From: BitTwister@mouse-potato.com   
      
   On Mon, 13 Jul 2020 14:27:07 +0200, Andrew wrote:   
   > Given a Linux-only system running on two discs (SSD and "normal"), I   
   > have been trying to work out how to change things to use the UEFI boot   
   > mechanism.   
   > The SSD ( /dev/sda ) has room to spare, although not at the start of the   
   > drive.  The system-main partition is also on that drive.   
   > The only instructions I have seen are for Debian-based systems.   
   > I'm aware that I could do an initial install - re-partitioning the SSD -   
   > and that would get me there, is that the only way?   
      
   As I misunderstand it, your boot loader looks for a partition with a   
   certain UUID/GUID. As a result of that you can have the "UEFI" partition   
   pretty much where you want it.   
      
   For example, I am running Mageia Linux, bios is set to legacy OS/CSM.   
   For grub to be able to boot the system, I created the bios grub partition   
   on the end of the drive.   
      
   In my stupid opinion, you could do the same thing without having to   
   re-partition the drive.   
      
   If it were I, I would boot a system rescue, click the Gparted icon   
   bottom left in task bar, shrink a partition some where, then set the   
   flags on the new partition as desired.   
      
   That should set the UUID to the value need for UEFI booting.   
   If not, you can use Gparted to set the desired value.   
      https://en.wikipedia.org/wiki/BIOS_boot_partition   
      
   Be aware you still need to get the partition filled with the desired   
   software.   
      
   Download link at  http://www.system-rescue-cd.org/   
   contains instructions on burning iso to thumb drive if desired.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)