Using cboot as bootloader

[Applicable to L4T R32.1.0 and later]

For Jetson AGX Xavier, NVIDIA provides only cboot as the bootloader, so there is no U-Boot recipe for that platform. For Jetson TX2, the default configuration uses both - cboot loads U-Boot, which then loads the Linux kernel. You can, however, use just cboot as the bootloader by setting

PREFERRED_PROVIDER_virtual/bootloader = "cboot-prebuilt"

in your build configuration. If you do this, cboot directly loads the Linux kernel and initial ramdisk from the LNX partition, and the kernel image is not added to the root filesystem.

Building cboot from sources

NVIDIA has, from time to time, made cboot source code available. For Jetson AGX Xavier platforms, the most recent source release was with L4T R32.2.3, published in the L4T public_sources archive.

Older releases (R28.x for TX2, R31.1 for Xavier) were restricted downloads. You must use your Developer Network login credentials to download the source package from the appropriate L4T page on NVIDIA's website and store that tarball on your build host. The NVIDIA_DEVNET_MIRROR variable is used to locate the sources; see the recipes for more details on naming.

To use cboot built from source in your build, set

PREFERRED_PROVIDER_virtual/bootloader = "cboot"