Monday, October 17, 2011

Problems with the Thinkpad X220 and GPT, UEFI, MBR and Legacy BIOS Booting

Crucial M4 SSD Thinkpad X220 7mm ModAfter several days banging my head against a brick wall and suffering the indifference of Lenovo/IBM tech support I have learnt a lot about UEFI, in regards to the X220 in particular.
  1. The X220 cannot/will not boot GPT disks using Legacy BIOS. I would call this a bug.
  2. The X220 will not boot /efi/*/*.efi unless "signed"(?) into BIOS, you have to copy it to /efi/boot/bootx64.efi. I guess this is a security feature, but I'm not sure how secure it is if you can bypass it so easily.
  3. Disabling the BIOS setting "USB UEFI BIOS Support" disables *all* USB booting, ie, both UEFI and legacy BIOS. If this isn't a bug then
    1. it at least needs relabelling,
    2. could be moved/linked to the boot menu and
    3. is redundant as you can disable USB booting using the Boot menu.
I should say that this was with BIOS version 1.22 (I think).

I recommend following these instructions to create a very useful and versatile boot disk for diagnosis.

If you want to use the X220 UEFI boot menu I recommend disabling booting from LAN as it adds a few seconds to the boot time. You have to disable it in several places in the BIOS to avoid the wait.

See also my more general post on Arch Linux on the X220.

3 comments:

Ethan Schoonover said...

Jamie, I just spent some time developing an automated Arch install script for a pure EFI setup on my own x220 tablet. At minimum there only need to be two partitions in my setup, and the EFI boot partition doesn't need an EFI directory anymore. It took me a while to get to this point and you might already be aware of this method, but I thought it would be good for those that find you blog to stumble on the relevant forum thread as well.

The script thread is on the Arch BBS:
https://bbs.archlinux.org/viewtopic.php?id=129885

and the actual script is on github:
https://github.com/altercation/arch-by-hand

Jamie said...

To be honest I think it would have been fine if I'd just started with the archboot install disk, as I could have used UEFI from the beginning. The problem was that I was moving my current installation from BIOS to UEFI.

btw, does anyone really use swap any more? Especially on SSDs?

Antony said...

I have the same situation as you did, back into June 2011. I managed to write it on my blog which is in Chinese language but I found its so complicated to explain them all.
My solution was no solution and I had chose to move all my GPT partitions to legacy BIOS partitions.

I used Intel M2 SSD on my Thinkpad Edge 14. And I later bought X220 and migrated the SSD to my X220. I have been like you consider to use eSATA SSD and to keep the harddrive. But there were not to many eSATA SSD in the market.