View source for Compiling Jetson TX2 source code L4T 32.3.1

= Introduction =
This wiki page contains instructions to download and build kernel source code for Jetson TX2, several parts of this wiki were based in the document: NVIDIA Tegra Linux Driver Package Development Guide 32.3.

L4T 32.3.1 is used by JetPack 4.3 (You can get more information from [https://developer.nvidia.com/embedded/jetpack-archive jetpack-archive]).

= Build kernel =

'''1. Download and install the Toolchain'''

NVIDIA recommends using the Linaro 7.3.1 2018.05 toolchain for L4T 32.3 ([https://docs.nvidia.com/jetson/archives/l4t-archived/l4t-3231/index.html#page/Tegra%2520Linux%2520Driver%2520Package%2520Development%2520Guide%2Fxavier_toolchain.html%23 toolchain])

Download the pre-built toolchain binaries from: http://releases.linaro.org/components/toolchain/binaries/7.3-2018.05/aarch64-linux-gnu/gcc-linaro-7.3.1-2018.05-x86_64_aarch64-linux-gnu.tar.xz and locate them under $HOME/l4t-gcc, or alternatively execute on console:

<syntaxhighlight lang="bash" style="background-color:cornsilk">
mkdir -p $HOME/l4t-gcc
cd $HOME/l4t-gcc
wget http://releases.linaro.org/components/toolchain/binaries/7.3-2018.05/aarch64-linux-gnu/gcc-linaro-7.3.1-2018.05-x86_64_aarch64-linux-gnu.tar.xz
</syntaxhighlight>

Execute the following commands to extract the toolchain:

<syntaxhighlight lang="bash" style="background-color:cornsilk">
tar xf gcc-linaro-7.3.1-2018.05-x86_64_aarch64-linux-gnu.tar.xz
</syntaxhighlight>


'''2. Download the kernel sources for L4T 32.3.1'''
<syntaxhighlight lang="bash" style="background-color:cornsilk">
mkdir -p $HOME/l4t-sources/tx2/
cd $HOME/l4t-sources/tx2
wget https://developer.download.nvidia.com/embedded/L4T/r32-3-1_Release_v1.0/Sources/T186/public_sources.tbz2
</syntaxhighlight>

Execute the following commands to extract the kernel sources:

<syntaxhighlight lang="bash" style="background-color:cornsilk">
tar -xvf public_sources.tbz2
cd Linux_for_Tegra/source/public
JETSON_TX2_KERNEL_SOURCES=$(pwd)
tar -xf kernel_src.tbz2
</syntaxhighlight>

Apply corresponding patches (if any) and follow to the next section.

'''3. Compile kernel and dtb'''

<syntaxhighlight lang="bash" style="background-color:cornsilk">
cd $JETSON_TX2_KERNEL_SOURCES

TOOLCHAIN_PREFIX=$HOME/l4t-gcc/gcc-linaro-7.3.1-2018.05-x86_64_aarch64-linux-gnu/bin/aarch64-linux-gnu-
TEGRA_KERNEL_OUT=$JETSON_TX2_KERNEL_SOURCES/build
KERNEL_MODULES_OUT=$JETSON_TX2_KERNEL_SOURCES/modules

make -C kernel/kernel-4.9/ ARCH=arm64 O=$TEGRA_KERNEL_OUT LOCALVERSION=-tegra CROSS_COMPILE=${TOOLCHAIN_PREFIX} tegra_defconfig
make -C kernel/kernel-4.9/ ARCH=arm64 O=$TEGRA_KERNEL_OUT LOCALVERSION=-tegra CROSS_COMPILE=${TOOLCHAIN_PREFIX} menuconfig
</syntaxhighlight>

here you have to select the modules you want to compile, for example for libguvc something like this is required:

<syntaxhighlight lang="bash" style="background-color:cornsilk">
 -> Device Drivers
    -> USB support (USB_SUPPORT [=y]) 
        -> USB Gadget Support (USB_GADGET [=y]) 
            -> USB Gadget Drivers (<choice> [=m]) 
</syntaxhighlight>

Now compile the image, dtbs and modules:

<syntaxhighlight lang="bash" style="background-color:cornsilk">
make -C kernel/kernel-4.9/ ARCH=arm64 O=$TEGRA_KERNEL_OUT LOCALVERSION=-tegra CROSS_COMPILE=${TOOLCHAIN_PREFIX} -j$(nproc) Image
make -C kernel/kernel-4.9/ ARCH=arm64 O=$TEGRA_KERNEL_OUT LOCALVERSION=-tegra CROSS_COMPILE=${TOOLCHAIN_PREFIX} -j$(nproc) dtbs
make -C kernel/kernel-4.9/ ARCH=arm64 O=$TEGRA_KERNEL_OUT LOCALVERSION=-tegra CROSS_COMPILE=${TOOLCHAIN_PREFIX} -j$(nproc) modules
make -C kernel/kernel-4.9/ ARCH=arm64 O=$TEGRA_KERNEL_OUT LOCALVERSION=-tegra INSTALL_MOD_PATH=$KERNEL_MODULES_OUT modules_install
</syntaxhighlight>

= Install image on the TX2 =

This guide assumes that the user already has sdk-manager installed. This link contains details about how to install sdk-manager: https://developer.nvidia.com/nvidia-sdk-manager https://docs.nvidia.com/sdk-manager/download-run-sdkm/index.html

NVIDIA_SDK_MANAGER contains the directory where Nvidia SDK manager was installed. For example:

<syntaxhighlight lang="bash" style="background-color:cornsilk">
export NVIDIA_SDK_MANAGER=$HOME/nvidia/nvidia_sdk/
</syntaxhighlight>

Export the following variables:

<syntaxhighlight lang="bash" style="background-color:cornsilk">
JETPACK_4_3_P3310=${NVIDIA_SDK_MANAGER}/JetPack_4.3_Linux_P3310/Linux_for_Tegra/
</syntaxhighlight>