Is is possible to load a .ko file (kernel object file) which was compiled in 64-bit processor system into 32 bit processor system?
Actually I am getting following error when I issue the insmod command in my system:
insmod: error inserting 'be2net.ko': -1 Invalid module format
It is not possible to run 64-bit code in a 32-bit system. Depending on the requirements, the reverse can be true (running 32-bit software or libraries in a 64-bit system), but a 32-bit architecture cannot understand 64-bit code. You will need to compile the module on your system.
First download the kernel source from kernel.org. Then extract, and cd into
linux/drivers/net/benet
Once there, type (as your regular user)
make
and then
sudo insmod be2net.ko
That should work for you.
No, it is not possible to load 64-bit modules to a 32-bit kernel, and that is why you are getting an error. The reason is that 64 and 32-bit program have an incompatible ABI (e.g. different calling conventions). That is also the reason 64-bit applications can't be linked with 32-bit libraries, for example.
Note that insmod generally gives vague error message. For a more detailed message look at the output of dmesg.
The processor where it was compiled matters not at all. The compiler and compiler options do matter. If it was compiled FOR a 64-bit processor, it cannot run on a 32-bit processor, because it uses a different instruction set.
However, a 64-bit processor can run a cross-compiler and create 32-bit binaries. It is unlikely that you've done this.
Related
Can someone explain the difference between the three architectures?
Actually when I built a 64-bit application in Linux, I got a link error saying:
skipping incompatible library.a when searching for library.a
Then I used objdump -f on that library and I got the below output:
a.o: file format elf32-x86-64
architecture: i386:x64-32, flags 0x00000011:
HAS_RELOC, HAS_SYMS
start address 0x00000000
Does it mean the library is 32-bit? Is that the reason I am getting the linker error?
There are 3 common ABIs usable on standard Intel-compatible machines (not Itanium).
The classic 32-bit architecture, often called "x86" for short, which has triples like i[3-6]86-linux-gnu. Registers and pointers are both 32 bits.
The 64-bit extension originally from AMD, often called "amd64" for short, which has GNU triple of x86_64-linux-gnu. Registers and pointers are both 64 bits.
The new "x32" ABI, with a triple of x86_64-linux-gnux32. Registers are 64 bits, but pointers are only 32 bits, saving a lot of memory in pointer-heavy workflows. It also ensures all the other 64-bit only processor features are available.
Each of the above has its on system call interface, own ld.so, own complete set of libraries, etc. But it is possible to run all 3 on the same kernel.
On Linux, their loaders are:
% objdump -f /lib/ld-linux.so.2 /lib64/ld-linux-x86-64.so.2 /libx32/ld-linux-x32.so.2
/lib/ld-linux.so.2: file format elf32-i386
architecture: i386, flags 0x00000150:
HAS_SYMS, DYNAMIC, D_PAGED
start address 0x00000a90
/lib64/ld-linux-x86-64.so.2: file format elf64-x86-64
architecture: i386:x86-64, flags 0x00000150:
HAS_SYMS, DYNAMIC, D_PAGED
start address 0x0000000000000c90
/libx32/ld-linux-x32.so.2: file format elf32-x86-64
architecture: i386:x64-32, flags 0x00000150:
HAS_SYMS, DYNAMIC, D_PAGED
start address 0x00000960
Now, if you're getting the message about "skipping incompatible library", that means something is messed up with your configuration. Make sure you don't have bad variables in the environment or passed on the command line, or files installed outside of your package manager's control.
Beyond usual full 64bit and good old 32bit ABI there is a special ABI (inspired by SGI n32 envirnment) where pointers are 32bit (thus they are 32bit apps), but it is designed to run on 64bit host and have full access to all x64 goodies:
native x64 registers and math
more registers
SSE2/3/4, AVX1/2/...
Full 4Gb address space on 64bit host
It is called x32 ABI, link: https://en.wikipedia.org/wiki/X32_ABI
UPDATE
On Ubuntu system I have to install two packages (with deps) to get x32 working:
> sudo apt install gcc-multilib
> sudo apt install libx32stdc++-5-dev
Then compiling simlple C++ code with g++ -mx32 hellow.cpp works, making x32 executable
> file a.out
./a.out: ELF 32-bit LSB executable, x86-64, version 1 (SYSV), dynamically linked, interpreter /libx32/ld-linux-x32.so.2, for GNU/Linux 3.4.0
After migrating a Debian 7.6 system from i368 to amd64 I encountered the problem to use some older ELF 32-bit LSB executables. Of course, there is the possibility to setup a secondary 32-bit system (in fact I could use my old one) and to apply chroot(8) or schroot(1). But I do not like the additional admin effort, the performance loss by a wrapper program and a different command sequence.
I am wondering whether there is really no way to run a 32-bit application directly on the x86_64 architecture (as possible, e.g., for HP-UX 11.0)? Both
$ /home/alf/prog32
and
$ /usr/bin/linux32 /home/alf/prog32
just lead to the failure message /home/alf/prog32: file or directory not found. This behavior is observed for all ELF 32-bit LSB executables (Debian i386, downloaded, self-written and compiled C-programs).
I am using a software for graph mining.
I have got the binary of that software in 2 folders for Linux mode and SunOs mode but don't have the source.
I am able to run the binary in Linux machine.
But when I want to run the binary in a Mac machine I am getting "command not found" for both the Linux and SunOs folders' binaries.
Could someone suggest if it can be able to run this in a MAC machine by any means like using a Linux shell or something
Gaurav
EDIT:I am getting "cannot execute binary" error when I set chmod to "u+x"
You'll need to recompile it for OS X or use a VM.
A command not found just means you're not executing it right, make sure it's chmod u+x and it's either on your PATH, or you specify the path explicitly.
If you use the file command you will see the difference, on the linux executable you'll have something like:
ELF 64-bit LSB executable, x86-64, version 1 (GNU/Linux), statically
linked, for GNU/Linux 2.6.15, not stripped
and something like this for OS X executables:
command: Mach-O universal binary with 2 architectures command (for
architecture x86_64): Mach-O 64-bit executable x86_64 command (for
architecture i386): Mach-O executable i386
Operating systems generally don't support executing object code any extra formats... If Mac osx decended from solaris or Linux, then there could be some incentive for legacy support. But just assume everything to be binarily incomparable if it was compiled for a different arch and platform. There are a few places where you inherit backwards compatibility, running 32 but code on 64 bit oses... Or ppc code support on intel macs, but I suspect that both of those, especially the latter were non trivial engineering tasks.
Here are your options...
Get the source and compile on the Mac, if it compiles on Linux and solaris good chance it will compile and run ok on Mac.
Run through an emulator or boot camp
Trying to run my program in FreeBSD OS, I have the following results:
$ ./myprogram
ELF binary type "0" not known
./myprogram: 1: Syntax error: "&" unexpected (expecting ")")
$ file myprogram
myprogram: ELF 32-bit LSB executable, Intel 80386, version 1 (SYSV),
dynamically linked (uses shared libs), for GNU/Linux 2.6.15,
not stripped
The program is built In GCC on Ubuntu computer. What can I do? Can I build the program for FreeBSD on my Ubuntu computer by changing some build options, or I need to build it in FreeBSD OS? Maybe there is some way to convert executable to format recognized by FreeBSD?
You can run a lot of Linux programs on FreeBSD, see http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/linuxemu.html.
If this doesn't work, the easiest solution would be to recompile your program on FreeBSD.
2021-06-21: This answer is outdated. As of 2021, FreeBSD includes Linux® binary compatibility, which will run most Linux binaries, save for those which "overly use i386™ specific calls, as enabling virtual 8086 mode".
A large number of Linux programs can be compiled on BSD systems however they are not the same operating system. Linux and BSD are technically not binary compatible.
These days BSD ships with an ABI (Application Binary Interface) for Linux which will translate Linux sys-calls on the fly (Much how WINE operates). This will allow you to run Linux ELF binaries on BSD systems with a small performance penalty.
That being said, they are not the same operating system and your best bet would be to compile for the target system either by gaining access to it or using a method of cross compiling.
Try branding the executable as a linux executable using brandelf (you still need all the dependent libraries setup though, or try linking it statically
http://www.freebsd.org/cgi/man.cgi?query=brandelf&apropos=0&sektion=0&manpath=FreeBSD+8.0-RELEASE&format=html
brandelf -t "Linux" and it should work.
As title said, I have C program complied and created a binary in 64-bit machine.Will this binary work under 32-bit ?
64-bit binaries cannot run on a 32-bit OS. If file reports ELF 64-bit, you have a 64-bit binary.
In order to build 32-bit binaries on a 64-bit Linux, you need pass -m32 to gcc. You also need to have 32-bit libraries installed (sudo apt-get install libc6-dev-i386).
The compiling machine does not matter. What matters is: is the code generated 32 bits (answer: yes) or 64 bits (answer: no).
Will it work on a 32-bit machine? One with a CPU which doesn't support 64-bit mode? No.
Will it work on a 64-bit VM on a 32-bit native OS? Yes, in my experience.
A surprising result is that 64-bit VMs CAN be run under a 32-bit host OS, provided the CPU is capable and you don't want to allocate too much ram (>2G or thereabouts) to the guest.