I’m using a Jetson Xavier NX (16GB eMMC) module on a custom carrier board. I’ve modified the DTB and pinmux configuration to support booting from an SD card, and moved the rootfs to the SD card successfully. The system now boots from SD.
I created a .img of the SD card using dd. (56GB with all dependecies installed )
Can I use this .img to replicate the setup on another Xavier NX SOM (with SD card)? Or do I also need to modify the eMMC bootloader or DTB again on the new SOM?
What would be the best approach for replicating this system?
Keep in mind that Jetsons do not have an actual hardware BIOS. Everything required of a BIOS, along with boot content, must be compatible with the release in the SD card. Fully flashing a Jetson more or less also flashes the software equivalent of the BIOS. If that non-o/s content on the new Jetson of exactly the same model, then you can just use that SD card. If you flash a non-eMMC model with the same settings, then the SD card should work.
Sometimes boot is set to bind to a particular UID for disk or partition, and this might need editing. On rare occasions there will be a udev reference to a network MAC address, and in that case this would also need editing. For the most part you can use your cloned SD card for both old and new Jetsons of the same model.
If you’ve set up this non-o/s content once, then you don’t need to update it again in most cases if you don’t cross the major release version. L4T is what gets flashed, which is just Ubuntu with NVIDIA content; JetPack/SDK Manager is the front end to the flash software. If your L4T release is R32.x and the SD card is for that, then minor changes in the SD card won’t need an actual Jetson update; if L4T is R35.x, and the SD card is R35.x, then you won’t need an actual Jetson update; if there is a cross between R32.x and R35.x, then you definitely will need to update the Jetson itself to accommodate that major release version difference.