GRUB Now Supports Multiple Early Initrd Images

GNU's GRUB bootloader has picked up another feature ahead of the GRUB 2.04 release expected later this year.

It's been almost one year since the GRUB 2.02 release while GRUB 2.04 continues being developed with new features and the latest addition landed just minutes ago.

This new addition to the GRUB 2.04 code-base is adding support for multiple, shared, early initrd images. These multiple early initrd images will be loaded prior to the proper initrd image -- with support for the Linux distribution specifying early initrd images and a separate hook for the user to specify any early images too.

Why do this? The primary use-case this was developed for is distributing CPU microcode updates for Spectre/Meltdown mitigation in this sane manner and allow them to be loaded very early by GRUB. It stems from this Gentoo bug report for trying to make it as easy as possible to load the Intel CPU microcode on the distribution.