Re: breakpoint extension for remote protocol

J.T. Conklin
1998-12-11T11:24:00Z

> > Here is the protocol elements that I'm currently working with:
> >
> > Insert Breakpoint: B<type>, [,<length>]
> > returns: ?? - A cookie representing the breakpoint
> > EX - breakpoint type not supported
> > - no breakpoint contexts available
> > - invalid/unsupported address
> > - invalid/unsupported length
>
> FYI, there is already a semi-official use of `B' as a generic remote
> breakpoint operation. The syntax is:
>
> B ,S Set a breakpoint
> B ,C Clear a breakpoint
>
> When using this, GDB assumes the target can handle all breakpoints.

Umm... I checked the current (98/11/21) GDB snapshot's remote.c, all
of the sample stubs, and remote.texi and could find no evidence of a
breakpoint command, much less a 'semi-official' one. So I went back
to a design Stu described to me some years ago as the foundation of my
current work.

I think the refined proposal I sent to the list yesterday is far
superior to the the one described above, as that would require yet
another set of commands for hardware break/watchpoints.

> With regard to the general question of extending the remote-gdb protocol
> so that it supports a generic hardware breakpoint mechanism. I agree it
> is needed. It is a missing part of the overall toolkit.

> Did you know that some targets actually implement hardware
> breakpoints by poking the registers directly?

I saw that. Yuck.

--jtc