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Comment by btgeekboy | Hacker News Reader

Out of curiosity, why have you disabled it?

I can't speak for OP but for me, I disable it because UEFI is an over-engineered mess that solves no problems for me.

You realize that in most cases "disabling UEFI" is really enabling a poorly-tested emulation of BIOS running on top of UEFI?

I love EFI! No more bootloaders!!!! Just rename your bzimage bzimage.efi, put it on a FAT fs, and select it with the firmware!

Yes, and if for some reason then you clear the CMOS (BIOS configuration error, discharged battery, or whatever) you can no longer boot your PC because the boot information regarding the parameters to pass to the kernel is lost...

That's why EFI variables should never be used. Just put whatever you want to boot into BOOTX64.EFI!

Ah the lovely naming hacks of UEFI. :-P I remember the troubles it took to boot Ubuntu on a Lenovo laptop because the EFI was 32 bit, while the system supported 64 bit.

Yeah, old devices with 32-bit EFI…

I have a Mac mini 2006 (upgraded to 2007). I compiled GRUB 2 for 32-bit EFI and it boots 64-bit FreeBSD from ZFS just fine :)

EFI variables are not stored in the "CMOS", note (misnomer that that is). They are stored in flash RAM.

* https://superuser.com/a/708332/38062

Then just select it again? It's maybe 4 key presses unless you have a lot of .efi files laying around...

Not OP, but I also disable it on my home boxes that run Linux, mainly because 1) I know how the BIOS boot process works very well (and I kinda like knowing how things work, especially on critical paths that can get broken sometimes), and 2) I know how to set up Linux with BIOS boot because I did it so many times before.

So I guess it boils down to "it's not broken for me, why change it?"

For the people who like knowing how things work:

* http://jdebp.eu./FGA/efi-boot-process.html

* http://jdebp.eu./FGA/arc-boot-process.html

* http://jdebp.eu./FGA/pcat-boot-process.html

Because it's old. Because it's painfully slow. Because messing with a FAT partition feels much better than messing with MBR or whatever weird "boot partition" thing that happens in a "legacy-BIOS-plus-GPT" situation.

Who said anything about GPT? I use MBR partitioning as well. Again, it's simple, and it works for my purposes, why change it?

And I don't consider a few seconds to be "painfully slow" for something that is done maybe once a week, if that (suspend is there for a reason...).

As far as "messing with MBR", why is that somehow problematic? MBR was specifically designed for this exact purpose - hosting a partition table and a boot loader. And there are tools to do precisely what needs to be done to it, and these tools have been there for a very long time - so I'm confident that they work right. On top of that, MBR structure is simple enough that I can manually inspect or edit it with dd directly on the block device in question.

Why would you do this? I doubt support for legacy mode will exist for much longer, either on motherboards or in distributions.

I would be surprised if distros got rid of it anytime soon. There's still a vast amount of relatively old non-UEFI hardware that people still use, and it's not going to suddenly change, because that hardware is plainly "good enough" for all practical purposes - so it's only going to be replaced if and when it fails. Even Windows hasn't so much as announced a switch to UEFI boot only, and Linux generally supports old hardware for much longer. So I wouldn't be surprised if it's still there in a decade - maybe not in all distros, but at least in some mainstream ones, especially more "hackerish" like Arch and Gentoo.

As for motherboards, I doubt they'd get rid of it that soon, either. If only because having it there means that OEMs can ship devices with FreeDOS preinstalled to dodge the licensing fees. As I understand, legacy mode is basically just an emulation layer on top of UEFI, and it's fairly cheap (and already there).

This is different for mobile and tablet devices like Surface, which aren't really advertised as general-purpose PCs in the first place. Since they're only expected to run whatever's preinstalled on them, so long as it only needs UEFI, they will likely ship with UEFI only. But I'm not running Linux on such things.

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