1

I wonder whether deleting EFI partition also erase the UEFI firmware that initialize hardware rendering boot mode impossible.

1 Answer 1

2

No, it will not brick your hardware. It is similar to overwriting the MBR in legacy BIOS systems: it makes that disk unbootable, so you will have to boot from some other media to reinstall a bootloader.

The UEFI firmware lives in the ROM or flash memory chip on the motherboard, while the EFI partition is the place on disk for UEFI-style bootloaders. Since UEFI bootloaders are essentially regular files, there can easily be more than one installed on the same disk, even on the same EFI partition.

The UEFI boot order information is stored in the system NVRAM (similar to BIOS settings), and is more detailed than with BIOS. It typically includes:

  • the PARTUUID of the EFI partition to boot from
  • the pathname of the bootloader *.efi on the EFI partition
  • a human-readable description
  • the partition number of the EFI partition and the absolute block number of its first block, and the size of the partition in blocks, for redundancy

In Linux, you can view this information by running efibootmgr -v as root, or modify it while the OS is running by using other efibootmgr options.

Sometimes this information can be lost, e.g. if the BIOS settings are cleared by removing the clock/NVRAM battery or shorting the "CMOS clear" jumper, or when flashing a new UEFI firmware version in some cases. This is a new kind of boot failure mode introduced by UEFI; however it is usually really easy to fix once you understand what is going on.

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .