Re: [ECOS] ARM Thumb - not working under Linux either

[Jonathan Larmour <jlarmour@redhat.com>]

"Lewin A.R.W. Edwards" wrote:
> 
> Hello Jonathan,
> 
> > > /tmp/ccSGafJS.s:544: Error: byte or halfword not valid for base register
> > > make[1]: *** [src/debug/dbg_gdb.o.d] Error 1
> >
> >It's a bug in gcc's reload. I've talked with people on the binutils list
> 
> Good, glad to know it is a known/recogized problem and not the evil demon
> riding on my shoulder. And at least now I can build the CVS sources of
> eCos, which is a big step.
> 
> Do you have any insight on why I can't get eCos compiled with Thumb
> interworking? It would be an acceptable workaround for me if I could have
> the OS in 32-bit mode and my app in Thumb mode, since the friskier parts
> are all in my app anyway. At the moment, we are only demoing the technology
> so it isn't vital to get everything tweaked to perfection; the final
> firmware doesn't have to ship until Q3 :)

I had a quick look. What you are seeing is messages like the following?

home/jlarmour/sourceware/test/arm-elf/H-i686-pc-linux-gnu/lib/gcc-lib/arm-elf/2.97/../../../../arm-elf/bin/ld:
_div_df.o(__divdf3): warning: interworking not enabled.

This object is actually from libgcc - part of the compiler. It has not been
built with -mthumb-interwork.

You probably need to edit (in your gcc sources) gcc/config/arm/t-arm-elf
and uncomment:

# MULTILIB_OPTIONS    += mno-thumb-interwork/mthumb-interwork
# MULTILIB_DIRNAMES   += normal interwork
# MULTILIB_EXCEPTIONS += *mapcs-26/*mthumb-interwork*

Then rebuild your compiler from scratch.

If that works, I'll add it to the thumb gcc building instructions.

Jifl
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