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Generally Ubuntu systems run with the stock Ubuntu kernels. However it is handy to be able to test with unmodified mainline kernels to help locate problems in the Ubuntu kernel patches, or to confirm that upstream has fixed the issue. To this end we now offer mainline kernel builds. These mainline kernels are made from unmodified kernel source but using the Ubuntu kernel configuration files. These are then packaged as Ubuntu .deb files for simple installation.
We currently build five sets of mainline kernels. All formal tags from Linus' tree and from the stable trees, plus:
the tip of the master branch from Linus' tree daily,
- the tip of the master branch of the debloat-testing tree daily,
This makes these kernels closer to the Lucid kernels which are based on 2.6.32 kernels with DRM backported from the 2.6.33 series.
Mainline Kernels Archive
The mainline kernels archive is located at the URL below, there is a directory for each mainline build:
The tagged releases are found under a directory matching their tag name and which kernel configuration they were built with (<tag>-<series>). Daily releases are found in the daily sub-directory named for the date they were made.
Each build directory contains the header and image .deb files for the i386 and amd64 architectures, generic flavour.
Mainline Kernel Mapping
In order to choose which is the closest mainline kernel to any particular Ubuntu release you can use the Ubuntu to mainline mapping table, which contains mappings from Ubuntu releases and pockets to mainline versions.
Most likely that you want to download and test against the most current version.
Installing Mainline Kernels
To use the mainline kernel as-is you only need to download and install the *image*.deb package that corresponds to your architecture, however if you need to build any external modules you also need the correct *header*.deb and *source*.deb packages.
To install, download the common headers, architecture specific headers, and the architecture specific image. For example for 18.104.22.168 we have the following files, for i386 you would need those marked with B and C, amd64 take those marked A & C:
A linux-headers-2.6.27-02062715-generic_2.6.27-02062715_amd64.deb B linux-headers-2.6.27-02062715-generic_2.6.27-02062715_i386.deb C linux-headers-2.6.27-02062715_2.6.27-02062715_all.deb A linux-image-2.6.27-02062715-generic_2.6.27-02062715_amd64.deb B linux-image-2.6.27-02062715-generic_2.6.27-02062715_i386.deb
For some releases you may also have a linux-image-extras package which you will also need to select and download:
A linux-image-extra-3.4.0-999-generic_3.4.0-999.201205280405_amd64.deb B linux-image-extra-3.4.0-999-generic_3.4.0-999.201205280405_i386.deb
Once you have those downloaded they will need to be installed using dpkg:
sudo dpkg -i *.deb
When this process completes you should have a new entry on your boot menu representing the mainline kernel. This will appear as an entry like this:
Ubuntu Intrepid, kernel 2.6.27-02062715-generic
Uninstalling Mainline Kernels
The mainline kernels have their own ABI namespace so they install side by side with the stock Ubuntu kernels (each kernel has a separate directory under /lib/modules/VERSION for example). This means that you can keep several mainline and Ubuntu stock kernels installed at the same time and select the one you need from the GRUB boot menu.
If you would like to uninstall a mainline kernel anyway, first use:
dpkg -l | grep "linux\-[a-z]*\-"
to find the exact name of the kernel packages you want to uninstall, and then do:
sudo apt-get remove KERNEL_PACKAGES_TO_REMOVE
Remember that several packages belong to one kernel version: common headers, architecture specific headers and the architecture specific image.
Why do mainline kernel builds have a -<series> suffix?
Each mainline build is named by the base upstream version suffixed with an Ubuntu release name, 2.6.35-maverick. This tells us the upstream version which was built, and additionally which configuration was used to build it. This tells us which release is most compatible with the kernel as built. This does not prevent the kernel being used on other releases, though it is most likely to work correctly on the release it is build for, or earlier ones. The further away from your base kernel release you are the more likely that there will be an incompatible userspace interaction which will prevent them working for you.
Do mainline kernel builds include Ubuntu specific drivers?
By definition the mainline kernel builds are made from virgin unaltered mainline kernel sources and therefore do not, and should not, include any Ubuntu patches or drivers. There are also no binary drivers for these kernels.
Submitting to kerneloops.org
Ubuntu's default infrastructure for handling OOPSes will not work for these builds as they are external to Ubuntu. To contribute this information to kerneloops.org you will need to make a couple of changes.
First, install the kerneloops-applet package which will handle the prompting and submission on any problem. Then edit /etc/kerneloops.conf and delete the submit-pipe line from the file, so that kerneloops-applet will be used. After a reboot kerneloops-applet will then prompt you if there are any problems and you can choose to submit the information to kerneloops.org.
Mainline Build Tool chain
These kernels are built with the tool chain (gcc etc) from the previous LTS (Ubuntu 8.04/10.04/12.04) depending on version, therefore out-of-tree kernel modules built with tools from other versions likely will not work. There is a file BUILD in later mainline builds detailing what was used.