[Buildroot] [RFC v2 16/31] linux: define license

[Luca Ceresoli <luca@lucaceresoli.net>]

Yann E. MORIN wrote:
> Lucas, All,
>
> On Wednesday 07 March 2012 21:58:16 Luca Ceresoli wrote:
>> Signed-off-by: Luca Ceresoli<luca@lucaceresoli.net>
>> ---
>>   linux/linux.mk |    2 ++
>>   1 files changed, 2 insertions(+), 0 deletions(-)
>>
>> diff --git a/linux/linux.mk b/linux/linux.mk
>> index ae236d4..e6f2388 100644
>> --- a/linux/linux.mk
>> +++ b/linux/linux.mk
>> @@ -4,6 +4,8 @@
>>   #
>>   ###############################################################################
>>   LINUX_VERSION=$(call qstrip,$(BR2_LINUX_KERNEL_VERSION))
>> +LINUX_LICENSE = GPLv2-ONLY
> What's the point of giving the version 'v2' and stating 'only'?
> I would rather see:
>    values        meaning
>    -------------------------------
>    GPLv2         GPLv2 only
>    GPLv2+        GPLv2 or later
>    LGPLv2.1      LGPLv2.1 only
>    LGPLv2.1+     LGPLv2.1 or later
>    ...           ...

When a project is GPL-licensed, it usually means it uses "either version X of
the License, or (at your option) any later version". There are rare cases
(Linux, Busybox, any other?) chose to use a specific version, no later version.

So the "default" meaning of "GPLvX" is "GPL version X or later". Those rare
cases that allow no upgrade are distinguished by adding "only".

This applies for example to:
- http://en.wikipedia.org/wiki/Linux_kernel
- http://en.wikipedia.org/wiki/Directfb
- http://en.wikipedia.org/wiki/Lzop

I prefer to do the same, and use a concise definition for the most frequent
case. Of course this is a personal preference.

If we wanted to stay on the extra-safe side, we might use:
   values         meaning
   -------------------------------
   GPLv2-ONLY     GPLv2 only
   GPLv2+         GPLv2 or later
   LGPLv2.1-ONLY  LGPLv2.1 only
   LGPLv2.1+      LGPLv2.1 or later
   ...            ...
so there is no ambiguity whatsoever. Might that "+" sign create doubts in
dummies reading it ("Hey, what's GPLv2+? a super-GPLv2?")?

Your opinions?

Luca