LinuxQuestions.org - "modprobe" question

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"modprobe" question

Hi again :)

This time I want to ask some questions about the modprobe command, it's error messages and in regard to that it's differences with the insdmod command.

So, that's how it looks like:
I need a driver to talk to the VME bus of a machine I'm working on. The driver comes with the distro (RHLE 8.0) in form of RPMs, I do as it is written in the INSTALL file and - voila - the module of the driver (vmemod.o) appears in the /lib/modules/$RELEASE/misc/ folder. I do a modprobe -l, and it says the following:

Code:

...

/lib/modules/2.4.25-rm01.mvme6100/misc/mv64360_dma.o

/lib/modules/2.4.25-rm01.mvme6100/misc/nvram.o

/lib/modules/2.4.25-rm01.mvme6100/misc/vmemod.o

/lib/modules/2.4.25-rm01.mvme6100/misc/watchdog.o

...

So I can take this for a proof that the module is inserted in the kernel. But when I do a lsmod, nothing appears, e.g. it seems as the module is not loaded. What is wrong? And what is the difference between insmod and modprobe? Is modprobe looking for modules only in /lib/modules?
When I try the following:

Code:

[root@host vme]# modprobe -n vmedrv.o

I get a "modprobe: Can't locate module vmedrv.o" message. What's wrong with that?

Another thing: When I insert the already compiled module vmemod.o with insmod, and then try to remove it with rmmod the system blocks. I can't understand why this is happening either.

So if someone has an idea why these problems are occuring and can gie some information abot the issues mentioned, I'll be thankful.

:newbie:

hi,

Quote:

What is wrong? And what is the difference between insmod and modprobe? Is modprobe looking for modules only in /lib/modules?

insmod u can do from the directory that contains that module and not installed in kernel
modprobe u can do when module sis installed in kernel and u can issue that command from any location.

Quote:

I get a "modprobe: Can't locate module vmedrv.o" message. What's wrong with that?

That mean Module sis not inserted in kernel.

Quote:

try to remove it with rmmod the system blocks. I can't understand why this is happening either.

That depends on what ur module is doing?

Well, basically the vmemod.o module is responsible for the data transfer on the VME bus. And since the CPU is located on a Single Board Computer in slot 1 of the rack, and the hard disk is located in slot 4, the module is serving the "correspondation" between the hard disk and the CPU. So I think it should be also installed in the kernel, because the system is running, which means the SBC and the hard are connected (there is no other way for them to exchange information except the VME bus).

Will a make modules_install fix the problem with the modprobe error output?

Hi,
Is this module to be installed is from kernel source only then nake module_install can fix. If u r installing it from external source other than kernel then check that source/its makefile

Well, it doesn't, perhaps only on my machine. But ALL other modules from /lib/modules/$RELEASE/ except vmemod.o were installed when I made make module_install... Strange...

The thing that bothers me most is that the VME bus runs OK, I mean after all the system boots from the hard drive which is on the VME bus. But I cannot end up with a solution to how to access the VME bus in my own programs...