From mboxrd@z Thu Jan 1 00:00:00 1970 To: Rolf.Fiedler@Ferrari.DE Cc: linuxppc-embedded@lists.linuxppc.org Subject: Re: debugging a PPC405GP target References: <388C1704.5F4E270C@Ferrari.DE> <388C220F.F3669689@Ferrari.DE> From: Jesper Skov Date: 24 Jan 2000 11:42:00 +0100 In-Reply-To: Rolf Fiedler's message of "Mon, 24 Jan 2000 10:57:35 +0100" Message-ID: Sender: owner-linuxppc-embedded@lists.linuxppc.org List-Id: >>>>> "Rolf" == Rolf Fiedler writes: Rolf> this is plain wrong. I do not have to use gdbserver, gdbserver Rolf> is just one possiblity. How can I use the hardware breakpoints Rolf> in the debug-hardware on the target or have breakpoints in ROM Rolf> when I use a low-tech debug approach like gdbserver? I didn't make myself clear, sorry: when you use gdbserver you have a "stub" which knows about the context in which the application runs (the Linux operating system). You can (potentially) show thread information, environment variables and the like [gdbserver doesn't have thread support at the moment]. It's hard to get the same functionality from the wiggler (because it only knows about the CPU state). But then it has other advantages as you say. >> You may be able to make the wiggler work as a regular serial >> connection, but I don't see what you gain by that over using a >> standard ethernet/serial connection (except if the only interface >> on the board is the wiggler one). Rolf> It would be not very smart to reduce the wiggler to a regular Rolf> serial connection, since I have more features then I can address Rolf> with the gdb remote protocol. The advantages are: - no software Rolf> on the target (bootstrapping) - use of 4 hw address and 2 hw Rolf> data breakpoints (try to use a watchpoint with gdbserver and Rolf> you'll learn what performance really means :-) There's nothing preventing you from implementing use of hardware watchpoints and breakpoints in gdbserver. Would probably require some kernel features to be added as well. But those debugging features are part of the CPU, not the wiggler hardware. As anything else OS, it's just a question of someone getting fed up with the current state of affairs and implement the new stuff, making the world a better place :) Jesper ** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/