porting bwfm from N/OBSD [was Re: Rebuilding brcmfmac Wi-Fi driver with the help of AI]

On Sun, 29 Mar 2026, Nuno Teixeira wrote:

Hi Nuno,

> It seems that OpenBSD and NetBSD have drivers for BCM43455. Could those
> drivers be imported fo FreeBSD?

There's been like at least 3 or 4 people I know off, if not more, who started
porting bwfm over the course of the last years; everyone went silent.

That's the reason we now do have a compiling brcmfmac driver for LinuxKPI
in the tree; it laods firmware on PCIe on X86 (and with a workaround on arm64)
(and in theory on USB in my dev tree).
In another dev tree sits a 85% finished SDIO implementation mostly tested
on rtw88, where I already create wlan interfaces and have scanning results,
etc.

The one thing which is missing for brcmfmac really is a cfg80211/netdev
compat shim to drive this, of which we porbably have half as well already
in LinuxKPI.
But that's kind-of disruptive to the other ongoing work for all the other
mac80211-based drivers and so I have not really had a good look.
It could boil down to three functions, it could boil down to a lot more.

Preliminary LinuxKPI USB support is blocked on cleaning up some older
compiler options in the tree, which we currently do not yet understand.
Getting SDIO out as-is simply "need time to sit down", rebase and open
reviews.

In other words I need to finish the rtw8x (and mt76) work before I can
find free time to look at it.  rtw8x/LinuxKPI I really want in 15.1-R
and the time for that is ticking.

/bz

-- 
Bjoern A. Zeeb                                                     r15:7