I’m having an issue updating the device tree on my nano. I have many running this version, and have to stick with that version:
NVIDIA Jetson Nano (Developer Kit Version) L4T 32.2.0 [ JetPack 4.2.1 ] Ubuntu 18.04.3 LTS Kernel Version: 4.9.140-tegra
I would like to enable spi, and this requires a device tree update. I have the
.dtb file I would like to flash. First, I tried updating
extlinux.conf to add an
FTD entry, which had no effect after a reboot. I found somewhere that this version doesn’t support the
FTD flag, which is very unfortunate, and finally discovered the
DTB partition which stores the encrypted and signed device tree file.
I have managed to produce an encrypted and signed
.dtb, and flashed that partition, but after a reboot, it still has no effect. I tried writing junk to that partition and removing all
/boot/*.dtb files to see if it was loading it from somewhere else, and finally realized that it must be storing it in the
qspi storage, and I have to figure out how to overwrite that.
I have two questions:
Is there a way to make the
extlinux.confentry work so I can specify an unecrypted and unsigned
.dtbfile? I read somewhere about
security fuseswhich I didn’t fully understand, but if I can reset these and regain control of the device tree, I would like to. Even if I can just get the bootloader/kernel to read the device tree from the
DTBpartition, that would be ideal.
Is there a simple way for me to flash the
qspi? I’m guessing
flash.shis able to do it. Is there a way to avoid going into recovery mode? If
flash.shis able to do this, is there a subcommand that I can run directly? Also, with
flash.sh, does it matter what version I use? Should I use the version for the software that I’m running, or will it not matter?