[U-Boot-Users] GPL Licensing issues

[Wolfgang Denk <wd@denx.de>]

In message <6.1.1.1.0.20040926174406.01e1d130@wheresmymailserver.com> you wrote:
> The files in the examples directory - since everything needs to be linked 
> to u-boot to work, and u-boot is released under the GPL, does that mean 
> that custom user applications are also under the GPL - or do you use 
> Linus's relationship of kernel/application separation?

Standalone applications only use exported U-Boot  services.  They  do
not  have  to  be linked against any U-Boot code. So ther eis no need
for  standalone  applications  to  be  GPLed  -  exactly   like   the
kernel/application separation in Linux.

> Either is OK - I was just going to be talking to some people and wanted to 
> make sure they understood things about how to keep their secret sauce to 
> them selves.

See http://www.denx.de/twiki/bin/view/UBootdoc/Presentation for some
materrial I prepared for soem U-Boot presentations myself; it covers
this topic in
http://www.denx.de/twiki/bin/view/UBootdoc/StandalonePrograms

> I assume that if it does use U-Boot functions, then the application is a 
> derivative work, and should be covered under the GPL (must make available 

But standalone applications doe not use U-Boot functions by  linking,
only through the exported interface. Just like Linux system calls.

> source, per the GPL). If the application does not use any U-boot functions, 
> it would not be classified a derivative work - because it could be stand 
> alone program, and burned into flash without U-boot to load it.

No. You can burn it into flash, but you still need U-boot to run it -
like you need  a  Linux  kernel  to  run  a  proprietary  application
program.


Best regards,

Wolfgang Denk

-- 
Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-4596-87  Fax: (+49)-8142-4596-88  Email: wd at denx.de
I am an atheist, thank God!