Usage: grub-mount [OPTION...] IMAGE1 [IMAGE2 ...] MOUNTPOINT
Debug tool for filesystem driver.

  -C, --crypto               Mount crypto devices.
  -d, --debug=STRING         Set debug environment variable.
  -K, --zfs-key=FILE|prompt  Load zfs crypto key.
  -r, --root=DEVICE_NAME     Set root device.
  -v, --verbose              print verbose messages.
  -?, --help                 give this help list
      --usage                give a short usage message
  -V, --version              print program version

Mandatory or optional arguments to long options are also mandatory or optional
for any corresponding short options.