Hi there, For these like me who want to change their root filesystem to F2FS, I have enabled support for adding the F2FS module in the EFI signed image of grub in Debian (commit) . So the grub EFI image can load configuration, kernel images and initrd from a /boot that is formatted in F2FS (the upstream grub supports the filesystem since 2.04). Now that the kernel is loading it must be able to mount the rootfs. In Debian, a lot of features like some filesystems or some drivers are built as modules, this allow to be able to boot and work on a lot of different machines without have to build-in statically everything into the linux kernel image. This is why we use an initramfs , it offers a variety of cool features and detects magically some details for you like "load the brtfs module or your favorite emmc driver as module". If you want to use F2FS as your main filesystem on your rootfs, we need to add F2FS as base module into initramfs-tools (that handles all the scripts and