b43 opensource firmware for monitor mode

b43 opensource firmware for monitor mode

[Michael Buesch]

Release early, release often.
Here's the first testing release of the b43 opensource firmware.
http://bu3sch.de/misc/b43-openfw-20080604.tar.bz2

Currently only the receive path is partially implemented. So that
means we can only run it in monitor mode for now. This firmware is
able to receive packets and push them without special handling (like
decrypting) to the driver.
There are lots of bugs, of course. Sometimes the PLCP header is corrupted.
That will result in a kernel driver warning in xmit.c.

This firmware does _only_ work on wireless core revisions 5, 6, 7, 8 or 10.
You can see the core revision by turning on SSB debugging.
It will print something like:
ssb: Core X found: IEEE 802.11 (cc 0x812, rev 0x05, vendor 0x4243)
As you can see there's the revision number in hex.

If you want to test this, please get the tarball and extract it.
The tarball contains the full sourcecode and a set of prebuilt binaries.
(If you want to rebuild the stuff, you need to get the assembler toolchain
from http://git.bu3sch.de/git/b43-tools.git).

Simply get the *.fw files from bin/rev5/ in the tarball and copy them
into /lib/firmware/b43-open.
Then load b43 from latest wireless-testing.git with the module
parameter fwpostfix=-open

Setup monitor mode and see packets coming in. Or not...

-- 
Greetings Michael.

Re: b43 opensource firmware for monitor mode

[Pavel Roskin]

On Wed, 2008-06-04 at 17:16 +0200, Michael Buesch wrote:
> Release early, release often.
> Here's the first testing release of the b43 opensource firmware.
> http://bu3sch.de/misc/b43-openfw-20080604.tar.bz2
> 
> Currently only the receive path is partially implemented. So that
> means we can only run it in monitor mode for now. This firmware is
> able to receive packets and push them without special handling (like
> decrypting) to the driver.
> There are lots of bugs, of course. Sometimes the PLCP header is corrupted.
> That will result in a kernel driver warning in xmit.c.
> 
> This firmware does _only_ work on wireless core revisions 5, 6, 7, 8 or 10.

That's great news!  Having distributable firmware would simplify
installation, placing b43 to the same league as Intel devices.  But
having free firmware would be unique to Broadcom card and extremely
attractive for research in wireless communications and development of
novel devices using non-standard protocol extensions.

As a short term goal, maybe bcm4328 could be dumbed down to work with
b43?

I've tried it with bcm4318 first, and it hung hard on module load.  Even
Alt-SysRq would not work.  It turns out it was revision 9 missing in
your list.

Then I tries a bcm4306 device with rev 5 core.  The module loaded.  I
brought it up in managed mode first.  Scanning didn't work.  I brought
the device down and set monitor mode.  But the system hung when I tried
to bring the interface back up.

Anyway, I'm glad to see progress in that direction.

-- 
Regards,
Pavel Roskin

Re: b43 opensource firmware for monitor mode

[Michael Buesch]

On Thursday 05 June 2008 04:46:28 Pavel Roskin wrote:
> On Wed, 2008-06-04 at 17:16 +0200, Michael Buesch wrote:
> > Release early, release often.
> > Here's the first testing release of the b43 opensource firmware.
> > http://bu3sch.de/misc/b43-openfw-20080604.tar.bz2
> > 
> > Currently only the receive path is partially implemented. So that
> > means we can only run it in monitor mode for now. This firmware is
> > able to receive packets and push them without special handling (like
> > decrypting) to the driver.
> > There are lots of bugs, of course. Sometimes the PLCP header is corrupted.
> > That will result in a kernel driver warning in xmit.c.
> > 
> > This firmware does _only_ work on wireless core revisions 5, 6, 7, 8 or 10.
> 
> That's great news!  Having distributable firmware would simplify
> installation, placing b43 to the same league as Intel devices.  But
> having free firmware would be unique to Broadcom card and extremely
> attractive for research in wireless communications and development of
> novel devices using non-standard protocol extensions.
> 
> As a short term goal, maybe bcm4328 could be dumbed down to work with
> b43?
> 
> I've tried it with bcm4318 first, and it hung hard on module load.  Even
> Alt-SysRq would not work.  It turns out it was revision 9 missing in
> your list.
> 
> Then I tries a bcm4306 device with rev 5 core.  The module loaded.  I
> brought it up in managed mode first.  Scanning didn't work.  I brought
> the device down and set monitor mode.  But the system hung when I tried
> to bring the interface back up.

There shouldn't be a reason for a freeze. It might crash, yes, but it always
prints out useful messages first for me.

-- 
Greetings Michael.

Re: b43 opensource firmware for monitor mode

[Michael Buesch]

On Thursday 05 June 2008 16:37:18 Felipe Maya wrote:
> 
> root@OpenWrt:/# insmod b43.ko fwpostfix=-open
> Segmentation fault
> root@OpenWrt:/# dmesg
> Unhandled kernel unaligned access[#1]:

Ah well. The alignment is not completely implemented, yet ;)
Working on that...

-- 
Greetings Michael.