In this tutorial, I will present how to make a RT Preempt Linux with Ubuntu 18.04.02

1. install Ubuntu 18.04.02 in your computer. Let me skip the details since there are so many other tutorials for this.

2. Once the install is finished. Download Linux kernel and RT Patch

• Linux Kernel Download at

https://mirrors.edge.kernel.org/pub/linux/kernel/v4.x/

• RT patch download at https://mirrors.edge.kernel.org/pub/linux/kernel/projects/rt/4.4/

3. Prepare to compile the kernel

cd Downloads/
xz -cd linux-4.4.208.tar.xz | tar xvf -
cd linux-4.4.208/
xzcat ../patch-4.4.208-rt191.patch.xz | patch -p1
sudo apt install libncurses5-dev build-essential cmake libssl-dev git flex bison
make menuconfig

• Set “High Resulution Timer Support” 
• Set “Fully Preemptible Kernel (RT)

• (optional) set Local version name
• Save the config file

4. Compile and install the kernel ( WARNING: It takes very long time)

make -j20
sudo make modules_install -j20
sudo make install -j20

Here -jx is to specify the number of CPU cores, if you just choose a high number, it go with your all CPU cores.

5. Grub setting

sudo gedit /etc/default/grub

Then, edit the text as below:

To select the booting option in GRUB

GRUB_TIMEOUT_STYLE=hidden -> GRUB_TIMEOUT_STYLE=menu

To increase the time out for selecting a menu

GRUB_TIMEOUT=0 -> GRUB_TIMEOUT=3

To reduce the visual effect

GRUB_CMDLINE_LINUX_DEFAULT=”quiet splash” -> GRUB_CMDLINE_LINUX_DEFAULT=”quiet”

If you want to boot without graphical desktop (terminal mode)

GRUB_CMDLINE_LINUX=”” -> GRUB_CMDLINE_LINUX=”3″

5. Rebooting

sudo update-grub
sudo reboot

6. Select RT-preempt kernel in GRUB

select Advanced and RT-Linux

(Optional)  If you want to customize GRUB more, then use grub-customizer (grub editor with GUI)

sudo add-apt-repository ppa:danielrichter2007/grub-customizer 
sudo apt update
sudo apt install grub-customizer

Other readings

Now you are ready to develop or run an RT application on RT Preempt Linux. If you need to know how to write a RT thread running with a periodic cycle, read another article of mine.

• C++ Class for Loop Time Histogram Statistics
• Parallel RT Processes with Same Periodic Cycles
• RT Periodic Thread Code and Scheduler Policy and Priority

Good luck!