I just wanted to drop a note that could be helpful in case you are running into issues flashing you AGX Xavier.
Last night, I successfully flashed my unit using an Ubuntu VM on a Windows 10 host using VMWare. It will only work with VMWare because it seems to manage USB-C connections better than VirtualBox (Host can see it but it can’t pass it to the Guest) and Hyper-V (does not handle USB-C Connections at all due to an inherent limitation of Type-1 hypervisors).
The ‘trick’ was to install VMWare but ensure you’ve selected USB passthrough. Then once you connect the AGX Xavier to ensure the Linux guest can see it using lsusb in the Terminal.
From there, just follow the steps to install and flash using the SDK Manager.