[U-Boot] How to get GPL free standalone programs with u-boot

[Wolfgang Denk]

Dear "Neugebauer, Manfred",

In message <1B9C02DB7C62FE44B8FAC992AAC75E8E16472581 at DEFTHW99E85MSX.ww902.siemens.net> you wrote:
>
> I have a question concerning standalone programs based on u-boot and
> GPL, since I'm not really sure whether the way how the u-boot source
> files are set up allows GPL free standalone programs.

This is the intention; if the current code or documentation should
conflict with this intention, it should be fixed.

> However, when looking at the GPL details, I'm not sure whether this
> really works with the current u-boot sources (from a legal point of
> view):
> 
> (a) the source code of the hello_world example for a standalone
> application has a GPL header. If you are legally strict, this can
> mean every standalone application is a derived work from this example
> and therefore restricted to GPL.

I disagree.

You should be able to write standalone aplications without ever
looking at the hello_world.c file.

> (b) When you want to write a standalone application you need - as a
> minimum - to include "exports.h" (for the interface definitions),
> which requires "common.h" as additional header file. Both files are
> not included in the COPYING information which allows the use outside
> of GPL. The header file "common.h" (and other header files, which are
> included within common.h) even have a GPL header.

"exports.h" should be added to the "allowed" file list; there should
be no need to include "common.h". Eventually this needs fixing.
Patches are welcome.

> (c) you need to link your standalone application against stub.o (or
> the corresponding library). I did not find any statement (e.g.,
> within stub.c), that this part is GPL-free (e.g., similar to LGPL).

"examples/standalone/stubs.c" should be added to the "allowed" file
list (the ppc_*jmp.S files are LGPLed).

> So, from my point of view (although I'm not a lawyer), there are some
> doubts about a GPL free standalone application based on the actual

There should be no doubts - the intention is clear, the current state
may need improvement. Help (read: patches) welcome.

> u-boot sources. I believe there should be some enhancements to
> clarify this subject:
> 
> (1) GPL free standalone examples
> (2) a really GPL free exports.h (similar to include/image.h)
> (3) some explanations that the use of the source file
> "examples/standalone/stub.c" is not GPL restricted.

Agreed.

> I know that this is a very strict view to this subject (but that is
> the way legal people look at it). I'm interested in a feedback from
> others who already were involved with this issue.

There is two ways to deal with licenses: either ignore them
completely, or be really strict about them. I think we all agree that
we cannot ignore them, so we have little choice but trying to improve
what we have.

Best regards,

Wolfgang Denk

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