pfSense

Current 2.5 kernel contains only rtwn firmwares:

# kldstat -v | grep rtwn
        310 rtwn_rtl8821aufw_fw
        309 rtwn_rtl8812aufw_fw
        308 rtwn_rtl8192eufw_fw
        307 rtwn_rtl8192cfwU_fw
        306 rtwn_rtl8192cfwT_fw
        305 rtwn_rtl8192cfwE_B_fw
        304 rtwn_rtl8192cfwE_fw
        303 rtwn_rtl8188eufw_fw
        302 rtwn_rtl8188eefw_fw

to correctly compile PCI and USB rtwn modules, 'rtwn_pci' and 'rtwn_usb' must be added to conf,
see https://www.freebsd.org/cgi/man.cgi?query=rtwn&sektion=4&apropos=0&manpath=FreeBSD+12.1-RELEASE+and+Ports:

To    compile    this driver into the kernel, place the following lines in your
     kernel configuration file:

       device rtwn
       device rtwnfw
       device rtwn_usb
       device rtwn_pci
       device wlan
       device firmware