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

[Slawa Olhovchenkov]

On Fri, Dec 16, 2016 at 11:43:18AM -0600, 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 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.

Live cd/USB can be fallback for this case.