I'm newbie to emulator. Nowadays I try to view src code of mgba(GBA Emulator).
https://github.com/mgba-emu/mgba
I built and found option -g.
-g option means Start GDB session (default port 2345) from help.
Is it able to be debugged with GDB?
How can I debug with GDB?
Please tell me how to or other methods to trace source code?
(Sorry for my poor English.)
The -g option means you can remotely debug your rom with a remote debugger of gdb like gdb, ghidra or radare2. You will need another tool as mentioned before.
Sadly you can not debug remotely a classic gameboy rom. It only works for gameboy advance roms.
If you just want to debug the rom with no remote debugging access you can still use gdb from mgba with no remote debugging using the command
mgba -d your_rom.gb
a terminal should start. Then use gdb commands such as c to continue.
If you do not like gdb, you can get a look at BGB if you prefer a more graphic debugger.
Related
Let us say I am on a Windows machine and I goto its command line terminal and type 'gdb' there. I get gdb prompt (gdb) as shown in the following image. It means gdb.exe is installed on the machine.
My understanding is that the GDB is client-server application. I want to know is this gdb.exe the gdbserver or gdbclient? If its the former then where would be the later and if its the later then where would be the former in this case?
GDB can be a client server application, but it doesn't have to be.
What you started is gdb itself, so, the client side. The server is actually called, gdbserver.
Usually, you'd make use of gdbserver when you want to debug something running on a different machine over a network (though there's nothing to stop you running gdbserver on the same machine as gdb itself).
You can also use gdb to directly start an application to debug, so at the (gdb) prompt you might do:
(gdb) file /path/to/some/executable
(gdb) break main
(gdb) run
For further reading the manual has lots of details, there's a simple example session and more details on remote debug.
I'm trying to debug a remote embedded system.
On the target machine I run:
gdbserver localhost:port myapp
And on the host machine I run:
gdb-multiarch myapp
(gdb) target remote ip-address:port
It works and I can debug normally.
I'd like to debug this embedded program in vim as I do using Termdebug to debug normal program.
Is there a way to run gdb-multiarch when calling Termdebug? Or is there a better alternative?
First of all, load the term debugger plugin
:packadd termdebug
Then you can use the debugger the way you know how
:Termdebug
It's in the docs 🙂
I want to run GDB on my ARM embedded board...
I have referred online that we can set up GDB server and can do remote debugging but still i am missing proper steps to set up whole environment for GDB Debugging..
Can anyone please provide me a proper guidance from cross compiling GDB to running my gdb for debugging on embedded board ??
I appreciate any inputs
I assume you have a toolchain that lets you build applications for your embedded linux platform. This should include gdb (named something like arm-linux-gdb).
Next check if linux for your board already includes gdb/gdbserver. If it does, you don't have to build anything. If it does not, configure gdb like this:
./path/to/gdb/source/configure --host=arm-linux --target=arm-linux --prefix=/path/to/installation/directory
Then make and make install.
Note that --host and --target will probably match your toolchains prefix.
As part of this installation you will get gdbserver. Install it on your board.
Then use it, as explained here. It depends on your connection type (TCP, serial), but you need to run program under gdbserver on board (gdbserver binary), then run you toolchain's gdb on PC and connect to board using "target remote" command.
Have you already looked at Buildroot? It will take care of cross-compiler and root file system. You can choose to compile host and target gdb/gdbserver, so that you'll have everything from one hand. See BR's documentation.
Remote debugging of embedded systems:
GDB, as a server, must be compiled into the debugging target build in order to support connected GDB clients. When running on the client side, there must exist a copy of the target source as well as an unstripped (of symbols) version of the executable.
GCC compilation should be done with the -g flag.
On the target/server side, run with
gdbserver <port> --attach <pid> or gdbserver host:<port> <program>
On the client side, run gdb and then
(gdb) target remote IP:PORT
What gdb client to run? Must be built with the right target processor in mind, for example
.../toolchain/bin/powerpc-linux-gdb core/mydaemon/src/mydaemon -x gdb-command-script
-x is a filename option
Hope this helps!
Remote debugging of embedded systems: GDB, as a server, must be compiled into the debugging target build in order to support connected GDB clients. When running on the client side, there must exist a copy of the target source as well as an unstripped (of symbols) version of the executable.
GCC compilation should be done with the -g flag.
On the target/server side, run with
gdbserver --attach or gdbserver host:
On the client side, run gdb and then
(gdb) target remote IP:PORT
What gdb client to run? Must be built with the right target processor in mind, for example
.../toolchain/bin/powerpc-linux-gdb core/mydaemon/src/mydaemon -x gdb-command-script
-x is a filename option
Hope this helps!
Valgrind produced a vgcore.NNNN file -- how do I debug the core using GDB? Do I need to use the original executable and supply the core, or is there some other way to do it?
Using valgrind as the root executable doesn't seem to work, and using the executable that was being run under valgrind directly in GDB with the core seems to produce bad backtraces.
This works fine for me:
gdb ./a.out vgcore.21650
and that's how you are supposed to use the vgcore.
If your program corrupted stack before crashing, then obviously you wouldn't get good stack traces from vgcore. You might want to expand your question with actual Valgrind report that led to the crash.
I have a XCode which builds and runs under XCode.
I would like to know if it is possible to debug it using a gdb I build under Mac OSX (gdb 7 to be specified). If yes, can you please tell me how can I do that?
Thank you.
gdb-7.0 reverse debugging currently can only work with two classes of targets:
1) a remote simulator/emulator/virtual-machine that supports going backwards, or
2) the built in "process record" target, which at present has only been ported to x86-linux, x86-64 linux, and moxie linux.
Well, now -- I take that back. I recently discovered that process record can work with any remote x86 target, so if you're connecting with your macintosh target via "target remote", you might just be able to do it!
There is an online tutorial for process record here:
http://www.sourceware.org/gdb/wiki/ProcessRecord/Tutorial
More info about process record here:
http://www.sourceware.org/gdb/wiki/ProcessRecord
And about gdb reverse debugging here:
http://www.sourceware.org/gdb/wiki/ReverseDebug
So you want to use your own version of gdb to debug your executable? Easy!
Open Terminal, and do something like this:
$ cd <directory where Xcode project lives>
$ cd build/Debug (for example - depends on project configuration)
$ /usr/local/bin/my-gdb ./MyExecutable
Of course, specifying the actual path to your custom gdb version.
XCode's debugger is gdb (likely with Apple-specific modifications.) When you debug an application you can get to the gdb command line by opening the Console from the Run menu.
What requirements are imposed on your application that would require you to debug with your own version of gdb?