building a proper debian source package with dkms

How can one use DKMS to build a proper debian source package? The ‘mkdsc’ command will actually generate one automatically, but there are a few more steps to simplify it, and bring it up to date.

First follow the steps in [1] for setting up a DKMS package. Make sure you can build it using dkms. Then do the following:

#First pull in some dependencies as necessary
sudo apt-get install devscripts debhelper

# Create the debian source package
sudo dkms mkdsc -m hello -v 0.1

# Create a directory to work in, and let’s copy those files into it
mkdir ~/dsc && cd ~/dsc
cp /var/lib/dkms/hello/0.1/dsc/* .

# Extract the .dsc to be able to edit the directory
dpkg-source -x hello-dkms_0.1.dsc 
cd hello-dkms-0.1

If we run debuild -uc -us, we see a few lintian errors and warnings:

W: hello-dkms source: package-file-is-executable debian/changelog
W: hello-dkms source: package-file-is-executable debian/control
W: hello-dkms source: package-file-is-executable debian/copyright
W: hello-dkms source: package-file-is-executable debian/dirs
E: hello-dkms source: no-human-maintainers
W: hello-dkms source: debian-rules-ignores-make-clean-error line 28
W: hello-dkms source: debian-rules-missing-recommended-target build-arch
W: hello-dkms source: debian-rules-missing-recommended-target build-indep
W: hello-dkms source: ancient-standards-version 3.8.1 (current is 3.9.3)
E: hello-dkms: no-copyright-file
E: hello-dkms: extended-description-is-empty
W: hello-dkms: non-standard-dir-perm usr/src/hello-0.1/ 0655 != 0755

The errors are normal, and if this was a real package those will be taken care of since that information will need to be filled in anyway.

To address the executable issues, just chmod -x those files.

chmod -x debian/co* debian/dirs debian/ch*

To address some of the other issues, we can just completely modify and change the rules file. Because debhelper has a helper for DKMS specifically we should use it.

In addition, if we do something like dch -i you’ll notice some errors, since our source directory is hardcoded to hello-0.1. So we can modify it to be in a ‘src’ directory and get around this.

mv hello-0.1 src

Here is how I modified my debian/rules file:

#!/usr/bin/make -f
# -*- makefile -*-

# Uncomment this to turn on verbose mode.
#export DH_VERBOSE=1

NAME=hello
DEB_NAME=$(NAME)-dkms
VERSION=$(shell dpkg-parsechangelog |grep ^Version:|cut -d ' ' -f 2)

%:
        dh $@ --with dkms

override_dh_install:
        dh_install src/ usr/src/$(NAME)-$(VERSION)
        find "debian/$(DEB_NAME)/usr/src/$(NAME)-$(VERSION)" -type f -exec chmod 644 {} \;

override_dh_dkms:
        dh_dkms -V $(VERSION)

override_dh_auto_build:
override_dh_auto_install:

Now there are some things that can be removed from the package completely:

rm common.postinst Makefile

Now to update the control file to use modern versions, a proper description, and make yourself a maintainer!

Source: hello-dkms
Section: misc
Priority: optional
Maintainer: Dude Bodacious <dude@awesomeradical.com>
Build-Depends: debhelper (>= 8), dkms
Standards-Version: 3.9.3

Package: hello-dkms
Architecture: all
Depends: dkms, ${misc:Depends}
Description: hello driver in DKMS format.
A completely useful kernel module.

Now debuild -uc -us and fix remaining issues.

References

1. https://wiki.ubuntu.com/Kernel/Dev/DKMSPackaging
2. https://help.ubuntu.com/community/Kernel/DkmsDriverPackage
3. http://basilevsthecat.blogspot.com/2011/11/how-to-build-dkms-debian-package.html