General question about Broadcom b43 driver and its source.

General question about Broadcom b43 driver and its source.

[Tom Cipollone]

Hello. I am new to this forum but have been designing hardware for 33
years. I am new, however, to wireless software. I have designed
modem/residential gateway boards with BCM63138 and others but not the
software so please forgive what may seem like simpleton questions.

My question concerns the b43 driver. The documentation claims that it
was reverse engineered from the BCM4306 component. I expect that the
4306 documentation is very proprietary because I was not able to find
it even though I have customer access to Broadcom customer support.

1) I have a RT-N16 router, with a BCM4718 WiFi. I expect that the
BCM4718 is backwards compatible with the BCM4306?

2) Where can I find the reverse engineered source code for the b43
driver? I have OpenWrt loaded and have compiled it before loading the
.trx file onto my RT-N16. I have been looking on liinux-wireless but
was referred to kernel-backports.

Thank You

Re: General question about Broadcom b43 driver and its source.

[Dan Williams]

On Fri, 2015-02-20 at 09:36 -0800, Tom Cipollone wrote:
> Hello. I am new to this forum but have been designing hardware for 33
> years. I am new, however, to wireless software. I have designed
> modem/residential gateway boards with BCM63138 and others but not the
> software so please forgive what may seem like simpleton questions.
> 
> My question concerns the b43 driver. The documentation claims that it
> was reverse engineered from the BCM4306 component. I expect that the
> 4306 documentation is very proprietary because I was not able to find
> it even though I have customer access to Broadcom customer support.
> 
> 1) I have a RT-N16 router, with a BCM4718 WiFi. I expect that the
> BCM4718 is backwards compatible with the BCM4306?

I wouldn't necessarily expect so; the 4306 is a really old 802.11g part
from 2003, while the 4718 is a newer 802.11n dual-band part from 2009.
There are a ton of different parts, and 6 years is a *lot* of time.
Don't expect they'll be compatible in any way; any compatibility they do
have is a gift.

But there's already b43 (and brcmsmac) support for the 4718 (via the
4716 of which it's based) in the upstream kernel, AFAICT.

> 2) Where can I find the reverse engineered source code for the b43
> driver? I have OpenWrt loaded and have compiled it before loading the
> .trx file onto my RT-N16. I have been looking on liinux-wireless but
> was referred to kernel-backports.

In the Linux kernel:

(4718)
https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/drivers/net/wireless/b43

(4306)
https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/drivers/net/wireless/b43legacy

Dan