These are my notes for the L4T 3.0 installation, there are newer versions now available but keeping these details around.
This is also the first step for installing Fedora, L4T will be used to bootstrap. The L4T instructions, for reference, are here.
# Insert your microsd-card, 32+ GB # Find the microsd-card device, write the image, it's 13GB decompressed. # Took here for me 133min (Samsung EVO 64GB) or 17min (Toshiba 32GB) cat /proc/partitions 7z x switchroot-ubuntu-3.2.0-2020-10-05.7z pv switchroot-ubuntu-3.2.0-2020-10-05 >/dev/mmcblk0 # mount the card, unzip hekate, copy hekate. # Warnings about permissions not being copied are normal, as this is FAT32. mount /dev/mmcblk0p1 /mnt/tmp unzip hekate_ctcaer_5.1.4_Nyx_0.8.7.zip tar cf - bootloader/|(cd /mnt/tmp && tar xfv -) umount /mnt/tmp