-This is a test line for tags testing.
-
- README for GDBserver
- by Stu Grossman
+ README for GDBserver & GDBreplay
+ by Stu Grossman and Fred Fish
Introduction:
implemented in remote.c, and various *-stub.c files. They communicate via
either a serial line or a TCP connection.
+For more information about GDBserver, see the GDB manual.
+
Usage (server (target) side):
First, you need to have a copy of the program you want to debug put onto
target> gdbserver /dev/com1 emacs foo.txt
-This tells gdbserver to debug emacs with an argument of foo.txt, and to
-communicate with GDB via /dev/com1. Gdbserver now waits patiently for the
+This tells GDBserver to debug emacs with an argument of foo.txt, and to
+communicate with GDB via /dev/com1. GDBserver now waits patiently for the
host GDB to communicate with it.
To use a TCP connection, you could say:
want for the port number as long as it does not conflict with any existing TCP
ports on the target system. This same port number must be used in the host
GDBs `target remote' command, which will be described shortly. Note that if
-you chose a port number that conflicts with another service, gdbserver will
+you chose a port number that conflicts with another service, GDBserver will
print an error message and exit.
+On some targets, GDBserver can also attach to running programs. This is
+accomplished via the --attach argument. The syntax is:
+
+ target> gdbserver --attach COMM PID
+
+PID is the process ID of a currently running process. It isn't necessary
+to point GDBserver at a binary for the running process.
+
Usage (host side):
You need an unstripped copy of the target program on your host system, since
(gdb) target remote the-target:2345
communicates via a TCP connection to port 2345 on host `the-target', where
-you previously started up gdbserver with the same port number. Note that for
-TCP connections, you must start up gdbserver prior to using the `target remote'
+you previously started up GDBserver with the same port number. Note that for
+TCP connections, you must start up GDBserver prior to using the `target remote'
command, otherwise you may get an error that looks something like
`Connection refused'.
-Building:
-
-Currently, the only target system supported by the server is Lynx. To build
-the server for Lynx, make a new copy of the distribution onto a disk that is
-NFS shared with the Lynx system. Lets say that's in a directory called xyzzy.
-Then, follow these steps under the host system:
-
- 1) cd xyzzy/gdb/gdbserver
- 2) ../../configure --target i386-none-lynx
-
-When that completes, do the following on the Lynx system:
-
- 3) cd xyzzy/gdb/gdbserver
- 4) make CC=gcc
-
-It should build with only a minor complaint about NULL being redefined. That's
-a LynxOS problem, and can be ignored.
-
-It's also possible that you may have a cross-compiler to Lynx. In that case,
-you can skip the stuff about NFS. You would replace steps 3 & 4 with:
-
- make CC=lynx-target-compiler...
+Building GDBserver:
+
+The supported targets as of November 2006 are:
+ arm-*-linux*
+ crisv32-*-linux*
+ cris-*-linux*
+ i[34567]86-*-cygwin*
+ i[34567]86-*-linux*
+ i[34567]86-*-mingw*
+ ia64-*-linux*
+ m32r*-*-linux*
+ m68*-*-linux*
+ m68*-*-uclinux*
+ mips*64*-*-linux*
+ mips*-*-linux*
+ powerpc[64]-*-linux*
+ s390[x]-*-linux*
+ sh-*-linux*
+ spu*-*-*
+ x86_64-*-linux*
+ xscale*-*-linux*
+
+Configuring GDBserver you should specify the same machine for host and
+target (which are the machine that GDBserver is going to run on. This
+is not the same as the machine that GDB is going to run on; building
+GDBserver automatically as part of building a whole tree of tools does
+not currently work if cross-compilation is involved (we don't get the
+right CC in the Makefile, to start with)).
+
+Building GDBserver for your target is very straightforward. If you build
+GDB natively on a target which GDBserver supports, it will be built
+automatically when you build GDB. You can also build just GDBserver:
+
+ % mkdir obj
+ % cd obj
+ % path-to-gdbserver-sources/configure
+ % make
+
+If you prefer to cross-compile to your target, then you can also build
+GDBserver that way. In a Bourne shell, for example:
+
+ % export CC=your-cross-compiler
+ % path-to-gdbserver-sources/configure your-target-name
+ % make
+
+Using GDBreplay:
+
+A special hacked down version of GDBserver can be used to replay remote
+debug log files created by GDB. Before using the GDB "target" command to
+initiate a remote debug session, use "set remotelogfile <filename>" to tell
+GDB that you want to make a recording of the serial or tcp session. Note
+that when replaying the session, GDB communicates with GDBreplay via tcp,
+regardless of whether the original session was via a serial link or tcp.
+
+Once you are done with the remote debug session, start GDBreplay and
+tell it the name of the log file and the host and port number that GDB
+should connect to (typically the same as the host running GDB):
+
+ $ gdbreplay logfile host:port
+
+Then start GDB (preferably in a different screen or window) and use the
+"target" command to connect to GDBreplay:
+
+ (gdb) target remote host:port
+
+Repeat the same sequence of user commands to GDB that you gave in the
+original debug session. GDB should not be able to tell that it is talking
+to GDBreplay rather than a real target, all other things being equal. Note
+that GDBreplay echos the command lines to stderr, as well as the contents of
+the packets it sends and receives. The last command echoed by GDBreplay is
+the next command that needs to be typed to GDB to continue the session in
+sync with the original session.