UEFI stands for Unified Extensible Firmware Interface. It's a modern replacement for the traditional BIOS (Basic Input/Output System) firmware found on most computers. UEFI provides more functionality and flexibility compared to BIOS, including:

  • support for larger hard drives
  • faster boot times
  • improved security features
  • support for newer hardware standards

UEFI firmware is stored on a special non-volatile memory chip on the motherboard of a computer, known as the SPI (Serial Peripheral Interface) flash memory. This memory chip holds the UEFI firmware code and data necessary to initialize hardware components and boot the operating system.

Faster boot then legacy BIOS

Check if system is using UEFI

ls /sys/firmware/efi

Check boot order

# View entries

BootCurrent: 0000
Timeout: 1 seconds
BootOrder: 0003,0000,0006,0007,0002,0001
Boot0000* ubuntu
Boot0001  Network Card
Boot0002* UEFI: Built-in EFI Shell
Boot0003  Hard Drive
Boot0006* ubuntu
Boot0007* UEFI OS

# Changing Boot Order
sudo efibootmgr -o 0013,0012,0014

# Add entry
sudo apt install grub-efi
sudo mount /dev/sda7 /boot/efi/
sudo grub-install /dev/sda --target=x86_64-efi --efi-directory=/boot/efi/

# Deleting entry
sudo efibootmgr -b <bootnum> -B

/boo/efi during installation

root@supermicro:~# cat /etc/fstab
# /etc/fstab: static file system information.
# Use 'blkid' to print the universally unique identifier for a
# device; this may be used with UUID= as a more robust way to name devices
# that works even if disks are added and removed. See fstab(5).
# systemd generates mount units based on this file, see systemd.mount(5).
# Please run 'systemctl daemon-reload' after making changes here.
# <file system> <mount point>   <type>  <options>       <dump>  <pass>
# / was on /dev/sdb2 during installation
UUID=d007fa48-229f-40d9-a1d1-b7e90a2249ac /               ext4    errors=remount-ro 0       1
# /boot/efi was on /dev/sdb1 during installation
UUID=FEB1-680E  /boot/efi       vfat    umask=0077      0       1
# swap was on /dev/sdb3 during installation
UUID=fc18ccfa-e8da-400d-9ab7-8e7fe19e9056 none            swap    sw              0       0