[OpenIndiana-discuss] Status of UEFI boot support in OI-hipster-gui-20250606 installer

[James Madgwick]

I tried to reinstall on one of my machines today and afterwards it
would no longer boot with UEFI.

This machine had OI installed from a 2023 image using UEFI with legacy
mode disabled. It installed and booted using UEFI back then. I did not
do anything manually to get this to work.

After installing with the latest installer image (using the GUI
installer) it appears that UEFI support is no longer working correctly.

I found that despite booting the installer USB in UEFI mode, the
installation it created (I selected "use full disk") was actually using
an MBR partition table with no EFI partition - this is why I couldn't
boot after installing. After enabling legacy mode, I could boot this
new installation.

This seems to be a regression and a fairly significant issue, as many
new systems don't have a legacy mode at all.

Has anyone else experienced this, or is it a quirk with my machine and
newer snapshots? Any idea how to get the installer to use UEFI mode or
find out why it is incorrectly deciding to do a legacy install?

If this is reproducible, then we should update the docs with any
workarounds, else many people will end up with new installations that
won't boot.

Thanks, James