weak hook preinit() #2111 #2133 #2136

cores/esp8266/Arduino.h

@@ -219,6 +219,7 @@ uint8_t shiftIn(uint8_t dataPin, uint8_t clockPin, uint8_t bitOrder);
 void attachInterrupt(uint8_t pin, void (*)(void), int mode);
 void detachInterrupt(uint8_t pin);
 
+void preinit(void);
 void setup(void);
 void loop(void);
 

cores/esp8266/core_esp8266_main.cpp

@@ -63,7 +63,7 @@ static uint32_t s_micros_at_task_start;
 
 extern "C" {
 extern const uint32_t __attribute__((section(".ver_number"))) core_version = ARDUINO_ESP8266_GIT_VER;
-const char* core_release = 
+const char* core_release =
 #ifdef ARDUINO_ESP8266_RELEASE
  ARDUINO_ESP8266_RELEASE;
 #else
@@ -243,18 +243,26 @@ extern "C" void ICACHE_RAM_ATTR app_entry (void)
  return app_entry_custom();
 }
 
+extern "C" void preinit (void) __attribute__((weak));
+extern "C" void preinit (void)
+{
+ /* do nothing by default */
+}
+
 extern "C" void user_init(void) {
  struct rst_info *rtc_info_ptr = system_get_rst_info();
  memcpy((void *) &resetInfo, (void *) rtc_info_ptr, sizeof(resetInfo));
 
  uart_div_modify(0, UART_CLK_FREQ / (115200));
 
- init();
+ init(); // in core_esp8266_wiring.c, inits hw regs and sdk timer
 
  initVariant();
 
  cont_init(g_pcont);
 
+ preinit(); // Prior to C++ Dynamic Init (not related to above init() ). Meant to be user redefinable.
+
  ets_task(loop_task,
  LOOP_TASK_PRIORITY, s_loop_queue,
  LOOP_QUEUE_SIZE);

libraries/ESP8266WiFi/examples/EarlyDisableWiFi/EarlyDisableWiFi.ino

@@ -0,0 +1,58 @@
+
+#include <ESP8266WiFi.h>
+
+#ifndef STASSID
+#define STASSID "your-ssid"
+#define STAPSK "your-password"
+#endif
+
+// preinit() is called before system startup
+// from nonos-sdk's user entry point user_init()
+
+void preinit() {
+ // Global WiFi constructors are not called yet
+ // (global class instances like WiFi, Serial... are not yet initialized)..
+ // No global object methods or C++ exceptions can be called in here!
+ //The below is a static class method, which is similar to a function, so it's ok.
+ ESP8266WiFiClass::preinitWiFiOff();
+}
+
+void setup() {
+ Serial.begin(115200);
+ Serial.setDebugOutput(true);
+ Serial.println("sleeping 5s");
+
+ // during this period, a simple amp meter shows
+ // an average of 20mA with a Wemos D1 mini
+ // a DSO is needed to check #2111
+ delay(5000);
+
+ Serial.println("waking WiFi up, sleeping 5s");
+ WiFi.forceSleepWake();
+
+ // amp meter raises to 75mA
+ delay(5000);
+
+ Serial.println("connecting to AP " STASSID);
+ WiFi.mode(WIFI_STA);
+ WiFi.begin(STASSID, STAPSK);
+
+ for (bool configured = false; !configured;) {
+ for (auto addr : addrList)
+ if ((configured = !addr.isLocal() && addr.ifnumber() == STATION_IF)) {
+ Serial.printf("STA: IF='%s' hostname='%s' addr= %s\n",
+ addr.ifname().c_str(),
+ addr.ifhostname(),
+ addr.toString().c_str());
+ break;
+ }
+ Serial.print('.');
+ delay(500);
+ }
+
+ // amp meter cycles within 75-80 mA
+
+}
+
+void loop() {
+}

libraries/ESP8266WiFi/src/ESP8266WiFiGeneric.cpp

@@ -579,4 +579,25 @@ void wifi_dns_found_callback(const char *name, CONST ip_addr_t *ipaddr, void *ca
  esp_schedule(); // resume the hostByName function
 }
 
-
+//meant to be called from user-defined preinit()
+void ESP8266WiFiGenericClass::preinitWiFiOff () {
+ // https://github.com/esp8266/Arduino/issues/2111#issuecomment-224251391
+ // WiFi.persistent(false);
+ // WiFi.mode(WIFI_OFF);
+ // WiFi.forceSleepBegin();
+
+ //WiFi.mode(WIFI_OFF) equivalent:
+ // datasheet:
+ // Set Wi-Fi working mode to Station mode, SoftAP
+ // or Station + SoftAP, and do not update flash
+ // (not persistent)
+ wifi_set_opmode_current(WIFI_OFF);
+
+ //WiFi.forceSleepBegin(/*default*/0) equivalent:
+ // sleep forever until wifi_fpm_do_wakeup() is called
+ wifi_fpm_set_sleep_type(MODEM_SLEEP_T);
+ wifi_fpm_open();
+ wifi_fpm_do_sleep(0xFFFFFFF);
+
+ // use WiFi.forceSleepWake() to wake WiFi up
+}

libraries/ESP8266WiFi/src/ESP8266WiFiGeneric.h

@@ -88,6 +88,8 @@ class ESP8266WiFiGenericClass {
  bool forceSleepBegin(uint32 sleepUs = 0);
  bool forceSleepWake();
 
+ static void preinitWiFiOff (); //meant to be called in user-defined preinit()
+
  protected:
  static bool _persistent;
  static WiFiMode_t _forceSleepLastMode;