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Is Linksys Violating The GPL?
jap writes "According to this post on LKML, Linksys is shipping firmware for (at least their) 802.11g access-points based on Linux - without any sourcecode available or mentioning of it on their site. This could be interesting: it might provide the possibility of building an ueber-cool accesspoint firmware with IPsec and native ipv6 support etc etc, using this information!"
Sorry - not true.
http://www.tivo.com/linux/index.html
Hi,
Sorry for the very lengthly posting, but I want to be as precise as possible in describing this problem.
Awhile ago, I mentioned that the Linksys WRT54G wireless access point used several GPL projects in its firmware, but did not seem to have any of the
source available, or acknowledge the use of the GPLed software. Four weeks ago, I spoke with an employee at Linksys who confirmed that the system did use Linux, and also mentioned that he would work with his management to ensure that the source was released. Unfortunately, my e-mails to this
individual over the past three weeks have gone unanswered. Of course, I also tried contacting Linksys through their common public e-mail accounts (, ) to no avail.
However, it is hard for me to know if my contact in the company has just gone on a three week vacation (and not set an auto-responder), or has been asked to not answer anymore mail on this subject. Also, I should note that I don't own this product, so I can't determine if the source is shipped with it.
However, I have gone through all the available information on the Linksys website, and can find no reference to the GPL, Linux (as it relates to this product), or the firmware source code. Also, the firmware binary (see below) is freely available from their website. There is no link from the download page to the source, or any mention of Linux or the GPL. Finally, it would be
strange if the source was included in the physical package, as my contact at Linksys was initially unaware Linux was used in this product.
The following steps can be used to determine the exact nature of the possible GPL violation.
1. Go to the following URL:
http://www.linksys.com/download/firmware.asp?fwid= 178
2. Download the "firmware upgrade files":
ftp://ftp.linksys.com/pub/network/WRT54G_ 1.02.1_US _code.bin
(MD5SUM: b54475a81bc18462d3754f96c9c7cc0f)
3. While it is downloading, confirm that there is nothing on the webpage to indicate that this binary contains GPLed software.
4. Once the download is complete, copy the contents of the file from offset 0xC0020 onward into a new file.
dd if=WRT54G_1.02.1_US_code.bin of=test.dump skip=24577c bs=32c
5. Notice that this file is an image of a CramFS filesystem. Mount it.
6. Explore the filesystem. You will notice that the system appears to be based on Linux 2.4.5. Incidentally, there is at least one other GPLed project in the firmware: the BusyBox userland component: (http://www.busybox.net/)
7. The Linux kernel (I think) is mixed up with a bunch of other stuff in: bin/boot.bin
You might want to know why I am interested in getting the code for the kernel used in this device.
There's been some discussion here about Linux's lack of wireless support for a few of the newer 802.11b and (nearly?) all 802.11g chips. Incidentally, Linux has excellent support for at least one manufacturer's wireless family.
The following Broadcom chips all appear to be supported under Linux -- if you happen to be running Linux on a MIPS processor in a Linksys router:
Broadcom BCM4301 Wireless 802.11b Controller
Broadcom BCM4307 Wireless 802.11b Controller
Broadcom BCM4309 Wireless 802.11a Controller
Broadcom BCM4309 Wireless 802.11b Controller
Broadcom BCM4309 Wireless 802.11 Multiband Controller
Broadcom BCM4310 Wireless 802.11b Controller
Broadcom BCM4306 Wireless 802.11b/g Controller
Broadcom BCM4306 Wireless 802.11a Controller
Broadcom BCM4306 Wireless 802.11 Multiband Controller
This list was produced by running strings on:
lib/modules/2.4.5/kernel/drivers/net/wl/wl.o
I am trying to determine exactly how tightly coupled these drivers are to the kernel.
As an aside, I know that some wireless companies have been hesitant of releasing open source drivers because they are worried their radios might be pushed out of spec. However, if the drivers are alre
If they're not rewriting the source code, using it in a form that they themselves obtained it in (pre-compiling), they might not have to provide source if they disclose their source location. Also, if they were smart enough to create independent kernel modules for the rest of the device, they wouldn't have to release those anyway.
It would be nice if they included at least a copy of the GPL and a linux installation CD in the back of their manual though, since that would be a way of distributing the code, if not more than the code, and would probably make them in compliance.
Hell, TurboLinux install CDs came with hardware that Linux couldn't even use, for a while...
Do not look into laser with remaining eye.
And I'm sure you know this, but they are not required to release all of their source code, only the code for gpl parts of tivo. Just because the OS is linux doesn't mean they have to release code for everything running on it.
However, the GPL still requires that they provide source, even if they have not modified it. If you redistribute, you must provide source, or at least a written offer for the source.
.. they are obligated to provide a copy of the source (sans their changes, if they are not within the scope of the gpl)
You can (section c) simply pass along the written offer YOU received, if you are simply redistributing, and not modifying, but only if it's NON-COMMERCIAL, and only if you yourself received the written offer. IF they are using stock linux kernels, there is no written offer, so
3. You may copy and distribute the Program (or a work based on it, under Section 2) in object code or executable form under the terms of Sections 1 and 2 above provided that you also do one of the following:
* a) Accompany it with the complete corresponding machine-readable source code, which must be distributed under the terms of Sections 1 and 2 above on a medium customarily used for software interchange; or,
* b) Accompany it with a written offer, valid for at least three years, to give any third party, for a charge no more than your cost of physically performing source distribution, a complete machine-readable copy of the corresponding source code, to be distributed under the terms of Sections 1 and 2 above on a medium customarily used for software interchange; or,
* c) Accompany it with the information you received as to the offer to distribute corresponding source code. (This alternative is allowed only for noncommercial distribution and only if you received the program in object code or executable form with such an offer, in accord with Subsection b above.)
Just been hacking around a Belkin 54k WAP/Router box I bought a few weeks back. NMap identifies it as Linux 2.4.0-2.4.5.
...
The Belkin Networking downloads page gives an updated firmware for this. Sure enough, at offset 790393 there's a CRAM Filesystem. Mounting that shows a stock 2.4.5 kernel with three custom modules (one for the wireless card, one for the ethernet card, one for the front panel LEDs). These three modules aside it looks like non-modified GPL stuff.
However, reading any of the binary files shows the string : "GCC: (GNU) 3.0 20010422 (prerelease) with bcm4710a0 modifications" - Modifications you say? Oh dear, I don't remember seeing a Broadcom patch submitted to GCC