ESP8266 Community Forum

Yes thats also what was told to me at the openocd irc channel.
Still wondering if johnsmirl just misread/misunderstood something or if he found openocd with xtensa support somewhere...

Would be great to have debugging on the ESP and if I knew that beforehand that no official openocd support for xtensa exists I wouldn't had
put this expensive FT2232H on my devboard (And ordered the parts) . But well thats alone my fault I didn't checked that before and took some forum claims for serious ....

I had found a web page describing OpenOCD on xtensa. I had not tried because I had no hardware at that time. I can ask on the xtensa mailing list and see what they say.

The Xtensa Tools OCD Daemon supports FT2232 (or at least some way of hooking it up). And it's not licensed. Not sure about redistributing the installer, but if someone picks up the latest Xtensa Tools software eval, it's in there.
http://ip.cadence.com/support/sdk-evaluation-request
Works best with the Xtensa Tools GDB (xt-gdb, also in there) rather than the mainline GDB version, and xt-gdb isn't licensed either.

I've connected FTDI 2232-based JTAG probe to ESP-03 and connected to it with xt-ocd + xt-gdb.
Used ARM-USB-TINY-H probe and the following topology.xml:

It kind of works, at least I'm able to dump/change memory or write to peripheral registers and see signals on output pins.
It's not very stable though, sometimes it gets reset or its debug FSM starts jumping between 'stopped' and 'debugged' states.