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Re: [OCLUG-Tech] trying to install centos 6.5 on USB drive on UEFI-enabled laptop

  • Subject: Re: [OCLUG-Tech] trying to install centos 6.5 on USB drive on UEFI-enabled laptop
  • From: Alex Pilon <alp [ at ] alexpilon [ dot ] ca>
  • Date: Tue, 31 Dec 2013 14:20:48 -0500
I am not an EFI expert. Assume little of me in that regard.

On Tue, Dec 31, 2013 at 06:22:41AM -0500, Robert P. J. Day wrote:
> >  I have no experience booting Linux under UEFI but am interested in
> > your experience as I await the arrival of a new Zenbook which I plan
> > to dual-boot Win8 and likely Fedora 20.
> 
>   yes, i'll want to know how to do things like that as well, so we
> should start collecting notes.

Tried to fix Ubuntu 13.10 (I disclaim being a Ubuntu user myself) on
Eric Brackenbury's Thinkpad x120e. If anybody has that model, don't
bother trying to install under EFI, unless you can somehow get past the
automatic recreation of boot entries, not reclaiming space immediately
upon deletion of EFI variables, running out of space for EFI variables
such that one can't even add new boot entries, etc. Ended up just
forcing CSM boot only.

At least it wasn't a certain Samsung firmware from a few years ago where
using up more than half of the space for pstore and EFI vars would brick
the firmware. Samsung even had the gall to turn around and blame Linux
for it, and not refund customers.

> >  One thought that occurs to me after reading through your install
> > process is that the installed USB drive will be unbootable following
> > the OS install as it will be lacking a EFI System Partition.
> 
>   i thought that might be the case as well, but with only the target
> USB drive inserted in the laptop, when i booted and stopped in the
> BIOS, i had three possibilities under "Boot Override":
> 
>   * Windows Boot Manager ...

Speaking of such boot entry, I've read, but can't recall where, that
some firmwares apparently are so cruddy, they use
\EFI\Microsoft\Boot\bootmgfw.efi that as their fallback, or hardcode it
as the only boot entry.

> so the sony USB drive apparently shows up as both a UEFI and non-UEFI
> device, and i simply selected the non-UEFI choice, and it booted just
> fine.

Does the EFI choice work too? Hybrid install media are quite feasible.
That's what archiso does too:

* https://projects.archlinux.org/archiso.git/commit/?id=9069e2c103555520aa92954e9f4cf9a392925e5b
* https://projects.archlinux.org/archiso.git/commit/?id=6caa5bcb69037442fac2b30ac5b20e4350a11056
* https://projects.archlinux.org/archiso.git/commit/?id=d902b8f32c58823fa8fa9f769e3603cfad657329
* https://projects.archlinux.org/archiso.git/commit/?id=f19f6173c8650ebc43dc166ee2a2f3f92a753afe

Anybody familiar wih El-Torito and EFI here?

> if anyone has pointers to good intros to the topic, let's hear them.

I highly recommend Rod's Books, which was already mentionned in a
previous thread.

See above and below:

* http://www.uefi.org/specs/access
* http://www.intel.com/content/www/us/en/architecture-and-technology/unified-extensible-firmware-interface/efi-homepage-general-technology.html
* http://wiki.gentoo.org/wiki/UEFI_Gentoo_Quick_Install_Guide
* http://sourceforge.net/apps/mediawiki/tianocore/index.php?title=Welcome

Some tools:

* http://freedesktop.org/wiki/Software/gummiboot/
* https://github.com/vathpela/efibootmgr
* https://fedoraproject.org/wiki/Testing_secureboot_with_KVM
* http://www.linuxfoundation.org/news-media/blogs/browse/2012/10/linux-foundation-uefi-secure-boot-system-open-source
* https://wiki.archlinux.org/index.php/Syslinux#UEFI_Systems (nothing of
  note on the Syslinux wiki)

The Ubuntu documentation has a few snippets that may be of use:

* https://help.ubuntu.com/community/UEFIBooting
* https://help.ubuntu.com/community/UEFI

I wouldn't recommend using GRUB 2 though, under any circumstances except
for dealing with Secure Boot if there is no alternative. GRUB 2 is an
overcomplicated mess. Just use the core of Syslinux (version 6, which of
course was neither in of the Ubuntu or Debian repositories), Gummiboot,
or rEFInd (if on Mac, and not rEFIt, which is no longer maintained).
The sooner changes in bootloader forks get upstreamed, the better. Ditto
for other boot managers and bootloaders supporting Secure Boot. 

Also, don't buy an EFI computer with an NVIDIA card and expect the
proprietary driver to work.

Regards,

Alex Pilon

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