we have a old AIX server and it has an executable file and we want to rewrite the same logic of the executable file on linux server, so we are trying to read it but could not find a way to do that.could you please let us know if there is a way to decipher this file
$ file execfile
execfile: executable (RISC System/6000) or object module
The IBM RS/6000 has a POWER architecture CPU, possibly a PowerPC 603 or PowerPC 604, or possibly one of the newer models like POWER1, POWER2, POWER3, etc. The most recent (current) systems use POWER7 or POWER8.
Anyway, if the system has the compiler and toolchain installed on it then there should be a decent symbolic debugger included, and you should be able to use that to disassemble any executable. Depending on exactly which version of the OS it was compiled on, and which compiler was used, you might even be able to use PowerPC tools on some other OS, such as MacOS, or even potentially a cross-compiler toolchain on any type of system, to disassemble the program. For example GDB built for PowerPC may be able to disassemble the program.
However if the executable has been stripped of symbols (as was typically the case on AIX systems, IIRC), and especially if it had been run through the most powerful optimizing stage of the compiler, then you'll be pretty much lost and what you are trying to do will be impractical and require many man hours to decipher -- indeed many thousands of man hours for any significantly sized program, even if you're able to hire someone to help who is familiar with the code generation patterns of the particular compiler which was used.
You might be better off trying to hire an archeologist to help you dig through the specific landfill where you might hope to find listings or backup tapes or CDs or disks containing the original source code, or specification documents, etc., for this program. Seriously.
Or try to find and (re-)hire the original author(s).
Related
I'm new to working with Coq, and I'm progressing through the first volume of the Software Foundations book, but I can't for the life of me figure out how to compile the Basics.v file for the second chapter on induction.
I've seen things floating around about using the Coqc command on the command line, but I don't know how to access the terminal, or at least the windows terminal doesn't recognize the command. If anyone could walk me through this it'd be much appreciated!
In case you are using CoqIDE, there is a menu item "Compile/Compile buffer", which creates a .vo file for the currently loaded .v file. For a few files and early stages of learning, this might be the easiest way.
Then SF likely comes with a make file which you can just run with make. You didn't say what OS your are using - on Linux and Mac this should be trivial, on Windows it depends on how you did install Coq. The Windows installer doesn't come with make, but if you used the Coq Platform scripts to setup Coq on Windows, everything is there.
Otherwise it might get a bit complicated - you need to pass the right options to coqc (which CoqIDE and make do automatically for you).
I'm working on some OpenCL code within a larger project. The code only gets compiled at run-time - but I don't want to deploy a version and start it up just for that. Is there some way for me to have the syntax of those kernels checked (even without consider), or even compile them, at least under some restrictions, to make it easier to catch errors earlier?
I will be targeting AMD and/or NVIDIA GPUs.
The type of program you are looking for is an "offline compiler" for OpenCL kernels - knowing this will hopefully help with your search. They exist for many OpenCL implementations, you should check availability for the specific implementation you are using; otherwise, a quick web search suggests there are some generic open source ones which may or may not fit the bill for you.
If your build machine is also your deployment machine (i.e. your target OpenCL implementation is available on your build machine), you can of course also put together a very basic offline compiler yourself by simply wrapping clBuildProgram() and friends in a basic command line utility.
I had this question on my exam, now in diagrams I saw, we have : hardware, kernel, system call interface to the kernel, then (compilers, shells, sys.libs) and on top some applications. Does OS scope include only kernel, and everything else is just some additional functions we choose to install , or does a Unix OS include everything from the list I gave above?
OS have more or less 2 definitions :
academic : OS is soft for doing a abstraction layer between
hardware and software
pragmatic : OS is soft that come with hardware when we buy it.
Compiler and shell don't enter in definition 1. It can be enter in definition 2.
And usually, users that are interesting by a compiler or a shell prefer to consider OS as asbtraction layer (academic definition).
Simple answer, No. They are not an internal part of Unix but additional functionality to help make the Operating System more usable.
The OS scope applies primarily to the kernel only.
Whilst you need a compiler to build the kernel, you don't necessarily require one for the general day to day use of the system. Most operating systems don't ship the compiler by default and instead, the kernel and applications is built on one machine and then the resulting binarys are packaged and distributed either with the computer directly (Windows/Unix) or via the internet for others to download and install (Linux/BSD)
Likewise with the shell. Although all operating systems ship with a default one (sh/bash/dash on Linux|Unix systems, Command Prompt/Powershell on Windows), most general users can go their entire lives without using it.
Having said that, if you were to delete the shell, you'll almost certainly find your system won't boot up. This is because a lot of core start-up scripts rely on the shell to stop / start the services presenting interfaces between the user and the kernel.
In summary:
You need a compiler to build the kernel and applications but not for running the OS.
You need a shell to execute applications (which also includes the compiler)
I have an openmp code written in C. I executed the code on Intel MIC on Stampede. I want to profile the code to find the hotspots in the code so that it will be helpful for me to optimize the code further. I tried to use the profiler gprof but I read somewhere that gprof cannot be used on MIC directly. I tried to use perf by going through tutorial. I could go till a certain step after which when the perf annotate step comes and I execute the code, it gives me the error ")" unexpected. So I am not knowing how to proceed to profile my code. Can anybody please help ??
This is the site where I referred to the perf tutorial : sandsoftwaresound.net/perf/perf-tutorial-hot-spots/ .
80% of optimization for the Xeon Phi is the same as for the host (Xeon). Use gprof, printf, compiler options, and the rest of your toolkit and carry your optimization as far as you can executing your code on the host only. After you can do no more, then focus on specific Xeon Phi optimizations.
As you are on Stampede, I assume you are using the Intel compiler. The compiler has a lot of diagnostic capabilities to profile your code and even provide suggestions. I'd provide you with more specific URLs but am on vacation with limited bandwidth.
Though this isn't specific to your question, here are some other suggestions. If you aren't, you'll most likely get a substantial boost using it. Intel compilers are danged good at optimizations, especially on Intel architectures. Also, you should use Intel MKL where possible. All of MKL's routines are optimized for the different IA architectures, and the most relevant to HPC are optimized specifically for MIC.
You have a few options.
The heavyweight approach is to use Intel Vtune. Firstly add -g to your compiler flags.
I use Vtune from the host command line quite a bit, here is the command I use to profile an application on the MIC. (This is executed on the host machine, Vtune on the host uses ssh
to launch the application on the MIC.)
amplxe-cl -collect knc-hotspots -source-search-dir=/mysrc/dir -search-dir=/mybin/dir -- ssh mic0 /home/me/myapp
Assume the app on the MIC is at /home/me/myapp, and the source dir and source search dir on the host. (With Vtune update 15 at least, I need to specify both of these separately in order to get the Vtune GUI to show me symbol info)
Once your app has finished, run the Vtune GUI on the host with amplxe-gui and open your result set.
There are also some simplified open source profiling tools developed by Intel that support the MIC, Speedometer and Overhead, you can find information about them here
Hopefully this is enough info to get you started.
In a nutshell, the question is: I just finished my first application using Qt Creator on a computer running under Linux Ubuntu, now how do I make this available for everyone. Now follows the more detailed version ;)
I must apologize for asking this, I am aware that this question has probably been asked many times and that there is official documentation that I can read. I am just completely new to programming and I am very confused by everything I've read so far. If you are kind enough to help, please assume I know absolutely nothing :)
Here we go: I've just finished designing my first application (a scientific program) with Qt creator on my laptop which runs under Linux Ubuntu. It works fine and I'm very proud of it ;)
Here's what my project consists of: 40 header files, 42 source files, 1 pro file, 1 qrc file, 1 html file and 7 png files. In the code, I use #include for a bunch of fairly standard Qt classes (QWidget, QTextBrowser and so forth, maybe like 40 of those).
Now I'd like to make it available to other people. For Linux and Mac users, I've figured a way to do that: I can compress the folder containing my project, tell them to install Qt on their computer, then download and extract the files on their hard disk, open a terminal in the folder and run
qmake myProject.pro
qmake
make
That seems to work fine (by the way, does it matter that this is not precisely what Qt creator does? The qmake step there is qmake-qt4 myProject.pro -r -spec linux-g++ and the make step is make -w). Now, I assume there is a solution where I don't ask them to download and install something like 200Mo of Qt material. As for Microsoft Windows users, I don't have a clue.
I would be very grateful if you could explain to me in a very concrete way what I need to do. Needless to say, I'll go for the best and easiest solution, I don't need to understand everything about deployment. Many thanks in advance!
Edit: In case that's useful : I've been using Qt Creator 2.5.0 based on Qt 4.8.1 (64 bit), I'm working on a laptop with Ubuntu 12.04 64bits
For Linux and Mac users, I would compile the software for them in 32 and 64bit formats - no-one likes compiling unknown software from source. Obviously keep the source code option for those on more unusual architectures/OSs (and provide a shell script for them that mimics the commands Qt Creator calls!). As Qt runtimes are available from package managers on just about every distro (and come pre-installed on most anyway, KDE requires them for example), by not asking them to compile from source your users will have a much smaller download (if any) and won't require them to download software from a website potentially unknown to them. Of course the best way would be to try to get your software added as a package into the major distros' repositories, but that may take some time to organise.
Compile your software for Windows users for both 32 and 64bit formats. It's generally frowned upon to ask users to download runtime libraries they potentially don't know, and put them into their system32 folder... So most applications bundle all the libraries they need with their application. Qt-based applications are no different, and so put the runtimes into the folder where the executable is. Also it is much more professional to create a proper installer, there are a few free installer applications for Windows, a web search will give you the most popular (I think I saw a thread on SO about it as well).
As you can see the platforms aren't too dissimilar, the main point I would make is: Do not force people to compile from source! The vast majority of people on Earth do not even know what compiling is, so provide for the major arrchitectures/OSs yourself.