English probably isn't your native language, "
is it up to do something" makes very little sense in this context.
Firmware that's in
/etc/firmware is loaded onto the device, it is a little binary file that is only ever executed by the devices chipset.
Some devices embed firmware on the device, but others require that it be loaded at runtime by the driver..
OpenBSD's
zyd(4) loads a firmware from
/etc/firmware..
zd1211 or
zd1211.. FreeBSD's
zyd(4) stores the firmware for that chipset in
/usr/src/sys/dev/usb/wlan/if_zydfw.h as a large array of bytes.
Because rebooting/reconnecting the device worked, it was likely because the device was left in an inconsistent state by another operating system.. as would explain the allocation error described by Carpetsmoker.
Just because
zyd(4) doesn't use
/etc/firmware, doesn't mean other drivers do not.
Hope that helps.