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ARM7, remote GDB, Software Breakpoints
- From: Torsten Mohr <tmohr at s dot netic dot de>
- To: gdb <gdb at sources dot redhat dot com>
- Date: Wed, 12 Feb 2003 06:59:36 +0100
- Subject: ARM7, remote GDB, Software Breakpoints
i have several questions related to the GDB remote protocol
server i wrote ( http://www.s.netic.de/tmohr/pppcb-0.5.0.tar.bz2 ),
it would be great if someone could give me some hints.
1. I could handle HW breakpoints, how can i tell GDB that it should
use HW breakpoints? Just answering requests for SW breakpoints with
"ENN" doesn't seem to make GDB use HW breakpoints.
2. When i use SW breakpoints and download and start a program on
the target, first the program is downloaded and then the SW
breakpoints are set. SW breakpoints are done by replacing the
instruction at that address with a "breakpoint instruction".
When the program stops on a "breakpoint instruction", and i
then do a "step" or "continue", that original instruction is
NOT EXECUTED, it seems i have to restore that value temporarily,
do a "single step" and put back that "breakpoint instruction"
From watching the communication between target and server i assume
it is like this, i just want to make sure this is the way to handle
it and i don't miss anything.
3. Thumb mode is not handled at all at the moment, what do i need
to do to handle Thumb mode?
If GDB downloads a program into the target and sets the PC to a
certain address, how does my server know if it should execute this
in ARM or in Thumb mode?