Porting L4Re and Fiasco.OC to the Ben NanoNote and Letux 400

Paul Boddie paul at boddie.org.uk
Wed May 9 01:22:29 CEST 2018

On Thursday 26. April 2018 08.23.21 Matthias Lange wrote:
> On [23-04-2018 12:23], Paul Boddie wrote:
> > 
> > I don't have a GitHub account, but I did wonder whether the content of my
> > patches would be acceptable as currently formulated.
> There is at least a path towards this. Have you had a chance to read our
> contributors guide [1]? The submit and review procedures outlined there are
> tailored for github, but if you like we can discuss the patches publicly on
> the mailing list or privately. Just let us know.

Sorry to be so slow in replying to this! I have actually been trying to do 
some more work with L4Re and this has kept me distracted from getting back to 
this particular topic. (I wonder whether there is much scope for discussion 
about L4Re on this list because it seems very quiet and not much is said about 
L4Re even when there are messages.)

My aim will be to distill the patches to the essentials to support these 
systems in Fiasco.OC and L4Re. I think that some of the patch files more or 
less encapsulate these essential changes (those having the topics "fiasco", 
"l4re" and "platform"). As noted earlier, I am not really sure about the form 
of some of the changes, but I guess things can be redone appropriately.

In general, I am not very enthusiastic about signing agreements with entities 
where I get to relinquish various rights or privileges. Ideally, I would just 
license my changes using the same licence as the work and then contribute 
them. Failing that, I would rather permissively license my changes and they 
would then be taken up in the upstream code. But at the same time I understand 
that it is rather difficult to formulate permissively-licensed patches on a 
copyleft-licensed project [*] and, contrary to popular belief, there are still 
obligations when incorporating permissively-licensed work.

However, given that most of my changes have little originality, some being 
copy-and-paste additions based on existing code in the sources, I imagine that 
I could effectively submit them in a CC0-equivalent form and pretend that the 
maintainers did the extra work to support these systems themselves. This 
includes the CI20-related changes which are practically trivial.

As noted above, I have been exploring L4Re and writing code to expose hardware 
functions as drivers in various forms. I intend to make this available in a 
more convenient form later, and I will be licensing my own contributions to it 
under the GPL version 2 or later. Since some things arguably borrow from some 
L4Re code, I imagine that the result may only be GPL version 2 only, unless we 
wave away such similarities. It is unfortunate that a strict licence version 
policy has been chosen, but I guess that may have been decided by the lawyers.

I will try and look at the contributor documentation again. Thanks for 
following up on this and apologies once again for being slow to respond!


[*] I am aware that the GPL permits modifications where those modifications 
are permissively licensed, provided that the licensing is GPL-compatible. 
However, it gets a bit difficult to put the necessary boilerplate on some 
patches. I imagine that this would really involve me publishing complete files 
or even complete sources with the necessary boilerplate included somewhere.

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