[sitkack]

It was only opaquely supported by GCC, no LLVM, so no Rust.

It is a cool design, but it was a major PITA for awhile. Xtensa is parametric so every instance of a cpu has a custom instruction set.

[Kiboneu]

Heh. Yep. Reverse engineering firmware for a custom xtensa cpu is also a lot of “fun” (and also fun).