Stripping down 8.0

[Mouse <mouse%Rodents-Montreal.ORG@localhost>]

I'm trying to strip down 8.0/amd64 as far as I can (for a turnkey
system at work).

When trying to strip down the kernel, I've run into three issues.  Two
of them seem to arise because the system in question has no use for IP
networking, but does use Ethernet; I've been a little surprised at what
has exploded - and what hasn't - when I include Ethernet devices but
turn off both INET and INET6.

I've run into two issues which I've handled OK:

(1) if_loop.c has an unused variable csum_flags (which I made
    conditional on defined(INET) || defined(INET6)).

(2) ix_txrx.c has a set-but-not-used variable l3d (I made its
    definition and the code to set it similarly conditional).

But now I've run into something I don't understand enough to deal with.
I'm not even sure whether it's because of "Ethernet + !INET + !INET6"
or not - I suspect not, but I'm very unsure of that.

Specifically, wmi_acpi.c is referring to acpiec_bus_write and
acpiec_bus_read, which are coming up undefined in the link.  They
appear to come from acpi_ec.c - apparently there's a hidden dependency
somewhere; I appear to have stripped out enough devices that acpi_ec.c
isn't being included, but left in enough that wmi_acpi.c is, and I'm
not sure which one(s) they are or how to find them.  I'm also not sure
what the correct fix would be, though I suspect that for my purposes I
may be able to just tweak the list of devices included in the kernel
config.  But there are enough devices in the config that trying all
subsets is prohibitive, and trying random subsets is only marginally
better.  If I knew enough about ACPI and/or WMI to know what they are
and how they relate, I might have a guess - but I don't.

So, does anyone happen to know the WMI ACPI stuff enough to tell me
what I'm doing wrong and/or what to do to work around it?  Or,
alternatively, is there a way to ask config(1) why a given file is
being included or excluded from the build?  I don't see anything
obvious in the manpage....

There's nothing secret about the config file in question, so, in case
anyone wants to look at it, is up on ftp.rodents-montreal.org in
/mouse/misc/nb8.0 under the name mwi_acpi-config (that's not what I
called it when using it; I called it INSTALLER, but that's a pretty
meaningless name for the FTP area).

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