For SlugOS (DebianSlug, OpenSlug) kernel modules are available from the slugos feeds
(see the contents of (/initrd)/etc/ipkg/cross-feed.conf in the flash for the exact feed for you kernel).

Note: While installing the module one can get error due to the architecture mismatch:

NSLU2:~# dpkg -i your_module_ixp4xxle.ipk
dpkg: error processing your module_ixp4xxle.ipk (--install):
package architecture (ixp4xxle) does not match system (arm)
Errors were encountered while processing:
your_module_ixp4xxle.ipk

You have three choices:

1) Boot from flash, ipkg install the files there (do not ipkg update, download the files and ipkg install specific files), copy the modules to the disk, reboot back into Debian.

2) Ignore the dependency errors (which are to be expected if you are installing SlugOS packages when running from a Debian rootfs) and force the installation.

3) Unpack the .ipk files manually, copy the files into place, and run depmod manually.