diff --git a/boards.txt b/boards.txt
index 818b26ce25..c9667733f9 100644
--- a/boards.txt
+++ b/boards.txt
@@ -1,5 +1,6 @@
 menu.UploadSpeed=Upload Speed
 menu.CpuFrequency=CPU Frequency
+menu.CrystalFrequency=Crystal Frequency
 menu.FlashSize=Flash Size
 menu.FlashMode=Flash Mode
 menu.FlashFreq=Flash Frequency
@@ -23,6 +24,7 @@ generic.serial.disableRTS=true
 
 generic.build.mcu=esp8266
 generic.build.f_cpu=80000000L
+generic.build.f_crystal=1
 generic.build.board=ESP8266_ESP01
 generic.build.core=esp8266
 generic.build.variant=generic
@@ -36,6 +38,13 @@ generic.menu.CpuFrequency.80.build.f_cpu=80000000L
 generic.menu.CpuFrequency.160=160 MHz
 generic.menu.CpuFrequency.160.build.f_cpu=160000000L
 
+generic.menu.CrystalFrequency.26=26 MHz
+generic.menu.CrystalFrequency.26.build.f_crystal=1
+generic.menu.CrystalFrequency.40=40 MHz
+generic.menu.CrystalFrequency.40.build.f_crystal=0
+generic.menu.CrystalFrequency.24=24 MHz
+generic.menu.CrystalFrequency.24.build.f_crystal=2
+
 generic.menu.FlashFreq.40=40MHz
 generic.menu.FlashFreq.40.build.flash_freq=40
 generic.menu.FlashFreq.80=80MHz
@@ -246,6 +255,7 @@ esp8285.serial.disableRTS=true
 
 esp8285.build.mcu=esp8266
 esp8285.build.f_cpu=80000000L
+esp8285.build.f_crystal=1
 esp8285.build.board=ESP8266_ESP01
 esp8285.build.core=esp8266
 esp8285.build.variant=generic
@@ -351,6 +361,7 @@ espduino.serial.disableRTS=true
 
 espduino.build.mcu=esp8266
 espduino.build.f_cpu=80000000L
+espduino.build.f_crystal=1
 espduino.build.board=ESP8266_ESP13
 espduino.build.core=esp8266
 espduino.build.variant=ESPDuino
@@ -414,6 +425,7 @@ huzzah.serial.disableRTS=true
 
 huzzah.build.mcu=esp8266
 huzzah.build.f_cpu=80000000L
+huzzah.build.f_crystal=1
 huzzah.build.board=ESP8266_ESP12
 huzzah.build.core=esp8266
 huzzah.build.variant=adafruit
@@ -465,6 +477,7 @@ espresso_lite_v1.upload.wait_for_upload_port=true
 
 espresso_lite_v1.build.mcu=esp8266
 espresso_lite_v1.build.f_cpu=80000000L
+espresso_lite_v1.build.f_crystal=1
 espresso_lite_v1.build.board=ESP8266_ESPRESSO_LITE_V1
 espresso_lite_v1.build.core=esp8266
 espresso_lite_v1.build.variant=espresso_lite_v1
@@ -570,6 +583,7 @@ espresso_lite_v2.upload.wait_for_upload_port=true
 
 espresso_lite_v2.build.mcu=esp8266
 espresso_lite_v2.build.f_cpu=80000000L
+espresso_lite_v2.build.f_crystal=1
 espresso_lite_v2.build.board=ESP8266_ESPRESSO_LITE_V2
 espresso_lite_v2.build.core=esp8266
 espresso_lite_v2.build.variant=espresso_lite_v2
@@ -675,6 +689,7 @@ phoenix_v1.upload.wait_for_upload_port=true
 
 phoenix_v1.build.mcu=esp8266
 phoenix_v1.build.f_cpu=80000000L
+phoenix_v1.build.f_crystal=1
 phoenix_v1.build.board=ESP8266_PHOENIX_V1
 phoenix_v1.build.core=esp8266
 phoenix_v1.build.variant=phoenix_v1
@@ -780,6 +795,7 @@ phoenix_v2.upload.wait_for_upload_port=true
 
 phoenix_v2.build.mcu=esp8266
 phoenix_v2.build.f_cpu=80000000L
+phoenix_v2.build.f_crystal=1
 phoenix_v2.build.board=ESP8266_PHOENIX_V2
 phoenix_v2.build.core=esp8266
 phoenix_v2.build.variant=phoenix_v2
@@ -889,6 +905,7 @@ nodemcu.serial.disableRTS=true
 
 nodemcu.build.mcu=esp8266
 nodemcu.build.f_cpu=80000000L
+nodemcu.build.f_crystal=1
 nodemcu.build.board=ESP8266_NODEMCU
 nodemcu.build.core=esp8266
 nodemcu.build.variant=nodemcu
@@ -953,6 +970,7 @@ nodemcuv2.serial.disableRTS=true
 
 nodemcuv2.build.mcu=esp8266
 nodemcuv2.build.f_cpu=80000000L
+nodemcuv2.build.f_crystal=1
 nodemcuv2.build.board=ESP8266_NODEMCU
 nodemcuv2.build.core=esp8266
 nodemcuv2.build.variant=nodemcu
@@ -1018,6 +1036,7 @@ modwifi.serial.disableRTS=true
 
 modwifi.build.mcu=esp8266
 modwifi.build.f_cpu=80000000L
+modwifi.build.f_crystal=1
 modwifi.build.board=MOD_WIFI_ESP8266
 modwifi.build.core=esp8266
 modwifi.build.variant=generic
@@ -1072,6 +1091,7 @@ thing.serial.disableRTS=true
 
 thing.build.mcu=esp8266
 thing.build.f_cpu=80000000L
+thing.build.f_crystal=1
 thing.build.board=ESP8266_THING
 thing.build.core=esp8266
 thing.build.variant=thing
@@ -1125,6 +1145,7 @@ thingdev.serial.disableRTS=true
 
 thingdev.build.mcu=esp8266
 thingdev.build.f_cpu=80000000L
+thingdev.build.f_crystal=1
 thingdev.build.board=ESP8266_THING_DEV
 thingdev.build.core=esp8266
 thingdev.build.variant=thing
@@ -1174,6 +1195,7 @@ esp210.serial.disableRTS=true
 
 esp210.build.mcu=esp8266
 esp210.build.f_cpu=80000000L
+esp210.build.f_crystal=1
 esp210.build.board=ESP8266_ESP210
 esp210.build.core=esp8266
 esp210.build.variant=generic
@@ -1233,6 +1255,7 @@ esp210.menu.FlashSize.4M1M.build.spiffs_pagesize=256
 #
 # wifio.build.mcu=esp8266
 # wifio.build.f_cpu=80000000L
+# wifio.build.f_crystal=1
 # wifio.build.board=ESP8266_WIFIO
 # wifio.build.core=esp8266
 # wifio.build.variant=wifio
@@ -1265,6 +1288,7 @@ d1_mini.serial.disableRTS=true
 
 d1_mini.build.mcu=esp8266
 d1_mini.build.f_cpu=80000000L
+d1_mini.build.f_crystal=1
 d1_mini.build.board=ESP8266_WEMOS_D1MINI
 d1_mini.build.core=esp8266
 d1_mini.build.variant=d1_mini
@@ -1330,6 +1354,7 @@ d1.serial.disableRTS=true
 
 d1.build.mcu=esp8266
 d1.build.f_cpu=80000000L
+d1.build.f_crystal=1
 d1.build.board=ESP8266_WEMOS_D1MINI
 d1.build.core=esp8266
 d1.build.variant=d1
@@ -1397,6 +1422,7 @@ espino.serial.disableRTS=true
 
 espino.build.mcu=esp8266
 espino.build.f_cpu=80000000L
+espino.build.f_crystal=1
 espino.build.board=ESP8266_ESP12
 espino.build.core=esp8266
 espino.build.variant=espino
@@ -1472,6 +1498,7 @@ espinotee.serial.disableRTS=true
 
 espinotee.build.mcu=esp8266
 espinotee.build.f_cpu=80000000L
+espinotee.build.f_crystal=1
 espinotee.build.board=ESP8266_ESP13
 espinotee.build.core=esp8266
 espinotee.build.variant=espinotee
@@ -1536,6 +1563,7 @@ wifinfo.serial.disableRTS=true
 
 wifinfo.build.mcu=esp8266
 wifinfo.build.core=esp8266
+wifinfo.build.f_crystal=1
 wifinfo.build.variant=wifinfo
 wifinfo.build.board=WIFINFO
 wifinfo.build.spiffs_pagesize=256
@@ -1667,6 +1695,7 @@ coredev.serial.disableRTS=true
 
 coredev.build.mcu=esp8266
 coredev.build.f_cpu=80000000L
+coredev.build.f_crystal=1
 coredev.build.board=ESP8266_ESP01
 coredev.build.core=esp8266
 coredev.build.variant=generic
diff --git a/cores/esp8266/core_esp8266_phy.c b/cores/esp8266/core_esp8266_phy.c
index 67604174e5..264b762b9f 100644
--- a/cores/esp8266/core_esp8266_phy.c
+++ b/cores/esp8266/core_esp8266_phy.c
@@ -28,6 +28,10 @@
  #include "ets_sys.h"
  #include "spi_flash.h"
 
+#ifndef F_CRYSTAL
+#define F_CRYSTAL 1
+#endif
+
 static const uint8_t ICACHE_FLASH_ATTR phy_init_data[128] =
 {
     [0] = 5,  // Reserved, do not change
@@ -88,9 +92,7 @@ static const uint8_t ICACHE_FLASH_ATTR phy_init_data[128] =
     // 0: 40MHz
     // 1: 26MHz
     // 2: 24MHz
-    [48] = 1,
-
-
+    [48] = F_CRYSTAL,
 
     // sdio_configure
     // 0: Auto by pin strapping
diff --git a/package.json b/package.json
new file mode 100644
index 0000000000..c0be382ec5
--- /dev/null
+++ b/package.json
@@ -0,0 +1,7 @@
+{
+    "name": "framework-arduinoespressif8266",
+    "description": "Arduino Wiring-based Framework (ESP8266 Core)",
+    "system": "all",
+    "url": "https://github.com/esp8266/Arduino",
+    "version": "1.20500.0-dev"
+}
diff --git a/platform.txt b/platform.txt
index f8f79de6c9..87e24aa934 100644
--- a/platform.txt
+++ b/platform.txt
@@ -71,13 +71,13 @@ recipe.hooks.core.prebuild.1.pattern=bash -c "mkdir -p {build.path}/core && echo
 recipe.hooks.core.prebuild.1.pattern.windows=
 
 ## Compile c files
-recipe.c.o.pattern="{compiler.path}{compiler.c.cmd}" {compiler.cpreprocessor.flags} {compiler.c.flags} -DF_CPU={build.f_cpu} {build.lwip_flags} {build.debug_port} {build.debug_level} -DARDUINO={runtime.ide.version} -DARDUINO_{build.board} -DARDUINO_ARCH_{build.arch} -DARDUINO_BOARD="{build.board}" {compiler.c.extra_flags} {build.extra_flags} {includes} "{source_file}" -o "{object_file}"
+recipe.c.o.pattern="{compiler.path}{compiler.c.cmd}" {compiler.cpreprocessor.flags} {compiler.c.flags} -DF_CPU={build.f_cpu} -DF_CRYSTAL={build.f_crystal} {build.lwip_flags} {build.debug_port} {build.debug_level} -DARDUINO={runtime.ide.version} -DARDUINO_{build.board} -DARDUINO_ARCH_{build.arch} -DARDUINO_BOARD="{build.board}" {compiler.c.extra_flags} {build.extra_flags} {includes} "{source_file}" -o "{object_file}"
 
 ## Compile c++ files
-recipe.cpp.o.pattern="{compiler.path}{compiler.cpp.cmd}" {compiler.cpreprocessor.flags} {compiler.cpp.flags} -DF_CPU={build.f_cpu} {build.lwip_flags} {build.debug_port} {build.debug_level} -DARDUINO={runtime.ide.version} -DARDUINO_{build.board} -DARDUINO_ARCH_{build.arch} -DARDUINO_BOARD="{build.board}" {compiler.cpp.extra_flags} {build.extra_flags} {includes} "{source_file}" -o "{object_file}"
+recipe.cpp.o.pattern="{compiler.path}{compiler.cpp.cmd}" {compiler.cpreprocessor.flags} {compiler.cpp.flags} -DF_CPU={build.f_cpu} -DF_CRYSTAL={build.f_crystal} {build.lwip_flags} {build.debug_port} {build.debug_level} -DARDUINO={runtime.ide.version} -DARDUINO_{build.board} -DARDUINO_ARCH_{build.arch} -DARDUINO_BOARD="{build.board}" {compiler.cpp.extra_flags} {build.extra_flags} {includes} "{source_file}" -o "{object_file}"
 
 ## Compile S files
-recipe.S.o.pattern="{compiler.path}{compiler.c.cmd}" {compiler.cpreprocessor.flags} {compiler.S.flags} -DF_CPU={build.f_cpu} {build.lwip_flags} {build.debug_port} {build.debug_level} -DARDUINO={runtime.ide.version} -DARDUINO_{build.board} -DARDUINO_ARCH_{build.arch} -DARDUINO_BOARD="{build.board}" {compiler.c.extra_flags} {build.extra_flags} {includes} "{source_file}" -o "{object_file}"
+recipe.S.o.pattern="{compiler.path}{compiler.c.cmd}" {compiler.cpreprocessor.flags} {compiler.S.flags} -DF_CPU={build.f_cpu} -DF_CRYSTAL={build.f_crystal} {build.lwip_flags} {build.debug_port} {build.debug_level} -DARDUINO={runtime.ide.version} -DARDUINO_{build.board} -DARDUINO_ARCH_{build.arch} -DARDUINO_BOARD="{build.board}" {compiler.c.extra_flags} {build.extra_flags} {includes} "{source_file}" -o "{object_file}"
 
 ## Create archives
 recipe.ar.pattern="{compiler.path}{compiler.ar.cmd}" {compiler.ar.flags} {compiler.ar.extra_flags} "{build.path}/arduino.ar" "{object_file}"