This section documents the configuration options available when debugging remote programs. For the options related to the File I/O extensions of the remote protocol, see system-call-allowed.
set remoteaddresssize bits
Set the maximum size of address in a memory packet to the specified number of bits. GDB will mask off the address bits above that number, when it passes addresses to the remote target. The default value is the number of bits in the target’s address.
Show the current value of remote address size in bits.
set serial baud n
Set the baud rate for the remote serial I/O to n baud. The value is used to set the speed of the serial port used for debugging remote targets.
show serial baud
Show the current speed of the remote connection.
set serial parity parity
Set the parity for the remote serial I/O. Supported values of parity are:
odd. The default is
show serial parity
Show the current parity of the serial port.
If set to on, GDB sends a
BREAK signal to the remote
when you type Ctrl-c to interrupt the program running
on the remote. If set to off, GDB sends the ‘Ctrl-C’
character instead. The default is off, since most remote systems
expect to see ‘Ctrl-C’ as the interrupt signal.
Show whether GDB sends
BREAK or ‘Ctrl-C’ to
interrupt the remote program.
set remoteflow on
set remoteflow off
Enable or disable hardware flow control (
on the serial port used to communicate to the remote target.
Show the current setting of hardware flow control.
set remotelogbase base
Set the base (a.k.a. radix) of logging serial protocol
communications to base. Supported values of base are:
hex. The default is
Show the current setting of the radix for logging remote serial protocol.
set remotelogfile file
Record remote serial communications on the named file. The default is not to record at all.
Show the current setting of the file name on which to record the serial communications.
set remotetimeout num
Set the timeout limit to wait for the remote target to respond to num seconds. The default is 2 seconds.
Show the current number of seconds to wait for the remote target responses.
set remote hardware-watchpoint-limit limit
set remote hardware-breakpoint-limit limit
Restrict GDB to using limit remote hardware watchpoints
or breakpoints. The limit can be set to 0 to disable hardware
watchpoints or breakpoints, and
unlimited for unlimited
watchpoints or breakpoints.
show remote hardware-watchpoint-limit
show remote hardware-breakpoint-limit
Show the current limit for the number of hardware watchpoints or breakpoints that GDB can use.
set remote hardware-watchpoint-length-limit limit
Restrict GDB to using limit bytes for the maximum
length of a remote hardware watchpoint. A limit of 0 disables
hardware watchpoints and
unlimited allows watchpoints of any
show remote hardware-watchpoint-length-limit
Show the current limit (in bytes) of the maximum length of a remote hardware watchpoint.
set remote exec-file filename
show remote exec-file
Select the file used for
extended-remote. This should be set to a filename valid on the
target system. If it is not set, the target will use a default
filename (e.g. the last program run).
set remote interrupt-sequence
Allow the user to select one of ‘Ctrl-C’, a
‘BREAK-g’ as the
sequence to the remote target in order to interrupt the execution.
‘Ctrl-C’ is a default. Some system prefers
is high level of serial line for some certain time.
Linux kernel prefers ‘BREAK-g’, a.k.a Magic SysRq g.
BREAK signal followed by character
show remote interrupt-sequence
Show which of ‘Ctrl-C’,
is sent by GDB to interrupt the remote program.
BREAK-g is BREAK signal followed by
also known as Magic SysRq g.
set remote interrupt-on-connect
Specify whether interrupt-sequence is sent to remote target when
GDB connects to it. This is mostly needed when you debug
Linux kernel. Linux kernel expects
BREAK followed by
which is known as Magic SysRq g in order to connect GDB.
show remote interrupt-on-connect
Show whether interrupt-sequence is sent to remote target when GDB connects to it.
set tcp auto-retry on
Enable auto-retry for remote TCP connections. This is useful if the remote
debugging agent is launched in parallel with GDB; there is a race
condition because the agent may not become ready to accept the connection
before GDB attempts to connect. When auto-retry is
enabled, if the initial attempt to connect fails, GDB reattempts
to establish the connection using the timeout specified by
set tcp connect-timeout.
set tcp auto-retry off
Do not auto-retry failed TCP connections.
show tcp auto-retry
Show the current auto-retry setting.
set tcp connect-timeout seconds
set tcp connect-timeout unlimited
Set the timeout for establishing a TCP connection to the remote target to
seconds. The timeout affects both polling to retry failed connections
set tcp auto-retry on) and waiting for connections
that are merely slow to complete, and represents an approximate cumulative
value. If seconds is
unlimited, there is no timeout and
GDB will keep attempting to establish a connection forever,
unless interrupted with Ctrl-c. The default is 15 seconds.
show tcp connect-timeout
Show the current connection timeout setting.
The GDB remote protocol autodetects the packets supported by your debugging stub. If you need to override the autodetection, you can use these commands to enable or disable individual packets. Each packet can be set to ‘on’ (the remote target supports this packet), ‘off’ (the remote target does not support this packet), or ‘auto’ (detect remote target support for this packet). They all default to ‘auto’. For more information about each packet, see Remote Protocol.
During normal use, you should not have to use any of these commands. If you do, that may be a bug in your remote debugging stub, or a bug in GDB. You may want to report the problem to the GDB developers.
For each packet name, the command to enable or disable the
set remote name-packet. If you configure a packet, the
configuration will apply for all future remote targets if no target is selected.
In case there is a target selected, only the configuration of the current target
is changed. All other existing remote targets’ features are not affected.
The command to print the current configuration of a packet is
show remote name-packet. It displays the current remote target’s
configuration. If no remote target is selected, the default configuration for
future connections is shown. The available settings are:
|Command Name||Remote Packet||Related Features|
|Detecting multiple threads|
|Stepping or resuming multiple threads|
|Display MS-Windows Thread Information Block.|
|Remote communications parameters|
|Querying remote process attach state.|
|Install tracepoint in tracing|
|Debug multiple processes and remote process PID awareness|
|Tracking thread lifetime.|
|Set thread event reporting options.|
|Tracking thread lifetime.|
The number of bytes per memory-read or memory-write packet for a remote target
can be configured using the commands
set remote memory-read-packet-size and
set remote memory-write-packet-size. If set to ‘0’ (zero) the
default packet size will be used. The actual limit is further reduced depending
on the target. Specify ‘fixed’ to disable the target-dependent restriction
and ‘limit’ to enable it. Similar to the enabling and disabling of remote
packets, the command applies to the currently selected target (if available).
If no remote target is selected, it applies to all future remote connections.
The configuration of the selected target can be displayed using the commands
show remote memory-read-packet-size and
show remote memory-write-packet-size. If no remote target is
selected, the default configuration for future connections is shown.