How to netboot Ubuntu 26.04

The Ubuntu 26.04 (resolute) images are compatible with NBD out of the box, but have a slightly different layout in their boot partition which requires some changes to how nobodd-prep is called.

Boot assets under current/

Ubuntu 26.04 (resolute) has a new layout on the boot partition, implementing A/B boot. Many of the boot files remain in the root of the boot partition, but some have moved under a directory named current/. In particular, for the purposes of preparing an image with nobodd-prep, the cmdline.txt file is now current/cmdline.txt.

Thus, when preparing an image for use (as in the Tutorial), you also need to specify the nobodd-prep --cmdline parameter, like so:

$ nobodd-prep --nbd-name ubuntu-noble --serial 10000000abcd1234 \
> --tftpd-conf tftpd-noble.conf --nbd-conf nbd-noble.conf \
> --cmdline current/cmdline.txt \
> ubuntu-26.04-preinstalled-server-arm64+raspi.img

Warning

Please note this section has been written in anticipation of resolute’s forthcoming release and thus may be wildly inaccurate! In fact, at the time of writing, the current daily images aren’t booting successfully with nbd.