It is a fact that mkinitrd, today, is unaware of your new system of
obtaining firmware from the kernel source[or build] tree.
Certainly it is aware of the need to copy firmware in general, but that
doesn't change the fact that the tg3 firmware will not make it into
initramfs, without additional steps taken.
So, no, it doesn't "work fine" -- the firmware doesn't make it into the
initramfs.
Jeff
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