How to disable UEFI ??

[Brian Cluff]

That sounds like the exact problem I was describing that most people 
encounter.  People new to UEFI don't realize that you have to have a 
special partition with a file type of "EFI System" and formatted with 
vfat to store boot loaders.  There's even a lot of people that have done 
a bunch of installs where they over wrote windows also don't realize 
that they have to have that partition either since it already existed on 
the drive from factory.  You can also run into problems if you use the 
legacy MBR style of drive since UEFI requires GPT in order to boot 
properly... and switching from one to the other isn't very obvious.  
That switch ate a day of my life once before I realized what I did wrong.

Like I said it a completely different way to booting and it's takes a 
bit to wrap your head around but once you understand it you realize it's 
a much better system than the old system of poking a few bytes of code 
at the beginning of a drive that will hopefully bootstrap into a boot 
loader as long as everything lines up and stays lined up and nothing 
overwrites those first few bytes with something else that point to a 
different place and your boot loader doesn't get moved around or put too 
far into the drive where it can't access it any more.

With UEFI, you just put your boot loader into the EFI partition and 
register it with UEFI system and your done.  You don't have to worry 
about finding any and all other operating systems loaded in the system 
so you can create boot entries for them, so that you can continue to 
access those other OSes.  In fact you can have multiple different boot 
loaders for the same system loaded in parallel, in case you would like 
to load a new one while still keeping your GRUB system intact.

Now if UEFI accessible for visually impaired persons and BIOS was, 
that's something that needs to be fixed.  I was under the impression 
that neither of them had any accessibility features, but from what I've 
seen of UEFI if either of them had accessibility features I would have 
thought that UEFI would be the one since there is usually a command line 
mode that UEFI can be put into with the gui simply being a wrapper for it.

Brian Cluff

On 05/05/2018 09:51 PM, Eric Oyen wrote:
> that's weird. I must have a broken implementation here then. the machine I tried to replace a HDD on was a windows laptop with a completely blank disk (not even a filesystem) and the machine wouldn't even allow me to install an OS there from Windows, Linux or even one of the BSD's.  It took someone here telling me that the UEFI screen showed the following error: no EFI partition present.