Subj : uefi
To : Kai Richter
From : Gerrit Kuehn
Date : Tue May 24 2022 08:00 am
Hello Kai!
24 May 22 05:39, Kai Richter wrote to Gerrit Kuehn:
GK>> On the bright side, UEFI does reliably come with a shell (if
GK>> everything else fails) that allows starting other systems manually.
KR> I still don't see the need. Doesn't have any todays operating system
KR> have a boot manager? The result is that the menu to select the
KR> starting OS is moved from the disk to the BIOS.
I talked about cases where something is broken and your system doesn't boot (maybe not even the bootmanager comes up). With MBR this means reconfiguring BIOS boot order, probably getting some USB media to boot a rescue system from it etc.
With the built-in UEFI shell, you can already check your partitions and even select what to boot without having to reconfigure anything or to provide a rescue system on USB. In many cases I was able to manually boot the failed system with this and use the system itself then to fix booting.
Some manufacturers provide firmware and bios update tools on efi meanwhile. In that case, you can just drop the new firmware and the upgrade tool on a USB stick and use UEFI-shell to run it from there. In the MBR-days you would have needed to have a MSDOS-system on the USB stick in addition (and hope that the manufacturer would still provide a DOS-based update tool that is able to run on your newly bought server or workstation).
