1GDBSERVER(1) GNU Development Tools GDBSERVER(1)
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6 gdbserver - Remote Server for the GNU Debugger
7
9 gdbserver comm prog [args...]
10 gdbserver --attach comm pid
12 gdbserver --multi comm
14
16 gdbserver is a program that allows you to run GDB on a different
17 machine than the one which is running the program being debugged.
18 Usage (server (target) side):
20 First, you need to have a copy of the program you want to debug put
22 onto the target system. The program can be stripped to save space if
23 needed, as gdbserver doesn't care about symbols. All symbol handling
24 is taken care of by the GDB running on the host system.
25 To use the server, you log on to the target system, and run the
27 gdbserver program. You must tell it (a) how to communicate with GDB,
28 (b) the name of your program, and (c) its arguments. The general
29 syntax is:
30 target> gdbserver <comm> <program> [<args> ...]
32 For example, using a serial port, you might say:
34 target> gdbserver /dev/com1 emacs foo.txt
36 This tells gdbserver to debug emacs with an argument of foo.txt, and to
38 communicate with GDB via /dev/com1. gdbserver now waits patiently for
39 the host GDB to communicate with it.
40 To use a TCP connection, you could say:
42 target> gdbserver host:2345 emacs foo.txt
44 This says pretty much the same thing as the last example, except that
46 we are going to communicate with the "host" GDB via TCP. The
47 "host:2345" argument means that we are expecting to see a TCP
48 connection from "host" to local TCP port 2345. (Currently, the "host"
49 part is ignored.) You can choose any number you want for the port
50 number as long as it does not conflict with any existing TCP ports on
51 the target system. This same port number must be used in the host GDBs
52 "target remote" command, which will be described shortly. Note that if
53 you chose a port number that conflicts with another service, gdbserver
54 will print an error message and exit.
55 gdbserver can also attach to running programs. This is accomplished
57 via the --attach argument. The syntax is:
58 target> gdbserver --attach <comm> <pid>
60 pid is the process ID of a currently running process. It isn't
62 necessary to point gdbserver at a binary for the running process.
63 To start "gdbserver" without supplying an initial command to run or
65 process ID to attach, use the --multi command line option. In such
66 case you should connect using "target extended-remote" to start the
67 program you want to debug.
68 target> gdbserver --multi <comm>
70 Usage (host side):
72 You need an unstripped copy of the target program on your host system,
74 since GDB needs to examine its symbol tables and such. Start up GDB as
75 you normally would, with the target program as the first argument.
76 (You may need to use the --baud option if the serial line is running at
77 anything except 9600 baud.) That is "gdb TARGET-PROG", or "gdb --baud
78 BAUD TARGET-PROG". After that, the only new command you need to know
79 about is "target remote" (or "target extended-remote"). Its argument
80 is either a device name (usually a serial device, like /dev/ttyb), or a
81 "HOST:PORT" descriptor. For example:
82 (gdb) target remote /dev/ttyb
84 communicates with the server via serial line /dev/ttyb, and:
86 (gdb) target remote the-target:2345
88 communicates via a TCP connection to port 2345 on host `the-target',
90 where you previously started up gdbserver with the same port number.
91 Note that for TCP connections, you must start up gdbserver prior to
92 using the `target remote' command, otherwise you may get an error that
93 looks something like `Connection refused'.
94 gdbserver can also debug multiple inferiors at once, described in the
96 GDB manual in node "Inferiors Connections and Programs" -- shell
97 command "info -f gdb -n 'Inferiors Connections and Programs'". In such
98 case use the "extended-remote" GDB command variant:
99 (gdb) target extended-remote the-target:2345
101 The gdbserver option --multi may or may not be used in such case.
103
105 There are three different modes for invoking gdbserver:
106 • Debug a specific program specified by its program name:
108 gdbserver <comm> <prog> [<args>...]
110 The comm parameter specifies how should the server communicate with
112 GDB; it is either a device name (to use a serial line), a TCP port
113 number (":1234"), or "-" or "stdio" to use stdin/stdout of
114 "gdbserver". Specify the name of the program to debug in prog.
115 Any remaining arguments will be passed to the program verbatim.
116 When the program exits, GDB will close the connection, and
117 "gdbserver" will exit.
118 • Debug a specific program by specifying the process ID of a running
120 program:
121 gdbserver --attach <comm> <pid>
123 The comm parameter is as described above. Supply the process ID of
125 a running program in pid; GDB will do everything else. Like with
126 the previous mode, when the process pid exits, GDB will close the
127 connection, and "gdbserver" will exit.
128 • Multi-process mode -- debug more than one program/process:
130 gdbserver --multi <comm>
132 In this mode, GDB can instruct gdbserver which command(s) to run.
134 Unlike the other 2 modes, GDB will not close the connection when a
135 process being debugged exits, so you can debug several processes in
136 the same session.
137 In each of the modes you may specify these options:
139 --help
141 List all options, with brief explanations.
142 --version
144 This option causes gdbserver to print its version number and exit.
145 --attach
147 gdbserver will attach to a running program. The syntax is:
148 target> gdbserver --attach <comm> <pid>
150 pid is the process ID of a currently running process. It isn't
152 necessary to point gdbserver at a binary for the running process.
153 --multi
155 To start "gdbserver" without supplying an initial command to run or
156 process ID to attach, use this command line option. Then you can
157 connect using "target extended-remote" and start the program you
158 want to debug. The syntax is:
159 target> gdbserver --multi <comm>
161 --debug
163 Instruct "gdbserver" to display extra status information about the
164 debugging process. This option is intended for "gdbserver"
165 development and for bug reports to the developers.
166 --remote-debug
168 Instruct "gdbserver" to display remote protocol debug output. This
169 option is intended for "gdbserver" development and for bug reports
170 to the developers.
171 --debug-file=filename
173 Instruct "gdbserver" to send any debug output to the given
174 filename. This option is intended for "gdbserver" development and
175 for bug reports to the developers.
176 --debug-format=option1[,option2,...]
178 Instruct "gdbserver" to include extra information in each line of
179 debugging output.
180 --wrapper
182 Specify a wrapper to launch programs for debugging. The option
183 should be followed by the name of the wrapper, then any command-
184 line arguments to pass to the wrapper, then "--" indicating the end
185 of the wrapper arguments.
186 --once
188 By default, gdbserver keeps the listening TCP port open, so that
189 additional connections are possible. However, if you start
190 "gdbserver" with the --once option, it will stop listening for any
191 further connection attempts after connecting to the first GDB
192 session.
193
195 The full documentation for GDB is maintained as a Texinfo manual. If
196 the "info" and "gdb" programs and GDB's Texinfo documentation are
197 properly installed at your site, the command
198 info gdb
200 should give you access to the complete manual.
202 Using GDB: A Guide to the GNU Source-Level Debugger, Richard M.
204 Stallman and Roland H. Pesch, July 1991.
205
207 Copyright (c) 1988-2022 Free Software Foundation, Inc.
208 Permission is granted to copy, distribute and/or modify this document
210 under the terms of the GNU Free Documentation License, Version 1.3 or
211 any later version published by the Free Software Foundation; with the
212 Invariant Sections being "Free Software" and "Free Software Needs Free
213 Documentation", with the Front-Cover Texts being "A GNU Manual," and
214 with the Back-Cover Texts as in (a) below.
215 (a) The FSF's Back-Cover Text is: "You are free to copy and modify this
217 GNU Manual. Buying copies from GNU Press supports the FSF in
218 developing GNU and promoting software freedom."
219gdb-Fedora 12.1-1.fc36 2022-05-06 GDBSERVER(1)