Hello Everyone,
I am trying to insert a .ko into my kernel and I am getting the 'invalid module format' error. But the kernel object is being generated from or is included in a binary which sets up and populates a driver path when run.

How can I tell what architecture/target/anything that .ko is meant for?

I know that I can use the uname and /proc/cpuinfo to see my current info, but I am also not sure what I might need to do to get them to sync up.

I am running on a minimal, cli-install of Ubuntu8.10 right now. It's freshly installed (onto a 2GB USB drive) & imaged, so bring on the drastic changes.

Thanks,
Shawn

Have you tried 'file your_dodgy.ko' ?

Ah, I have not. That seems like a useful command, thanks
But the `file x.ko` says:
ELF 32-bit LSB relocatable, Intel 80386, version 1 (SYSV), not stripped
And uname -a returns:
Linux ubuntu 2.6.27-17-generic #1 SMP Fri Mar 12 03:09:00 UTC 2010 i686 GNU/Linux
But that's i386 and i686, and those are compatible, right?

File is definitely the easiest way. You can get some additional information including the "vermagic" string by using modinfo as well.

The "vermagic" string is used to figure out if the module is compatible with the running kernel. That may be a good starting point for further investigations.

1 members found this post helpful.

Thanks Zuulie.
modinfo returned the vermagic string: "2.6.24-12-generic SMP mod_unload 586"
(Is there some documentation on the vermagic fields? I don't find anything in the man pages.)
So is the problem just that I have a newer kernel? I guess there's no backwards compatibility there?

No, there is never any compatibility for modules.

For a module to be compatibel :
1) The same Linux OS
2) The same gcc compiler
3) The same kernel
Nothing but an exact match will work.
.....

That is semi untrue.
If there is no major differences, it may work.
Hey i have even had a 2.4 module work in a 2.6 kernel.

So does the kernel version have to match completely, or is matching the first 3 places (2.6.24-*) going to work?
On a brief search I found that the Ubuntu 8.04 uses kernel 2.6.24-16 kernel. If I switch to this Ubuntu, will that allow me to use this .ko for 2.6.24-12-generic?
I see now that the 8.04 release is marked LTS, for another year or so. Maybe that would be better if that works.

I say give it a shot.
Worst case is it kernel panics and you have to reboot and it does not work.
Best case is it does not make a difference.

I'm installing the 8.04 minimal cli Ubuntu now to try it out. Thanks for all the help! I'll let you know if I get stuck again.