RTEMS 4.7.99.2 Available -- PowerPC/virtex feedback
Robert S. Grimes
rsg at alum.mit.edu
Tue Aug 14 14:03:33 UTC 2007
Chris and Greg, you seem to be right - see below.
gregory.menke at gsfc.nasa.gov wrote:
> I ended up using the newlib printf suite as the test- if fp registers
> are shown in the instructions, then it meant I had a build problem w/
> newlib. The assembly is dramatically different when the fp registers
> are excluded.
>
Don't know what you are talking about ("newlib printf suite"), so I
checked my own code.
> Chris Caudle writes:
> > Doesn't that imply that the tools for PPC405 should already be using soft
> > float?
> > Everyone is scurrying around figuring out how to rebuild tools with soft
> > float, but it looks like that should be the default already, and so far no
> > one has presented any code which confirms that the exception was actually
> > caused by using a floating point register.
> >
> > Shouldn't looking at the instructions to see if that is a feasible
> > explanation be the first step?
>
>
I did this instruction:
$ powerpc-rtems-objdump -d --architecture=powerpc:403 myprog.exe >
myprog.exe.disasm.txt
and examined the results. Now, I'm not 100% sure what I'm looking for,
but I figured the floating point store instructions (e.g.stfd, stfx,
etc.) were good candidates. In fact, searching for "stf" turned up
nothing. I also couldn't find any floating point load, nor any of the
operations that I looked for. So I think, Chris, your comment from your
first email on this is likely closer to the truth:
"More accurately it is "program exception," which is also triggered
by illegal opcode."
You had followed this up by asking if the tool chain had changed between
head from a month ago and 4.7.99.2, and the answer is: No.
So I'm a bit stumped right now. On the one hand I have an application
that works with the older RTEMs, but fails on startup with 4.7.99.2 -
sounds bad for 4.7.99.2! On the other hand, its failure sounds a bit
like that of my earlier post regarding "isync, exceptions, et. al" from
last Thursday - similar, but worse.
Any ideas?
Does it seem correct to rule out (at least temporarily) the tool chain
as the culprit?
Thanks!
-Bob
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