…lash* upstream/master: (72 commits)  Typo error in ESP8266WiFiGeneric.h (esp8266#7797)  lwip2: use pvPortXalloc/vPortFree and "-free -fipa-pta" (esp8266#7793)  Use smarter cache key, cache Arduino IDE (esp8266#7791)  Update to SdFat 2.0.2, speed SD access (esp8266#7779)  BREAKING - Upgrade to upstream newlib 4.0.0 release (esp8266#7708)  mock: +hexdump() from debug.cpp (esp8266#7789)  more lwIP physical interfaces (esp8266#6680)  Rationalize File timestamp callback (esp8266#7785)  Update to LittleFS v2.3 (esp8266#7787)  WiFiServerSecure: Cache SSL sessions (esp8266#7774)  platform.txt: instruct GCC to perform more aggressive optimization (esp8266#7770)  LEAmDNS fixes (esp8266#7786)  Move uzlib to master branch (esp8266#7782)  Update to latest uzlib upstream (esp8266#7776)  EspSoftwareSerial bug fix release 6.10.1: preciseDelay() could delay() for extremely long time, if period duration was exceeded on entry. (esp8266#7771)  Fixed OOM double count in umm_realloc. (esp8266#7768)  Added missing check for failure on umm_push_heap calls in Esp.cpp (esp8266#7767)  Fix: cannot build afteresp8266#7060 on Win64 (esp8266#7754)  Add the missing 'rename' method wrapper in SD library. (esp8266#7766)  i2s: adds i2s_rxtxdrive_begin(enableRx, enableTx, driveRxClocks, driveTxClocks) (esp8266#7748)  ...

It seems that the global dhcpSoftAP is used to encapsulate some of theDHCP functionality. Make use of the new API.See upstream change:esp8266/Arduino#6680

esp_yield() now also calls esp_schedule(), original esp_yield() function renamed to esp_suspend().Don't use delay(0) in the Core internals, libraries and examples. Use yield() when the code issupposed to be called from CONT, use esp_yield() when the code can be called from either CONT or SYS.Clean-up esp_yield() and esp_schedule() declarations across the code and use coredecls.h instead.Implement helper functions for libraries that were previously using esp_yield(), esp_schedule() andesp_delay() directly to wait for certain SYS context tasks to complete. Correctly use esp_delay()for timeouts, make sure scheduled functions have a chance to run (e.g. LwIP_Ethernet uses recurrent)Related issues:-#6107 - discussion about the esp_yield() and esp_delay() usage in ClientContext-#6212 - discussion about replacing delay() with a blocking loop-#6680 - pull request introducing LwIP-based Ethernet-#7146 - discussion that originated UART code changes-#7969 - proposal to remove delay(0) from the example code-#8291 - discussion related to the run_scheduled_recurrent_functions() usage in LwIP Ethernet-#8317 - yieldUntil() implementation, similar to the esp_delay() overload with a timeout and a 0 interval

esp_yield() now also calls esp_schedule(), original esp_yield() function renamed to esp_suspend().Don't use delay(0) in the Core internals, libraries and examples. Use yield() when the code issupposed to be called from CONT, use esp_yield() when the code can be called from either CONT or SYS.Clean-up esp_yield() and esp_schedule() declarations across the code and use coredecls.h instead.Implement helper functions for libraries that were previously using esp_yield(), esp_schedule() andesp_delay() directly to wait for certain SYS context tasks to complete. Correctly use esp_delay()for timeouts, make sure scheduled functions have a chance to run (e.g. LwIP_Ethernet uses recurrent)Related issues:-esp8266#6107 - discussion about the esp_yield() and esp_delay() usage in ClientContext-esp8266#6212 - discussion about replacing delay() with a blocking loop-esp8266#6680 - pull request introducing LwIP-based Ethernet-esp8266#7146 - discussion that originated UART code changes-esp8266#7969 - proposal to remove delay(0) from the example code-esp8266#8291 - discussion related to the run_scheduled_recurrent_functions() usage in LwIP Ethernet-esp8266#8317 - yieldUntil() implementation, similar to the esp_delay() overload with a timeout and a 0 interval