The file /etc/kernel-pkg.conf or /.kernel-pkg.conf is actually a Makefile snippet included during the kernel packages build process, and hence you may put any legal Makefile directive in that file (just make very sure you know what you are doing). If the per user configuration file /.kernel-pkg.conf exists, it is laoded in favour of the system wide confguration file /etc/kernel-pkg.conf.
All the variables have reasonable default values, and maybe overridden on a per run or a per individual basis by using environment variables. Some of the variables can further be overridden by options to make-kpkg.
At the moment, the user modifiable variables supported are:
Local kernel-* package maintainer. Set up at package installation by the postinst. Can be overridden by the environment variable KPKG_MAINTAINER. Please note that any apostrophes __
The email address of that person. Set up at package installation by the postinst. Can be overridden by the environment variable KPKG_EMAIL.
Name to search for in the pgp database iff separate modules (like pcmcia etc) are being built in /usr/src/modules/. Can be overridden by the environment variable PGP_SIGNATURE, and is overridden (again) by the --pgpsign option of make-kpkg. Defaults to maintainer. (Optional)
The Debian revision of the kernel packages. Can be overridden by the environment variable DEBIAN_REVISION, and is overridden (again) by the --revision option of make-kpkg. Defaults to 1.0.0.Custom (Optional)
Normally unset. Ifthis, or the environment variable DEBIAN_REVISION_MANDATORY are set, then not providing a debian revision results in an error (and make-kpkg shall not provide a default vvalue of 1.0.0.Custom)
Set to True if you want the kernel image vmlinuz in /boot rather than the default /. Can be overridden by the environment variable IMAGE_IN_BOOT. Defaults to undefined. (Optional)
The kernel image type (i.e. zImage or bzImage). Can be overridden from the environment variable IMAGE_TYPE, and is overridden (again) by the options --zimage or --bzimage of make-kpkg. Defaults to bzImage. (Optional)
Whether to use symlinks to the image file. Can be overridden by the environment variable NO_SYMLINK Mutualy exclusive to reverse_symlinks. Can be used with image_in_boot. The image is placed in vmlinuz (instead of /boot/vmlinuz-X.X.XX). The old vmlinuz is moved to vmlinuz.old unconditionally. (Normally, that is only done if the version of the new image differes from the old one). This restricts you to two images, unless you take additional action and save copies of older images. This is for people who have /boot on a system that does not use symbolic links (and say, they use loadlin as a boot loader). This is a Hack. Defaults to undefined (optional)
Whether to use reverse symlinks (that is, the real file is the one without the version number, and the numberd version is the link) to the image file. Can be overridden by the environment variable REVERSE_SYMLINK Mutualy exclusive to no_symlinks. Can be used with image_in_boot. Just like no_symlinks, except that the /boot/vmlinuz-X.XX is symlinked to the real new image, vmlinuz. This, too, restricts you to just two images unless further action is taken. The older symlinks are left dangling. This is for people with /boot on umsdos, and who can't see the link in dos, but do want to know the image version when in Linux. This is a Hack. Defaults to undefined. (optional)
This is an experts only variable. If set to YES (ENV variable PATCH_THE_KERNEL overrides this), the build process causes run-parts to be run over /usr/src/kernel-patches/$(architecture)/apply and (hopefully) reverses the process during clean by running run-parts over /usr/src/kernel-patches/$(architecture)/unpatch. The special architecture all is used for arch independent patches.
What type of configure step to do. Defaults to oldconfig, which is good for non-interactive (or minimally interactive) runs. If you are setting patch_the_kernel to YES and some of the patches change what configuration settings are available, then you may wish to set this to something else (like menuconfig or xconfig). (ENV variable CONFIG_TARGET overrides this setting.) If the value of config_target is other than config, oldconfig, menuconfig or xconfig then it is reset to oldconfig.
This is an experts only variable. If set to NO (ENV variable USE_SAVED_CONFIG overrides this), the file .config.save in the top level directory is ignored.
This should be set to a means of gaining superuser access (for example, `sudo' or as needed by dpkg-buildpackages' -r option. The environment variable ROOT_CMD overrides this. The environment variable UNSIGN_SOURCE adds to this command an option to have dpkg-buildpackage not sign the source, similarily, the environment variable UNSIGN_CHANGELOG adds to this command an option to have dpkg-buildpackage not sign the changelog.
If set to YES, the symbolic link /lib/modules/$VERSION/build shall be removed from the resulting .deb package. The environment variable DELETE_BUILD_LINK overrides this.
Set to anything but YES, this shall forego the make clean done in the kernel source tree after building the kernel image package. The environment variable CLEAN_SOURCE overrides this.
This variable should be set to the path of any extra documentation that should be installed in /usr/share/doc/kernel-image-X.X.XX/ directory. There is no checking for name conflicts, and the files are not compressed. Hence, if you want the files to be compressed, please precompress it and provide the path of the compressed file. The environment variable EXTRA_DOCS overrides this, and would most likely be how extra documentation is specified.
This is meant to be used by the libc6 maintainer, when he compiles libc6, to also package up the corresponding headers. DO NOT SET THIS unless you know what you are doing, since a mismatch between the headers you package and libc6 may well create a subtle instablity in all code compiled on your machine. You have been warned. The environment variable MAKE_LIBC_HEADERS overrides this.
If defined, this variable sets the concurrency level of make used to compile the kenel and the modules set using -j flags to the sub make in the build target of make-kpkg. Should be a (small) integer, if used.
If defined, this variable causes make-kpkg to use an extended name for the kernel image package by embedding the subarchitecture in the image name, so one could write a script to create multiple subarchitectures one after the other. Please note that only the package name is affected, not module locations etc.
This variable should be set to a directory which contains architecture specific .config files (look at /usr/share/kernel-package/Config for examples). This is useful for people who need to compile for several architectures. Defaults to /usr/share/kernel-package/Config
If you want the image to be stored elsewhere than /boot set this variable to the dir where you want the image. This may be of help to loadlin users. Defaults to /boot.
Set this variable, either in the environment or in the config file, to point to the location where the add-on modules are located. Defaults to /usr/src/modules
Set this variable, either in the environment or in the config file, to point to the location where the kernel config files are located. Defaults to /usr/share/kernel-package/Config
Set this variable, either in the environment or in the config file, to point to the location where the add-on kernel patches are located. Defaults to /usr/src/kernel-patches/ARCHITECTURE
Set this variable, either in the environment or in the config file, to point to the location where the add-on arch independent kernel patches are located. Defaults to /usr/src/kernel-patches/all
The value of a variable can be set so:
Defaults exist in the rules file. These are the values used if no customization is done.
Variables can be set in the config file /etc/kernel-pkg.conf. These values override the defaults.
Variables can also be set by setting a corresponding environment variable. These values override the config file and the defaults.