I happen to own one spare Linksys WP54G wireless card. When inserting it into the Laptop, FreeBSD complains:
cardbus0: Expecting link target, got 0x3 cardbus0: Resource not specified in CIS: id=10, size=2000 cardbus0: Resource not specified in CIS: id=14, size=20000 cardbus0: <network> at device 0.0 (no driver attached)
But behold! There is a solution: It basically consists of compiling your own NDIS driver. This procedure is also known as "Project Evil". It's very straightforward, so I will outline the steps necessary for the installation of an WPC54G, EU version:
LSTINDS.INF, LSTINDS.cat,
FwRad16.bin and
tnet1130x.sys from the Linksys CD-ROM. For your
convenience, I uploaded these files (a note to Linksys here: please
don't sue me for I am helping people using your great wireless cards
under more operating systems. This will surely increase your shareholder
value - sooner or later.), so you can grab them.
FwRad16.bin into a
directory of your choice. FwRad16.bin has to be placed in
/compat/ndis/.
ndisgen. This text-interface will guide you through
the installation if you choose "Convert Driver". If prompted for the .INF-file, specify the path to
LSTINDS.INF. If prompted for the .sys-file, specify the
path to tnet1130x.sys. Additional files are not needed.
tnet1130x_sys.ko. This file
should be placed in /boot/kernel/.
/boot/loader.conf:
ndis_load="YES" if_ndis_load="YES" tnet_1130x_sys_load="YES"
I haven't tested the lines in /boot/loader.conf because I
use a shell script for loading the device drivers and connecting to my
favourite access points. Please drop me a line if it works.