"pm open,type:2 0" output on Serial with Debug Level 'None' on udp.begin()

[liebman]

Basic Infos

Hardware

Hardware: ESP-12f
Core Version: current git

Description

Problem description

With Debug Level set to 'None' a message is printed on Serial when the begin() method of WiFiUDP is called. Grepping the for the message points to libpp.a

zod:esp8266 chris.l$ grep -r "pm open,type" .
Binary file ./tools/sdk/lib/libpp.a matches

Settings in IDE

Module: Generic ESP8266 Module
Flash Size: 4MB/1MB
CPU Frequency: 80Mhz
Flash Mode: qio
Flash Frequency: 40Mhz
Upload Using: SERIAL
Reset Method: nodemcu

Sketch

/*
 *  This sketch sends data via HTTP GET requests to data.sparkfun.com service.
 *
 *  You need to get streamId and privateKey at data.sparkfun.com and paste them
 *  below. Or just customize this script to talk to other HTTP servers.
 *
 */

#include <ESP8266WiFi.h>
#include <WiFiUdp.h>

const char* ssid     = "XXXXXX";
const char* password = "XXXXXX";

WiFiUDP udp;

void setup() {
  Serial.begin(115200);
  delay(10);

  // We start by connecting to a WiFi network

  Serial.println();
  Serial.println();
  Serial.print("Connecting to ");
  Serial.println(ssid);
  
  /* Explicitly set the ESP8266 to be a WiFi-client, otherwise, it by default,
     would try to act as both a client and an access-point and could cause
     network-issues with your other WiFi-devices on your WiFi-network. */
  WiFi.mode(WIFI_STA);
  WiFi.begin(ssid, password);
  
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }

  Serial.println("");
  Serial.println("WiFi connected");  
  Serial.println("IP address: ");
  Serial.println(WiFi.localIP());

  udp.begin(1234);
}

void loop() {
  delay(10000);
}

Debug Messages

tail 8
chksum 0x2d
csum 0x2d
va2e7c7d0
~ld


Connecting to XXXXXX
.
WiFi connected
IP address: 
192.168.0.17
pm open,type:2 0

[cprasmu]

Same issue here too

wifi evt: 0
....wifi evt: 3
.
WiFi connected
IP address:
192.168.1.110
pm open,type:2 0

[igrr]

This is output from the SDK, which gets enabled whenever you set 'Debug Port' to something other than 'None', or call Serial.setDebugOutput(true); from the sketch.

[liebman]

Thanks @igrr - good to know!

[regpa]

Dear @igrr, could you please elaborate about the meaning to this SDK output: "pm open,type:2 0" ?

[igrr]

@regpa Sorry, can't tell for sure — it comes from the closed source part.
I assume it is related to sleep mode ("pm", "power management") being enabled ("open"), in which case "2" in "type:2" should match the selected sleep mode.