UPXtreme-RT-kernel
Custom PREEMPT_RT kernel on UP! Xtreme based on UP! kernel hwe-5.4-upboard. Only tested on UP Xtreme i7C1-8565U
Disclaimer: use at your own risk!
Lets get started!
mkdir ~/kernel
cd ~/kernel
git clone https://github.com/AaeonCM/ubuntu-bionic-up.git
cd ubuntu-bionic-up
git checkout hwe-5.4-upboard
make kernelversion --Gives information on kernel version-- in my case (5.4.65)--
Find RT patch equal or close to kernel version from make kernelversion output---
wget https://mirrors.edge.kernel.org/pub/linux/kernel/projects/rt/5.4/older/patch-5.4.66-rt38.patch.xz
unxz -cd patch-5.4.66-rt38.patch.xz | patch -p1
make defconfig
xdg-open .config
Apply RT OPTIONS on kernel
HIGH_RES_TIMERS=y
CONFIG_PREEMPT_RT_FULL=y
CONFIG_HZ_1000=y
CONFIG_HZ=1000
CONFIG_OF=n
IF make fails turn off AUFS
CONFIG_AUFS_FS=n
Optional
disable the CPU idle state and to set the default CPU frequency governor to performance
CONFIG_CPU_IDLE=n
CONFIG_INTEL_IDLE=n
CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE=y
Optional isolcpus
To check.
Building
make (NOTE: You can use “make -jX” option if you have thread support. X is number of core + 1. It will compile faster)
Make modules and install
sudo make modules_install -j2
sudo make install -j2
Check new kernel file and update grub boot loader to start Linux with new RT-Kernel
cd /boot
ls
You will see new kernel. (UPDATE TEXT HERE)
Update grub and reboot machine
sudo update-grub
sudo reboot
Check kernel version to be sure.
uname -a
Install upboard-extras
sudo apt install upboard-extras
cd ~/temp
wget https://github.com/raess1/UPxtreme-RT-kernel/blob/main/permissiongroups.sh
chmod +x permissiongroups.sh
./permissiongroups.sh
after that you need to add the user that needs to access the HAT functionality to the corresponding groups:
GPIO
sudo usermod -a -G gpio ${USER}
LEDs
sudo usermod -a -G leds ${USER}
SPI
sudo usermod -a -G spi ${USER}
I2C
sudo usermod -a -G i2c ${USER}
UART
sudo usermod -a -G dialout ${USER}
to apply the permission changes after issuing the previous command a reboot is needed
sudo reboot
GPIO test
echo 26 > /sys/class/gpio/export
echo out > /sys/class/gpio/gpio26/direction
echo 1 > /sys/class/gpio/gpio26/value
Should make pin37 output 3.3v (measure)
echo 0 > /sys/class/gpio/gpio26/value
Should make pin37 output 0V (measure)
LED test
The UP Board includes 3 LEDs (yellow, green, red) on the underside of the board (underneath the 4 USB2.0 Type-A sockets), which are controlled by the pin control CPLD on the board. As root, you can use the following commands to control the LEDs:
echo 1 > /sys/class/leds/upboard\:green\:/brightness
echo 0 > /sys/class/leds/upboard\:green\:/brightness
RT-Tests
sudo apt-get install build-essential libnuma-dev
mkdir ~/rt
cd ~/rt
git clone git://git.kernel.org/pub/scm/utils/rt-tests/rt-tests.git
cd rt-tests
git checkout stable/v1.0
make all
make install
Run tests
To run one test thread per CPU or per CPU core, each thread on a separate processor, type
sudo ./cyclictest -a -t -n -p99
Benching from 5.4.0-1-generic #0~upboard2-Ubuntu SMP vs RT
On a non-realtime system, you may see something like
T: 0 ( 1946) P:99 I:1000 C: 21097 Min: 1 Act: 3 Avg: 2 Max: 177
T: 1 ( 1947) P:99 I:1500 C: 14064 Min: 1 Act: 3 Avg: 3 Max: 152
T: 2 ( 1948) P:99 I:2000 C: 10548 Min: 1 Act: 1 Avg: 3 Max: 152
T: 3 ( 1949) P:99 I:2500 C: 8439 Min: 1 Act: 3 Avg: 3 Max: 168
T: 4 ( 1950) P:99 I:3000 C: 7032 Min: 1 Act: 3 Avg: 3 Max: 139
T: 5 ( 1951) P:99 I:3500 C: 6027 Min: 1 Act: 3 Avg: 3 Max: 169
T: 6 ( 1952) P:99 I:4000 C: 5274 Min: 1 Act: 3 Avg: 3 Max: 170
T: 7 ( 1953) P:99 I:4500 C: 4688 Min: 1 Act: 2 Avg: 4 Max: 123
RT-PREEMPT
T: 0 ( 4614) P:99 I:1000 C: 5507 Min: 1 Act: 3 Avg: 3 Max: 30
T: 1 ( 4615) P:99 I:1500 C: 3671 Min: 1 Act: 4 Avg: 3 Max: 26
T: 2 ( 4616) P:99 I:2000 C: 2753 Min: 1 Act: 6 Avg: 3 Max: 23
T: 3 ( 4617) P:99 I:2500 C: 2202 Min: 2 Act: 6 Avg: 3 Max: 30
T: 4 ( 4618) P:99 I:3000 C: 1835 Min: 2 Act: 7 Avg: 3 Max: 11
T: 5 ( 4619) P:99 I:3500 C: 1573 Min: 1 Act: 5 Avg: 3 Max: 36
T: 6 ( 4620) P:99 I:4000 C: 1376 Min: 1 Act: 4 Avg: 3 Max: 42
T: 7 ( 4621) P:99 I:4500 C: 1223 Min: 2 Act: 4 Avg: 4 Max: 21