As Koakuma confirmed on bugs@, their machine exhibited strange behaviour with such outdated firmware while at least the latest version runs fine as expected.
I'd like to mention this in the FAQ. Feedack? OK? Index: sparc64.html =================================================================== RCS file: /cvs/www/sparc64.html,v retrieving revision 1.403 diff -u -p -r1.403 sparc64.html --- sparc64.html 19 May 2020 02:02:10 -0000 1.403 +++ sparc64.html 28 Jun 2020 10:33:46 -0000 @@ -230,6 +230,11 @@ and SPARC Enterprise T5120/T5220 may req before OpenBSD can be successfully installed. The SPARC Enterprise T5120/T5220 needs at least OBP 4.28.0. +On machines like the Oracle SPARC T4-2, older firmware versions from +around 2011 are known to cause kernel panics and crashes in +<a href="https://man.openbsd.org/sparc64/ldomd.8";>ldomd</a>; later +versions, at least from 2018, are known to work. + <h4>Supported devices</h4> <ul>
