RT kernel by boot from NVME

[sabina.greenberg]

i try to boot with real-time kernel package that is describe in Kernel Customization — Jetson Linux<br/>Developer Guide 34.1 documentation section: To install the real-time kernel package
but after all steps after reboot (my boot is from nvme) command uname -a get me info:Linux lumenis-desktop 4.9.253-tegra #1 SMP PREEMPT Sun Apr 17 02:37:44 PDT 2022 aarch64 aarch64 aarch64 GNU/Linux - no RT package. is it possible to boot with RT-package without building it? or may be the problem is that i boot from nvme?

[DaneLLL]

Hi,
ON Jetpack 5, there is no prebuilt RT-kernel. Please download the source code and apply the patches to build kernel image.

[sabina.greenberg]

Hi,
I’m working with JetPack 4.6.2.
Should it support RT-kernel without recompile it? May be you have any script or link to help RT-kernel compiling.
Thanks, Sabina

[DaneLLL]

Hi,
The default package is for rootfs on eMMC. For rootfs on NVMe SSD, you would need to manually build kernel image, overwrite original kernel image and flash rootfs to NVMe SSD.

For building kernel image, please refer to this topic:
Applying a PREEMPT-RT patch to JetPack 4.5 on Jetson Nano - #4 by ajcalderont

[sabina.greenberg]

Thank you very much,
It work for kernel 4.9.
when i try to build kernel 5.10 i get an error:

my steps are:
wget https://developer.nvidia.com/embedded/l4t/r35_release_v1.0/release/jetson_linux_r35.1.0_aarch64.tbz2
wget https://developer.nvidia.com/embedded/l4t/r35_release_v1.0/release/tegra_linux_sample-root-filesystem_r35.1.0_aarch64.tbz2
wget https://developer.nvidia.com/embedded/l4t/r35_release_v1.0/sources/public_sources.tbz2

sudo tar xpf jetson_linux_r35.1.0_aarch64.tbz2
cd Linux_for_Tegra/rootfs/
sudo tar xpf …/…/tegra_linux_sample-root-filesystem_r35.1.0_aarch64.tbz2
cd …/…/
tar -xvf gcc-linaro-7.3.1-2018.05-x86_64_aarch64-linux-gnu.tar.xz
sudo tar -xjf public_sources.tbz2
tar -xjf Linux_for_Tegra/source/public/kernel_src.tbz2
cd kernel/kernel-5.10/
./scripts/rt-patch.sh apply-patches
TEGRA_KERNEL_OUT=jetson_agx_kernel
mkdir $TEGRA_KERNEL_OUT
export CROSS_COMPILE=$HOME/jetson_agx_35/gcc-linaro-7.3.1-2018.05-x86_64_aarch64-linux-gnu/bin/aarch64-linux-gnu-
make ARCH=arm64 O=$TEGRA_KERNEL_OUT tegra_defconfig

could you pls help with it?

[sabina.greenberg]

the problem resolved after install

sudo apt-get install libncurses-dev flex bison openssl libssl-dev dkms libelf-dev libudev-dev libpci-dev libiberty-dev autoconf

All work! :) Thanks!