Work on the SIS ERC32 Emulator

Work on the SIS ERC32 Emulator

[Jose E. Marchesi]

Hello.

My employers decided to pay me to improve the 'sis' ERC32 emulator which
is part of the gdb distribution (sim/erc32 in the redhat repo).  In
principle they will be paying 4 hours per week.  The investment may be
increased depending on the outcome of the activity.

The main goals of the activity are:

- To improve the performance of the emulator.  We will start
  implementing the basic performance tricks: threaded code, caching of
  condition codes, etc.

- To make the emulator flexible enough to simulate boards used in
  current spacecrafts.

- Eventually, to advance 'sis' to emulate LEON2 and LEON3 as well as
  ERC32.

Regarding licensing,

- The copyright holder of the modified code would be my Employer.  That
  seems reasonable given that SIS is copyrighted by ESA and/or Jiri
  Gaisler.

- We would prefer to release the code under GPLv3+, but GPLv2+ would be
  fine as well.

Are those goals and requirements compatible with your roadmap?

We are or course willing to consider any technical suggestion you may
have and to adapt to the development guidelines/policies of gdb.

-- 
Jose E. Marchesi    jemarch@gnu.org
GNU Project         http://www.gnu.org

Re: Work on the SIS ERC32 Emulator

[Tristan Gingold]

On Apr 18, 2011, at 2:14 PM, Jose E. Marchesi wrote:

> 
> Hello.
> 
> My employers decided to pay me to improve the 'sis' ERC32 emulator which
> is part of the gdb distribution (sim/erc32 in the redhat repo).  In
> principle they will be paying 4 hours per week.  The investment may be
> increased depending on the outcome of the activity.
> 
> The main goals of the activity are:
> 
> - To improve the performance of the emulator.  We will start
>  implementing the basic performance tricks: threaded code, caching of
>  condition codes, etc.
> 
> - To make the emulator flexible enough to simulate boards used in
>  current spacecrafts.
> 
> - Eventually, to advance 'sis' to emulate LEON2 and LEON3 as well as
>  ERC32.

Just a side note: if you are looking for performance, qemu is much faster than sis.

Tristan.

Re: Work on the SIS ERC32 Emulator

[Jose E. Marchesi]

    
    Just a side note: if you are looking for performance, qemu is much
    faster than sis.

Certainly.  But we have good reasons for preferring to use an
interpreter like sis.
    
--
Jose E. Marchesi    jemarch@gnu.org
GNU Project         http://www.gnu.org

Re: Work on the SIS ERC32 Emulator

[Joel Brobecker]

> Regarding licensing,
> 
> - The copyright holder of the modified code would be my Employer.  That
>   seems reasonable given that SIS is copyrighted by ESA and/or Jiri
>   Gaisler.

Unfortunately, I don't think that this is going to be possible.
The FSF should be assigned the copyright for all software contributions
to GDB. There is actually some legal paperwork to go through with
the FSF in order to put a copyright assignment agreement in place.
The simulator is part of GDB, so gdb/CONTRIBUTE is a good source of
information on how to contribute to the project.

> - We would prefer to release the code under GPLv3+, but GPLv2+ would be
>   fine as well.

We have transitioned GDB to GPL v3, so that's not going to be a problem.

-- 
Joel

Re: Work on the SIS ERC32 Emulator

[Jose E. Marchesi]

    > - The copyright holder of the modified code would be my Employer.  That
    >   seems reasonable given that SIS is copyrighted by ESA and/or Jiri
    >   Gaisler.
    
    Unfortunately, I don't think that this is going to be possible.  The
    FSF should be assigned the copyright for all software contributions
    to GDB.

Ok.  I though the policy was different for the sims, since they are full
of non-FSF copyrighted code.  All right, I have to talk with my Employer
about this.  I am pretty familiar with the copyright assignment process
with the FSF, but my Employer is not and it may take some time.

    > - We would prefer to release the code under GPLv3+, but GPLv2+ would be
    >   fine as well.
    
    We have transitioned GDB to GPL v3, so that's not going to be a
    problem.

Do you plan to upgrade the files under 'sis' from GPLv2+ to GPLv3+?

-- 
Jose E. Marchesi    jemarch@gnu.org
GNU Project         http://www.gnu.org

Re: Work on the SIS ERC32 Emulator

[Joel Brobecker]

> Ok.  I though the policy was different for the sims, since they are full
> of non-FSF copyrighted code.  All right, I have to talk with my Employer
> about this.  I am pretty familiar with the copyright assignment process
> with the FSF, but my Employer is not and it may take some time.

We failed to follow the normal guidelines, and I've heard the reason
for that in some of the cases, but that was a long time ago. IMO,
that was a mistake, for several reasons I don't want to detail here.
However, as you have noticed, because the FSF is not the copyright
holder of some of the files, we couldn't update the license to GPLv3.

> Do you plan to upgrade the files under 'sis' from GPLv2+ to GPLv3+?

I only see 2 "sis" files: erc32/sis.[hc]. Are these the files you
are referring to? I don't know how "easy" it's going to be doing
that upgrade, since the FSF does not hold the copyright to these
files. I don't think we can upgrade the license on our own, can we?

-- 
Joel

Re: Work on the SIS ERC32 Emulator

[Ralf Corsepius]

On 04/20/2011 06:19 PM, Joel Brobecker wrote:

>> Do you plan to upgrade the files under 'sis' from GPLv2+ to GPLv3+?
>
> I only see 2 "sis" files: erc32/sis.[hc]. Are these the files you
> are referring to? I don't know how "easy" it's going to be doing
> that upgrade, since the FSF does not hold the copyright to these
> files. I don't think we can upgrade the license on our own, can we?

These files are licensed GPLv2+.

I.e. anybody can opt to relicense them under "a GPLv2+" license,
e.g. GPLv3.

Ralf

Re: Work on the SIS ERC32 Emulator

[Joel Brobecker]

> These files are licensed GPLv2+.
> 
> I.e. anybody can opt to relicense them under "a GPLv2+" license,
> e.g. GPLv3.

I got confirmation that it is OK to change the GPL version number.
So we'll try to do that. There are 170 files that are still showing
version 2 just in sim/ alone, so it's probably not going to happen
soon, or might happen peacemeal (I want to take that opportunity
to fix the paragraph that tells how to contact the FSF as well).
Volunteers are welcome, of course :-)!

-- 
Joel

Re: Work on the SIS ERC32 Emulator

[Jose E. Marchesi]

    > I.e. anybody can opt to relicense them under "a GPLv2+" license,
    > e.g. GPLv3.
    
    I got confirmation that it is OK to change the GPL version number.

Great! :)

    So we'll try to do that. There are 170 files that are still showing
    version 2 just in sim/ alone, so it's probably not going to happen
    soon, or might happen peacemeal (I want to take that opportunity
    to fix the paragraph that tells how to contact the FSF as well).
    Volunteers are welcome, of course :-)!

I will help as soon as I get my papers signed.

-- 
Jose E. Marchesi    jemarch@gnu.org
GNU Project         http://www.gnu.org

Re: Work on the SIS ERC32 Emulator

[Joel Sherrill]

On 04/20/2011 11:19 AM, Joel Brobecker wrote:
>> Ok.  I though the policy was different for the sims, since they are full
>> of non-FSF copyrighted code.  All right, I have to talk with my Employer
>> about this.  I am pretty familiar with the copyright assignment process
>> with the FSF, but my Employer is not and it may take some time.
> We failed to follow the normal guidelines, and I've heard the reason
> for that in some of the cases, but that was a long time ago. IMO,
> that was a mistake, for several reasons I don't want to detail here.
> However, as you have noticed, because the FSF is not the copyright
> holder of some of the files, we couldn't update the license to GPLv3.
>
Are they all copyrighted Jiri Gaisler and ESA?

Did Jiri have an FSF assignment on file when at ESA?

Does ESA have an assignment on file?

If the ESA assignment is in place, then it should just be
a matter of asking Jiri. Gaisler/Aeroflex has an assignment
on file now.

I will email Jiri and see what he remembers.  Joel B., do
you have access to the assignment list at FSF?  Or do
we need to ask them?
>> Do you plan to upgrade the files under 'sis' from GPLv2+ to GPLv3+?
> I only see 2 "sis" files: erc32/sis.[hc]. Are these the files you
> are referring to? I don't know how "easy" it's going to be doing
> that upgrade, since the FSF does not hold the copyright to these
> files. I don't think we can upgrade the license on our own, can we?
>



-- 
Joel Sherrill, Ph.D.             Director of Research&  Development
joel.sherrill@OARcorp.com        On-Line Applications Research
Ask me about RTEMS: a free RTOS  Huntsville AL 35805
    Support Available             (256) 722-9985

Re: Work on the SIS ERC32 Emulator

[Joel Brobecker]

Thanks Joel.

> I will email Jiri and see what he remembers.  Joel B., do
> you have access to the assignment list at FSF?  Or do
> we need to ask them?

I have access to the assignment list. If we can transfer the copyright
to the FSF, I think it would be helpful.  For the other issue of
upgrading the license version, I think  Jose is right, and we might
be able to do so without transfering the copyright. I'm verifying...

-- 
Joel

Re: Work on the SIS ERC32 Emulator

[Joel Brobecker]

> upgrading the license version, I think  Jose is right, and we might
                                         ^^^^^ s/Jose/Ralf/

Sorry about that...

-- 
Joel

Re: Work on the SIS ERC32 Emulator

[Jose E. Marchesi]

Hi.
    
    We failed to follow the normal guidelines, and I've heard the reason
    for that in some of the cases, but that was a long time ago. IMO,
    that was a mistake, for several reasons I don't want to detail here.

I fully agree with the FSF policy of requiring copyright assignments for
the "important" projects :)

    However, as you have noticed, because the FSF is not the copyright
    holder of some of the files, we couldn't update the license to
    GPLv3.

They are GPLv2+, so you can simply "relicense" to GPLv3+.  It is not
really relicensing, but just choosing a subset of the available set of
licenses the files are distributed under.
    
    > Do you plan to upgrade the files under 'sis' from GPLv2+ to GPLv3+?
    
    I only see 2 "sis" files: erc32/sis.[hc]. Are these the files you
    are referring to?

Sorry.  I meant the files under sim/erc32.

-- 
Jose E. Marchesi    jemarch@gnu.org
GNU Project         http://www.gnu.org

Re: Work on the SIS ERC32 Emulator

[Jose E. Marchesi]

Hi.
    
    I’ve just sent a message to the list with a possible problem with
    SIS. I’m not sure if the fix will come quickly, or if this could be
    in your to-do list.

Where did you report the bug? gdb-prs? At the moment I am subscribed to
gdb@sourceware.org only.  I am now subscribing to gdb-patches as well,
but I am still getting familiar with the mechanisms of gdb development
:)

    Good luck with your work on SIS!

Thanks :)
    
-- 
Jose E. Marchesi    jemarch@gnu.org
GNU Project         http://www.gnu.org