The term "rdbgd" (pronounced "R-debug-D") is the name of the multi-process Debug Target Server used by ACCESS Linux Platform. rdbgd is a server which runs on the target to provide process information, start gdbservers, download and launch applications, and the like. It is used primarily by ACCESS-provided Eclipse plug-ins, although you can connect to it and interact with it using telnet.
rdbgd is part of the root filesystem and is launched automatically at target startup.
rdbgd Protocol (Commands)
The following sections detail the elements of the rdbgd protocol. After connecting to rdbgd using telnet, you can enter these protocol elements manually, treating them as commands.
cd
Purpose
Sets the current working directory in the context of the rdbgd process using chdir. This is the starting point for path searches for pathnames not beginning wth '/'.
Syntax
cd /working/directory/target/path
Output
close
Purpose
Closes the current rdbgd client connection.
Syntax
Output
There is no output string. The connection is simply closed.
connect
Purpose
Attach a gdbserver to an already running process.
Syntax
Output
- errno is the numeric failure code (0 on success) and port is the number of the TCP port on which the new gdbserver is listening.
install
Purpose
Transfer a file to the target system.
Syntax
install /path/to/destination/on/target N username groupname mode
- N is the size of the file in bytes, username and groupname are the names of the file's intended owner and group identity, and mode is the numeric permissions mask to be set on the destination file via
chmod(). The N bytes of file data must immediately follow the command string's trailing LF character.
Output
kill
Purpose
Deliver a kill signal to a process.
Syntax
- signal is the number of the signal to deliver and pid is the numeric process ID of the target application.
Output
- errno is the numeric failure code (0 on success). Note that this reflects the success of signal delivery, not a guarantee that any specific result has occurred. In particular, even if delivering a signal 9 (SIGKILL), the target application is not guaranteed to have been terminated.
launch
Purpose
Execute a program under gdbserver.
Syntax
launch [-terminal] /path/to/program/on/target [arg1 arg2 ...]
- The optional command-line arguments to the program are separated by whitespace (which is stripped when invoking the program) and where the
-terminaloption creates a port from which stdin is read and to which stdout is written for the executed program.
Output
launch errno gdbserverPort [terminalPort]
- errno is the numeric failure code (0 on success), and gdbserverPort is the number of the TCP port on which the new gdbserver is listening. An optional terminalPort value is passed back if the
-terminaloption was specified. This is the number of the TCP port to which stdout, stdin and stderr are redirected.
list
Purpose
Syntax
Output
list N
followed by N lines of proc[pid]/stat output, one line per process.
package
Purpose
Interact with an ACCESS Linux Platform bundle.
Syntax
package install /path/on/target/to/package.bar
package run com.access.PackageName
package debug com.access.PackageName
package register {/path/on/target/to/package.bar | /package/directory/on/target}
package unregister com.access.PackageName
package delete com.access.PackageName
package exit [com.access.PackageName]
For package install and package register, /path/on/target/to/package.bar is the target path to an ACCESS Linux Platform bundle. Use the regular install command to get it there if necessary. com.access.PackageName is the installed name of an ACCESS Linux Platform bundle.
Output
Output string for install, run, register, unregister, or delete:
Output string for package debug:
- errno is the numeric failure code (0 on success), and pid is the process ID of the ACCESS Linux Platform application waiting to be debugged.
Output string for package names:
package errno
... N lines of bundle names
- errno is the numeric failure code (0 on success). Following this are the bundle names, one on each line.
printenv
Purpose
Prints the environment variables in the context of the rdbgd process.
Syntax
Output
printenv errno
...N lines of "ENV=value" output
run
Purpose
Execute a program independently of gdb/gdbserver.
Syntax
run [-terminal] /path/to/program/on/target [arg1 arg2 ...]
- The optional command-line arguments to the program are separated by whitespace (which is stripped when invoking the program). The
-terminaloption creates a port from which stdin is read and to which stdout is written for the executed program.
Output
- errno is the numeric failure code (0 on success). An optional terminalPort value is passed back if the
-terminaloption was specified. This is the number of the TCP port to which stdout, stdin and stderr are redirected.
setenv
Purpose
Sets the specified environment variable in the context of the running rdbgd executable, using putenv.
Syntax
Output
version
Purpose
Returns the protocol version of rdbgd.
Syntax
Output
Basic rdbgd Tasks
Launching rdbgd
You do not need to explicitly launch rdbgd; it is automatically launched on the target or in the Simulator at bootup.
Installing and Debugging an Application
First, make sure that the rdbgd tool is running on the target. The target could be your native system.
telnet 192.168.2.101 5038
where the 192.168.2.101 is replaced by the IP address of your target. The port should be 5038, since that is the default rdbgd port (unless you changed it on startup).
- Install the application on the target by copying it over to the appropriate place in the location of the rootfs on the host. (Although you could use an rdbgd command, it is much easier to simply copy it over).
- Launch a gdbserver session using the rdbgd connection:
launch /path/on/target/to/executable
For instance, to launch the built-in calculator application, you would use:
launch /opt/alp/bundles/com.access.apps.calc/ libalp_calc.so
launch 0 5023
This output tells you that the launch was successful and that the gdbserver is listening on port 5023.
Connecting to an Existing Process (ARM)
First Host Session:
telnet 192.168.2.101 5038
connect <PID from step 2, above>
connect <errno> <port>
Second Host Session:
<your ARM GDB> <host path to executable>
target remote 192.168.2.101:<port from the
connect command, above>
You are now connected to the target process.
