Experimental Physics and
Industrial Control System

Joel Sherrill <[email protected]> · Thu, 12 Sep 2002 06:58:08 -0500

Congratulations.

Till Straumann wrote:
> 
> Today I had some good results :-)
> 
> I could successfully load a major
> C++ application (EPICS example)
> into a running RTEMS system!
> 
> Works like a charm.
> 
> I recently ported my C-Expression interpreter
> and symbol table utility from libelf to BFD
> and it now features:
> 
> - C expression interpreter with a simple type
>   engine (char, char*, int, int*, int(*)(), double...)
>   and access to symbols.
> - user variables (also typed - can be used to
>   define aliases etc.)
> - runtime loader; object modules can be loaded
>   to and unloaded from a running system
> - disassembler (comes free with BFD)
>
> Cexp/BFD is pretty portable, the full featured
> tool works not only on RTEMS but under several
> ELF platforms (linux-i386, linux-ppc, solaris-sparc).
> I suppose that the runtime loader needs some
> porting work when other BFD backends
> are used.

This is (to me) a hint that your dynamic loading solution shares
nothing with Glen Cornell's.  As I understand it, he used the 
Xfree86 ELF dynamic loader to avoid problems with the GPL.  
His solution is still stuck with the GPL for the disassembler
but that can be left out.

> C++ (exception) support is probably limited to gcc
> (and could unfortunately even be gcc-version sensitive)

That is good enough.

> Nevertheless, working with RTEMS begins to rock...

Yes.  I can't believe we went all these years with no
dynamic loading and now we have two solutions to look at
and merge.

> -- Till
> 
> PS: Alas, I have to resolve annoying licensing issues
> before I can release this...

Maybe by merging the best of the two solutions, that would
be addressed.  I know Glen doesn't have a PowerPC to test on
anyway.  He has been working solely with the x86.

Regardless this is great news.  I just hope we can get the 
two solutions merged into one superior one and merge the result.

-- 
Joel Sherrill, Ph.D.             Director of Research & Development
[email protected]                 On-Line Applications Research
Ask me about RTEMS: a free RTOS  Huntsville AL 35805
   Support Available             (256) 722-9985

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System