controller as we use in boot blocks (querying status register until
bit 1 goes off). If that doesn't happed during reasonable period assume
that the hardware doesn't have AT-style keyboard controller. This makes
FreeBSD working almost OOB on MacBook Pro (still there are issues with
putting second CPU core on-line, but since installation CD comes with
UP kernel with this change one should be able to install FreeBSD without
playing tricks with hints). Other legacy-free hardware (e.g. IBM NetVista
S40) should benefit from this as well, but since I don't have any I can't
verify.
It should make no difference on the ordinary i386 hardware (since in
that case that hardware already would be having an issues with A20
routines in boot blocks). I don't know much about AT-style keyboard
controller on other platforms (and don't have dedicated access to one),
therefore, the code is restricted to i386 for now. I suspect that amd64
may need this as well, but I would rather leave this decision to someone
who knows better about the platform(s) in question.
I have tested this change on as many "ordinary i386 boxes" as I can get
my hands on, and it doesn't create any false negatives on hardware with
AT-style keyboard present.
MFC after: 1 month
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