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

[Eric van Gyzen]

On 12/16/2016 11:39, Slawa Olhovchenkov wrote:
> On Fri, Dec 16, 2016 at 06:08:34PM +0100, Fernando Herrero Carrón 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