Add support for version update on netboot

  • When the "boot" argument on cmdline.txt points to ISCSI, NBD or NFS, then updates are not supported and the file "/dev/.update_disabled" is created.

    What is the reason for this? If done properly, a networked boot should be upgradable.

    Please, add an option to cmdline.txt for allowing upgrades when using a networked boot.

  • Netbooting is used by a microscopic percentage of our total users, and zero project staff. As long as we continue to receive the occasional "it still works" post when we make major changes there's no reason for us to remove netboot support, but we're equally not looking to expand support. Sorry.