Re: [Qemu-devel] Cirrus Logic

[Bartosz Fabianowski]

> I've never heard using published documentation to implement a clone 
> or emulation of something being an issue unless you are under NDA or
> it involves a patented algorithm. Am I not understanding the
> problem?

I don't anticipate the emulation of a graphics card itself to be an
issue. Unless, of course, that emulation infringes on some trademarks,
trade secrets, patents, the DMCA or some other rule that I can't think
of right now. What I think is problematic though is the way in which the
information needed to program the emulation is acquired.

When documentation is published without any disclaimer, there might be
no issue. However, in this case, the documentation we are talking about
specifically states that you are not allowed to create or sell any items
based on it. The very purpose of this disclaimer seems to be to prevent
the competition from reading the documentation and creating clones based
on it.

Of course QEMU can hardly be considered a competitor and since the chip
is several years old, Cirrus Logic probably doesn't care whether QEMU
uses the documentation to implement an emulation or not. However,
legally, that does not mean the disclaimer is any less valid, expired,
or not apply to QEMU. And this is the issue I am interested in. I am
wondering whether it would be possible to obtain from Cirrus Logic the
express permission to use the documentation in order to implement an
emulation of their chip.

> I wonder if Microsoft has a similar clause in their Win32 
> documentation, and whether that would stop the Wine project.

That's a very interesting question along the same lines as the Cirrus
Logic issue. I have read excerpts from the Win32 SDK documentation when
I needed them, but I never looked at any introductory chapters or
disclaimers. If there is a similar clause in there, the Wine people will
have probably given it some thought already and one could ask them to
what conclusion they came.

> In any event, if you do find someone to ask the convervative answer 
> from their lawyers would most likely be "no." That's the knee-jerk 
> reaction when their shareholder interest is orthogonal to the request
> or possibly could negatively impact their shareholders. Then what?

Yes, I anticipate that answer as well. Even if QEMU does not hurt them,
they might just say "no" to be on the safe side, not to permit anybody
to do anything if they don't have to. Now, if the only legal issue is
with using their documentation, that shouldn't be too hard to resolve.
One way would be to simply not use the documentation. Use other -
acceptable - ways of obtaining information about how the chip works. The
other way to solve the problem would be if it turns out that for one
reason or another the disclaimer does not apply. The Wine folks might
come in handy at that point should they have dealt with a similar issue
already.

> If you were to get a positive response, you'd have to come up with 
> some reasoning that shows that it is in their shareholders interest 
> to allow their documentation and hardware to be used to make an 
> emulation. Otherwise I can almost promise that you will get a "no."

Having the legacy of their chip design live on is pretty much all I can
think of and that is hardly going to motivate them.

> Better to ask forgiveness than permission in some cases.

Quite often, that is probably all that's left. Very unfortunate though
because I would like to resolve this nicely.

> You'd be more likely to get the answer you want from an independent 
> lawyer than the successors-in-interest of Cirrus whoever they may be.

I still don't think Cirrus Logic sold their graphics hardware business
to anybody, so it should still be Cirrus you'd need to talk to.

- Bartosz

PS: And here's my own little disclaimer - better be safe than sorry. I
am not a lawyer and all that I wrote in this mail is my personal opinion.