New UEFI guide on the wiki

[Chris Murphy]

On Feb 4, 2014, at 12:49 PM, Andrew Lutomirski <luto at mit.edu> wrote:

> On Tue, Feb 4, 2014 at 11:28 AM, Adam Williamson <awilliam at redhat.com> wrote:
>> On Tue, 2014-02-04 at 10:03 -0800, Andrew Lutomirski wrote:
>> 
>>> This reminds me: I *always* install with a GPT partition table, an ESP
>>> partition, a BIOS Boot partition, and a smallish (1 or 2 GB) ext4
>>> /boot near the beginning of the disk.  All Linuxes seem perfectly
>>> happy to install this way (assuming you can figure out how to
>>> partition the disk like that in the first place) and booting that way
>>> in BIOS or EFI mode.  Given that this wastes at most a few MB, should
>>> anaconda just partition like that by default?
>> 
>> Definitely not. We tried doing BIOS installs to GPT disks by default in
>> Fedora 16, and it was basically a complete disaster.
> 
> What failed?

Firmware face planted. For many it was the lack of an MBR entry with an active bit set, so there is now this PMBRboot flag where the 0xEE has an active bit set. And that pisses off other firmware. So it's no win.


>  I'm guessing that userspace improvements since then have
> mostly fixed this.

It wasn't a user space problem. It was a firmware problem.


>  I've never seen any problem on F18 (IIRC) and up
> with GPT partition tables being BIOS-booted.  It seems to Just Work
> (™).

None are Lenova computers are they?

> 
> Also, isn't this already sort of necessary on large disks?

Yes but long ago Microsoft's edict was basically GTFO and buy a new computer with UEFI if you want to boot from 2+TB drives. The Windows installer requires MBR for boot disks on BIOS computers. And it requires GPT for boot disks on UEFI computers.

Since most firmware testing involves seeing if Windows installs and boots successfully, it essentially means there's a lot of BIOS hardware out there that simply will not support 2+TB drives for booting, ever.


> (I maintain at least ten machines like this, running Fedora and
> various Ubuntus, some installed graphically and some installed by
> untarring a system image.  I haven't had any problem at all.)

Karma.


Chris Murphy