This repository contains boot-related tools for Tegra platforms, which augment and/or replace the boot control and bootloader upgrade tools provided in the L4T BSP for Jetson TX2 and Xavier platforms.
The tegra-bootinfo tool provides a simple boot-count mechanism.
The native bootloaders on the TX2 and Xavier have some support for
automatic failover in the event of a boot failure, but they give up
after some number of failover attempts, eventually placing the device
in recovery when the limit is exceeded - not a desirable outcome
if the device runs unattended and is possibly subject to power outages
that can happen at boot time.
The tega-bootinfo tool is intended to be run from the initrd on
these systems. It records (in a sector of the eMMC, or in the QSPI
boot flash on Xavier NX development kits) that a boot is in progress,
and notifies the NVIDIA bootloader that the boot was successful (marking
the boot slot successful and setting its priority to 15).
A second invocation of tegra-bootinfo should be used at (or close to)
the end of the system startup sequence to record the successful completion
of the start of the OS.
Service unit files (bootcountcheck.service for the early boot phase and
update_bootinfo.service for the later boot phase) are provided, as is
a bootcountcheck script that can be used directly in non-systemd
initramfs environments for the early check.
The tool also supports storage and retrieval of named strings, similar to U-Boot environment variables. The number of flash sectors allocated for variable storage is configurable at build time.
On T210 (Jetson TX1 and Nano) systems, U-Boot can be configured provide the boot count mechanism and appropriate failover behavior. This tool will work on those systems as well, however.
This tool can be used to parse a bootloader update (BUP) payload generated
by the Tegra flashing tools, as well as program the appropriate contents
of a BUP payload into the boot partitions. It can replace the
nv_update_engine tool provided in the L4T BSP for tegra186/tegra194
platforms, and the l4t_payload_updater_t210 tool on tegra210
platforms.
- No need for the
/etc/nv_boot_control.conffile. The TNSPEC used to determine boot component compatibility is directly derived from the CVM EEPROM contents. - No
nv_update_verifierservice at boot time. Such a service could be implemented, if desired, but for full A/B upgrades that include the rootfs, the verify-and-overwrite feature of the L4T update verifier is undesirable. - The tool can be used to completely initialize all boot components, provided the BUP payload contains all of them (default BUP generation in L4T does not do this).
- This tool compares the contents of each boot component from the current content before updating and skips unneeded writes, saving update time on Xavier NX systems that store boot components in QSPI flash.
- This tool automatically enables A/B redundancy during an update if it has not yet been enabled.
- Written in C, rather than Python.
- Boot partition information is read from a configuration file at runtime, rather than being hard-coded into the tool.
- Automatically handles either SPI flash or eMMC boot partitions, without depending on the MACHINE name as the Python tool does.
This tool replaces the nvbootctrl program provided with the L4T BSP,
and can be used to display or modify the boot slots on a tegra186
or tegra194-based platform.
- The interface is different, using option specifiers instead of commands.
Output from the the
--statusoperation uses different formatting thannvbootctrl dump-slots-info. - For the
--mark-successfuloperation, if the boot slot being marked successful is also the current boot slot, the slot priority is automatically reset to the highest value (15), rather than requiring a separate--set-activeoperation to do this, which ensures that the current boot slot remains the default active boot slot on subsequent reboots.
This package uses GNU Autotools to build. If you have cloned the repository,
you should use autoreconf -i to generate the configure script and other
files needed to configure and build.
This package depends on systemd, libz, and tegra-eeprom-tool.
For tegra210-based platforms, a configuration file enumerating the boot partitions, with offsets and sizes, is expected at runtime. This file should be generated from the flash layout XML file for the target.
Distributed under license. See the LICENSE file for details.
Header files under the nvidia/t18x and nvidia/t19x directories are from NVIDIA, with a BSD 3-clause license. See the individual header files for details.