I’ll tell you more.
If I leave the sudo apt upgrade to update the kernel, the following boot will select 5.15.148-tegra NOT realtime.
Even following Kernel Customization — NVIDIA Jetson Linux Developer Guide 1 documentation next, the RT packages are related the old version 5.15.148-rt-tegra-36.4.0-20241014173246.
nvidia@nvidia-orin-rt:~$ cat /etc/nv_tegra_release
#R36 (release), REVISION: 4.3, GCID: 38968081, BOARD: generic, EABI: aarch64, DATE: Wed Jan 8 01:49:37 UTC 2025
#KERNEL_VARIANT: oot
TARGET_USERSPACE_LIB_DIR=nvidia
TARGET_USERSPACE_LIB_DIR_PATH=usr/lib/aarch64-linux-gnu/nvidia
nvidia@nvidia-orin-rt:~$ uname -a
Linux nvidia-orin-rt 5.15.148-tegra #1 SMP PREEMPT Tue Jan 7 17:14:38 PST 2025 aarch64 aarch64 aarch64 GNU/Linux
nvidia@nvidia-orin-rt:~$
nvidia@nvidia-orin-rt:~$ sudo apt install nvidia-l4t-rt-kernel nvidia-l4t-rt-kernel-headers nvidia-l4t-rt-kernel-oot-modules nvidia-l4t-display-rt-kernel
Reading package lists… Done
Building dependency tree… Done
Reading state information… Done
The following NEW packages will be installed:
nvidia-l4t-display-rt-kernel nvidia-l4t-rt-kernel nvidia-l4t-rt-kernel-headers
nvidia-l4t-rt-kernel-oot-modules
0 upgraded, 4 newly installed, 0 to remove and 1 not upgraded.
Need to get 52.7 MB of archives.
After this operation, 197 MB of additional disk space will be used.
Get:1 https://repo.download.nvidia.com/jetson/rt-kernel r36.4/main arm64 nvidia-l4t-rt-kernel arm64 5.15.148-rt-tegra-36.4.0-20241014173246 [29.3 MB]
Get:2 https://repo.download.nvidia.com/jetson/rt-kernel r36.4/main arm64 nvidia-l4t-display-rt-kernel arm64 5.15.148-rt-tegra-36.4.0-20241014173246 [1,174 kB]
Get:3 https://repo.download.nvidia.com/jetson/rt-kernel r36.4/main arm64 nvidia-l4t-rt-kernel-headers arm64 5.15.148-rt-tegra-36.4.0-20241014173246 [17.8 MB]
Get:4 https://repo.download.nvidia.com/jetson/rt-kernel r36.4/main arm64 nvidia-l4t-rt-kernel-oot-modules arm64 5.15.148-rt-tegra-36.4.0-20241014173246 [4,382 kB]
…
Rebooting after installing RT by OTA, prevent the correct booting with the error bash: cannot set terminal process group (-1): Inappropriate ioctl for device:
boot_rt_36.4.3.log (70.0 KB)