Linux · GRUB & Boot Process

With UEFI Secure Boot active, GRUB is not the first thing EFI runs. What runs before it, and why was that extra step introduced?

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More in GRUB & Boot Process

On a BIOS-based machine, you swap out a failed software-RAID disk, add its partitions back with mdadm, and the array resyncs cleanly. Why can that disk still fail to boot the machine?

You want to encrypt an entire Linux system including the root partition. Why can't you simply encrypt every partition and be done?

What role does GRUB play the instant a PC is switched on, and what three jobs does it handle?

On an EFI computer with three operating systems installed side by side, which component actually decides which OS boots — and where does that leave GRUB's menu?

On an EFI machine, where does GRUB's code physically live, and what must be true of that partition?

The kernel file is named /boot/vmlinuz. What does the trailing z signify, and what single parameter must the bootloader always pass to it?

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