cuda nvcc cross compiler - windows

I want to compile CUDA code on mac but make it executable on Windows.
Is there a way to set up an nvcc CUDA cross compiler?
The problem is that my desktop windows will be inaccessible for a while due to traveling, however i do not want to wasted time by waiting til i get back and compile the code. If I have to wait then it would be a waste of time to debug the code and make sure it compiles correct and the likes. My mac is not equipped with cuda capable hardware though.

The short answer, is no, it is not possible.
It is a common misconception, but nvcc isn't actually a compiler. It is a compiler driver, and it relies heavily on the host C++ compiler in order to steer compilation both host and device code. To compile CUDA for Windows, you must using the Microsoft C++ compiler. That compiler can't be run on Linux or OS X, so cross compilation to a Windows target is not possible unless you are doing the compilation on a Windows host (so 32/64 bit cross compilation is possible, for example).
The other two CUDA platforms are equally incompatible, despite requiring gcc for compilation, because the back ends are different (Linux is an elf platform, OS X is a mach platform), so even cross compilation between OS X and Linux isn't possible.
You have two choices if compilation on the OS X platform is the goal
Install the OS X toolkit. Even though your hardware doesn't have a compatible GPU, you can still install the toolkit and compile code.
Install the Windows toolkit and visual studio inside a virtual windows installation (or a physical boot camp installation), and compile code inside Windows on the Mac. Again, you don't need NVIDIA compatible hardware to do this.
If you want to run code without a CUDA GPU, there is a non-commercial (GPU Ocelot) and commercial (PGI CUDA-x86) option you could investigate.

Related

what does 'build a gcc cross compiler' mean?

I am very new to linux and GCC. The price of raspberry pi lured me in. I am interested in using GCC to cross compile some C Code to target some embedded hardware, specifically a Cortex-M3 micro. I eventually want to have a full suite of compiler/programmer/debugger, but for now I'm starting with compiler.
So I did a quick non-cross compile test on the RP3, and all was well. Now I am researching how to cross compile and target my uc. The gcc documentation online seems to indicate that I can use the plain vanilla gcc, and just specify some command line options to perform cross compilation: https://gcc.gnu.org/onlinedocs/gcc/ARM-Options.html
But searching around, I find a lot of people mentioning building a gcc cross compiler. What does this mean?
Does gcc have options to double as a cross compiler? If so, why would one desire "building" a cross compiler?
A cross-compiler is one that is created on machine type A (combination of hardware and o/s) and either runs on a different machine type B or runs on type A but produces software to be run on a different machine type B.
Thus, if you have a Linux machine using an x86_64 CPU and running on some version of Linux, but you compile GCC so that it will run on an IBM PowerPC platform running some version of AIX, you would be creating a cross-compiler.
Another variant might be having a compiler on Linux using an x86_64 CPU that runs on the Linux machine but produces code for an embedded hardware chip. You'd then benefit from the CPU power of the Linux machine while deploying to a much smaller, less powerful system that maybe has no o/s of its own, or only a minimal o/s.

can gcc cross compile for different CPU?

Is it possible for gcc, installed on fedora 16, to cross compile for a different CPU, say SPARC?
I have build a certain understanding, need some expert to correct me if I am wrong. Different operating systems differ by the system calls they use to access the kernel or entirely by the kernel they use. IS THIS CORRECT? different kernels understands different systems calls for accessing underlying hardware. binaries or executables or programs are nothing but a bunch of system calls only. therefore every OS has its own executable. an executable meant to run to on windows wound not run on linux. by cross compiling the source code of any windown's executable we can generate executable for other OSs. word PLATFORM means operating system. POSIX are certain design standards for UNIX-like OSs.
we usually cross compile for different OSs. BUT can we cross compile for different hardware too? for example, in case of a microcontroller which does not have an OS?
No. You can't use native machine (x86) gcc for compiling program files for a different architecture. For that you require a cross-compiler-gcc that is specific to that processor architecture.
Your understanding about system calls for OS is correct. Each OS has its own set of system call which is been used by library. These libraries at the end will be translated into machine language for the processor.
Each Processor Architecture has its own set of instruction know as Instruction Set Architecture(ISA). So when a program written in high-level-language (like C) is compiled, it should be converted into machine language from its ISA. This job is done by the compiler(gcc). A compiler will be specific to only one processor architecture. For example gcc is for x86 processor. So if you want a compiler for different processor in you x86 machine you should go for a cross-compiler of that processor.
You would have to build such a version. That's part of the process of porting gcc to a new platform. You build a version that cross-compiles, then you cross-compile that version, then you test that version on the new platform, debug, rinse, and repeat.

Execute 32 bit object file on 64 bit environment

I made a cross compiling toolchain for arm-gcc, configuring binutils, newlib, gcc and gdb for the arm-elf target. The problem I am having is, when I compile a program with arm-elf-gcc on my Mac, it generates a 32 bit executable with cannot be executed in the 64 bit environment.
What is the easiest way to circumvent this? I could place the 32 bit executables to an arm environment, but I am interested to know if I could execute the file in my Mac in any way?
--Added--
I should have done this before, but let me inform that the target of my program is a Beagleboard, and I was expecting that I would compile and generate the objects using arm-gcc on my Mac OS X and transfer the *.o to the Beagleboard to view output. Alas, it gives the same error on the Beagleboard as well when I do a ./hello.o.
Thanks,
Sayan
There are several issues preventing you from running your executable on a Mac.
1) Architecture. Your Mac is probably an x86/x86_64 machine (or PowerPC) but your binary is compiled for ARM architecture (which is the whole point of using a cross-compiler). These instruction sets are not compatible.
2) Your binary is linked as an ELF object file, whereas Macs use the Mach-O object file format. Your OS cannot load this executable format.
3) Your executable is linked against newlib (for some target which is probably not Mac OS) instead of the Mac OS libc. Your system calls are not correct for this platform.
If your program is a standard unix executable, you may be able to simply compile it with the standard system gcc and it will run. Otherwise, you can run it in an ARM emulator, though this may be pretty complicated to set up.
The fact that it's 32-bit is irrelevant - you can't execute ARM code on a Mac (unless you can find some kind of ARM emulator).

what is cross compilation?

what is cross compilation?
Cross-compilation is the act of compiling code for one computer system (often known as the target) on a different system, called the host.
It's a very useful technique, for instance when the target system is too small to host the compiler and all relevant files.
Common examples include many embedded systems, but also typical game consoles.
A cross-compiler is compiles the source code from one architecture to another architecture.
For example: hello.c
gcc hello.c (gcc is a compiler for x86 architecture.)
arm-cortexa8-linux-gnueabihf-gcc hello.c
(arm-....-gcc is a compiler for the arm architecture.) This you are compiling on the host pc for a target board (e.g rpi, beaglebone, wega board). In this example arm-cortexa8-linux-gnueabihf-gcc is called the 'cross compiler'.
This process is called cross compilation.
see the link for more info cross compilation
To "cross compile" is to compile source on say a Linux box with intent on running it on a MAC or Windows box. This is usually done using a cross compilation plugin, which are readily available from various web servers across the net. If one is to install a cross compilation plugin onto their Linux box that is designed to compile for Windows boxes. Then they may compile for either a Linux/*NIX box as well as have the option to compile and link a Windows-ready executable. This is extremely convenient for a freelance programmer whom has access to no more than a single Linux/Windows/MAC box. Note that various cross compilation plugins will allow for multitudes of applications, some of which you may or may not perceive as useful, thus a thorough perusal of the plugin's README file.
Did you have a particular project in mind that you would like to apply the method of cross compilation to?
In a strict sense, it is the compilation of code on one host that is intended to run on another.
Most commonly it is used with reference to compilation for architectures that are not binary-compatible with the host -- for instance, building RISC binaries on a CISC CPU platform, or 64-bit binaries on a 32-bit system. Or, for example, building firmware intended to run on embedded devices (perhaps using the ARM CPU architecture) on Intel PC-based OSs.
A Cross Compiler is a compiler capable of creating executable code for a platform other than the one on which the compiler is running.
For e.g. a compiler that runs on a Windows 7 PC but generates code that runs on Android smartphone is a cross compiler.
A cross compiler is necessary to compile for multiple platforms from one machine.
A platform could be infeasible for a compiler to run on, such as for the microcontroller of an embedded system because those systems contain no operating system.
In paravirtualization one machine runs many operating systems, and a cross compiler could generate an executable for each of them from one main source.

Cross compiler for embedded platform in Windows

I wish to build a compiler (GCC port) for Linux, so that the built GCC runs on Windows and creates executables for an embedded platform.
Is the above possible?
Yes, it is possible.
It also utterly painful to try to do this yourself -- it is OK on Linux, mostly, but very tricky on Windows. My suggestion is to see if some ready-built compiler from a place like DENX.de, CodeSourcery, or the manufacturer of your embedded platform is available.
I have become a huge fan of the CodeSourcery compilers for platforms like MIPS and Power Architecture. They tend to come with variants for big- and little-endian, various Libc flavors, and to have both bare-metal and linux-target versions available. See their pages about their Lite edition
Building your own cross-compiler and toolset is a right pain.
If your target is running Linux, I suggest doing your cross-work on a Linux box as well, saving you plenty of pain. I use VmWare for that express purpose. You cannot expect to build a Linux for a target on Windows, for example.
In embedded systems compilers are referred based on processor architecture and not on OS. What you probably want is to build a "cross compiler" for a processor other than the one running in your Windows machine. This is of course possible. See for example the WinAVR and WinARM projects. These are compilers for AVR and ARM processor architectures, based on GCC and running in Windows machines. Another example is yagarto. These aren't just a compiler, but a full tool chain that will allow you to built Linux executables (for ARM processors), if the requires libraries are available.
Because GCC relies on POSIX functionality that is not available in Windows natively, you need a Linux-like environment for Windows (such as Cygwin or MinGW).
http://cegcc.sourceforge.net
If you are satisfied to running it on Windows then at www.gnupit.org you can donwload ready GCC cross toolchain for free. There are many target platforms.
You have to build GCC on Windows using MinGW or Cygwin for your target platform (e.g. ARM little endian).

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