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To uefi, or not to uefi? That is the questiion . . .
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The Doctor
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PostPosted: Mon Mar 23, 2015 9:02 pm    Post subject: Reply with quote

jamtat wrote:
My questions about that statement are as follows: why is it necessary to be running from a UEFI-enabled boot medium when installing Gentoo onto a UEFI-capable system? Can it NOT be done using a non-UEFI-capable boot medium? If not, why so? Just curious. Input will be appreciated.
It should work just fine as long as you don't need to change the UEFI variables. Just name your kernel what the UEFI expects it to be named. If you did your job correctly, this should work.

If you want a fancy name or don't want to overwrite the default bootup file (ie, if you are dual booting) you need the UEFI media so you can add an entry to the boot menu.
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Apologies if I take a while to respond. I'm currently working on the dematerialization circuit for my blue box.
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jamtat
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PostPosted: Tue Mar 24, 2015 12:09 am    Post subject: Reply with quote

The Doctor wrote:
I would use it (efibootmgr) to create a second kernel so I could boot from the old kernel if my new one failed, but that is just a personal preference.

Others have pointed to this potential scenario as justifying addition of either a boot loader or a utility like efibootmgr as well. But wouldn't an equally effective fall-back--in the event of a non-booting system, resulting from an errant kernel compilation--be to simply copy a known-working kernel onto a FAT32-formatted USB drive, under a efi/boot directory, naming it bootx64.efi? If one were to keep such a USB drive on hand, that, it seems to me, might be an equally effective way to deal with a kernel misadventure of the sort mentioned.
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The Doctor
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PostPosted: Tue Mar 24, 2015 4:56 am    Post subject: Reply with quote

Sure, but then you need a flash drive. I don't know about equally effective since it literally costs a flash drive while the second kernel on the disk is practically free.

Efibootmgr is really friendly once you get to know it. I don't think there is any reason to be afraid of it.
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jonathan183
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PostPosted: Wed Mar 25, 2015 12:07 am    Post subject: Reply with quote

The Doctor wrote:
It might help to think of UEFI as BIOS+bootloader. In fact, I don't think adding a bootloader is particularly helpful even with multiple OSes on the same box.

For me having grub2 is handy for things like ...
Code:
menuentry "SYSRESCUECD iso image on sda9 - OK for distro fixing but not Mint :-(" --users "" {
        insmod part_msdos
        insmod ext2
        set root='(hd0,gpt9)'
        search --no-floppy --fs-uuid --set 229f7a75-d77c-4fee-a60b-03d1933a5f46
        set iso=/systemrescuecd-x86-3.8.1.iso
        loopback loop ${iso}
        linux  (loop)/isolinux/rescue64 grml2ram fb1920x1080 keyboard=uk setkmap=gb isoloop=${iso}
        initrd (loop)/isolinux/initram.igz
}

I have a default uefi boot arrangement for my main Gentoo install that can be used by family (a just switch the PC on and let it boot option), I can also boot a few other distros and the systemrescuecd from an iso image ... with user and password required to select this option.
Using a bootloader is not mandatory with uefi ... but its nice to have the option available 8)
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OldTango
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PostPosted: Mon Mar 30, 2015 12:03 am    Post subject: Re: To uefi, or not to uefi? That is the questiion . . . Reply with quote

jamtat wrote:
So I want to start off by asking who has installed a UEFI system here, as opposed to turing off UEFI and installing in legacy mode. If you did/didn't, why so? What do you see as the pros and cons?
I installed my system using UEFI some time ago when most install mediums didn't support booting in UEFI mode like they do now. If your system is UEFI capable than I agree with
The Doctor wrote:
Use it. There shouldn't be a question here.
The question is whether to use a secondary boot loader like GRUB2 or not. If you wish to test a lot of kernels or operating systems and want to store then in some location other than the (ESP) EFI System Partition than you will need something like GRUB2. If you decide you don't want or need a secondary boot loader and chose to use the system UEFI firmware for booting, your Kernel Images must be in the (ESP). Just make sure the (ESP) is large enough to hold a couple of Kernels, one working or backup, one testing and any other files that may be necessary. To be complete my (ESP) is set up as follows
Code:
boot/efi/EFI/gentoo/
where the gentoo directory houses two Kernel Images named "gs310x64.efi" and "gs317x64.efi".

I also use efibootmgr to modify the "UFEI Firmware" boot entries and order. So each Kernel is named Gentoo310 and Gentoo317 in the UEFI Boot Menu and the default, is to boot Gentoo317.

jamtat wrote:
I went most of the way through an installation using a non-UEFI-capable boot medium and things seemed to be going ok. I finally ended up with a non-booting system though.
Why wouldn't it boot? What were the errors you encountered? This would have been a good place to start by posting your install process and any errors you encountered so folks could help you solve the problem. If you wish to proceed to install Gentoo and use UEFI booting than follow the handbook paying close attention to the UEFI sections and kernel config requirements to get UEFI boot working. If you still have problems please post the in the forums and I am sure help will soon arrive.

There are PROS and CONS to both methods. So it really depends on what an individual requires out of his own system. The BIG pro for me is I don't need to install or maintain another application like GRUB to boot any OS on my system.


:)
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