Linux, as distributed by Linus Torvalds et al, contains non-Free Software, i.e., software that does not respect your essential freedoms, and it induces you to install additional non-Free Software that it doesn't contain.

GNU Linux-libre is a project to maintain and publish 100% Free versions of Linux, removing the offending portions.

libeRTy

libeRTy is a sub-project that contains .debs of Linux-libre compiled with the PREEMPT_RT patch for realtime operation on 32- and 64-bit x86 CPUs. Please write to the mailing list or visit #linux-libre on irc.freenode.net if you need support for additional CPU architectures.

How To Use

To use it edit the file /etc/apt/sources.list on your system and add the line:

deb mirror://linux-libre.fsfla.org/pub/linux-libre/liberty/mirrors.txt liberty main

Your package manager will select an appropriate mirror. You can also access the mirrors.txt file and instead put the the address of a specific mirror in place of mirror:// but please use the automatic method shown above if possible.

Either way, once your sources.list file is updated you should also fetch and install the GPG key with which the repository is signed:

sudo apt-key adv --keyserver pool.sks-keyservers.net --recv-keys F611A908FFA165C699584ED49D0DB31B545A3198

You can also check that that it's the right key:

apt-key finger

Make sure that you see the same fingerprint:

F611 A908 FFA1 65C6 9958 4ED4 9D0D B31B 545A 3198

Now you will now be able to update your package manager and install Linux-libre:

sudo apt update && sudo apt install linux-libre-rt

You may also need to install the package linux-libre-rt-headers, depending on whether you need the kernel headers or not.

Sources

You may download the tarball containing the complete and corresponding source code, kernel configuration files, and the instructions to compile and install the kernel from https://linux-libre.fsfla.org/pub/linux-libre/liberty/

Be Free!