This is a processor plugin for IDA 7.x, to support the Xtensa core found in Espressif ESP8266 and ESP32. It does not support other configurations of the Xtensa architecture, but that is probably (hopefully) easy to implement.
This is a beta release, for your hacking pleasure.
Copy the file to the procs/ directory in your IDA install. Ta-daa!
GPLv2!