What font is used during verbose boot mode?
The font used seems to be a somewhat nameless cowboy apparently just called Iso-Font and was made by Ka-Ping Yee. He doesn't seem to care about this accomplishment, since he does not list it on his CV.

The sources for this font are compiled into the kernel and the sources to that are to be found at https://opensource.apple.com/source/xnu/xnu-3789.70.16/

In there it simply says:

/*
 * ISO Latin-1 Font
 *
 * Copyright (c) 2000
 * Ka-Ping Yee &lt;ping@lfw.org&gt;
 *
 * This font may be freely used for any purpose.
 */


This rather unsatisfactory naming seems to be accurate nevertheless, as an email transcript on Russian site reveals:

Ka-Ping Yee ISO Latin-1 Font in linux kernel

That site also illustrates how to use this on a Linux console and  will show you how it looks when booting linux: