Re: UEFI installation

[Mark Davies <mark%ecs.vuw.ac.nz@localhost>]

On 15/08/23 12:13, Greg Troxel wrote:
> It is an Optiplex 3070 SFF, from 2019, with 32 GB RAM and i7-9700 (9th
> gen) and Intel UHD Graphics 630.  It came with a Kingwin SSD with
> Windows which I swapped out for a bigger one I have more confidence in,
> and can only really handle a single 2.5" drive.

Yeah we have Optiplex 7070's from then.  BIOS will be the same.

> Have there been Dell or HP systems that don't let you turn off Secure
> Boot?  That would make them useless ;-(

Not aware of any Dell systems yet that don't allow you to turn Secure 
boot off.  That indeed would be an issue.


> It turns out that if you just turn off Secure Boot and leave the rest,
> it will boot UEFI off USB if present, and if not the internal SATA disk.
> There are options for "legacy option ROM" and MBR boot that confused me
> into thinking that it would not boot off USB without them, but I think
> they meant would not boot MBR from USB.

Yes switching secure boot off is the thing to do, as you note.
The "legacy option ROM" option controls whether it will let you do a 
legacy boot at all and in this generation only from external devices.

You can basically set it to three Boot modes:
    UEFI: Secure Boot On
    UEFI: Secure Boot Off
    Legacy  (external devices only).

Note that if you press F12 while booting you will get a one time boot 
menu that will let you select the device to boot from rather than just 
the first bootable device it finds in its list.

cheers
mark