--- In Christopher Friedt <>
wrote:
>
> j.chitte wrote:
> > I have managed to find some information on the subject which
seemed
> > to indicate fp emulation could be done but I'd need uclibc which
in
> > itself required a 2.6.x kernel (which is not currently supported
by
> > TS).
>
> This is not the case. uclibc and glibc both have soft-floats, it's
just
> a question of how they're handled. You can do software floating
point at
> the moment, but it will be quite slow - I think that's the
intention of
> the warning.
>
Hmm, in view of the complexity of this I may have to see if I can
live with that solution.
> > I need to asses how much customisation effort this is going to
imply
> > and whether I need to find another way to implement what I need
> > without fp.
>
> You could also used fixed point integer arithmetic, and go without
any
> system calls for softfloat - maybe there's even a flag you could
pass to
> gcc to optimize for fixed-point integer math? It won't be terribly
fast
> though.
>
> >
> > Could someone give me details on what is needed to achieve softfp
on
> > 7250?
>
> If you're interested in using something new(er) to speed up FP,
then you
> probably would want to use the EABI. It speeds up soft-floats by a
large
> factor.
>
> http://www.linuxdevices.com/articles/AT5920399313.html
> http://wiki.debian.org/ArmEabiPort
>
> I don't know if anyone has actually gotten an eabi kernel /
userland
> running on the 7[23]xx boards yet, but I'm currently working on it.
I've
> built a toolchain as follows:
>
> USE="-*" crossdev -v \
> --kernel 2.6.21 \
> --libc 2.5-r3 \
> --binutils 2.17 \
> --gcc 4.2.0 \
> --target arm-softfloat-linux-gnueabi
>
OK, I tried to follow what you posted earlier but glibc failed
telling my headers where too old (2.6.20). Is 2.6.21 an minimum here
or is that possibly a bug? I thought EABI work started around 2.6.11 .
I've been having some issues building qemu as well. Odd since I had
it working beatifully a few months back.
Could you cast an eye over this topic if you have a chance?
http://forums.gentoo.org/viewtopic-p-4162111.html#4162111
I'm quite interested in your idea of using this as a means of doing
"native" arm compiling form gentoo as you suggested.
Thanks for all your explainations. It's taken some digging but I'm
starting to get an overview of the start of the art on all this.
js.
> Both the userland and kernel should either both be compiled w/ the
EABI
> or both not, ... it's possible to have a mixed environment but it
would
> likely be very complicated.
>
> ... I have yet to get a functional kernel out of EABI though :P I
seem
> to be hitting the 'invalid machine id' problem in the list's
archives,
> which leads me to believe that the compiler isn't generating the
right
> endianness or some other register issue. I probably just need to
change
> my cflags when compiling linux to point specifically to the ep93xx
> devices, but haven't touched it for a few days.
>
>
> Let us know if you make any interesting progress?
>
> ~/Chris
>
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