Re: [Qemu-devel] I want to add the ARMv6 instructions, who can give some advices?

[Jamie Lokier <jamie@shareable.org>]

Paul Brook wrote:
> > So would you have any problem contributing to Qemu after ARMv6 support
> > was integrated, if the person who contributes ARMv6 support states
> > that they have never seen the ARM document and refers to the sources
> > they have used instead?
> 
> As I mentioned before I have significant local patches implementing
> unreleased Arm features. The only way to avoid cross contamination
> between that and a third party qemu implementation two would be for
> me to stop contributing anything (or at minimum anything ARM
> related) back to qemu.

The idea is for someone else, working completely independently of you,
and without ever seeing those patches of yours, to provide the later
ARM support.

I know it doesn't feel good to think about someone else duplicating
the work you have done, but that's not a reason to not do it, if it's
the only legal solution to a useful feature.

So why "anything ARM related" and not "anything ARMv6 or later related"?

Isn't it sufficient for you to avoid contributing anything related to
the versions/features the restrictive license covers, so that you
could continue to contribute ARM related things for the older,
publically documented features?

That may feel uncomfortable, but it is no different than your present
situation.  And for other people, it would provide a useful feature.

> Basing work on the gcc/binutils code doesn't help me either because I wrote 
> most of that code in the first place :-)

Since the idea is for someone else do it, that doesn't matter.

I'm wondering why, if it were done, it would be a problem for you to
contribute in future in the areas which you contribute to now.

-- Jamie