()```, ```ESP.wdtDisable()```, and ```ESP.wdtFeed()``` provide some control over the watchdog timer.
-
-```ESP.reset()``` resets the CPU.
+```ESP.restart()``` restarts the CPU.
 
 ```ESP.getFreeHeap()``` returns the free heap size.
 
@@ -171,6 +169,16 @@ Several APIs may be used to get flash chip info:
 
 ```ESP.getCycleCount()``` returns the cpu instruction cycle count since start as an unsigned 32-bit.  This is useful for accurate timing of very short actions like bit banging.
 
+```ESP.getVcc()``` may be used to measure supply voltage. ESP needs to reconfigure the ADC
+at startup in order for this feature to be available. Add the following line to the top
+of your sketch to use ```getVcc```:
+```
+ADC_MODE(ADC_VCC);
+```
+TOUT pin has to be disconnected in this mode.
+
+Note that by default ADC is configured to read from TOUT pin using ```analogRead(A0)```, and 
+```ESP.getVCC()``` is not available.
 
 #### OneWire (from https://www.pjrc.com/teensy/td_libs_OneWire.html) ####
 
diff --git a/cores/esp8266/Esp.cpp b/cores/esp8266/Esp.cpp
index 73367683a..617dd9cba 100644
--- a/cores/esp8266/Esp.cpp
+++ b/cores/esp8266/Esp.cpp
@@ -32,12 +32,6 @@ extern struct rst_info resetInfo;
 
 // #define DEBUG_SERIAL Serial
 
-//extern "C" void ets_wdt_init(uint32_t val);
-extern "C" void ets_wdt_enable(void);
-extern "C" void ets_wdt_disable(void);
-extern "C" void wdt_feed(void) {
-    
-}
 
 /**
  * User-defined Literals
@@ -85,46 +79,42 @@ unsigned long long operator"" _GB(unsigned long long x) {
 
 EspClass ESP;
 
-EspClass::EspClass()
-{
-
-}
-
 void EspClass::wdtEnable(uint32_t timeout_ms)
 {
-    //todo find doku for ets_wdt_init may set the timeout
-	ets_wdt_enable();
 }
 
 void EspClass::wdtEnable(WDTO_t timeout_ms)
 {
-    wdtEnable((uint32_t) timeout_ms);
 }
 
 void EspClass::wdtDisable(void)
 {
-	ets_wdt_disable();
 }
 
 void EspClass::wdtFeed(void)
 {
-	wdt_feed();
 }
 
 void EspClass::deepSleep(uint32_t time_us, WakeMode mode)
 {
-	system_deep_sleep_set_option(static_cast<int>(mode));
- 	system_deep_sleep(time_us);
+    system_deep_sleep_set_option(static_cast<int>(mode));
+    system_deep_sleep(time_us);
 }
 
+extern "C" void esp_yield();
+extern "C" void __real_system_restart_local();
 void EspClass::reset(void)
 {
-	((void (*)(void))0x40000080)();
+    __real_system_restart_local();
 }
 
 void EspClass::restart(void)
 {
     system_restart();
+    esp_yield();
+    // todo: provide an alternative code path if this was called
+    // from system context, not from continuation
+    // (implement esp_is_cont_ctx()?)
 }
 
 uint16_t EspClass::getVcc(void)
diff --git a/cores/esp8266/Esp.h b/cores/esp8266/Esp.h
index d264690a9..df41be399 100644
--- a/cores/esp8266/Esp.h
+++ b/cores/esp8266/Esp.h
@@ -61,6 +61,15 @@ enum RFMode {
 #define WAKE_NO_RFCAL    RF_NO_CAL
 #define WAKE_RF_DISABLED RF_DISABLED
 
+enum ADCMode {
+    ADC_TOUT = 33,
+    ADC_TOUT_3V3 = 33,
+    ADC_VCC = 255,
+    ADC_VDD = 255
+};
+
+#define ADC_MODE(mode) extern "C" int __get_adc_mode() { return (int) (mode); }
+
 typedef enum {
      FM_QIO = 0x00,
      FM_QOUT = 0x01,
@@ -71,8 +80,6 @@ typedef enum {
 
 class EspClass {
     public:
-        EspClass();
-
         // TODO: figure out how to set WDT timeout
         void wdtEnable(uint32_t timeout_ms = 0);
         // note: setting the timeout value is not implemented at the moment
diff --git a/cores/esp8266/core_esp8266_phy.c b/cores/esp8266/core_esp8266_phy.c
index 2ac33a8a6..faa601184 100644
--- a/cores/esp8266/core_esp8266_phy.c
+++ b/cores/esp8266/core_esp8266_phy.c
@@ -224,6 +224,7 @@ static uint8_t phy_init_data[128] =
 
 extern int __real_register_chipv6_phy(uint8_t* init_data);
 extern int __wrap_register_chipv6_phy(uint8_t* unused) {
+    phy_init_data[107] = __get_adc_mode();
     return __real_register_chipv6_phy(phy_init_data);
 }
 
@@ -243,6 +244,10 @@ extern int __get_rf_mode()
     return 0;  // default mode
 }
 
-
+extern int __get_adc_mode() __attribute__((weak));
+extern int __get_adc_mode()
+{
+    return 33; // default ADC mode
+}
 
 
diff --git a/cores/esp8266/core_esp8266_wiring_analog.c b/cores/esp8266/core_esp8266_wiring_analog.c
index 53451b713..74d5dd5d3 100644
--- a/cores/esp8266/core_esp8266_wiring_analog.c
+++ b/cores/esp8266/core_esp8266_wiring_analog.c
@@ -17,17 +17,18 @@
   You should have received a copy of the GNU Lesser General Public
   License along with this library; if not, write to the Free Software
   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+  
+  
+  18/06/2015 analogRead bugfix by Testato
 */
+
 #include "wiring_private.h"
 #include "pins_arduino.h"
 
-extern uint16_t readvdd33(void);
-
-void analogReference(uint8_t mode) {}
 
 extern int __analogRead(uint8_t pin) {
   if(pin == 17){
-    return readvdd33() >> 2; // readvdd33 is 12 bit
+    return system_adc_read();
   }
   return digitalRead(pin) * 1023;
 }
diff --git a/libraries/ESP8266WebServer/src/ESP8266WebServer.cpp b/libraries/ESP8266WebServer/src/ESP8266WebServer.cpp
index df067f0c9..4a0fbd3f5 100644
--- a/libraries/ESP8266WebServer/src/ESP8266WebServer.cpp
+++ b/libraries/ESP8266WebServer/src/ESP8266WebServer.cpp
@@ -115,7 +115,7 @@ void ESP8266WebServer::handleClient()
   _handleRequest();
 }
 
-void ESP8266WebServer::sendHeader(String name, String value, bool first) {
+void ESP8266WebServer::sendHeader(const String& name, const String& value, bool first) {
   String headerLine = name;
   headerLine += ": ";
   headerLine += value;
@@ -129,7 +129,7 @@ void ESP8266WebServer::sendHeader(String name, String value, bool first) {
   }
 }
 
-void ESP8266WebServer::send(int code, const char* content_type, String content) {
+void ESP8266WebServer::send(int code, const char* content_type, const String& content) {
   String response = "HTTP/1.1 ";
   response += String(code);
   response += " ";
@@ -155,15 +155,15 @@ void ESP8266WebServer::send(int code, const char* content_type, String content)
   sendContent(response);
 }
 
-void ESP8266WebServer::send(int code, char* content_type, String content) {
+void ESP8266WebServer::send(int code, char* content_type, const String& content) {
   send(code, (const char*)content_type, content);
 }
 
-void ESP8266WebServer::send(int code, String content_type, String content) {
+void ESP8266WebServer::send(int code, const String& content_type, const String& content) {
   send(code, (const char*)content_type.c_str(), content);
 }
 
-void ESP8266WebServer::sendContent(String content) {
+void ESP8266WebServer::sendContent(const String& content) {
   size_t size_to_send = content.length();
   size_t size_sent = 0;
   while(size_to_send) {
diff --git a/libraries/ESP8266WebServer/src/ESP8266WebServer.h b/libraries/ESP8266WebServer/src/ESP8266WebServer.h
index d787e4e3f..888e36b4a 100644
--- a/libraries/ESP8266WebServer/src/ESP8266WebServer.h
+++ b/libraries/ESP8266WebServer/src/ESP8266WebServer.h
@@ -77,15 +77,15 @@ public:
   // code - HTTP response code, can be 200 or 404
   // content_type - HTTP content type, like "text/plain" or "image/png"
   // content - actual content body
-  void send(int code, const char* content_type = NULL, String content = String(""));
-  void send(int code, char* content_type, String content);
-  void send(int code, String content_type, String content);
+  void send(int code, const char* content_type = NULL, const String& content = String(""));
+  void send(int code, char* content_type, const String& content);
+  void send(int code, const String& content_type, const String& content);
 
   void setContentLength(size_t contentLength) { _contentLength = contentLength; }
-  void sendHeader(String name, String value, bool first = false);
-  void sendContent(String content);
+  void sendHeader(const String& name, const String& value, bool first = false);
+  void sendContent(const String& content);
 
-template<typename T> size_t streamFile(T &file, String contentType){
+template<typename T> size_t streamFile(T &file, const String& contentType){
   setContentLength(file.size());
   if (String(file.name()).endsWith(".gz") && 
       contentType != "application/x-gzip" &&
diff --git a/libraries/ESP8266WiFi/src/include/slist.h b/libraries/ESP8266WiFi/src/include/slist.h
index 3ea09cd48..0606f7243 100644
--- a/libraries/ESP8266WiFi/src/include/slist.h
+++ b/libraries/ESP8266WiFi/src/include/slist.h
@@ -9,14 +9,12 @@ public:
 protected:
 
   static void _add(T* self) {
-    DEBUGV("%s %08x %08x\n", __func__, (uint32_t) self, (uint32_t) _s_first);
     T* tmp = _s_first;
     _s_first = self;
     self->_next = tmp;
   }
 
   static void _remove(T* self) {
-    DEBUGV("%s %08x %08x\n", __func__, (uint32_t) self, (uint32_t) _s_first);
     if (_s_first == self) {
       _s_first = self->_next;
       self->_next = 0;