"Our VGA BIOS is a binary ... it may be possible to find BIOS source code
somewhere."
From the first part, they only provide a binary? The second part seems as if
they're blowing you off. It's "somewhere" - go look for it, whatever - we
don't care - we're not distributing it - we're only going to provide the
binary.
If the Bochs / Qemu VGA BIOS source code can be used why don't they and why
don't they distribute that? If the Bochs / Qemu VGA BIOS is free and can be
used then that's great but that their response is as if they don't care is
what concerns me.
There's also the matter that most FPGA still have non-free software needed.
In a way it seems the non-free stuff morphs & moves. That's not necessarily a
reflection on these folk though; just something to think on.