Overview

This project serves two purposes:

To make building and developing for the Nvidia Jetson kernel easier.
To publish D3 Jetson modifications to the public in a clean and easy-to-use manner.

Please note that this hasn't been used extensively with Nano and likely has some issues.

Getting the Code

This project uses git submodules to pull in repositories publish by Nvidia. The use of git submodules requires extra steps that are not needed for git repositories that do not use submodules.

After the initial clone choose a branch corresponding to the release you would like to build. The master branch only provides this documentation; all working code is contained in branches. D3 specific code will be added on different branches in the near future. The following will checkout the nvidia branch with Linux for Tegra r32.2.1 submodules.

git checkout nvidia/r32.2.1
git submodule update --init

The --init flag is only needed one time.

Anytime a branch is changed be sure to update the submodules as git does not do this automatically by default!

git submodule update

Use of git-prompt is recommended as it will alert you when your submodules need updating.

Dependencies

Ubuntu 16.04 or 18.04.
Linux For Tegra host-side tools as installed by Nvidia's SDK Manager
rsync: for efficiently transferring files to the Jetson target
TODO: track down the required Ubuntu packages

Building

Autoconf is utilized to make it easier to choose different systems and various other options. The basic steps required are below.

./bootstrap
./configure
make linux-defconfig
make -j8

There are options for customizing the build. If, for example, you are developing for Xavier you would execute:

./bootstrap
./configure --with-system-type=xavier
make linux-defconfig
make -j8

Configure Options

--with-system-type

The choices are xavier, tx2, or nano. The default is tx2. This option influences the L4T directory. If you have installed the L4T host utilities in the default locations from Nvidia's SDK Manager then this will choose the correct path and there is no need to specify --with-l4t.

--with-dtb

Specifies a path to a device tree blob. This is used for the make target 'flash-dtb'. Normally a path to the build directory is used:

./configure --with-dtb=$(realpath build/deploy/boot/tegra186-quill-e3313-1000-a00-00-e2598.dtb)

--with-target-host

Normally this is not required. This specifies an IP address or hostname that is used when sending files to the target Jetson device. The default is 192.168.55.1 which is the default IP address for the USB connection to the Jetson.

--with-kconfig

Optionally specify a non-default location for the kernel configuration file.

--with-l4t

Normally this is not required as a suitable default is chosen based on the system type (see --with-system-type). If you have installed L4T in a non-standard location you can use this to direct the build tools to the correct location. This situation might arise, for example, on a dedicated build server.

Installing

The only step required to install the kernel, modules, and dtb is make sync. This target copies the required files to the target device, taking into account differences between Xavier, Tx2, and Nano.

Makefile Targets

all             - alias for deploy which builds everything
clean           - deletes build artifacts in the kernel and deployment trees
deploy          - builds kernel and DTB
deploy-clean    - deletes build artifacts in the deployment tree
sync            - rsyncs kernel, kernel modules, and dtb to target
sync-debug      - rsyncs debug/ to target
sync-kernel     - (Xavier only) copies signed kernel image to device and dd's it to the kernel memory partition
sync-modules    - rsyncs kernel modules to target
sync-dtb        - copies signed dtb to device and dd's it to the kernel-dtb memory partition
flash-dtb       - flashes dtb to target via USB (device in recovery mode)
flash-kernel    - (Xavier only) flashes kernel to target via USB (device in recovery mode)
linux-defconfig - prepares kernel with default D3 configuration
linux-menuconfig- launches curses based kernel config editor
linux-dtbs      - builds dtbs
linux-dtbs-install- installs dtbs
linux-clean     - deletes build artifacts in the kernel tree
reboot          - reboots target
shutdown        - halts target
sign-dtb        - signs dtb file with L4T
sign-kernel     - (Xavier only) signs kernel image with L4T
bin-kernel      - creates kernel .deb package
show-config     - show the configuration supplied to configure