[LAU] RT kernel

[Ralf Mardorf]

Hi,

use    export CONCURRENCY_LEVEL=[...]    if you want to build with
several jobs. You could use fake root, if you dislike to build with
root privileges. However, this are the commands you need to run, when
building with root privileges.

Replace [...] with what's missing, use a browser to visit those sites.
The rt patch must exactly fit to the kernel version.

  wget https://www.kernel.org/pub/linux/kernel/[...].tar.gz
  wget https://www.kernel.org/pub/linux/kernel/projects/rt/[...].patch.gz
  sudo -i

Extract the kernel

  tar zxf linux-[...]

Rename the extracted directory to the rt name

  mv linux-[...] linux-[...]-rt[...]

Change into the extracted directory and patch the kernel.

  cd linux-[...]-rt[...]
  gzip -dc ../patch-[...].patch.gz | patch -p1

Copy the config of e.g. an Arch rt kernel or the config of the non-rt
you are running to the directory

  https://aur.archlinux.org/cgit/aur.git/snapshot/linux-rt.tar.gz
  https://aur.archlinux.org/cgit/aur.git/snapshot/linux-rt-lts.tar.gz

respectively

  cp /boot/config-$(uname -r) config

Configure the kernel

  make oldconfig

Build the kernel

  make-kpkg clean
  make-kpkg --initrd kernel-image kernel-headers

Building the kernel most likely fails two or three times, you most
likely need to disable a few configurations. To do this read the error
messages and use

  make menuconfig

it has got a search option, so you easily could find what to disable,
OTOH sometimes it's faster to use an editor and directly disable an
option.

Repeat running

  make oldconfig
  make-kpkg clean
  make-kpkg --initrd kernel-image kernel-headers

Use    apt install    or    dpkg -i    to install the packages.

This is the Debian way to build a kernel, that works without failure for
Ubuntu, too. Actually there's an Ubuntu way that is a little bit different.
This is how I successfully build rt patched kernels for Ubuntu countless
times.

If you should be inexperienced in configuring a kernel, 1. oldconfig's and
menuconfig's help, 2. Google and 3. this list are your friends, in exactly
that order ;). 

Regards,
Ralf