Porting SageTV to run on D-Link DSM-520

[MTisza]

I was involved for a while in an effort to "break open" the DSM-520 firmware. Here's what we found:

1. Dlink does comply with the GPL license. See there website for details. Or just google "dlink gpl". I have copies of the source code.
**Edit: I'm realizing now that the kernel sources are not included.

2. The hard part from a software point of view was to get the sdk for the Si8210L that runs the DSM-520. However I obtained a copy of that too. You can also. See this thread for details. http://www.openmss.org/forum/viewtop...006805d726dfdb

3. Then comes the real hard part. It appears that DLINK/RedSonic have done a real good job of hiding the JTAG port. Which means that even if we could write software for it, you have to be real careful not to turn it into a brick, because there is no way to unbirck it, short of desoldering the flash and soldering in a new one.

4. I was able to get console access both local via RS232 and remotely via telnet. Follow these instructions http://www.suphammer.net/Hardware/DSM520

5. You can connect a usb flash drive to the included USB port, but it always mounts it as read only. It was easy to change the mounting to read-write. This gave me the ability to test that the toolchain from step 1 works. I wrote ahello world program and it worked fine.

6. So it is possible. And the device is very capable of handling several media formats.

I would really like to start thinks up again, but after a while it seemed like I was the only one trying. I spent at least two months of time after work (and some during) trying to find the JTAG port, without success. If anyone has an idea of how to continue without it, I'm all ears.

[_Demo_]

Thanks for all the information. I have downloaded the dlink source package but the kernel source code was missing. I have tried to contact redsonic about it but I was told that Sigma didn't let them release the source. (even though they are supposed to)

Could you let me know if this source is now available from dlink and I haven't found it.

Thanks

_Demo_

[PGPfan]

In my opinion this NEEDS to be done! I just looked at the link to this D-link machine and I'm VERY impressed, especially for it's price! Having HDMI on the box was the clincher.

Perhaps organizing a email 'bombardment' campain might be in order to shake loose the necessary source code? Anyone with any ideas?

-PGPfan

[BobPhoenix]

Originally Posted by PGPfan

Perhaps organizing a email 'bombardment' campain might be in order to shake loose the necessary source code? Anyone with any ideas?

-PGPfan

Sounds like a great idea. If DLink would just realize they could probably increase there sales significantly. Especially if more PVR apps than just SageTV created extender options. I mean they don't have to support it or anything. They can specifically say they only support their applications afterall.

BobP.

[SHS]

Key problem is not the manufacturers like Sigma Designs which have no chosse in the matter it all point back to MPPA and RIAA.
If all recall some of you may that Sigma Designs had cut VIP pins of REALmagic Xcard but we could add them back on then later on they end made a new ver board layout that had it fully disable even with them solder back on.

[insomniac]

Are there any sagetv users lawyers? Maybe it would take a short legal draft to explain to them that they are obligated to release the source. If its a legal paper, it will make it past the first layer of BS and right into the Administration of the company....

Just a thought...

I.

[PGPfan]

Originally Posted by SHS

Key problem is not the manufacturers like Sigma Designs which have no chosse in the matter it all point back to MPPA and RIAA.
If all recall some of you may that Sigma Designs had cut VIP pins of REALmagic Xcard but we could add them back on then later on they end made a new ver board layout that had it fully disable even with them solder back on.

I'm not entirely sure I agree with you, shs. Afterall, we aren't talking about breaking encryption, just making the unit boot off different code to implement the Sage UI. Seems to me that it's no different (philosophically) than what we do now with the MVP. The key issue is access to the IP, and if they leveraged Linux to develope the thing, they OWE the user community the software to make it happen.

-PGPfan

[xred]

Originally Posted by MTisza

I was involved for a while in an effort to "break open" the DSM-520 firmware. Here's what we found:

1. Dlink does comply with the GPL license. See there website for details. Or just google "dlink gpl". I have copies of the source code.

I would really like to start thinks up again, but after a while it seemed like I was the only one trying. I spent at least two months of time after work (and some during) trying to find the JTAG port, without success. If anyone has an idea of how to continue without it, I'm all ears.

Is the source code availability for the non HD models (DSM-320 / DSM 320RD) any better, or is it specifically the 520 thats restricted?

[bcjenkins]

Originally Posted by insomniac

Are there any sagetv users lawyers? Maybe it would take a short legal draft to explain to them that they are obligated to release the source. If its a legal paper, it will make it past the first layer of BS and right into the Administration of the company....

Just a thought...

I.

The FSF is good for this.

B

[BobPhoenix]

Originally Posted by xred

Is the source code availability for the non HD models (DSM-320 / DSM 320RD) any better, or is it specifically the 520 thats restricted?

It's the same for the DSM-320. The file on DLink's site is bigger for the DSM-520 which is why I thought it might contain everything that Sage would need originally but they reported back that it was still missing the key components needed just like the DSM-320 firmware source.

BobP.

[MTisza]

Wow, I'm pleasantly surprised at the level of responses here. GREAT!!!

I'm downloading the latest version of the GPL sources from dlink to check if the kernel sources are included. Two things, I'm a hardware engineer and don't know how to tell if the kernel source is included. Please chime in if you can help me. The other is that it is based on uclinux. Does this change things as far as GPL requirements are concerned?

I think the best thing would be to combine an email and legal effort to get the full sources. The marketing departments should also be informed of the opportunity cost they'll be losing by not releasing sources.

Also legally who's responsible to release the sources: the OEM (DLink), the design house (Redsonic), or the company who probably customized the kernel for the SI8210 (Sigma)?

[MTisza]

The kernel sources don't appear to be included.

[JUC]

Originally Posted by insomniac

Are there any sagetv users lawyers? Maybe it would take a short legal draft to explain to them that they are obligated to release the source. If its a legal paper, it will make it past the first layer of BS and right into the Administration of the company....

Just a thought...

I.

I'm an attorney although my areas of expertise are definately not in this field (i'm an environmental/land use attorney). But-if someone was willing to draft up a formal inquiry stating the authority for requiring the disclosure of the information--i can clean it up if need be--i would have no problem submitting in on my letterhead. If often just takes the .esq at the end of a signature to get the ball rolling. PM me if I could be of any help.

JUC

[PGPfan]

Originally Posted by MTisza

Wow, I'm pleasantly surprised at the level of responses here. GREAT!!!

I think the best thing would be to combine an email and legal effort to get the full sources. The marketing departments should also be informed of the opportunity cost they'll be losing by not releasing sources.

Also legally who's responsible to release the sources: the OEM (DLink), the design house (Redsonic), or the company who probably customized the kernel for the SI8210 (Sigma)?

As far as who's legally resposible to release sources, I don't think it matters that much. A 'shotgun' approach (in my opinion) should be used so that at least somebody (one of the fore mentioned, or all of them) makes good on their obligation. Best case, we get all 3 to comply and cough up the source.

Regardless, I really believe we should persue this. I don't need this machine since I have a dedicated client PC already, but this is WAY cheaper than MCE with their XBOX 360 extender. Sage really needs this to 'de-fang' MCE.

-PGPfan

[MTisza]

I just figured I'd collect some data here that should go into the legal notice to comply.

First off I did a bit of research and it seems that legally only Linus and the other developers of the kernel, have the right to enforce the license.

Second it is specifically v2 of the GNU GPL that covers the kernel.

It is section 3 of the license that they are violating by not distributing the complete source code.

From the GPL section 3:

For an executable work, complete source
code means all the source code for all modules it contains, plus any
associated interface definition files, plus the scripts used to
control compilation and installation of the executable.

DLinks Corp. address:
DLink Corporation
17595 Mt. Herrmann
Fountain Valley, CA 92708

RedSonic's Address:
Resonic Technology Corporation
1231 E. Dyer Road, Suite 230
Santa Ans, CA 92705

Sigma Design's Corp. address:
Sigma Designs, Inc.
1221 California Circle
Milpitas, CA 95035 USA

Everyone can/should throw their two cents in now as far as what should go in this letter.

[PGPfan]

JUC,

Is there any chance you could post a 'form letter' example that we could collectively enhance to suit the needs of this task? Without a 'legalese' format, it's hard to know where to begin (at least for me).

I wonder if we commited to sending one email each day, to one of the companies per day, from each of us that expressed an interest in this would be a good way to start the email campain. We wouldn't have to limit it to one email per company, just limit the repeats to once every 3 days. Does this make sense?

-PGPfan

[JUC]

I can try to work on something on wed. or thurs. If anyone can just clarify what exactly is being withheld (kernal source code?). I have very little experience with Linux or open source apps so my terminology is unfortunately lacking
Thanks,
JUC

[bcjenkins]

Originally Posted by JUC

I can try to work on something on wed. or thurs. If anyone can just clarify what exactly is being withheld (kernal source code?). I have very little experience with Linux or open source apps so my terminology is unfortunately lacking
Thanks,
JUC

I believe...

The entire source tree for building the linux image is what we are after. This includes, but is not limited to, the kernel source files, binary modules for drivers which source code is not provided, scripts and applications which provided the operating environment for the device.

This is all somehwat similiar to the router firmware development community efforts. I don't belive the companies have to release source code for applications or device drivers to which they wholly own the IP. It only has to be released for items which were developed under the appropriate licenses. i.e. the kernel itself.



HIH

B

While you're at it can you ask for the diagrams to the flux-capacitor?

[JUC]

Alright-I had some time this morning to do a quick read of the GNU GPL v2 and am getting a hang of the language (as best a 2 minute read can provide me anyway). I might be able to post a draft letter up this afternoon. I am definately going to need people to rephrase some of the specific language as it relates to the source code and such but I should be able to pull something off.

My only concerns come from MTisza's post above where it was mentioned only the linux authors and the developers can enforce the license. I didn't find any language like that in my quick read--not saying its not there though. If you can find this language please post it. If this is the case--this might be a dead end as the companies will surely pick up on this and put a halt to our request. We can still send the letter (and corresponding emails) and see how it goes though.


bcjenkins--we can save the request for the flux-capacitor diagrams for next week

[MTisza]

I got that info from the Free Software Foundation's website as well as a GNU website. AFAIK the FSF are the writers of the GNU GPL itself (not the IP that the licesnse protects). They have a section on what to do if you notice a violation.
http://www.gnu.org/licenses/gpl-violation.html

Quote from the GNU website:

Note that the GPL, and other copyleft licenses, are copyright licenses. This means that only the copyright holders are empowered to act against violations. The FSF acts on all GPL violations reported on FSF copyrighted code, and we offer assistance to any other copyright holder who wishes to do the same.

I've been under the impression from the beginning that we'd be sending a letter requesting that they comply, but truly not having any legal standing until a kernel developer joins our cause.