Dynamic Kernel Module System (DKMS)

This intention of this README is to explain how DKMS can be used in conjunction with tarballs which contain a dkms.conf file within them.

The DKMS project (and any updates) can be found at: https://github.com/dell/dkms

Installation

Installation is performed from the source directory with one of the following commands:

make install
make install_debian
make install-redhat

Distribution specific installations (RPM, DEB, etc.) are not contained in this source repository.

Installation via DKMS Tarballs

DKMS can install directly from the following:

Generic module source tarballs which contain a dkms.conf file
Specially created DKMS tarballs with module source, pre-built module binaries and a dkms.conf file
Specially created DKMS tarballs with pre-built module binaries and a dkms.conf file
Manual placement of module source and dkms.conf file into /usr/src/<module>-<moduleversion>/ directory

In order to load any tarball into the DKMS tree, you must use the following command:

# dkms ldtarball /path/to/dkms_enabled.tar.gz

This command will first inspect the tarball to ensure that it contains a dkms.conf configuration file for that module. If it cannot find this file anywhere within the archive, then the ldtarball will fail.

From here, it will place the source in the tarball into /usr/src/<module>-<moduleversion>/. If source already exists in the directory, it will not overwrite it unless the --force option is specified. If the tarball is of type "c" above and does not contain source, it will only continue to load the tarball if existing module source is found in /usr/src/<module>-<moduleversion>/ or if the --force option is specified.

Continuing on, if the tarball is of type "b" or "c" it will then load any pre-built binaries found within the tarball into the dkms tree, but will stop short of installing them. Thus, all pre-built binaries will then be of in the built state when checked from the dkms status command. You can then use the dkms install command to install any of these binaries.

To create a tarball of type "1" above, you need only to take module source and a dkms.conf file for that module and create a tarball from them. Tarballs of type 2 or type 3 are created with the dkms mktarball command. To create a type 3 tarball, you must specify the flag --binaries-only with the mktarball.

Installation on Systems with no Module Source and/or Compiler

If you choose not to load module source on your system or if you choose not to load a compiler such as gcc onto your system, DKMS can still be used to install modules. It does this through use of DKMS binary only tarballs as explained in this README under tarballs of type c.

If your system does not have module source, loading the dkms tarball will fail because of this. To avoid this, use the --force flag, as such:

# dkms ldtarball /path/to/dkms_enabled.tar.gz --force

This will load the pre-built binaries into the dkms tree, and create the directory /usr/src/<module>-<moduleversion>/ which will only contain the module's dkms.conf configuration file. Once the tarball is loaded, you can then use dkms install to install any of the pre-built modules.

Of course, since module source will not be located in your dkms tree, you will not be able to build any modules with DKMS for this package.

Further Documentation

Once DKMS is installed, you can reference its man page for further information on different DKMS options and also to understand the formatting of a module's dkms.conf configuration file.

You may also wish to join the dkms-devel public mailing-list at https://lists.us.dell.com/mailman/listinfo/dkms-devel.

The DKMS project is located at: https://github.com/dell/dkms

Module signing

On an UEFI system with Secure Boot enabled, modules require signing before they can be loaded. First of all make sure the commands openssl and mokutil are installed.

For further customizations (scripts, certificates, etc.) please refer to the manual page (dkms(8)).

To check if Secure Boot is enabled:

# mokutil --sb-state
SecureBoot enabled

To proceed with Signing with the standard settings, proceed as follows.

First uncomment the sign_tool line in /etc/dkms/framework.conf, this allow using the script declared in that variable as a hook during the module build process for signing modules:

sign_tool="/etc/dkms/sign_helper.sh"

The script by defaults expects a private key and a matching certificate in the root home folder. To generate the key and the self signed certificate:

# openssl req -new -x509 -nodes -days 36500 -subj "/CN=DKMS modules" \
    -newkey rsa:2048 -keyout /root/dkms.key \
    -outform DER -out /root/dkms.der

After generating the key, enroll the public key:

# mokutil --import /root/dkms.der

You'll be prompted to create a password. Enter it twice, it can also be blank.

Reboot the computer. At boot you'll see the MOK Manager EFI interface, press any key to enter it.

"Enroll MOK"
"Continue".
"Yes".
Enter the password you set up just now.
Select "OK" and the computer will reboot again.

After reboot, you can inspect the MOK certificates with the following command:

# mokutil --list-enrolled | grep DKMS
        Subject: CN=DKMS modules

To check the signature on a built DKMS module that is installed on a system:

# modinfo dkms_test | grep ^signer
signer:         DKMS modules

The module should be able to be loaded without issues.

nickdesaulniers / dkms