How to map partitions to a computer and not recognize them as a storage device by orin nx

[fu.qiang]

Now based on orin nx ubuntu debugging, it is necessary to plug the board into the computer to recognize the entire file system. Now when plugged into the computer, an L4T-README disk will be recognized, and the system partition will be/dev/loop0. Is there a way to map the system disk? Or map out a partition

[linuxdev]

The virtual USB devices are set up in “/opt/nvidia/l4t-usb-device-mode/”. The virtual network device and the virtual storage devices are in human readable scripts there, and then run as a service. You can see these with:
systemctl status nv-l4t-usb-device-mode.service

You can also stop and start that service with sudo. The service itself uses the nv-l4t-usb-device-mode-[start or stop].sh" scripts. This is not NVIIDA’s code, it is just setting up the Linux Gadget API. USB itself can work with custom hardware, but certain “standardized” classes have drivers provided which come with USB. For devices which follow those standards the Gadget template can be filled in to create virtual gadgets (devices). This is what that code does.

You can use more than one USB device on a single cable, and what you’re seeing is the setup of a network device and virtual storage.

Keep in mind that if you make your entire Jetson available, that you lose security. Everything would be exported as ext4 partition type, so Linux hosts would understand this, but Windows would not. It is quite possible that this would end up being run as root, and it might be that anyone with access to such a device could for example read and write password files or ssh setup and private keys. This is why one would normally set up a DMZ partition.

In the particular example a file is covered with loopback (which allows the loopback device to be treated as a partition or a disk), formatted as VFAT (so Windows can read it), and then that partition is named in the Gadget specification.