[clug] UEFI BOOTING?

[Paul Wayper]

On 23/1/19 9:51 am, Chris Smart via linux wrote:
> On Tue, 22 Jan 2019, at 21:55, Peter Ellis via linux wrote:
>>>
>>> Maybe I asked before. Can I or HOW can I boot past UEFI, say with a USB2
>>> or 3 drive? I've not found any advice that looks positive. (I now have an
>>> effectively dead elcheapo device that I'd like to recover docs from if I
>>> can get in with a recovery USB.
> 
> If you have not configured your UEFI to support legacy booting (CSM mode) then your USB boot device needs to be UEFI compatible and  potentially support Secure Boot if you didn't turn that off  (Fedora Live images are).

I recently had to be a bit trickier with getting to boot my laptop off a USB
key.  I couldn't get to the UEFI 'select a boot device' screen, for
complicated reasons not relevant here.  However, I could get to GRUB 2's boot
screen.  I then used its command prompt and 'ls' command to find the USB
device and file system that contained the device I wanted to boot off, and
found its /EFI/BOOT/grubx64.efi file.  I then used the 'chainloader' command
to get grub to boot off this device, and 'boot' to start the boot process.

Hope that helps,

Paul