QEMU runs a full-blown firmware (SeaBIOS or UEFI) so it does not need this. You can, if you want, pass the kernel on a command line but it's not the default.
However, Firecracker can only boot from a manually-provided kernel so you need this in order to boot from a partition. It is still not a complete replacement for e.g. Grub, which supports boot from various filesystems and from LVM, including encrypted logical volumes.
However, Firecracker can only boot from a manually-provided kernel so you need this in order to boot from a partition. It is still not a complete replacement for e.g. Grub, which supports boot from various filesystems and from LVM, including encrypted logical volumes.