Re: Arm toolchain with gcc / newlib / VFP / hard float - can it be done?

[Freddie Chopin <freddie_chopin at op dot pl>]

W dniu 2013-02-26 10:57, Joe Button pisze:
> > That's why I suggested taking a look at the linaro toolchain, as in it
> > newlib is built so that newlib takes multilib into account. What does
> > your gcc say when you do:
> > <prefix>-gcc -print-multi-lib
> ./arm-none-eabi-gcc -print-multi-lib
> .;
> thumb;@mthumb
> fpu;@mfloat-abi=hard

So this look a bit short... In here I got sth like:

> >arm-none-eabi-gcc -print-multi-lib
> .;
> thumb;@mthumb
> fpu;@mfloat-abi=hard
> armv6-m;@mthumb@march=armv6s-m
> armv7-m;@mthumb@march=armv7-m
> armv7e-m;@mthumb@march=armv7e-m
> armv7-r/thumb;@mthumb@march=armv7-r
> armv7e-m/softfp;@mthumb@march=armv7e-m@mfloat-abi=softfp@mfpu=fpv4-sp-d16
> armv7e-m/fpu;@mthumb@march=armv7e-m@mfloat-abi=hard@mfpu=fpv4-sp-d16
> armv7-r/thumb/softfp;@mthumb@march=armv7-r@mfloat-abi=softfp@mfpu=vfpv3-d16
> armv7-r/thumb/fpu;@mthumb@march=armv7-r@mfloat-abi=hard@mfpu=vfpv3-d16

The lines you have are for "default arch", which - as I said - (from 
what I know) is ARMv4 (ARM7TDMI etc.), for your chip I guess you should 
have sth like (just a guess):
"armv5/fpu;@march=armv5@mfloat-abi=hard"

And your GCC can generate code for ARMv5 (it would probably happily 
generate code for Cortex-A15 too (; ), it just doesn't have libraries 
for it, so you cannot use anything that comes from library (like sqrt(), 
printf(), malloc(), ...).

4\/3!!