Ubuntu on UEFI and Win 8

[Avi Greenbury]

JD wrote:
> 
> On 01/06/2013 05:23 AM, william drescher wrote:
> >On 1/6/2013 6:02 AM, Colin Law wrote:
> >>Is there a definitive guide to dual booting Ubuntu with Win 8 with (or
> >>without?) UEFI BIOS?  It seems strange that neither [1] nor [2] make
> >>any mention of this but a couple of minutes googling suggests it is
> >>problematic.
> >>
> >>[1] http://www.ubuntu.com/download/help/install-desktop-latest
> >>[2] https://help.ubuntu.com/community/BootFromCD
> >>
> >>Colin
> >>
> >
> >This is not a definitive guide.  I suspect the problem is that
> >Win8 does not shut down when it shuts down.  A recent article in
> >Windows Secrets told how you can actually get it to shut down and
> >then if you do a cold boot you can choose which to boot.
> >http://windowssecrets.com/
> >
> >
> If you are using a uefi bios, 

UEFI is not a BIOS, it is a BIOS replacement.

> then the OS must have a Microsoft-issued signature
> in order for bios to boot it.

If it has secure-boot, which is an optional feature of UEFI, enabled
then it will only boot things which are signed with a key matching one
in its own keyring.

Windows 8 certified devices must have secure boot enabled and must
have at least the Windows 8 keys in them. Windows 8 certified devices
shipping hardware not supported by Windows 8 itself (i.e. requiring
non-MS drivers) will also need the keys from MS's signing service,
which is the means MS offer to have your software signed for approval
in this way, primarily aimed at OEMs who need to ship drivers.

> I do not know if Linux Distros will cave in and ask Microsoft to
> bless their Linux
> kernels with a MS issued signature.

MJG's 'shim' has been signed so, using MS's keysigning service, and
can effectively be used to boot arbitrary OSes. It should work on any
hardware that ships with non-MS drivers which doesn't include MS
Surface but will probably come to include most or all  non-MS hardware.

> On the Fedora mailing list, this issue was discussed to great lengths,
> sometimes with a great amount of acrimony and insults going back and forth.
> The thing that I remember one knowledgeable OP mention, is that if you
> disable the UEFI in Bios, then you can boot whatever you like,
> including Linux.

You would disable secure boot in UEFI. There is no BIOS and UEFI
itself has no necessity for secure-boot, it's Windows that does.

-- 
Avi