On Sat, Aug 10, 2019 at 09:12:23PM +0100, Chavdar Ivanov wrote: > I was thinking that if ZFS were in the kernel, it might be easier to > get ZFS root.
You don't need to build ZFS into the kernel to boot it as a root mount (same for FFS). The code to load modules from the bootloader already exists. You do, however, need to write/port the functionality to do a root mount, and teach the bootloader to read ZFS to find the kernel (unless you use EFI boot, then maybe put the kernel on the FAT partition).
