Fedora 40 is eyeing the next phase of its unified kernel (UKI) support within the distribution that will include the ability to support booting to unified kernel image files directly without having to go through a traditional bootloader like GRUB or SD-Boot.

The second phase of Fedora's unified kernel support is looking at a boot path from the EFI SHIM to UKI directly without any bootloader present. The UEFI boot configuration will get an entry for each kernel installed, newly-installed kernels are configured to be booted once but will then be made permanent after a successful boot, and also enabling UKI support for 64-bit Arm (AArch64).

This latest UKI work for Fedora will lead to better UEFI Secure Boot support, better supporting TPM measurements and confidential computing, and a more robust boot process.

Those interested in the latest UKI efforts for Fedora 40 can see this Fedora mailing list thread with more details.