libffi on Cortex M4?

[Tor Krill]

Dear list,

I'm trying to crosscompile libffi for a Cortex-M4 platform running
uClinux but this fails miserably during compilation with a:

../src/arm/sysv.S: Assembler messages:
../src/arm/sysv.S:152: Error: selected processor does not support ARM
opcodes
../src/arm/sysv.S:154: Error: attempt to use an ARM instruction on a
Thumb-only processor -- `stmfd sp!,{r0-r3,fp,lr}'
../src/arm/sysv.S:156: Error: attempt to use an ARM instruction on a
Thumb-only processor -- `mov fp,sp'
../src/arm/sysv.S:161: Error: attempt to use an ARM instruction on a
Thumb-only processor -- `sub sp,fp,r2'

My question is simply, is thumb2 on a cortex m4 supported by libffi?
I.e. is it my build setup that is faulty and this should work or is this
unsupported?

sysv.S have indications that it should support thumb instructions but it
seems to be ignored when i compile libffi.

Best!

/Tor