From mboxrd@z Thu Jan 1 00:00:00 1970 From: "J.T. Conklin" To: Andrew Cagney Cc: gdb@cygnus.com Subject: Re: breakpoint extension for remote protocol Date: Fri, 11 Dec 1998 11:24:00 -0000 Message-id: <199812111924.LAA25449@jtc.redbacknetworks.com> References: <36708ED8.B84B67E0@cygnus.com> X-SW-Source: 1998/msg00190.html > > Here is the protocol elements that I'm currently working with: > > > > Insert Breakpoint: B,
[,] > > 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