From mboxrd@z Thu Jan  1 00:00:00 1970
From: Andrew Cagney <ac131313@cygnus.com>
To: gdb@cygnus.com
Subject: Re: breakpoint extension for remote protocol
Date: Thu, 10 Dec 1998 19:27:00 -0000
Message-id: <36708ED8.B84B67E0@cygnus.com>
References: <199812041858.KAA25185.cygnus.gdb@jtc.redbacknetworks.com>
X-SW-Source: 1998/msg00188.html

"J.T. Conklin" wrote:

> Here is the protocol elements that I'm currently working with:
>
>     Insert Breakpoint:     B<type>,<address>[,<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<address>,S    Set a breakpoint
    B<address>,C    Clear a breakpoint

When using this, GDB assumes the target can handle all breakpoints.

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?

    enjoy,
        Andrew