[ltp] Advice on UEFI vs. BIOS

Steve McIntyre linux-thinkpad@linux-thinkpad.org
Fri, 23 May 2014 16:22:59 +0100

On Wed, May 21, 2014 at 06:39:35PM +0200, Jochen Spieker wrote:
>I decided to overcome my doubts and order an X240. It still appears to
>be the best option with respect to battery life and screen resolution
>for a laptop of that size.
>Anyway, I plan to re-use my existing SSD (128GB Samsung 840 Pro) which
>is currently formatted using a traditional partition table. That's why I
>ordered my X240 with the cheapest disk option available, a 500GB
>spinning disk. Could you please verify whether my assumptions are
>- Debian testing/unstable supports UEFI in general. I just have to
>  disable Secure Boot in the "BIOS".

Correct, yes. We haven't done anything (yet) in Debian for Secure Boot

>- Debian testing/unstable (with or without Windows in the same disk)
>  does not brick an X240 anymore, provided I use the most recent BIOS
>  from Lenovo.


>- UEFI requires a GPT which means I will have to reformat my old SSD
>  using GTP and transfer my data afterwards. (What about grub?)

Nope, UEFI should also work with a DOS partition table. However,
you'll want a FAT(32) partition on the disk to use as the EFI System
Partition. That may well mean you'll end up needing to re-partition
and reformat anyway. :-/

Grub: You'll want to install the grub-efi package and remove the
grub-pc package. To do that, you'll need to boot in EFI mode once (use
an installer CD to boot in rescue mode), then from there install
grub-efi and it should do the right things. The system already needs
to be in EFI mode for grub-efi and efibootmgr to work correctly.

>- And, a little off-topic: I cannot easily transfer the Windows 8
>  installation to my SSD, even if I were to sacrifice the precious space
>  on my (comparably tiny) SSD.

Pass, I don't do Windows. :-)

Steve McIntyre, Cambridge, UK.                                steve@einval.com
"I suspect most samba developers are already technically insane... Of
 course, since many of them are Australians, you can't tell." -- Linus Torvalds