The GRand Unified Bootloader (GRUB) used in many architectures supported by RHEL (x86_64, aarch64 and ppc64le OF) is a fully featured bootloader that is able to initialize a variety of peripherals, read file systems from storage devices, access the network among other things.

All these features make GRUB a very flexible and powerful bootloader, but also to resemble an Operating System in terms of complexity. This comes with a maintenance cost, since not only bugs in all these drivers have to be fixed but also enabling new hardware means duplicating the effort in Linux and GRUB.

The goal is to replace GRUB with a Linux-based user-space bootloader, to have all these features but at the same time reduce the maintenance burden by relying on the existing support found in the Linux kernel and user-space tools. This would not only reduce the attack surface but also avoid duplicating the effort when enabling new functionality.

The assessment is still a work in progress so the requirements, tasks and risks are being written in this document.

A more detailed feature description will be added once this initial assessment is done.