On Fri, Dec 12, 2025 at 4:02 AM Radoslav Kolev via Grub-devel <[email protected]> wrote: > > The default ESP partition on some systems is limited in > space and storing a number of kernel and initrd images > can fill it up quickly. > > It's not always practical to increase the size of the > existing ESP, so the Boot Loader Spec defines a new Extended > Boot Loader Partition (XBOOTLDR) with GPT type GUID of > bc13c2ff-59e6-4262-a352-b275fd6f7172 to be searched for BLS > enties and UKIs in addition to the ESP. > > Currently searching for this partition is based on the $root > variable, but the spec requires for this partition to be on the same > device as the ESP. In many cases that would be the case for $root, but > there may be exceptions. After looking into it a bit I'm thinking it may be > better in this case to select the device to search based on $cmdpath instead > Please let me know your oppinion on this. > > More datails can be found at > https://uapi-group.org/specifications/specs/boot_loader_specification/ > > Radoslav Kolev (2): > blsuki: scan XBOOTLDR partition for BLS/UKIs if it exists > blsuki: search default location on XBOOTLDR partition, even if entries > found on ESP > > grub-core/commands/blsuki.c | 95 ++++++++++++++++++++++++++++++++---- > include/grub/gpt_partition.h | 7 +++ > 2 files changed, 93 insertions(+), 9 deletions(-) > > -- > 2.51.1 >
Would it be worth it to consider also searching the ROOT volume too (in /boot/loader/entries) similarly to XBOOTLDR, especially in the case where /boot is part of the main disk volume? This case exists in Fedora Cloud (F44+ as a Btrfs subvolume[1]), RHEL (RHEL10+ as a folder in the root XFS volume[2]), and SUSE distributions (where /boot is a folder in the root subvolume and contents of it are subvolumes[3]). It's now common enough that basic autodiscovery of those cases makes sense to be able to consider. [1]: https://fedoraproject.org/wiki/Changes/BtrfsBootForCloud [2]: https://docs.redhat.com/en/documentation/red_hat_enterprise_linux/10/html/10.0_release_notes/new-features-and-enhancements#Jira-RHELDOCS-18902 [3]: https://rootco.de/2018-01-19-opensuse-btrfs-subvolumes/ -- 真実はいつも一つ！/ Always, there's only one truth! _______________________________________________ Grub-devel mailing list [email protected] https://lists.gnu.org/mailman/listinfo/grub-devel
