Evaluating a port to RTEMS (embedded OS with single address space and no processes)

[Shinose]

On Thu, Feb 4, 2016 at 7:49 PM, Christian Mauderer <
christian.mauderer at embedded-brains.de> wrote:

> Am 04.02.2016 um 14:46 schrieb Roland Mainz:
> > On Thu, Feb 4, 2016 at 1:40 PM, Christian Mauderer
> > <christian.mauderer at embedded-brains.de> wrote:
> >> I am searching a SSH server for remote administration of an embedded
> >> application running on RTEMS (https://www.rtems.org). This environment
> >> has neither virtual memory nor user and kernel space. So this is like an
> >> application running in kernel mode only.
> >>
> >> Would it be possible to run (a very basic version of) OpenSSH in such an
> >> environment using e.g. threads instead of forking new subprocesses? Is
> >> there already some known similar configuration (e.g. on another embedded
> >> OS)?
> >
> > Well, not much harder than a port to the original m68k AmigaOS or most
> > of the military-oriented embedded OSes... not hard but lots of work
> > (unless you have an existing POSIX(-like) layer emulation), mostly
> > related to resource tracking and the socket stuff.
> >
>
> Hello Roland,
>
> thanks for the quick answer. I must have overlooked these ports. I have
> mostly seen the list of full Unixes on this page:
>
>   http://www.openssh.com/portable.html
>
> After your hint, I noted that there are a lot more ports in the sources.
> Is there some kind of porting guide or a hint where to begin reading
> documentation?
>
> If we would create a port: Would it be theoretically possible to
> contribute it to the official sources?
>
> For the POSIX-layer: RTEMS implements a part of the POSIX standard (or
> at least of the embedded subset of POSIX). But like I said it doesn't
> have processes but only threads.
>
> Kind Regards
>
> Christian Mauderer
>
> --
> --------------------------------------------
> embedded brains GmbH
> Christian Mauderer
> Dornierstr. 4
> D-82178 Puchheim
> Germany
> email: christian.mauderer at embedded-brains.de
> Phone: +49-89-18 94 741 - 18
> Fax:   +49-89-18 94 741 - 08
> PGP: Public key available on request.
>
> Diese Nachricht ist keine geschäftliche Mitteilung im Sinne des EHUG.
> _______________________________________________
> openssh-unix-dev mailing list
> openssh-unix-dev at mindrot.org
> https://lists.mindrot.org/mailman/listinfo/openssh-unix-dev
>


Hi,

We have successfully ported OpenSSH along with SFTP-Server for a Greenhills
platform, where it was only having single address space and threads.

But I could say it was really a painful work to resolve the global
variables and data structures to each threads.

We have used a total of 3 threads including the SFTP Server.

Thanks,
Shinose.