====== Raspberry PI4 ======
===== Overclock =====
<code bash>echo "force_turbo=1
over_voltage=8
arm_freq=2147
gpu_freq=750" >> /boot/config.txt
</code>

===== Matlab x86/amd64 binary auf raspberry ausfuehren =====
Getestet mit Matlab 2023a auf raspbian lite 64bit.
==== Mittels debootstrap eine amd64 Umgebung erstellen ====

<code bash>apt-get update
apt-get -y install qemu-user qemu-user-static binfmt-support debootstrap binutils
mkdir emu
debootstrap --foreign --arch amd64 bookworm emu http://deb.debian.org/debian/
cp /etc/passwd emu/etc/passwd</code>

==== chroot.sh ====
<code bash>#!/bin/bash
set -x
dir=/home/pi/emu
mount -t sysfs /sys $dir/sys/
mount -t proc /proc $dir/proc/
mount --bind /dev $dir/dev/
#mount --bind /dev/pts $dir/dev/pts/
mount --bind /dev/shm $dir/dev/shm/

chroot $dir /bin/bash
</code>

==== Abhaengigkeiten in chroot installieren ====
<code bash>./chroot.sh
apt-get update
apt-get -y install unzip gawk libgl-dev libxt6
</code>

==== MCR 9.14 in chroot installieren ====
<code bash>mkdir mcr
cd mcr
wget "https://ssd.mathworks.com/supportfiles/downloads/R2023a/Release/6/deployment_files/installer/complete/glnxa64/MATLAB_Runtime_R2023a_Update_6_glnxa64.zip"
unzip MATLAB_Runtime_R2023a_Update_6_glnxa64.zip
./install -agreeToLicense yes
</code>
==== /etc/bash.bashrc ====
In chroot folgendes hinzufuegen:
<code bash>
export LD_LIBRARY_PATH=/usr/local/MATLAB/MATLAB_Runtime/R2023a/runtime/glnxa64/:/usr/local/MATLAB/MATLAB_Runtime/R2023a/bin/glnxa64/
</code>

==== Matlab compiled binary ausfuehren ====
<code bash>file hello
hello: ELF 64-bit LSB executable, x86-64, version 1 (GNU/Linux), dynamically linked, interpreter /lib64/ld-linux-x86-64.so.2, for GNU/Linux 3.2.0, BuildID[sha1]=7e3a0e581d7a55241b73ca61c144529927a9b93e, stripped</code>
<code bash>root@raspberrypi:/# ./hello 
Hello World!
</code>



===== RT Kernel =====
  - <code bash>
git clone https://github.com/raspberrypi/linux.git
sudo apt install crossbuild-essential-armhf
</code>
  - [[https://mirrors.edge.kernel.org/pub/linux/kernel/projects/rt/|Hier]] schauen was der sinnvoll neueste RT Patch ist. Aktuell war es 5.10.90. Diesen herunterladen
  - <code bash>git log</code> und dort nach "5.10.90" suchen. Beispiel:<code>
commit d3e491a20d152e5fba6c02a38916d63f982d98a5
Author: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date:   Wed Jan 5 12:40:34 2022 +0100

    Linux 5.10.90
    
    Link: https://lore.kernel.org/r/20220103142053.466768714@linuxfoundation.org
    Tested-by: Salvatore Bonaccorso <carnil@debian.org>
    Tested-by: Guenter Roeck <linux@roeck-us.net>
    Tested-by: Linux Kernel Functional Testing <lkft@linaro.org>
    Tested-by: Jon Hunter <jonathanh@nvidia.com>
    Link: https://lore.kernel.org/r/20220104073841.681360658@linuxfoundation.org
    Tested-by: Jon Hunter <jonathanh@nvidia.com>
    Tested-by: Florian Fainelli <f.fainelli@gmail.com>
    Tested-by: Guenter Roeck <linux@roeck-us.net>
    Tested-by: Shuah Khan <skhan@linuxfoundation.org>
    Tested-by: Linux Kernel Functional Testing <lkft@linaro.org>
    Tested-by: Sudip Mukherjee <sudip.mukherjee@codethink.co.uk>
    Tested-by: Salvatore Bonaccorso <carnil@debian.org>
    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

</code> Datum merken.
  - Naechsten commit suchen, der arch/arm/config/bcm2711_defconfig enthaelt suchen und den auschecken.
  - RT Patch anwenden: <code bash>
wget "https://mirrors.edge.kernel.org/pub/linux/kernel/projects/rt/5.10/patch-5.10.90-rt60.patch.xz"
xzcat patch-5.10.90-rt60.patch.xz | patch -p1
</code>
  - Konfigurieren: <code bash>cd linux
KERNEL=kernel7l
make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- bcm2711_defconfig</code>
  - In menuconfig "fully preemptible" einschalten: <code bash>
make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- menuconfig
</code>
  - Bauen: <code bash>make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- zImage modules dtbs -j24</code>
  - Installieren: <code bash>mkdir mnt
mkdir mnt/fat32
mkdir mnt/ext4
sudo mount /dev/sdb1 mnt/fat32
sudo mount /dev/sdb2 mnt/ext4
sudo env PATH=$PATH make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- INSTALL_MOD_PATH=mnt/ext4 modules_install
sudo cp mnt/fat32/$KERNEL.img mnt/fat32/$KERNEL-backup.img
sudo cp arch/arm/boot/zImage mnt/fat32/$KERNEL.img
sudo cp arch/arm/boot/dts/*.dtb mnt/fat32/
sudo cp arch/arm/boot/dts/overlays/*.dtb* mnt/fat32/overlays/
sudo cp arch/arm/boot/dts/overlays/README mnt/fat32/overlays/
sudo umount mnt/fat32
sudo umount mnt/ext4
</code>
===== IRQ Prioritaeten =====
  - in /boot/cmdline.txt "threadirqsi" hinzufuegen.
  - <code bash>apt-get install rtirq-init</code>
  - In /etc/default/rtirq <code bash>RTIRQ_NAME_LIST="74 73"</code> editieren und <code bash>RTIRQ_RESET_ALL=1</code> einschalten.
===== Cores isolieren =====
  - in /boot/cmdline.txt "isolcpus=2,3" hinzufuegen.
  - Tasks bspw. mit <code bash>taskset --cpu-list 2-3 [TASK}</code> starten

===== Image von /boot =====
  * {{ :it:linux:raspi_4_boot_5.10.90_rt60_220203.tar.gz |}}
  * {{ :it:linux:kernel_6.4.6-rt8-v8_.tar.gz |}}

===== Links =====
  - [[https://www.raspberrypi.com/documentation/computers/linux_kernel.html]]
  - [[https://wiki.linuxfoundation.org/realtime/documentation/howto/applications/preemptrt_setup]]