The openSUSE project has recently announced a significant change in its Tumbleweed rolling-release distribution by making GRUB2-BLS the default bootloader for new installations in UEFI mode. This transition means that users installing openSUSE Tumbleweed on UEFI-based systems will automatically have GRUB2-BLS set as their bootloader by the YaST installer, especially beneficial for those utilizing full disk encryption (FDE) with systemd.
GRUB2-BLS, which is a modified version of GRUB2, was specifically patched by the Fedora project for compatibility with the Boot Loader Specification (BLS). This update allows boot entries to be stored as small text files in the /boot/efi/loader/entries directory. An important advantage of GRUB2-BLS is its ability to dynamically generate the boot menu at boot time, eliminating the need for manual configuration commands like grub2-mkconfig or grub2-install.
OpenSUSE’s system will manage the upgrade process seamlessly, particularly when integrated with the btrfs file system, utilizing sdbootutil update to manage snapshots and bootloader updates transparently. The GRUB2-BLS architecture involves a single EFI binary located in /boot/efi/EFI/opensuse, containing all essential components such as modules, configurations, fonts, and themes that were previously scattered in /boot/grub2.
Users can also modify kernel command line arguments effortlessly by adjusting the bootloader or the /etc/kernel/cmdline file, followed by running the sdbootutil update-all-entries command to implement their changes.
While technically feasible, upgrading existing systems from GRUB2 to GRUB2-BLS is not recommended due to potential complications regarding the size of the EFI System Partition (ESP). Users are encouraged to consult the official migration instructions for more detailed guidance.
For further details on the GRUB2-BLS announcement, visit the official openSUSE news page.