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Hey guys. Thanks for providing such a great site. I've found the information really helpful.

I'm hoping you could help me with a small problem. I was thinking of using IBM's Journaled File System (link) for the toy operating system I'm working on.

IBM released a version for linux under the GPL a while ago.

I found most of the relevent information via wikipedia and google that I need to impliment it, but I can't figure out whether I am restricted to using it in GPL'd code.

For example if I wrote my own JFS filesystem driver using code I had written myself and wanted to distribute it under a BSD style license would this be breaking the terms of the GPL?

As far as I am aware of the GPL only seems to apply to code but I find this issue confusing. Even if the layout of the filesystem isn't covered by the GPL, if my code uses the same data structures then is this also breaking the terms?

Enlighten me please.

kab000m wrote:Hey guys. Thanks for providing such a great site. I've found the information really helpful.

I'm hoping you could help me with a small problem. I was thinking of using IBM's Journaled File System (link) for the toy operating system I'm working on.

IBM released a version for linux under the GPL a while ago.

I found most of the relevent information via wikipedia and google that I need to impliment it, but I can't figure out whether I am restricted to using it in GPL'd code.

For example if I wrote my own JFS filesystem driver using code I had written myself and wanted to distribute it under a BSD style license would this be breaking the terms of the GPL?

As far as I am aware of the GPL only seems to apply to code but I find this issue confusing. Even if the layout of the filesystem isn't covered by the GPL, if my code uses the same data structures then is this also breaking the terms?

Enlighten me please.

It would only break the GPL if you used IBM's code. If everything is your own, then it would not break anything. This is why my implementation of ext2 has zero lines of Linux code!

Thanks.

pietro10 wrote:It would only break the GPL if you used IBM's code. If everything is your own, then it would not break anything.

Legally this is a bit fuzzy. A "GPL violation" case could be created if you use IBM's code as reference (i.e., not using it verbatim but as an information source).

I don't agree Solar, often the BSD developers use Linux drivers as a reference when no documentation exists, or is of poor quality..

It's legal, it's a method of reverse engineering... as you're not copying the code, you're learning from it.

I am talking from a de jure standpoint (what constitutes a "derived work"), not how it is lived de facto. That none of the BSD projects has been sued so far does not mean it won't happen ever. And even if you are right, the court proceedings to get your right can drive a private person into bankruptcy.

Sorry but regarding legal risks I'm paranoid.

Solar wrote:I am talking from a de jure standpoint (what constitutes a "derived work"), not how it is lived de facto. That none of the BSD projects has been sued so far does not mean it won't happen ever. And even if you are right, the court proceedings to get your right can drive a private person into bankruptcy.

Sorry but regarding legal risks I'm paranoid.

But of course the prosecution then have the problem of proving that you read the original source - if you wrote your own version, there should be no way they could ever prove you even looked at the original GPL'd code.

You'd be surprised what sleazy lawyers might argue as being "similarities in design that cannot have been arisen by mere chance"...

If "they" find a judge and court accepting their lawsuit, lawyer costs alone (calculated in percentage of value claimed) can drive you into bancruptcy long before it's decised that you are innocent and that the opposing party has to pay all expenses.

So you will settle out of court. Most likely by selling all your IP to the claimant.

Agreed this is a worst-case scenario, but it has happened in the cutthroat corporate world, and it might just as well happen in GPL land if someone gets on a rampage. Again agreed, a filesystem driver for a hobby OS is an unlikely target for such practice.

This whole "blurry" legalese is the reason PDCLib is developed without looking at Newlib or GLibC, ever...

Solar is basically right, but it is usually possible to rest your side of the case on the first day of the trial, to end the financial bleeding from the trial itself. The main reason that trials cost so much is that people try so very hard to win. But in the end, you have to trust the judge to make a rational decision. If it goes against you, then you declare a BK, if necessary. It's an unlikely scenario, and you simply have to live with the risk.