Debug xv6 on mac with CLion - macos

I've looked through the internet and searched for solution for debugging xv6 on mac with CLion and didn't find one. as you know it's difficult (or maybe impossible, I didn't succeeded anyway) to make gdb work on macOS.
So, how can I do it? How can I debug xv6 with CLion on macOS?

NOTE that in order to be able to debug xv6-riscv you will need to use riscv64-unknown-elf-gdb instead of gdb
as following:

run make qemu-gdb clean in terminal (in the project's directory of course), pay attention for the port, it may be different for some reason, for me it was 25501.
All I needed to do is the following:
kernel is good for debugging proc.c, if you want to debug other file, (i.e. sh.c) you should put _sh instead.

Related

How to strip a macOS app to remove debug information?

stripis a unix command to remove all the debug information from an executable, or other information that is not needed for execution. Is there a way to "strip" a macos app to make it smaller and make reverse engineering more difficult? I tried viewing package contents, and striping /macOS/MyGame executable, but then it claimed that it messed it up, and then refused to launch. How do I strip it without "invalidating the code signature" I already asked and I need help.
What is your purpose?
If you plan to distribute the app then using XCode's archiving options is the way to go.
strip command works in MACOS.
Here is a useful script:
https://gist.github.com/neonichu/1662881

How can I remove the need of wpcap.dll in my go program?

I use gopacket in my program. on linux, it runs perfectly.
But on windows the whole program crashes if i did not install WinPcap before.
My plan was to check if WinPcap is installed, and if not to inform the user that he needs this to use 100% of all features.
But i dont come to this point. i cant use gopacket if WinPcap is not available. I mean... not a single line of code of it (=> crash)
Has anyone an idea how i can solve this? im do not need gopacket actually. My plan was, if it is installed, fine, super! If not, dont care... do other things.
But now i have 2 choices... remove gopacket totally or find a way to start my program without the need of wpcap.dll. at least to tell the user that he needs it.
Please help me :(
You're wrong in that you are «not [using] a single line of code of it»: it's not hard to see that
its Windows-specific code calls into winpcap.dll.
What is more fun, is that
its Unix-specific code calls into libpcap.so, and this means you have it working on your local system simply due to the fact you have libpcap package installed (or whatever it's named in your code).
All this means that currently your program is not really portable
anyway (I mean, in the sense you supposedly think it is portable).
You can run something like
$ ldd ./yourbinary
and see it printing a reference to libpcap.so of some version.
There are several ways to solve this.
The easiest is to just try shipping winpcap.dll with your binary. Windows by default looks for DLLs in the current directory of the application trying to load them. Since gopacket uses cgo, it means the winpcap.dll is attempted to be linked it at the application startup, so the application has no chance of changing its working directory before that library is attempted to be found and linked in.
A more complicated approach is to make (or obtain) a static version of the winpcap library (remember that DLL is a library, just a special form of it) and then jump around building gopacket so that it picks that static library.
Install Npcap in "Wpcap API compatibility mode".

QtCreator + gdb on Mac OS X Yosemite doesn't give me source level debug info

Debugger shows me dissassembler code, while i am trying to step over the instructions of my program.
Using lldb under QtCreator.
Interesting thing is: debugging works fine, if i use it without QtCreator (via terminal)
Small projects seems to debug normally... So I've try to add peaces of my project gradually to small one.
I've found a peace of code, that resulting to crash:
QVector<myClass>::contains();
But if i try to make an empty project only with this realisation, problem disappeared.
I've lost about a week, trying to solve it.
Any ideas, what can go wrong?
EDIT:
Well, QtCreator still using GDB instead of LLDB, that i refer it to...
Looks like bug

.ASM file debugging tool

I am wondering which debugging tool I can use for an assembly program and how to use it.
I have written a simple bootloader in assembly. However, it is not quite working properly as I wished, even though I think the logic is correct. So, I am trying to use a debugger so that I can step through the bootloader, checking the register status and etc.
I tried GDB on Ubuntu, compiling my .asm to .elf and .o (Do I need to do it? If yes, what is the next step?) Also, I read that there is an internal debugger in Bochs simulator, but I can't quite find any document how to use it. I also have Visual Studio 2010, windbg, but I don't know how to use it for .asm file debugging.
If you have done this before, it would be an easy answer. Any help would be really appreciated.
Sincerely
If you want to debug bootloader code, you obviously need to run it in the same environment that the code itself is going to run in. As I'm sure you already know, bootloader code is executed in real mode once the BIOS finishes doing the POST. The bootloader is then loaded into memory at 7c00h and a jump to that address is executed.
Obviously, this kind of environment cannot be reliably emulated once you've got your computer running and a "real" operating system already loaded, since by that time your CPU is in protected mode (or long mode, if it's AMD64). Your only option at this point is to use QEMU or Bochs in order to emulate a real PC inside your operating system. I've used Bochs to debug some bootloader code I've written in the past and it worked quite well. Check the manual pages for more detailed instructions.

simple gui based gdb debugging over ssh

I ssh into a linux VM which is setup remotely. I use Vim to write my code. For debugging however, I use netbeans through X11 which can sometimes be painfully slow. I tried using gdb buts its an efficiency killer. I love to hover over my variable and get to now their value rather that doing p variable_name , plus I like see and navigate through the code. Is there something light simple gui based debugging tool I can use. I have tried to use clewn http://clewn.sourceforge.net/ , but that doesnt work because it has a missing netbeans_intg feature. Is there any other similar vim gui based debugging tool ?
You can try ddd
which is a gui for gdb, I think it's lighter than netbeans.
cgdb is an interface to gdb but it is not a graphical one. It does not offer the possibility of hovering over a variable, but it shows you a window with the source code.
Well, I was in sort of your situation sometime ago, and you can have a look at my question about using gdb with remote sources.
First of all, your problem with netbeans_intg feature is related to vim which has been compiled with no support for it. If you can rebuild vim yourself, you can then enable it. Otherwise, as you can see in the answer that I gave myself to my question, you can leverage clewn's remote-vim capabilities.
In a nutshell, you can have a "local" vim (i.e. on a desktop/laptop machine presumably), which must still be built with netbeans_intg support, but now it is a vim under your complete control (i.e. it's on "your" machine), while clewn will run on the linux host where gdb and your debuggee will run.
You can then keep the source files on your desktop/laptop and have the remote clewn sort of "drive" your local vim to the proper source files while debugging.
IOW: clewn will get information out of gdb to know exactly which file/line you're into and connect to remote vim and tell it: "hey, go grab this file and show it around this line", highlighting current line, breakpoints etc.
This is a great solution for when you have far-away deployed systems and you need to debug them with minimum impact on the host where they are running, and presumably no option to transfer there all of your source files.
I don't know if this fits in any way with what you're trying to do, but it did really change things for me.
Hth,
Andrea.
Check out GDB server. Theoretcially, you should be able to start gdb on your linux machine in server mode and connect via GUI of your choice. As long as that GUI supports remote gdb connections, which Netbeans does.

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