Merge remote-tracking branch 'upstream/master' into ota_commands_in_flash

* 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 after esp8266#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)
  ...

Author: davisonja

.github/workflows/pull-request.yml

@@ -30,7 +30,7 @@ jobs:
       uses: actions/cache@v2
       with:
         path: ./tools/dist
-        key: key-linux-toolchain
+        key: ${{ runner.os }}-${{ hashFiles('package/package_esp8266com_index.template.json', 'tests/common.sh') }}
     - name: Build Sketches
       env:
         TRAVIS_BUILD_DIR: ${{ github.workspace }}
@@ -62,7 +62,7 @@ jobs:
       uses: actions/cache@v2
       with:
         path: ./tools/dist
-        key: key-linux-toolchain
+        key: ${{ runner.os }}-${{ hashFiles('package/package_esp8266com_index.template.json', 'tests/common.sh') }}
     - name: Build Sketches
       env:
         TRAVIS_BUILD_DIR: ${{ github.workspace }}
@@ -90,7 +90,7 @@ jobs:
       uses: actions/cache@v2
       with:
         path: ./tools/dist
-        key: key-windows-toolchain
+        key: ${{ runner.os }}-${{ hashFiles('package/package_esp8266com_index.template.json', 'tests/common.sh') }}
     - name: Build Sketch
       env:
         TRAVIS_BUILD_DIR: ${{ github.workspace }}
@@ -122,7 +122,7 @@ jobs:
       uses: actions/cache@v2
       with:
         path: ./tools/dist
-        key: key-mac-toolchain
+        key: ${{ runner.os }}-${{ hashFiles('package/package_esp8266com_index.template.json', 'tests/common.sh') }}
     - name: Build Sketch
       env:
         TRAVIS_BUILD_DIR: ${{ github.workspace }}
@@ -260,7 +260,7 @@ jobs:
       uses: actions/cache@v2
       with:
         path: ./tools/dist
-        key: key-linux-toolchain
+        key: ${{ runner.os }}-${{ hashFiles('package/package_esp8266com_index.template.json', 'tests/common.sh') }}
     - name: Boards.txt diff
       env:
         TRAVIS_BUILD_DIR: ${{ github.workspace }}

.travis.yml

@@ -30,7 +30,7 @@ Starting with 1.6.4, Arduino allows installation of third-party platform package
 
 - Install the current upstream Arduino IDE at the 1.8.9 level or later. The current version is on the [Arduino website](https://www.arduino.cc/en/main/software).
 - Start Arduino and open the Preferences window.
-- Enter ```https://arduino.esp8266.com/stable/package_esp8266com_index.json``` into the *Additional Board Manager URLs* field. You can add multiple URLs, separating them with commas.
+- Enter ```https://arduino.esp8266.com/stable/package_esp8266com_index.json``` into the *File>Preferences>Additional Boards Manager URLs* field of the Arduino IDE. You can add multiple URLs, separating them with commas.
 - Open Boards Manager from Tools > Board menu and install *esp8266* platform (and don't forget to select your ESP8266 board from Tools > Board menu after installation).
 
 #### Latest release [![Latest release](https://img.shields.io/github/release/esp8266/Arduino.svg)](https://github.com/esp8266/Arduino/releases/latest/)