Upgrading boot from GPT(BIOS) to GPT(UEFI)

[Antony Uspensky]

On Fri, 16 Dec 2016, Eric van Gyzen wrote:

> On 12/16/2016 11:39, Slawa Olhovchenkov wrote:
>> On Fri, Dec 16, 2016 at 06:08:34PM +0100, Fernando Herrero Carr?n wrote:
>> 
>>> Hi everyone,
>>>
>>> A few months ago I got myself a new box and I have been happily running
>>> FreeBSD on it ever since. I noticed that the boot was not as fast as I had
>>> expected and I've realized that, while my disk is GPT partitioned, the boot
>>> process is still BIOS based:
>>>
>>> % gpart show
>>> =>       34  976773101  ada0  GPT  (466G)
>>>          34          6        - free -  (3.0K)
>>>          40       1024     1  freebsd-boot  (512K)
>>>        1064        984        - free -  (492K)
>>>        2048   67108864     2  freebsd-swap  (32G)
>>>    67110912  909662208     3  freebsd-zfs  (434G)
>>>   976773120         15        - free -  (7.5K)
>>>
>>> I am reading uefi(8) and it looks like FreeBSD 11 should be able to boot
>>> using UEFI straight into ZFS, so I am thinking of converting that
>>> freebsd-boot partition to an EFI partition, creating a FAT filesystem and
>>> copying /boot/boot.efi there.
>>>
>>> How good of an idea is that? Would it really be that simple or am I missing
>>> something? My only reason for wanting to boot with UEFI is faster boot,
>>> everything is working fine otherwise.
>>>
>>> Thanks in advance for your help.
>> 
>> I am also interesting by this case.
>> I think expand freebsd-boot to about 1M (size of /boot/boot1.efifat),
>> dding /boot/boot1.efifat and set to type to 'efi' may be enough. I am
>> never tried this.
>
> I expect that would work.  It's slightly risky, though, since it doesn't let you
> fall back to BIOS boot if EFI doesn't work.
>
> Eric

I would shrink ada0p1 down to 128K (size of gptzfsboot = 88K now) and 
place efi partition (~800K) on free space between new p1 and p2. No need 
to touch swap partition.
A.