Hey Gerd, On Fri, Jun 12, 2026, at 2:10 PM, Gerd Hoffmann wrote:
> This should not be needed. According to the boot loader spec a snippet > is optional for UKIs. The boot loader should pick up all UKI images in > EFI/Linux without config entries. It is allowed to add a snippet if > needed, for example to add command line arguments. > >> The generic UKI that fedora ships has only `console=tty0 >> console=ttyS0` on its kernel command line. In order for it to actually >> boot on your system, it needs more information, like the root >> filesystem UUID, > > This is not needed. Make sure the 'bli' module is included in the list > of modules for cc grub. With that the initrd should find the root > filesystem partition just fine if it is properly tagged: > > kraxel@fedora ~# sudo fdisk -l /dev/sda > [ ... ] > /dev/sda3 3328000 33552383 30224384 14.4G Linux root (ARM-64) > ^^^^^^^^^^^^^^^^^^^ > > When using btrfs the root sub-volume must be the default volume for that > to work. Yes, and any subvolumes that people want to be auto mounted should be nested under the default subvolume. Note that AFAIK Anaconda does not support creating nested subvolume layouts in `btrfs` and thus to keep compatibility none of the Fedora deliverables use such a layout (even when Anaconda is not-in-the-loop) except the Cloud UKI variant. There's also other arguments (`rootflags=compress=zstd:1`, as an example I guess) that might need to be included which can break the boot for a UKI if add-ons are not in use. Generally from what I've seen there's a reasonably tight coupling between the (potential) bootloader, UKI, and filesystems. > With CoreOS this is probably a bit different because it expects to get > the ostree root hash (which is not fixed) passed on the kernel command > line. So CoreOS probably has to actually do the addon signing dance, or > find some alternative way such as systemd credentials to configure this. No longer the case with the composefs native backend; I *assume* CoreOS is going that route as that's the route `bootc` sealed containers are taking at the moment (which use `systemd-boot` + UKI). There are still some plans or ideas to have `bootc` generate or select UKI add-ons as bootable containers could be deployed to any partition layout or filesystem layout and we don't want to couple them to a specific one. Regards, Simon -- _______________________________________________ devel mailing list -- [email protected] To unsubscribe send an email to [email protected] Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/[email protected] Do not reply to spam, report it: https://forge.fedoraproject.org/infra/tickets/issues/new
