core_version.h

#define ARDUINO_ESP8266_GIT_VER 0x00000000

// ARDUINO_ESP8266_RELEASE is defined for released versions as a string containing the version name, i.e. "2_3_0_RC1"
// ARDUINO_ESP8266_RELEASE is used in the core internally. Please use ESP.getCoreVersion() function instead.

// ARDUINO_ESP8266_RELEASE_<version number> are defined for releases, for use in #ifdef... constructs