Re: Firmware for reverse engineering b43?

["Joshua Peisach" <jpeisach@ubuntu.com>]

On Tue Apr 14, 2026 at 8:24 AM EDT, Jonas Gorski wrote:
> On Tue, Apr 14, 2026 at 1:31 PM Joshua Peisach <jpeisach@ubuntu.com> wrote:
>>
>> On Tue Apr 14, 2026 at 5:14 AM EDT, Johannes Berg wrote:
>> > I think there's no easy answer - what are you even trying to achieve?
>> > Does b43 not work sufficiently well? Do you even know if some specific
>> > calibration have a tendency to go out of whack? Is there later firmware
>> > that has some advantage (given how little actually happens in firmware
>> > in these devices, I'd be surprised by that) but isn't compatible with
>> > the driver now, and you want to change that?
>> >
>> > I'd be tempted to say that if there's no problem there don't try to fix
>> > anything, the hardware is ancient anyway, likely has few users, and
>> > those users would probably be fine with just leaving it?
>> >
>> > johannes
>>
>> The BCM4321 (nphy) doesn't connect to my 5G network, so I figured that
>> by filling in TODOs and FIXME's, I could eventually get something
>> working.
>>
>> Other than that, I was thinking of making improvements for the sake of
>> improving the driver.
>
> The initial version of the brcm80211 softmac driver [1] should also
> help in making sense of some of the code (flag names etc). While it
> officially only supports BCM43224 and newer on BCMA, it still had
> remnants of support for older N-PHY revisions, so may help in finding
> differences or explaining what code does.
>
> I once considered trying to clean up b43 based on brcmsmac, but never
> got around to it.

It does appear to be similar - even the current brcm80211. So much so
that I sometimes need to think about whether b43 is actually a
duplicated driver.

Since b43 is in an orphan state, I thought it would be a great place to
start for kernel development. 5G doesn't work on that iMac, some of the
PHYs, like the AC PHYs appear to be incomplete - it felt reasonable.

Because I'm one of those "there's always room for improvement people",
I was going to try to improve the driver, filling out TODOs, fixing
hardcoded register numbers, etc. But if it's best left alone.. then I
guess we can do that.

That is, assuming b43 is actually supposed to be a separate driver,
because if brcmsmac basically has the same code, then maybe we should
focus to centralizing everything? But then there's b43legacy.. hm...

-Josh

>
> Best regards,
> Jonas
>
> [1] https://github.com/torvalds/linux/tree/a9533e7ea3c410fed2f4cd8b3e1e213e48529b75/drivers/staging/brcm80211


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