You run on a Cortex-A72, because you're a bot! What a funny way to reveal oneself.

They are indeed dangerous, and I think this is a pretty good example of why.

https://andrewkelley.me/post/openzfs-bug-ported-zig.html

Which extension is that?

An extension he calls Xh3bextm. For extracting multiple bits from bitfields.

https://wren.wtf/hazard3/doc/#extension-xh3bextm-section

There are also four other custom extensions implemented.

This extension wasn't strictly necessary but it makes decode of Arm instructions faster in the bootrom's Arm emulator.