"invalid antenna gain in sprom"

[Carmel NY]

I just installed FreeBSD 12 onto an older PC, mostly just to play
around with it. Anyway, upon boot up I am presented with this message:

Autoloading module: if_bwi.ko                                                   
Autoloading module: if_bwn.ko                                                   
bwi0: <Broadcom BCM4318 802.11b/g Wireless Lan> mem 0xfdefe000-0xfdefffff irq 16
 at device 1.0 on pci2                                                          
bwi0: BBP: id 0x4318, rev 0x2, pkg 0                                            
bwi0: MAC: rev 9                                                                
bwi0: PHY: type 2, rev 7, ver 3                                                 
bwi0: RF: manu 0x17f, type 0x2050, rev 8                                        
bwi0: invalid antenna gain in sprom                                             
Configuring vt: keymap.                                                         
Autoloading module: uhid.ko                                                     
Autoloading module: ums.ko

I have not been able to get the wireless card to work, although I know
that it does because I had Windows 10 running on this PC. I also have
no idea what the "invalid antenna gain in sprom' means. Googling it has
not produced a lot of useful data. I am just wondering if anyone has
gotten this card to work and possible, what the 'sprom' warning is all
about.

-- 
Carmel