Hi Masaki,

> Please try 'print $dma0' on GDB (w/o my patch).
> dma0 is a register supported by m32c only.
> So the result of 'print $dma0' is ...
> In case m32c, it should be 'No registers.'
> In case m16c, it should be ''void' since it doesn't have dma0 register.

Thank you - that was the extra information that I needed in order to be 
able to diagnose this problem.

Please try out the attached patch and let me know if it works for you.

By the way, this has exposed a problem with GDB's set architecture 
command - it is not set up to allow the "ARCH:MACH" notation that is 
accepted by the BFD library.  Maybe someone will want to fix this one day...

Cheers
   Nick