RealTime (RT) Kernel

basierend auf : https://www.raspberrypi.com/documentation/computers/linux_kernel.html#building

• sudo apt install git bc bison flex libssl-dev make libncurses5-dev #I think this is all the tools required
• mkdir kernel && cd kernel/
• git clone --depth=1 --branch rpi-6.12.y https://github.com/raspberrypi/linux
• wget https://mirrors.edge.kernel.org/pub/linux/kernel/projects/rt/6.12/patch-6.12.39-rt11.patch.gz
  https://mirrors.edge.kernel.org/pub/linux/kernel/projects/rt/6.12/
• cd linux/
• zcat ../patch-6.12.39-rt11.patch.gz | patch -p1 --dry-run #check the patch fits
• zcat ../patch-6.12.39-rt11.patch.gz | patch -p1
• KERNEL=kernel8
• make ARCH=arm64 bcm2711_defconfig
• make ARCH=arm64 menuconfig

  • General setup  --->

  •          Preemption Model (Preemptible Kernel (Low-Latency Desktop))  --->
         [*] Fully Preemptible Kernel (Real-Time)
         [ ] Preemption behaviour defined on boot      

  • CPU Power Management aus !
  • Beim Exit Config Save → Yes
• nano .config
CONFIG_LOCALVERSION="-V8_DrKlipper_RT"
  • Hier auf gar keinen Fall Leerzeichen einbauen. Gibt sonst am Ende Compile und Kopierfehler!
• time make -j6 ARCH=arm64 Image.gz modules dtbs
  • CPU Cores * 1,5 → nproc

echo $KERNEL sudo make modules_install sudo cp arch/arm64/boot/dts/broadcom/*.dtb /boot/ sudo cp arch/arm64/boot/dts/overlays/*.dtb* /boot/overlays/ sudo cp arch/arm64/boot/dts/overlays/README /boot/overlays/ sudo cp arch/arm64/boot/Image.gz /boot/$KERNEL.img

• Der erste Part passiert auf einem Raspberry Pi 4 - Kompilierzeit ca. 2 Stunden
• USB Stick mounten
  sudo mkdir /mnt/copy
sudo mount -t ext4 /dev/sdb1 /mnt/copy
sudo chown -R pi:pi /mnt/copy
• Module kopieren
  sudo make ARCH=arm64 INSTALL_MOD_PATH=/mnt/copy modules_install
• Overlays und Kernel kopieren
  sudo mkdir -p /mnt/copy/boot/firmware/overlays
sudo cp arch/arm64/boot/Image.gz /mnt/copy/boot/firmware/$KERNEL.img
sudo cp arch/arm64/boot/dts/broadcom/*.dtb /mnt/copy/boot/firmware/
sudo cp arch/arm64/boot/dts/overlays/*.dtb* /mnt/copy/boot/firmware/overlays/
sudo cp arch/arm64/boot/dts/overlays/README /mnt/copy/boot/firmware/overlays/
• sudo umount /mnt/copy/
• Der zweite Part dann auf dem Raspberry Pi Zero 2W
• Libs kopieren
  sudo cp -r /mnt/copy/lib/modules/* /lib/modules/
• Kernel und Overlays kopieren
  KERNEL=kernel8
sudo cp -n /mnt/copy/boot/firmware/*.dtb /boot/firmware/
sudo cp -n /mnt/copy/boot/firmware/overlays/*.dtb* /boot/firmware/overlays/
sudo cp -n /mnt/copy/boot/firmware/overlays/README /boot/firmware/overlays/
sudo cp /mnt/copy/boot/firmware/$KERNEL.img /boot/firmware/$KERNEL.img

* sudo reboot''

• https://www.raspberrypi.com/documentation/computers/linux_kernel.html
• Ursprung: https://forums.raspberrypi.com/viewtopic.php?t=344994
• https://blog.emlid.com/raspberry-pi-real-time-kernel/
• ISO erstellen mit RT Kernel
  https://github.com/remusmp/rpi-rt-kernel