All of the kernel drivers listed here are released as kernel modules; therefore,
you must be sure to have a kernel which supports modules. In addition,
"module version" support should be enabled to aid the use of
kernels and modules which are not version matched, as described further below.
If you use a kernel from a reasonably recent Linux distribution, such module support
is most likely already enabled. If you're compiling the kernel yourself, then you
should already be aware of how to enable modules, via the
In any case, you can check to make sure that the following
settings exist in your kernel configuration file
(which is usually found under /usr/src/linux):
If you have an ISA Plug-n-Play modem, you will most likely
need to use isapnptools to allocate resources to the modem card.
For this, you need to have isapnptools installed and have an entry in
the /etc/isapnp.conf file
for the modem. You should read the manual pages and the
Plug-and-Play-HOWTO, but if you have no other
ISA devices you're concerned about, basically all you need to do is:
If possible, configure your BIOS to "Non-PNP OS."
As root, run pnpdump to generate a prototype isapnp.conf
file based on probed cards and your system's current resource usage.
Look for your modem in this output, and uncomment the lines
corresponding to the (otherwise unused) IRQ you wish to use for the
modem. For example, Sean's isapnp.conf for a Thinkpad i1411 with
a Lucent LT modem includes:
Strangely, in this case at least, it was necessary to leave
the #(ACT Y) commented out. If it doesn't work for you one way,
try it the other.
Copy the file to /etc/isapnp.conf
Reboot. You should see a message along the lines of 'Initializing
ISA PNP devices...OK' on booting. If it fails, you have probably selected
an IRQ/DMA setting which is already in use; try another of the options
given in the pnpdump output.
(Note that it is probably not necessary to reboot, if you run isapnp
with the right flags. However, it's easiest for the beginner to simply reboot
at this point.)
If you wish to know more about your PCI modem
than cat /proc/pci gives, utilities within the software package
pciutils are useful, such as scanpci and lspci.
In particular, lspci -vv gives lots of nice, useful information.
The following commands are useful when dealing with modules. Many
require root priveleges. See the manual pages (e.g., man insmod)
for more detailed information on these commands.
insmod, insmod -f, and modprobe
A version-matched kernel module should usually be inserted using the command
modprobemodule_name; modprobe will try to
insert any other modules on which your module depends (as determined
by depmod, described below).
A single module can be inserted (without those modules on which it depends)
using the command insmodmodule_name.
If the module were compiled under a different kernel than the current one,
insmod would report the version mismatch and refuse load the module.
One can, however, pass a flag to force the module to load despite the mismatch:
insmod -fmodule_name. If the kernel interface the
module uses did not actually change with the kernel version, the
module will be inserted and could be to some degree functional.
This is the case with, for example, the ESS modem module esscom.o
which, while compiled under 2.2.12, can be forcibly inserted with later kernels
and will function to a greater or lesser extent up through kernel version 2.2.14
without further changes; beyond 2.2.15, the patch to tty.h described
below is required. However, even forcing insertion fails for kernels
from the 2.4 series.
A module can be unloaded (removed from the kernel) after use by issuing
the command rmmod.
The depmod commands analyzes module dependencies.
The compatility of precompiled modules with a running kernel
can be checked with a command like:
depmod -e ltmodem.o
For the specific example of the ltmodem.o module compiled under kernel 2.2.12
with a running kernel 2.2.17, the returned information includes:
depmod: *** Unresolved symbols in ltmodem.o
and many others.
Using a module with unresolved symbols can be a dangerous thing, as described