Is stub support for the 's' packet optional or required?

[Kevin Buettner]

On Feb 18, 11:51am, Daniel Jacobowitz wrote:

> > [For remote MIPS/Linux targets, I've found some cases where GDB's
> > implementation of software singlestep causes some undesirable behavior
> > when doing the 'stepi' operation through some code that's hit by a number
> > of threads.  Yet, when software single step is implemented in the debug
> > agent (and disabled in GDB), the debugging behavior is much more useful
> > (and sensible).]
> 
> Is it just slow, or do different things actually happen?

Different things happen.  Specifically, GDB was getting a SIGTRAP due to
one of the other threads hitting the software single step breakpoint. 
This meant that I was unable to step through the function that I was
attempting to debug when GDB was setting the software single step
breakpoints.  When I moved that functionality (software single step)
to the debug agent, I was able to step through the code of interest
without any problem.

Kevin