Re: remote protocol extension for step out of range

[jtc at redback dot com (J.T. Conklin)]

>>>>> "jtc" == J T Conklin <jtc@redback.com> writes:
jtc> It turned out to be trival to implement the above.  I've enclosed a
jtc> patch for review.  The guts are ~50 lines, including comments.  The
jtc> rest is required for the CLI so the user can enable and disable the
jtc> new packets.

I got a chance to implement support for this in the debug stub used 
by one of our x86 based targets.  The result was spectacular.

Before this change, on a bit of random x86 code, each "step" caused
GDB to send an average of 3 to 4 "s" commands to the target.  After
the change, those "s" commands were replaced with a single "e".  This
greatly improves command latency.  This should be welcomed by anyone
who debugs over a slow debug channel, or cases where the target is 
half the world away.

Unfortunately, GDB still insists on inserting and removing breakpoints
around each step, so things aren't quite as efficent as they could be.
I think in time even that can be fixed.

        --jtc

-- 
J.T. Conklin
RedBack Networks