Jetson Setup

On first boot, always do a sudo apt update && sudo apt upgrade.

JTOP

If pip is not installed, run

sudo apt install python3-pip

To install jetson-stats (the command jtop):

sudo pip3 install jetson-stats

sudo is needed for jetson-stats to access system information. After installing, reboot the device. After reboot. running jtop will give live device information.

Issues

1. Nvidia L4T Kernel Updates on the Seeed Studio J401 Carrier Board

Put nvidia-l4t-kernel and related apt packages on hold:

sudo apt-mark hold nvidia-l4t-kernel

Support may change later on, but as of 25 Jun 2024, the L4T kernel on the official nvidia repo (repo.download.nvidia.com/jetson/common r36.3/main) does not support the J401.

2. USB Modem not recognised as USB Connection

This is due to the Jetpack 6.0 L4T Kernel including the necesary USB network configs / modules. Fix is the recompile the Linux kernel with the neccessary configs.

Problem

When plugging in a USB modem, the Wired Connection symbol should appear and connection should be through the USB interface. Instead connection to the modem is only possible through wifi, resulting in much lower connection speeds.

Quick Links

Forum Discussion: https://forums.developer.nvidia.com/t/jetson-orin-nano-usb-tethering-not-working-jetpack-6/295108

Kernel Customisation Documentation: https://docs.nvidia.com/jetson/archives/r36.3/DeveloperGuide/SD/Kernel/KernelCustomization.html

Guide to get kernel and filesystem sources and flashing: https://docs.nvidia.com/jetson/archives/r36.3/DeveloperGuide/IN/QuickStart.html#preparing-a-jetson-developer-kit-for-use

Diagnosis

To see the linux kernel configs on a running system, check either one of the following:

/proc/config.gz
/boot/config
/boot/config-$(uname -r)

For the Jetson, it will be /proc/config.gz. Run the following

cat /proc/config.gz | gunzip > running.config
cat running.config | grep CONFIG_USB_NET

For "normal" Ubuntu 22.04, it will be /boot/config-$(uname -r). You can cat the file directly.

If the configs needed for the modem are set to n, the modem would not work.

To see what each config param mean, see https://www.kernelconfig.io/index.html

Fix

Recompile the kernel with the following configs (NOTE: This is meant to be an exhaustive list, not a minimal one. If you care about kernel bloat, feel free to test for the minimally required set of configs.)

CONFIG_USB_NET_DRIVERS=m
CONFIG_USB_NET_AX8817X=m
CONFIG_USB_NET_AX88179_178A=m
CONFIG_USB_NET_CDCETHER=m
CONFIG_USB_NET_CDC_EEM=m
CONFIG_USB_NET_CDC_NCM=m
CONFIG_USB_NET_HUAWEI_CDC_NCM=m
CONFIG_USB_NET_CDC_MBIM=m
CONFIG_USB_NET_DM9601=m
CONFIG_USB_NET_SR9700=m
CONFIG_USB_NET_SR9800=m
CONFIG_USB_NET_SMSC75XX=m
CONFIG_USB_NET_SMSC95XX=m
CONFIG_USB_NET_GL620A=m
CONFIG_USB_NET_NET1080=m
CONFIG_USB_NET_PLUSB=m
CONFIG_USB_NET_MCS7830=m
CONFIG_USB_NET_RNDIS_HOST=m
CONFIG_USB_NET_CDC_SUBSET_ENABLE=m
CONFIG_USB_NET_CDC_SUBSET=m
CONFIG_USB_NET_ZAURUS=m
CONFIG_USB_NET_CX82310_ETH=m
CONFIG_USB_NET_KALMIA=m
CONFIG_USB_NET_QMI_WWAN=m
CONFIG_USB_NET_INT51X1=m
CONFIG_USB_NET_CH9200=m
CONFIG_USB_NET_AQC111=m
CONFIG_USB_NET_RNDIS_WLAN=m
CONFIG_USB_NET2272=m
CONFIG_USB_NET2272_DMA=y
CONFIG_USB_NET2280=m

Download and extract files

You need to download BSP, sample rootfs, kernel source from the Jetson Linux developer page (e.g. https://developer.nvidia.com/embedded/jetson-linux-r363 for Jetson Linux v36.3, Jetpack 6.0)

Three files in total, links for Jetson Linux v36.3, Jetpack 6.0 are pasted below:

https://developer.nvidia.com/downloads/embedded/l4t/r36_release_v3.0/release/jetson_linux_r36.3.0_aarch64.tbz2 https://developer.nvidia.com/downloads/embedded/l4t/r36_release_v3.0/release/tegra_linux_sample-root-filesystem_r36.3.0_aarch64.tbz2 https://developer.nvidia.com/downloads/embedded/l4t/r36_release_v3.0/sources/public_sources.tbz2

Download all files in the same directory (e.g. ~/flash_jetson). This will be the L4T_INSTALL_PATH. You can set this as an environment variable, for example:

export L4T_INSTALL_PATH=$HOME/flash_jetson

Set the following environment variables:

${L4T_RELEASE_PACKAGE} contains the name of the Jetson Linux release package: Jetson_Linux_<version>_aarch64.tbz2.
${SAMPLE_FS_PACKAGE} contains the name of the sample file system package: Tegra_Linux_Sample-Root-Filesystem_<version>_aarch64.tbz2.
${BOARD} contains the name of a supported configuration of Jetson module and the carrier board. Common values for this field can be found in the Configuration column in the Jetson Modules and Configurations table.

E.g. for flashing Jetpack 6.0 for the Orin NX / Orin Nano developer kit:

export L4T_RELEASE_PACKAGE=jetson_linux_r36.3.0_aarch64.tbz2
export SAMPLE_FS_PACKAGE=tegra_linux_sample-root-filesystem_r36.3.0_aarch64.tbz2
export BOARD=jetson-orin-nano-devkit

Extract and prepare the binary files:

tar xf ${L4T_RELEASE_PACKAGE}
sudo tar xpf ${SAMPLE_FS_PACKAGE} -C Linux_for_Tegra/rootfs/
cd Linux_for_Tegra/
sudo ./tools/l4t_flash_prerequisites.sh
sudo ./apply_binaries.sh

Extract the kernel source:

tar xf public_sources.tbz2 -C ${L4T_INSTALL_PATH}/Linux_for_Tegra/..
cd ${L4T_INSTALL_PATH}/Linux_for_Tegra/source
tar xf kernel_src.tbz2
tar xf kernel_oot_modules_src.tbz2
tar xf nvidia_kernel_display_driver_source.tbz2

Take note of .. after Linux_for_Tegra/ in the first line.

Install Pre-requisites

sudo apt install git-core

Your system must have the default Git port 9418 open for outbound connections.

Build Utilities

sudo apt install build-essential bc

Jetson Linux Toolchain

https://docs.nvidia.com/jetson/archives/r36.3/DeveloperGuide/AT/JetsonLinuxToolchain.html#at-jetsonlinuxtoolchain

Other C++ Tools

These are supposed to have been installed above, but if they are not, run:

sudo apt install flex bison

Change Kernel Configuration

Go to the directory Linux_for_Tegra/source/kernel/kernel-jammy-src/

Run:

make ARCH=arm64 defconfig
make ARCH=arm64 menuconfig

At this point, the Kernel Configuration Menu will appear. To see which settings need to be adjusted, see https://www.kernelconfig.io/index.html or press / to search.

Build Kernel, OOT and DTBs

NOTE: if at any time you change the terminal instance, re-set the environment variables below

export L4T_INSTALL_PATH=$HOME/flash_jetson
export L4T_RELEASE_PACKAGE=jetson_linux_r36.3.0_aarch64.tbz2
export SAMPLE_FS_PACKAGE=tegra_linux_sample-root-filesystem_r36.3.0_aarch64.tbz2
export BOARD=jetson-orin-nano-devkit
export CROSS_COMPILE=$HOME/l4t-gcc/aarch64--glibc--stable-2022.08-1/bin/aarch64-buildroot-linux-gnu-

Build the Jetson Linux Kernel

cd ${L4T_INSTALL_PATH}/Linux_for_Tegra/source

./generic_rt_build.sh "enable"

make -C kernel

export INSTALL_MOD_PATH=${L4T_INSTALL_PATH}/Linux_for_Tegra/rootfs/
sudo -E make install -C kernel
cp kernel/kernel-jammy-src/arch/arm64/boot/Image \
  ${L4T_INSTALL_PATH}/Linux_for_Tegra/kernel/Image

Build the NVIDIA Out-of-Tree Modules

cd ${L4T_INSTALL_PATH}/Linux_for_Tegra/source

export IGNORE_PREEMPT_RT_PRESENCE=1
export KERNEL_HEADERS=$PWD/kernel/kernel-jammy-src
make modules

export INSTALL_MOD_PATH=${L4T_INSTALL_PATH}/Linux_for_Tegra/rootfs/
sudo -E make modules_install

cd ${L4T_INSTALL_PATH}/Linux_for_Tegra
sudo ./tools/l4t_update_initrd.sh

Build the Device Tree Blobs

cd ${L4T_INSTALL_PATH}/Linux_for_Tegra/source

export KERNEL_HEADERS=$PWD/kernel/kernel-jammy-src
make dtbs

cp nvidia-oot/device-tree/platform/generic-dts/dtbs/* \
  ${L4T_INSTALL_PATH}/Linux_for_Tegra/kernel/dtb/

Flash the Developer Kit

https://docs.nvidia.com/jetson/archives/r36.3/DeveloperGuide/IN/QuickStart.html#to-flash-the-jetson-developer-kit-operating-software

Start from step 3.

SamuelFoo/jetson_guides