3 Added paragraph about checking /sys/firmware/efi
source | link

If you've booted using the UEFI firmware as opposed to using BIOS firmware then your system should make the EFI NVRAM variables available in:

/sys/firmware/efi/vars/

or

/sys/firmware/efi/efivars/

When booting using a BIOS (or the BIOS emulation mode of UEFI firmware) then these variables aren't available.

In fact, as @Santropedro pointed out, the path

/sys/firmware/efi

is missing when booting using a BIOS, which is easier to check.

If you've booted using the UEFI firmware as opposed to using BIOS firmware then your system should make the EFI NVRAM variables available in:

/sys/firmware/efi/vars/

or

/sys/firmware/efi/efivars/

When booting using a BIOS (or the BIOS emulation mode of UEFI firmware) then these variables aren't available.

If you've booted using the UEFI firmware as opposed to using BIOS firmware then your system should make the EFI NVRAM variables available in:

/sys/firmware/efi/vars/

or

/sys/firmware/efi/efivars/

When booting using a BIOS (or the BIOS emulation mode of UEFI firmware) then these variables aren't available.

In fact, as @Santropedro pointed out, the path

/sys/firmware/efi

is missing when booting using a BIOS, which is easier to check.

2 should be /sys
source | link

If you've booted using the UEFI firmware as opposed to using BIOS firmware then your system should make the EFI NVRAM variables available in:

/procsys/firmware/efi/vars/

or

/procsys/firmware/efi/efivars/

When booting using a BIOS (or the BIOS emulation mode of UEFI firmware) then these variables aren't available.

If you've booted using the UEFI firmware as opposed to using BIOS firmware then your system should make the EFI NVRAM variables available in:

/proc/firmware/efi/vars/

or

/proc/firmware/efi/efivars/

When booting using a BIOS (or the BIOS emulation mode of UEFI firmware) then these variables aren't available.

If you've booted using the UEFI firmware as opposed to using BIOS firmware then your system should make the EFI NVRAM variables available in:

/sys/firmware/efi/vars/

or

/sys/firmware/efi/efivars/

When booting using a BIOS (or the BIOS emulation mode of UEFI firmware) then these variables aren't available.

1
source | link

If you've booted using the UEFI firmware as opposed to using BIOS firmware then your system should make the EFI NVRAM variables available in:

/proc/firmware/efi/vars/

or

/proc/firmware/efi/efivars/

When booting using a BIOS (or the BIOS emulation mode of UEFI firmware) then these variables aren't available.