Re: unetbootin rendered system unbootable

[sashab]

Hi L,

please beware: all advice below are IMHO and AFAIK (and i'm a novice, too).

First of all, the obvious: Is your laptop set to boot "UEFI" (after you
may have tried to boot FreeDos via "legacy boot")?

Have you checked the contents of your EFI-Partition /dev/sda1?
Especially if there is EFI/fedora/grubx64.efi?

Have you checked the contents of your /boot partition /dev/sda2?
Especially if there are grub-modules inside /boot/grub/* and a valid
config in /boot/grub/grub.cfg.

For missing grub modules you may want to chroot in your installed os and
do a grub-install there. Maybe also append "--target=x86_64-efi" to that
command.
For missing config you probably want a "grub-mkconfig -O
/boot/grub/grub.cfg" within your chroot.

According efivars:
By pressing "F12" or something it should be possible to get a menu to
choose a boot option before the firmware actually tries to boot.
What are the entries presented there?
(You may wish do add --bootloader-id=test to your grub-install call to
be sure that you're choosing the right entry. However, after doing so
later you'll have to cleanup the efi variable mess.)
You may visit wiki.archlinux.org for more info on handling uefi stuff.

Regards,
    sashab



On 23/01/18 20:48, lejeczek wrote:
> hi everyone
> 
> I've run unetbootin to installed freeDos on a usb stick, which it did,
> but now my system does not boot. Gee..
> 
> I have a fedora27 on a Dell laptop in EFI mode.
> System attempts to boot, where it should do it waits just a few sec and
> says no bootable devices available, or something like that.
> 
> I boot a liveCD fedora, there I do:
> # efibootmgr -v
> ...
> Boot0008* f25
> PciRoot(9x)/Pci(0x17,0x0)/EDD10(0x2a010480)/HD(1,GPT,c9b2adc2-.....,0x800x0x64000/File(\EFI\fedora\grubx64.efi)
> 
> ...
> 
> that entry above was, should be my fedora installation. I do:
> # fdisk -l /dev/sda
> ...
> Device....
> /dev/sda1    2048    411647    4009600    200M EFI System
> /dev/sda2    411648    1435647    1024000    500M Linux filesystem
> /dev/sda3    1435648    5000117503    49...    237.8G Linux filesystem
> 
> So it seems like everything is there, right? I'm really asking, I'm a
> novice here on grub2/efi subject.
> 
> I tried mounting /dev/sda1 under /mnt in live fedora, then I did:
> # grub2-install --efi-directory=/mnt/EFI /dev/sda
> which command said id did without errors, but all I can see happened a
> new entry was added which efibootmgr would show, but that new boot id
> would not boot also.
> 
> Any help, advice on how to troubleshoot it I'd greatly!! appreciate.
> 
> many! thank, L.
> 
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