Re: Problems with 3.13.7 and PPC604/MV2304

[Andrew Johnson <anj@aps.anl.gov>]

Hammonds, John wrote:
> > I have been working with a transition between R3.13.5 and 
> > 3.13.7.  I finally got through problems with connecting with 
> > Channel Access with the help of Jeff and Janet.  Yesterday I 
> > tried to boot a crate with an MV2304 board and find that I 
> > cannot load iocCore.  This does work with the MV167 and 
> > MV172.  Errors are shown below.  I am using Tornado 2.02 on 
> > Solaris 7 to compile everything.  This does work if I drop 
> > back to 3.13.5 with everything else the same.  Any suggestions?
> >
> > ld < iocCore                                                  
> >                                                              
> > Relocation value does not fit in 24 bits.                     

To expand slightly on Geoff's reply, this occurs because you have more 
than 32MB of RAM on your board.  A full explanation is found at 
http://www.aps.anl.gov/epics/modules/base/ppc.php#Relocation as are some 
solutions.  I think we've accepted that option 2 is the only really 
sensible way to handle this.

Janet is adding some new target architectures to allow both short and long 
call versions to be built in the same EPICS tree.  Compiled PowerPC 
binaries are something like 20% larger when using long calls and the 
result will be slower (more instructions to execute and more cache misses 
too), so we'd like the build system to allow a short call version to be 
loaded by systems that only have 32MB.

- Andrew
--
"Life is what happens while you're busy making other plans." - John Lennon