boot(8) on FreeBSD
The text f53c56e67939, as FreeBSD 12.2-RELEASE shipped it.
system bootstrapping procedures
Flags it lists
-
-C -
-D -
-P -
-S -
-a -
-c -
-d -
-g -
-h -
-m -
-n -
-p -
-q -
-r -
-s -
-v