bwn firmware (bwn, bwi, fwcutter)

[grarpamp]

>> I'm using fwcutter 0.15 and fw 508.154 on a 4312 LP phy
>> with success under Linux. For FreeBSD the two port Makefiles
>> would seem to be a pretty easy update.

Would it be necessary to update the kernel drivers as well?
 sys/dev/bwn
 sys/dev/siba

Or are they abstracted enough from the firmware blobs that simply
cutting up and using any particular firmware version would suffice?

And can someone help me understand what the difference is between
the blob included in:
 http://www.broadcom.com/support/802.11/linux_sta.php
and those commonly found in these typical places:
 http://www.lwfinger.com/b43-firmware/
 http://mirror2.openwrt.org/sources/

Such as, what is the real source of the firware and method of producing
the the latter blobs?

Thanks.