When it boots, a screen pops up saying WARNING: Test Key is used. The screen then goes black and it boots ok most of the time but this morning it wouldn’t boot at all and I had to re-flash the SD card. I now have the same “Test Key is used” message as before.
Any ideas? I’ve looked through other forum posts and don’t seem to be able to find a fix. The Jetson and SD card are brand new, and it is the latest SD card image from the tutorial page.
I can’t give you a way to disable the message without causing other issues. Before I mention that, it might be useful to describe what the message really means.
Jetsons do not have a BIOS. On the SD card models the operating system partition is the only thing stored on the SD card. Everything which is the equivalent of what a BIOS would do, along with boot code, is in QSPI memory on the Jetson itself (think of this as partitions in another solid state memory device). When populating those “other” partitions during flash the partitions are signed with a key. Without the correct key, that content is refused.
On an eMMC model these would be actual partitions, but they use the same signing scheme. Jetsons all ship without security fuses burned, but a key is still needed: It is a NULL key, which the message is warning you about (this is what a test key is). There is no mechanism to remove the need for a key, there is only a mechanism to burn fuses for a one-time change to a private non-test key.
On SD card models you can’t actually burn any fuses. If this were an eMMC model, then you could set up a secret key and burn the fuses with that secret key, and the message would go away. That’s only for eMMC models, and it is a permanent (irreversible) thing, so it has consequences if you forget what the key is. I do not know any way to change this on SD card dev kit models. Maybe someone from NVIDIA can comment.
One reason for this arrangement with a difference between SD card models and eMMC models is that dev kits are not intended for commercial resale. Commercial products are intended to all derive from eMMC models, thus the less expensive SD card dev kit models don’t have the same exact setup as the eMMC models.
