breakpoint extension for remote protocol, take II

[Toshiyasu Morita]

> 
> >>>>> "Andrew" == Andrew Cagney <ac131313@cygnus.com> writes:
> Andrew> Have you considered what to do when there is a choice of
> Andrew> software breakpoints?  Jim Ingham's pointed out to me that in
> Andrew> the case of the MIPS/MIPS16 and ARM/THUMB the breakpoint might
> Andrew> be 2 bytes or 4 bytes in size (and the value different in each
> Andrew> case).
> 
> I was unaware processors with multiple software breakpoints existed.
> I assume that the 2 byte breakpoint instructions have to be inserted
> in "high-density" code segments and 4 byte breakpoints insns have to
> be inserted in "low-density" segments.

Is there a four-byte sequence which is an illegal instruction in both
MIPS16 and MIPS32 modes?

Toshi