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author | Stan Shebs <shebs@apple.com> | 1999-04-16 01:33:56 +0000 |
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committer | Stan Shebs <shebs@apple.com> | 1999-04-16 01:33:56 +0000 |
commit | 838ae13dc4ab603f1efdf1da653e2ca1b7b009e1 (patch) | |
tree | 8d3c114b0ba9d2a1f0dcadd192ba2aaeeafe7175 /gdb/gdbserver/README | |
download | gdb-838ae13dc4ab603f1efdf1da653e2ca1b7b009e1.tar.gz |
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-rw-r--r-- | gdb/gdbserver/README | 127 |
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diff --git a/gdb/gdbserver/README b/gdb/gdbserver/README new file mode 100644 index 00000000000..2281bf686c1 --- /dev/null +++ b/gdb/gdbserver/README @@ -0,0 +1,127 @@ + README for GDBserver & GDBreplay + by Stu Grossman and Fred Fish + +Introduction: + +This is GDBserver, a remote server for Un*x-like systems. It can be used to +control the execution of a program on a target system from a GDB on a different +host. GDB and GDBserver communicate using the standard remote serial protocol +implemented in remote.c, and various *-stub.c files. They communicate via +either a serial line or a TCP connection. + +Usage (server (target) side): + +First, you need to have a copy of the program you want to debug put onto +the target system. The program can be stripped to save space if needed, as +GDBserver doesn't care about symbols. All symbol handling is taken care of by +the GDB running on the host system. + +To use the server, you log on to the target system, and run the `gdbserver' +program. You must tell it (a) how to communicate with GDB, (b) the name of +your program, and (c) its arguments. The general syntax is: + + target> gdbserver COMM PROGRAM [ARGS ...] + +For example, using a serial port, you might say: + + 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 +host GDB to communicate with it. + +To use a TCP connection, you could say: + + target> gdbserver host:2345 emacs foo.txt + +This says pretty much the same thing as the last example, except that we are +going to communicate with the host GDB via TCP. The `host:2345' argument means +that we are expecting to see a TCP connection from `host' to local TCP port +2345. (Currently, the `host' part is ignored.) You can choose any number you +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 +print an error message and exit. + +Usage (host side): + +You need an unstripped copy of the target program on your host system, since +GDB needs to examine it's symbol tables and such. Start up GDB as you normally +would, with the target program as the first argument. (You may need to use the +--baud option if the serial line is running at anything except 9600 baud.) +Ie: `gdb TARGET-PROG', or `gdb --baud BAUD TARGET-PROG'. After that, the only +new command you need to know about is `target remote'. It's argument is either +a device name (usually a serial device, like `/dev/ttyb'), or a HOST:PORT +descriptor. For example: + + (gdb) target remote /dev/ttyb + +communicates with the server via serial line /dev/ttyb, and: + + (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' +command, otherwise you may get an error that looks something like +`Connection refused'. + +Building: + +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)). + +gdbserver should work on sparc-sun-sunos4* or Lynx. The following +instructions pertain to 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 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... + +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. |