Criando Kernel RT Ubuntu 14.04

Todas as informacoes aqui foram retiradas de: http://linuxaudioproduction.blogspot.com.br/2015/09/patching-compiling-and-installing.html

Testado com o Ubuntu 14.04.1

This guide is a condensed reference on how to patch, compile and install the 4.1.5. kernel.

Download kernel and patch:

https://www.kernel.org/pub/linux/kernel/v4.x/linux-4.1.5.tar.xz
https://www.kernel.org/pub/linux/kernel/projects/rt/4.1/patch-4.1.5-rt5.patch.xz

use sudo mode:

sudo su

Extract kernel archive and patch file:

tar -Jxf linux-4.1.5.tar.xz
tar -Jxf patch-4.1.5-rt5.patch.xz

Put the patch file one directory level above the kernel source.

cp linux-4.1.5 /usr/src
cp patch-4.1.5-rt5.patch /usr/src

Change directory to the newly created kernel source directory

cd /usr/src/linux-4.1.5

Apply the patch to the kernel.

less ../patch-4.1.5-rt5.patch | patch -p1

Get the latest configuration of new kernel

make oldconfig

The make will ask some questions, answer with the default option, EXCEPT the options about real time and debug mode. When asked for:

• "Preemption Model"
  • Choose "5. Fully Preemptible Kernel (RT) (PREEMPT_RT_FULL) (NEW)"

• "Debug preemptible kernel (DEBUG_PREEMPT)"
  • Choose "n"

Open up the kernel configuration tool:

make menuconfig

configure the IP_TABLES NAT support: On the Kernel Configuration go to:

Networking support > Networking Options > Network packet filtering framework (Netfilter) > IP: Netfilter Configuration
Find the options listed below and mark with <M>
	<M>iptables NAT support  
Other options will apear:

<M> MASQUERADE target support <M> NETMAP tarrget support <M> REDIRECT target support

save and exit

Build and install the kernel:

make
make modules
make INSTALL_MOD_STRIP=1 modules_install
make install

Update the bootloader (probably grub) if not done automatically.