[ECOS] License restrictions

Bart Veer bartv@redhat.com
Thu Mar 22 05:19:00 GMT 2001


>>>>> "Bill" == Bill Arbaugh <waa@cs.umd.edu> writes:

    Bill> The license shouldn't be a problem with most drivers. Take a
    Bill> look at OSKit from the Univ. of Utah. They essentially did
    Bill> that with a FreeBSD kernel as the base rather than eCos.

If you are talking about BSD drivers, there should not be a problem.
In fact the current eCos TCP/IP stack is BSD code. However, it is not
clear to me that many low-level BSD drivers would actually be useful.
If you are developing eCos on an x86 PC or similar hardware, and want
support for e.g. a specific ethernet chip, it would probably be ok.
However if you are developing on something like an SH or an AM33,
a driver intended for use inside a PC might not be all that useful.

There may also be problems when it comes to what those device drivers
expect from the kernel. If the device driver expects to be able to
make BSD kernel calls, manipulate mbufs, etc. then there will be
problems because those facilities will not be provided automatically
by eCos (although some of the required glue may be provided already by
the TCP/IP stack).

Obviously an existing driver can prove a very useful source of
information about hardware bugs and the like, and it is certainly
worthwhile looking at existing sources before attempting to write an
eCos device driver, but that is not the same as directly re-using an
existing driver.

When it comes to Linux there are serious licensing problems. A typical
existing Linux device driver will be licensed under the GPL. With eCos
application code is linked directly to the kernel and hence to the
device drivers, rather than being separated via a system call
interface. Therefore all of the code in the system, including all of
your application, needs to be under a license that is compatible with
the GPL. Typically this means that you would have to release all of
the application source code under an open source license. For most
eCos developers that would be unacceptable.

Bart


    Bill> On Wed, 21 Mar 2001, Robert Ritchey wrote:

    >> That seems like a great idea to me and I was going to explore
    >> it as I am new to both Linux and eCos but not if Linux drivers
    >> are restricted in some way that this is not legal.
    >> 
    >> At 01:28 PM 3/21/01 -0500, Bill Arbaugh wrote:
    >> >Has anyone looked at providing some "glue" such that UNIX drivers could
    >> >easily be used with eCOS ala OSKit?  I've thought about it, but haven't
    >> >had time to fully investigate.
    >> >
    >> >thanks, bill
    >> >
    >> > > How do the licenses for Linux and eCos intertwine, if at all.  If I 
    >> > wanted  to use a
    >> > > driver in Linux as a starting point for an eCos driver is there a 
    >> > problem  with that?
    >> > > What restrictions do I need to be aware of?  Thanks.
    >> > >
    >> > > Robert Ritchey
    >> > > Phoenix, AZ
    >> > > (480) 460-2652
    >> > >
    >> > >
    >> 
    >> Robert Ritchey
    >> Phoenix, AZ
    >> (480) 460-2652
    >> 
    >> 



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