Re: [gentoo-user] UEFI booting [solved]

[Rod]

On 08/17/2015 11:37 PM, Jeremi Piotrowski wrote:
> On Mon, 17 Aug 2015, Rod wrote:
>>      Hi list,
> Hi
>
>>      I'm trying to figure out how to make my boot partition to boot from UEFI,
>> I have grub2 installed, but I keep getting a error when I ask it to install
>> the boot information.
> First things first, are you installing gentoo from an UEFI booted
> installation media? From what I know the gentoo minimal install cd does
> not allow for this, and I will assume you are using that.
>
> If you're using some other installation method, check whether the
> directory /sys/firmware/efi/efivars has any content, try to mount efivarfs
> following the instructions in this link:
>
> https://wiki.gentoo.org/wiki/Efibootmgr#Configuration
>
> and then check again.
>
>> # efibootmgr
>> efibootmgr: EFI variables are not supported on this system.
>>
>>
>> # grub2-install --target=x86_64-efi /dev/sdc
>> Installing for x86_64-efi platform.
>> efibootmgr: EFI variables are not supported on this system.
>> efibootmgr: EFI variables are not supported on this system.
>> Installation finished. No error reported.
> In your case it seems that the system is not in an UEFI-booted state. But
> we can work around this by using a nice part of the UEFI specification,
> details below.
>
>> mount
>> /dev/sdc1                   201633        156     201478   1% /boot/efi
>>
>>      I have the /boot/efi part mounted ok..
> Before we go further make sure that the partition is a valid EFI boot
> partition: code EF00 (gdisk), partition flags boot/esp (for parted).
>
>>      How can I get this UEFI be become bootable without media to make it boot
>> in to that mode to begin with ?
> It's actually much easier than it may seem, and it's outlined here:
>
> https://wiki.gentoo.org/wiki/GRUB2#Alternative:_using_the_default_UEFI_firmware_location
>
> Basically, for all sorts of removable media there must be a way to tell
> UEFI what to boot without having to hardcode the entries into NVRAM (like
> efibootmgr does). Therefore UEFI firmware is supposed to check for the
> first ESP partition on a drive and boot \EFI\boot\bootx64.efi from it.
> This also works for harddrives, and since you can access a FAT partition
> even when booted in bios mode you just put grub there.
>
> Now this works perfectly well for a linux kernel with efi stub and cmdline
> built-in, but grub may have trouble finding it's configuration files, I do
> not know. So I suggest you try it. Find grubx64.efi in /boot/efi and copy
> it to /boot/efi/EFI/BOOT/BOOTX64.EFI. Voila, should boot just fine.
>
> On my first UEFI install I did not know about this, efibootmgr did not
> work, but the handbook says to place the kernel at /EFI/boot/bootx64.efi
> and it just magically worked.
>
> Generally you will find that provided the UEFI implementation of your
> vendor is not complete shit (lots of them exist) UEFI makes it generally
> easier to handle booting. One partition and the EFI variables and you can
> boot anything, no more hidden sectors.

     Ok, thnks for your help, all was checked out as you said, the boot 
partition was correct, boot, esp which was a good thing.


     Just found a slight problem, my .efi program that the system was 
trying to boot was /boot/efi/EFI/gentoo/grubx64.efi

     copying the .efi to /boot/efi/EFI/BOOT changed nothing, I filed to 
notice that the name was incorrect, as installing the UEFI with the 
bootloader (without the efivar loaded) resulted in a file named 
"grubx86.efi" which doesn't work when copied in to the BOOT directory :(

     Renaming this file    ->  mv grubx86.efi bootx86.efi

     System now happily boots in UEFI mode, I guess I didn't read "Find 
grubx64.efi in /boot/efi and copy it to /boot/efi/EFI/BOOT/BOOTX64.EFI" 
correctly :P

     during this time, the original sda drive I was using failed (SMART 
was reporting that I should replace it soon) and I guess it was slightly 
too soon, but I did have the chance to rsync the filesystem across :P

     Thanks heaps for your help :)

-- 
---

       Regards,
    
       Rod Smart
       0417 513 286