New configure option RTEMS_VIRTUAL

[Rempel, Cynthia]

>________________________________________
>From: rtems-devel-bounces at rtems.org [rtems-devel-bounces at rtems.org] on behalf of Philipp Eppelt [philipp.eppelt at mailbox.tu-dresden.de]
>Sent: Tuesday, September 17, 2013 5:49 AM
>To: rtems-devel at rtems.org
>Subject: New configure option RTEMS_VIRTUAL
>
<snip>
>The only satisfying way to compile the interrupt code dependent on
>native or virtual environment is to introduce a configuration option
>similar to RTEMS_SMP and RTEMS_MULTIPROCESSING:
>
>RTEMS_HYPERVISOR or RTEMS_VIRTUAL
>
>Other options:
>:Introduce a new CPU target:
>Besides i386 a new CPU i386-virtual could be introduced. This adds a lot
>of duplicated code. The only difference would be 160 lines of code.
>
>
>In the future this option can be used for other projects virtualizing
>RTEMS on top of some hypervisor with any target CPU.
>
>
>Do you have other ideas?
Yes, option 3 could be to give the user the option of i386-virtual which would set the ax_rtems_virtual macro in configure.ac, so it would look like option 2 to the user and look like option 1 to the build-system... but if we're planning to have a virtual bsp for different architectures, we'd want to decide if option 3 is more desirable than option 1 or 2...

>What do you think about this?
Could you provide links in your projects rtems wiki page to the 160 lines of code so a student making a virtual target for a different architecture would know where to start?
Could you also document why inline functions were unsatisfactory?
Thanks!
Cindy