Where can I find "tegra21_defconfig" for L4T R24.1?

I’m trying to cross compile the kernel for my TX1 from my Ubuntu 14.04 desktop. Looking at the R24.1 documents tar, I’m following the instructions found in the “Tegra Linux Driver Package Development Guide”, under Getting Started --> Building the NVIDIA Kernel.

The first step is to download the kernel source. I’ve already used JetPack-2.2.1 to flash my hardware, and so I looked under 64_TX1/Linux_for_Tegra_64_tx1/kernel/ to find kernel_headers.tbz2, which I’m assuming is the kernel source I need.

In step 2 of the build instructions, it says to run:

make O=$TEGRA_KERNEL_OUT tegra21_defconfig

This gives me an error:

Can't find default configuration "arch/arm64/configs/tegra21_defconfig"!

Looking under arch/arm64/, the configs directory is not there.

Do I have the correct kernel source? Do I need to build tegra21_defconfig before rebuilding the kernel? I’ve also searched my JetPack build directory for the missing file, but it’s not there either… please help!

You have to download the kernelsrc separately if you plan on building the kernel from source.

It can be downloaded here.